60 results on '"McNeil LK"'
Search Results
2. Correction: Neutrophil killing of Staphylococcus aureus in diabetes, obesity and metabolic syndrome: a prospective cellular surveillance study.
- Author
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Scully IL, McNeil LK, Pathirana S, Singer CL, Liu Y, Mullen S, Girgenti D, Gurtman A, Pride MW, Jansen KU, Huang PL, and Anderson AS
- Published
- 2024
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3. Lymph-node-targeted, mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer: the phase 1 AMPLIFY-201 trial.
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Pant S, Wainberg ZA, Weekes CD, Furqan M, Kasi PM, Devoe CE, Leal AD, Chung V, Basturk O, VanWyk H, Tavares AM, Seenappa LM, Perry JR, Kheoh T, McNeil LK, Welkowsky E, DeMuth PC, Haqq CM, and O'Reilly EM
- Subjects
- Humans, Proto-Oncogene Proteins p21(ras) genetics, Neoplasm Recurrence, Local pathology, Biomarkers, Tumor genetics, Peptides, Antigens, Neoplasm therapeutic use, Vaccines therapeutic use, Colorectal Neoplasms drug therapy, Colorectal Neoplasms genetics
- Abstract
Pancreatic and colorectal cancers are often KRAS mutated and are incurable when tumor DNA or protein persists or recurs after curative intent therapy. Cancer vaccine ELI-002 2P enhances lymph node delivery and immune response using amphiphile (Amph) modification of G12D and G12R mutant KRAS (mKRAS) peptides (Amph-Peptides-2P) together with CpG oligonucleotide adjuvant (Amph-CpG-7909). We treated 25 patients (20 pancreatic and five colorectal) who were positive for minimal residual mKRAS disease (ctDNA and/or serum tumor antigen) after locoregional treatment in a phase 1 study of fixed-dose Amph-Peptides-2P and ascending-dose Amph-CpG-7909; study enrollment is complete with patient follow-up ongoing. Primary endpoints included safety and recommended phase 2 dose (RP2D). The secondary endpoint was tumor biomarker response (longitudinal ctDNA or tumor antigen), with exploratory endpoints including immunogenicity and relapse-free survival (RFS). No dose-limiting toxicities were observed, and the RP2D was 10.0 mg of Amph-CpG-7909. Direct ex vivo mKRAS-specific T cell responses were observed in 21 of 25 patients (84%; 59% both CD4
+ and CD8+ ); tumor biomarker responses were observed in 21 of 25 patients (84%); biomarker clearance was observed in six of 25 patients (24%; three pancreatic and three colorectal); and the median RFS was 16.33 months. Efficacy correlated with T cell responses above or below the median fold increase over baseline (12.75-fold): median tumor biomarker reduction was -76.0% versus -10.2% (P < 0.0014), and the median RFS was not reached versus 4.01 months (hazard ratio = 0.14; P = 0.0167). ELI-002 2P was safe and induced considerable T cell responses in patients with immunotherapy-recalcitrant KRAS-mutated tumors. ClinicalTrials.gov identifier: NCT04853017 ., (© 2024. The Author(s).)- Published
- 2024
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4. Lymph node targeted multi-epitope subunit vaccine promotes effective immunity to EBV in HLA-expressing mice.
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Dasari V, McNeil LK, Beckett K, Solomon M, Ambalathingal G, Thuy TL, Panikkar A, Smith C, Steinbuck MP, Jakubowski A, Seenappa LM, Palmer E, Zhang J, Haqq CM, DeMuth PC, and Khanna R
- Subjects
- Mice, Animals, CD8-Positive T-Lymphocytes, Epitopes, T-Lymphocyte, Lymph Nodes, Vaccines, Subunit, Herpesvirus 4, Human, Epstein-Barr Virus Infections prevention & control
- Abstract
The recent emergence of a causal link between Epstein-Barr virus (EBV) and multiple sclerosis has generated considerable interest in the development of an effective vaccine against EBV. Here we describe a vaccine formulation based on a lymph node targeting Amphiphile vaccine adjuvant, Amphiphile-CpG, admixed with EBV gp350 glycoprotein and an engineered EBV polyepitope protein that includes 20 CD8
+ T cell epitopes from EBV latent and lytic antigens. Potent gp350-specific IgG responses are induced in mice with titers >100,000 in Amphiphile-CpG vaccinated mice. Immunization including Amphiphile-CpG also induces high frequencies of polyfunctional gp350-specific CD4+ T cells and EBV-specific CD8+ T cells that are 2-fold greater than soluble CpG and are maintained for >7 months post immunization. This combination of broad humoral and cellular immunity against multiple viral determinants is likely to provide better protection against primary infection and control of latently infected B cells leading to protection against the development of EBV-associated diseases., (© 2023. The Author(s).)- Published
- 2023
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5. Reliability in performance assessment creates a potential application of artificial intelligence in veterinary education: evaluation of suturing skills at a single institution.
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Kuzminsky J, Phillips H, Sharif H, Moran C, Gleason HE, Topulos SP, Pitt K, McNeil LK, McCoy AM, and Kesavadas T
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- Animals, Reproducibility of Results, Artificial Intelligence, Education, Veterinary
- Abstract
Objectives: To evaluate suturing skills of veterinary students using 3 common performance assessments (PAs) and to compare findings to data obtained by an electromyographic armband., Sample: 16 second-year veterinary students., Procedures: Students performed 4 suturing tasks on synthetic tissue models 1, 3, and 5 weeks after a surgical skills course. Digital videos were scored by 4 expert surgeons using 3 PAs (an Objective Structured Clinical Examination [OSCE]- style surgical binary checklist, an Objective Structured Assessment of Technical Skill [OSATS] checklist, and a surgical Global Rating Scale [GRS]). Surface electromyography (sEMG) data collected from the dominant forearm were input to machine learning algorithms. Performance assessment scores were compared between experts and correlated to task completion times and sEMG data. Inter-rater reliability was calculated using the intraclass correlation coefficient (ICC). Inter-rater agreement was calculated using percent agreement with varying levels of tolerance., Results: Reliability was moderate for the OSCE and OSATS checklists and poor for the GRS. Agreement was achieved for the checklists when moderate tolerance was applied but remained poor for the GRS. sEMG signals did not correlate well with checklist scores or task times, but features extracted from signals permitted task differentiation by routine statistical comparison and correct task classification using machine learning algorithms., Clinical Relevance: Reliability and agreement of an OSCE-style checklist, OSATS checklist, and surgical GRS assessment were insufficient to characterize suturing skills of veterinary students. To avoid subjectivity associated with PA by raters, further study of kinematics and EMG data is warranted in the surgical skills evaluation of veterinary students.
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- 2023
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6. Amphiphile-CpG vaccination induces potent lymph node activation and COVID-19 immunity in mice and non-human primates.
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Seenappa LM, Jakubowski A, Steinbuck MP, Palmer E, Haqq CM, Carter C, Fontenot J, Villinger F, McNeil LK, and DeMuth PC
- Abstract
Despite the success of currently authorized vaccines for the reduction of severe COVID-19 disease risk, rapidly emerging viral variants continue to drive pandemic waves of infection, resulting in numerous global public health challenges. Progress will depend on future advances in prophylactic vaccine activity, including advancement of candidates capable of generating more potent induction of cross-reactive T cells and durable cross-reactive antibody responses. Here we evaluated an Amphiphile (AMP) adjuvant, AMP-CpG, admixed with SARS-CoV-2 Spike receptor binding domain (RBD) immunogen, as a lymph node-targeted protein subunit vaccine (ELI-005) in mice and non-human primates (NHPs). AMP-mediated targeting of CpG DNA to draining lymph nodes resulted in comprehensive local immune activation characterized by extensive transcriptional reprogramming, inflammatory proteomic milieu, and activation of innate immune cells as key orchestrators of antigen-directed adaptive immunity. Prime-boost immunization with AMP-CpG in mice induced potent and durable T cell responses in multiple anatomical sites critical for prophylactic efficacy and prevention of severe disease. Long-lived memory responses were rapidly expanded upon re-exposure to antigen. In parallel, RBD-specific antibodies were long-lived, and exhibited cross-reactive recognition of variant RBD. AMP-CpG-adjuvanted prime-boost immunization in NHPs was safe and well tolerated, while promoting multi-cytokine-producing circulating T cell responses cross-reactive across variants of concern (VOC). Expansion of RBD-specific germinal center (GC) B cells in lymph nodes correlated to rapid seroconversion with variant-specific neutralizing antibody responses exceeding those measured in convalescent human plasma. These results demonstrate the promise of lymph-node adjuvant-targeting to coordinate innate immunity and generate robust adaptive responses critical for vaccine efficacy., (© 2022. The Author(s).)
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- 2022
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7. An Empirical Antigen Selection Method Identifies Neoantigens That Either Elicit Broad Antitumor T-cell Responses or Drive Tumor Growth.
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Lam H, McNeil LK, Starobinets H, DeVault VL, Cohen RB, Twardowski P, Johnson ML, Gillison ML, Stein MN, Vaishampayan UN, DeCillis AP, Foti JJ, Vemulapalli V, Tjon E, Ferber K, DeOliveira DB, Broom W, Agnihotri P, Jaffee EM, Wong KK, Drake CG, Carroll PM, Davis TA, and Flechtner JB
- Subjects
- Animals, Antigens, Neoplasm genetics, Biomarkers, Tumor genetics, Biomarkers, Tumor immunology, Cancer Vaccines administration & dosage, Cancer Vaccines immunology, Cell Line, Tumor, Clinical Trials as Topic, DNA Mutational Analysis, Disease Models, Animal, Disease Progression, Genomics methods, Humans, Immunogenicity, Vaccine, Melanoma, Experimental, Mice, Mutation, Neoplasms genetics, Neoplasms therapy, T-Lymphocytes metabolism, T-Lymphocytes pathology, Treatment Outcome, Vaccination, Antigens, Neoplasm immunology, Immunity, Cellular, Neoplasms immunology, Neoplasms pathology, T-Lymphocytes immunology
- Abstract
Neoantigens are critical targets of antitumor T-cell responses. The ATLAS bioassay was developed to identify neoantigens empirically by expressing each unique patient-specific tumor mutation individually in Escherichia coli , pulsing autologous dendritic cells in an ordered array, and testing the patient's T cells for recognition in an overnight assay. Profiling of T cells from patients with lung cancer revealed both stimulatory and inhibitory responses to individual neoantigens. In the murine B16F10 melanoma model, therapeutic immunization with ATLAS-identified stimulatory neoantigens protected animals, whereas immunization with peptides associated with inhibitory ATLAS responses resulted in accelerated tumor growth and abolished efficacy of an otherwise protective vaccine. A planned interim analysis of a clinical study testing a poly-ICLC adjuvanted personalized vaccine containing ATLAS-identified stimulatory neoantigens showed that it is well tolerated. In an adjuvant setting, immunized patients generated both CD4
+ and CD8+ T-cell responses, with immune responses to 99% of the vaccinated peptide antigens. SIGNIFICANCE: Predicting neoantigens in silico has progressed, but empirical testing shows that T-cell responses are more nuanced than straightforward MHC antigen recognition. The ATLAS bioassay screens tumor mutations to uncover preexisting, patient-relevant neoantigen T-cell responses and reveals a new class of putatively deleterious responses that could affect cancer immunotherapy design. This article is highlighted in the In This Issue feature, p. 521 ., (©2021 American Association for Cancer Research.)- Published
- 2021
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8. A lymph node-targeted Amphiphile vaccine induces potent cellular and humoral immunity to SARS-CoV-2.
- Author
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Steinbuck MP, Seenappa LM, Jakubowski A, McNeil LK, Haqq CM, and DeMuth PC
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- Adjuvants, Immunologic administration & dosage, Animals, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, COVID-19 virology, COVID-19 Vaccines immunology, Female, HEK293 Cells, Humans, Immunogenicity, Vaccine, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Neutralization Tests, Oligodeoxyribonucleotides administration & dosage, Oligodeoxyribonucleotides immunology, Protein Interaction Domains and Motifs immunology, Spike Glycoprotein, Coronavirus chemistry, Spike Glycoprotein, Coronavirus immunology, Treatment Outcome, Vaccination methods, Vaccines, Subunit immunology, COVID-19 prevention & control, COVID-19 Vaccines administration & dosage, Immunity, Cellular, Immunity, Humoral, Lymph Nodes immunology, SARS-CoV-2 immunology, Surface-Active Agents administration & dosage
- Abstract
The profound consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mandate urgent development of effective vaccines. Here, we evaluated an Amphiphile (AMP) vaccine adjuvant, AMP-CpG, composed of diacyl lipid-modified CpG, admixed with the SARS-CoV-2 Spike-2 receptor binding domain protein as a candidate vaccine (ELI-005) in mice. AMP modification efficiently delivers CpG to lymph nodes, where innate and adaptive immune responses are generated. Compared to alum, immunization with AMP-CpG induced >25-fold higher antigen-specific T cells that produced multiple T helper 1 (T
H 1) cytokines and trafficked into lung parenchyma. Antibody responses favored TH 1 isotypes (IgG2c and IgG3) and potently neutralized Spike-2-ACE2 receptor binding, with titers 265-fold higher than natural convalescent patient COVID-19 responses; T cell and antibody responses were maintained despite 10-fold dose reduction in Spike antigen. Both cellular and humoral immune responses were preserved in aged mice. These advantages merit clinical translation to SARS-CoV-2 and other protein subunit vaccines., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).)- Published
- 2021
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9. Gating Harmonization Guidelines for Intracellular Cytokine Staining Validated in Second International Multiconsortia Proficiency Panel Conducted by Cancer Immunotherapy Consortium (CIC/CRI).
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Price LS, Adamow M, Attig S, Fecci P, Norberg P, Reap E, Janetzki S, and McNeil LK
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- Flow Cytometry, Humans, Immunotherapy, Reproducibility of Results, Staining and Labeling, Cytokines, Neoplasms therapy
- Abstract
Results from the first gating proficiency panel of intracellular cytokine staining (ICS) highlighted the value of using a consensus gating approach to reduce the variability across laboratories in reported %CD8
+ or %CD4+ cytokine-positive cells. Based on the data analysis from the first proficiency panel, harmonization guidelines for a consensus gating protocol were proposed. To validate the recommendations from the first panel and to examine factors that were not included in the first panel, a second ICS gating proficiency panel was organized. All participants analyzed the same set of Flow Cytometry Standard (FCS) files using their own gating protocol. An optional learning module was provided to demonstrate how to apply the previously established gating recommendations and harmonization guidelines to actual ICS data files. Eighty-three participants took part in this proficiency panel. The results from this proficiency panel confirmed the harmonization guidelines from the first panel. These recommendations addressed the (1) placement of the cytokine-positive gate, (2) identification of CD4+ CD8+ double-positive T cells, (3) placement of lymphocyte gate, (4) inclusion of dim cells, (5) gate uniformity, and (6) proper adjustment of the biexponential scaling. In addition, based on the results of this proficiency gating panel, two new recommendations were added to expand the harmonization guidelines: (1) inclusion of dump channel marker to gate all live and dump negative cells and (2) backgating to confirm the correct placement of gates across all populations. © 2020 International Society for Advancement of Cytometry., (© 2020 International Society for Advancement of Cytometry.)- Published
- 2021
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10. Development and Evolution of the Clinical Skills Learning Center as an Integral Component of the Illinois Veterinary Professional Curriculum.
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Morin DE, Arnold CJ, Hale-Mitchell LK, McNeil LK, Lanzo S, Soder H, Williams D, Foreman JH, and Whiteley H
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- Animals, Clinical Competence, Curriculum, Humans, Illinois, Schools, Veterinary, Education, Veterinary, Veterinarians
- Abstract
The University of Illinois College of Veterinary Medicine opened a clinical skills laboratory in August 2009, making it one of the earliest North American veterinary schools to do so. The Clinical Skills Learning Center has been an integral component of the Illinois veterinary professional curriculum since its inception. However, its role in the curriculum has changed over time, which has had an impact on its size, scope, and staffing. In this article, we describe the development and growth of the Clinical Skills Learning Center, with an emphasis on its evolving curricular role and the lessons we have learned over nine years.
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- 2020
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11. Therapeutic HSV-2 vaccine decreases recurrent virus shedding and recurrent genital herpes disease.
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Bernstein DI, Flechtner JB, McNeil LK, Heineman T, Oliphant T, Tasker S, Wald A, and Hetherington S
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- Adjuvants, Immunologic administration & dosage, Adolescent, Adult, Female, Humans, Immunity, Cellular immunology, Immunotherapy methods, Male, Middle Aged, Vaccination methods, Young Adult, Herpes Genitalis immunology, Herpesvirus 2, Human immunology, Viral Vaccines immunology, Virus Shedding immunology
- Abstract
Background: Genital herpes simplex virus (HSV) type 2 is a common persistent infection that frequently reactivates to cause recurrent lesions and recurrent viral shedding which is incompletely controlled by antiviral therapy. GEN-003 is a candidate therapeutic vaccine containing 2 HSV-2 proteins, gD2 and ICP4, and Matrix-M2 adjuvant (M2)., Methods: HSV-2 seropositive persons with genital herpes were randomized into three dose cohorts of Gen-003 (60 µg antigen/50 µg M2, 60 µg/75 µg M2 or Placebo). Three intramuscular doses 21 days apart of GEN-003 or placebo were administered. Participants obtained genital area swabs twice-daily for HSV-2 detection and monitored genital lesions for 12 months. The rates of virus shedding and lesion rates before vaccination were compared to 3 defined periods after vaccination; Days 43-71, Month 6 and Month 12., Results: GEN-003 at a dose of 60 µg each antigen/50 µg M2 reduced HSV shedding immediately after dosing with a rate ratio of 0.58, compared to 0.75 for the GEN-003 60 µg/75 µg M2 and 1.06 for placebo. Lesion rates, recurrence rates, and duration of recurrences were also reduced. Reactogenicity was higher with the 75 µg M2 dose than the 50 µg M2 dose, specifically for pain, tenderness, malaise and fatigue. Antibody and cellular immune responses were stimulated by both doses and persisted to 12 months., Conclusions: GEN-003 vaccine manufactured with a scalable process gave results similar to those observed in prior clinical trials. GEN-003 had an acceptable safety profile and stimulated both humoral and cellular immune responses. The 60 µg antigen/50 µg M2 provided the maximal effect on virologic and clinical measures and warrants further development. (Funded by Genocea; ClinicalTrials.gov number NCT02515175)., (Copyright © 2019. Published by Elsevier Ltd.)
- Published
- 2019
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12. Effects of Different Doses of GEN-003, a Therapeutic Vaccine for Genital Herpes Simplex Virus-2, on Viral Shedding and Lesions: Results of a Randomized Placebo-Controlled Trial.
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Van Wagoner N, Fife K, Leone PA, Bernstein DI, Warren T, Panther L, Novak RM, Beigi R, Kriesel J, Tyring S, Koltun W, Lucksinger G, Morris A, Zhang B, McNeil LK, Tasker S, Hetherington S, and Wald A
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- Adjuvants, Immunologic, Adolescent, Adult, Female, Herpes Genitalis virology, Humans, Male, Middle Aged, Vaccination, Viral Vaccines administration & dosage, Virus Shedding, Young Adult, Herpes Genitalis therapy, Herpesvirus 2, Human immunology, Immunotherapy, Viral Vaccines therapeutic use
- Abstract
Background: GEN-003 is a candidate therapeutic vaccine for genital herpes simplex virus type 2 (HSV-2). We compared virologic and clinical impact of varying GEN-003 doses., Methods: Adults with symptomatic HSV-2 received placebo or GEN-003 (30 or 60 µg antigen with 25, 50, or 75 µg adjuvant). Viral shedding and lesion rates before vaccination were compared with those measured immediately after vaccination, then at weeks 29-33 and 53-57 after last dose., Results: Compared with baseline shedding rates, the rate ratios for viral shedding immediately after treatment were as follows: 0.82 (95% confidence interval [CI], 0.49-1.36), 30 µg antigen/25 µg adjuvant (30/25) dose; 0.64 (95% CI, 0.45-0.92), 30/50 dose; 0.63 (95% CI, 0.37-1.10), 30/75 dose; 0.56 (95% CI, 0.36-0.88), 60/25 dose; 0.58 (95% CI, 0.38-0.89), 60/50 dose; 0.45 (95% CI, 0.16-0.79), 60/75 dose; and 0.98 (95% CI, 0.76-1.26), placebo. Lesion rate reductions by GEN-003 ranged from 31% to 69%, but lesion rates also decreased among placebo recipients (62%). Reductions in shedding and lesion rate were durable for 12 months for the 60 µg antigen plus 50 or 75 µg adjuvant groups. No serious adverse events occurred with vaccination., Conclusions: The most efficacious vaccine combinations for GEN-003 were the 60 µg/50 µg and 60 µg/75 µg doses.
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- 2018
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13. Switching from a high-fat cellulose diet to a high-fat pectin diet reverses certain obesity-related morbidities.
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Bray JK, Chiu GS, McNeil LK, Moon ML, Wall R, Towers AE, and Freund GG
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Background: Reducing caloric intake is a proven intervention for mitigating and modulating morbidities associated with overnutrition. Caloric restriction is difficult to affect clinically, therefore, dietary interventions that ameliorate the adverse consequences of overnutrition in the presence of a high-calorie diet would be of value., Methods: Mice were fed an obesogenic diet containing 60% fat + 10% cellulose (HFC), or a control diet containing 10% fat + 10% cellulose (LFC) for 12 wks. Subgroups of mice were then switched from HFC to each of the following diets for an additional 5 wks: 1) 60% fat + 10% pectin (HFP), 2) LFC or 3) 10% fat + 10% pectin (LFP). To test for statistical differences, one-way or two-way ANOVAs were used with or without repeated measurements as needed., Results: In comparison to HFC, HFP prevented additional weight gain while LFC and LFP triggered weight loss of 22.2 and 25.4%, respectively. Mice continued on HFC experienced a weight increase of 26% during the same 5 wk. interval. After 12 wks, HFC decreased mouse locomotion by 18% when compared to control diet, but a diet switch to LFC or LFP restored mouse movement. Importantly, HFP, LFC, and LFP reduced fasting blood glucose when compared to HFC. Likewise, HFP, LFC and LFP improved glucose tolerance and decreased fatty liver by 37.9, 49.8, 53.6 and 20.2%, 37.2, 43.7%, respectively., Conclusions: Taken together, the results indicate that the dietary fiber pectin can mitigate some adverse consequences of overnutrition even in the presence of high-fat., Competing Interests: Animal use was conducted in accordance with Institutional Animal Care and Use Committee approved protocols at the University of Illinois.Not applicable.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
- Published
- 2018
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14. Predicting the Susceptibility of Meningococcal Serogroup B Isolates to Bactericidal Antibodies Elicited by Bivalent rLP2086, a Novel Prophylactic Vaccine.
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McNeil LK, Donald RGK, Gribenko A, French R, Lambert N, Harris SL, Jones TR, Li S, Zlotnick G, Vogel U, Claus H, Abad R, Vazquez JA, Borrow R, Findlow J, Taha MK, Deghmane AE, Caugant DA, Kriz P, Musilek M, Wang X, Vuong J, Mayer LW, Pride MW, Jansen KU, and Anderson AS
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- Blood Bactericidal Activity, Flow Cytometry methods, Humans, Neisseria meningitidis, Serogroup B chemistry, Neisseria meningitidis, Serogroup B isolation & purification, Anti-Bacterial Agents pharmacology, Antibodies, Bacterial pharmacology, Antigens, Bacterial analysis, Bacterial Proteins analysis, Meningococcal Vaccines immunology, Microbial Viability drug effects, Neisseria meningitidis, Serogroup B drug effects, Neisseria meningitidis, Serogroup B physiology
- Abstract
Bivalent rLP2086 (Trumenba), a vaccine for prevention of Neisseria meningitidis serogroup B (NmB) disease, was licensed for use in adolescents and young adults after it was demonstrated that it elicits antibodies that initiate complement-mediated killing of invasive NmB isolates in a serum bactericidal assay with human complement (hSBA). The vaccine consists of two factor H binding proteins (fHBPs) representing divergent subfamilies to ensure broad coverage. Although it is the surrogate of efficacy, an hSBA is not suitable for testing large numbers of strains in local laboratories. Previously, an association between the in vitro fHBP surface expression level and the susceptibility of NmB isolates to killing was observed. Therefore, a flow cytometric meningococcal antigen surface expression (MEASURE) assay was developed and validated by using an antibody that binds to all fHBP variants from both fHBP subfamilies and accurately quantitates the level of fHBP expressed on the cell surface of NmB isolates with mean fluorescence intensity as the readout. Two collections of invasive NmB isolates ( n = 1,814, n = 109) were evaluated in the assay, with the smaller set also tested in hSBAs using individual and pooled human serum samples from young adults vaccinated with bivalent rLP2086. From these data, an analysis based on fHBP variant prevalence in the larger 1,814-isolate set showed that >91% of all meningococcal serogroup B isolates expressed sufficient levels of fHBP to be susceptible to bactericidal killing by vaccine-induced antibodies. IMPORTANCE Bivalent rLP2086 (Trumenba) vaccine, composed of two factor H binding proteins (fHBPs), was recently licensed for the prevention of N. meningitidis serogroup B (NmB) disease in individuals 10 to 25 years old in the United States. This study evaluated a large collection of NmB isolates from the United States and Europe by using a flow cytometric MEASURE assay to quantitate the surface expression of the vaccine antigen fHBP. We find that expression levels and the proportion of strains above the level associated with susceptibility in an hSBA are generally consistent across these geographic regions. Thus, the assay can be used to predict which NmB isolates are susceptible to killing in the hSBA and therefore is able to demonstrate an fHBP vaccine-induced bactericidal response. This work significantly advances our understanding of the potential for bivalent rLP2086 to provide broad coverage against diverse invasive-disease-causing NmB isolates., (Copyright © 2018 McNeil et al.)
- Published
- 2018
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15. Neutrophil killing of Staphylococcus aureus in diabetes, obesity and metabolic syndrome: a prospective cellular surveillance study.
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Scully IL, McNeil LK, Pathirana S, Singer CL, Liu Y, Mullen S, Girgenti D, Gurtman A, Pride MW, Jansen KU, Huang PL, and Anderson AS
- Abstract
Background: Obesity, metabolic syndrome (MetS), and diabetes are frequent in surgical populations and can enhance susceptibility to postoperative surgical site infections. Reduced neutrophil function has been linked with diabetes and risk of Staphylococcus aureus infection. Therefore, neutrophil function in diabetic and obese subjects (± MetS) was assessed in this prospective serological and cellular surveillance study to determine whether vaccines administered to protect against infections after surgery could be effective in these populations., Methods: Neutrophil function (chemotaxis, phagocytosis, and opsonophagocytic killing of S. aureus ) was assessed in subjects classified according to diabetes status, body mass index, and presence/absence of MetS. Neutrophils were characterized within functional subsets by flow cytometry. A serologic assay was used to measure baseline antibody presence to each antigen in SA4Ag: capsular polysaccharide (CP) type 5, CP8, recombinant mutant Clumping factor A (rmClfA), and recombinant Manganese transport protein C (rMntC)., Results: Neutrophil function was similar for comorbid and healthy cohorts, with no significant between-group differences in cell counts, migration, phagocytosis ability, neutrophil subset proportions, and S. aureus killing ability when neutrophils were isolated 3-6 months apart (Visit 1 [n = 90] and Visit 2 [n = 70]) and assessed. Median pre-existing antibody titers to CP5, CP8, and rmClfA were comparable for all cohorts (insufficient subjects with rMntC titers for determination)., Conclusions: MetS, diabetes, and obesity do not impact in vitro neutrophil function with regard to S. aureus killing, suggesting that if an effective S. aureus vaccine is developed it may be effective in individuals with these comorbidities.
- Published
- 2017
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16. Longitudinal multiparameter single-cell analysis of macaques immunized with pneumococcal protein-conjugated or unconjugated polysaccharide vaccines reveals distinct antigen specific memory B cell repertoires.
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Jia B, McNeil LK, Dupont CD, Tsioris K, Barry RM, Scully IL, Ogunniyi AO, Gonzalez C, Pride MW, Gierahn TM, Liberator PA, Jansen KU, and Love JC
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- Animals, Antibodies, Bacterial immunology, Heptavalent Pneumococcal Conjugate Vaccine immunology, Immunization, Secondary, Immunologic Memory, Pneumococcal Vaccines immunology, Single-Cell Analysis, Streptococcus pneumoniae immunology, B-Lymphocytes metabolism, Heptavalent Pneumococcal Conjugate Vaccine administration & dosage, Macaca immunology, Pneumococcal Vaccines administration & dosage
- Abstract
Background: The efficacy of protein-conjugated pneumococcal polysaccharide vaccines has been well characterized for children. The level of protection conferred by unconjugated polysaccharide vaccines remains less clear, particularly for elderly individuals who have had prior antigenic experience through immunization with unconjugated polysaccharide vaccines or natural exposure to Streptococcus pneumoniae., Methods: We compared the magnitude, diversity and genetic biases of antigen-specific memory B cells in two groups of adult cynomolgus macaques that were immunized with a 7-valent conjugated vaccine and boosted after five years with either a 13-valent pneumococcal polysaccharide conjugate vaccine (13vPnC) or a 23-valent unconjugated pneumococcal polysaccharide vaccine (23vPS) using microengraving (a single-cell analysis method) and single-cell RT-PCR., Results: Seven days after boosting, the mean frequency of antigen-specific memory B cells was significantly increased in macaques vaccinated with 13vPnC compared to those receiving 23vPS. The 13vPnC-vaccinated macaques also exhibited a more even distribution of antibody specificities to four polysaccharides in the vaccine (PS4, 6B, 14, 23F) that were examined. However, single-cell analysis of the antibody variable region sequences from antigen-specific B cells elicited by unconjugated and conjugated vaccines indicated that both the germline gene segments forming the heavy chains and the average lengths of the Complementary Determining Region 3 (CDR3) were similar., Conclusions: Our results confirm that distinctive differences can manifest between antigen-specific memory B cell repertoires in nonhuman primates immunized with conjugated and unconjugated pneumococcal polysaccharide vaccines. The study also supports the notion that the conjugated vaccines have a favorable profile in terms of both the frequency and breadth of the anamnestic response among antigen-specific memory B cells.
- Published
- 2017
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17. Encouraging Critical Clinical Thinking (CCT) Skills in First-Year Veterinary Students.
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Ferguson DC, McNeil LK, Schaeffe DJ, and Mills EM
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- Education, Veterinary standards, Educational Measurement, Humans, Illinois, Program Evaluation, Schools, Veterinary standards, Clinical Competence, Curriculum trends, Education, Veterinary organization & administration, Problem-Based Learning, Schools, Veterinary organization & administration, Students, Medical
- Abstract
First-year didactic course instructors at the University of Illinois College of Veterinary Medicine leverage earlier clinical rotation experiences with weekly "Clinical Correlations" exercises to provide early exposure to critical clinical thinking (CCT). This study evaluated the efficacy of individual and paired group exercises on CCT development. Before and after instruction, the Cornell Critical Thinking Test (Level Z) (CCTTZ) was administered. Based on the hypothesis that students with higher scores would coach lower-scoring colleagues during group exercises, heterogeneous groups with similar mean scores were established for the year. Students completed 14 individual and paired group exercises over 6 months. Exercises were designed to increase in complexity and decline in scaffolding. Seven of the exercises were cases using the Applied Learning Platform (ALP) at http://www.whenknowingmatters.com . Student analyses were scored according to a six-category critical-thinking rubric using a 5-point scale. Consistent with our hypothesis, individual and group rubric scores increased significantly, plateauing near the end of the year. Contrary to our hypothesis, mean overall CCTTZ scores did not change, but there was a small statistically significant increase in the ability to assess the validity of an argument. Student attitudes were mixed. Positive comments focused on reinforcement of prior didactic instruction, while negative comments focused on preparation time needed to conduct research on clinical concepts, and on a lack of explicit evaluation by summative examinations. Nonetheless, end-of-year GPAs correlated linearly with cumulative individual rubric scores. In summary, the value of early curriculum CCT training was confirmed when discipline-specific criteria were applied.
- Published
- 2017
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18. Bactericidal activity of sera from adolescents vaccinated with bivalent rLP2086 against meningococcal serogroup B outbreak strains from France.
- Author
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Taha MK, Hawkins JC, Liberator P, Deghmane AE, Andrew L, Hao L, Jones TR, McNeil LK, O'Neill RE, Perez JL, Jansen KU, and Anderson AS
- Subjects
- Adolescent, Antigens, Bacterial analysis, Antigens, Bacterial genetics, Bacterial Proteins analysis, Bacterial Proteins genetics, Child, Complement System Proteins immunology, Disease Outbreaks, Female, France epidemiology, Gene Expression Profiling, Humans, Male, Meningococcal Vaccines administration & dosage, Microbial Viability, Neisseria meningitidis, Serogroup B genetics, Neisseria meningitidis, Serogroup B isolation & purification, Antigens, Bacterial immunology, Bacterial Proteins immunology, Blood Bactericidal Activity, Meningococcal Vaccines immunology, Neisseria meningitidis, Serogroup B immunology
- Abstract
Objectives: Bivalent rLP2086 (Trumenba®; MenB-FHbp), composed of two factor H binding proteins (FHbps), is a vaccine approved in the United States for prevention of Neisseria meningitidis serogroup B (MnB) invasive meningococcal disease (IMD). Bactericidal activity of sera from subjects vaccinated with bivalent rLP2086 was assessed against MnB isolates from recent disease outbreaks in France., Methods: MnB isolates from IMD cases were characterized by whole genome sequencing and FHbp expression was assessed using a flow cytometry-based assay. Sera from subjects (11-<19years old) vaccinated with bivalent rLP2086 at 0, 2, and 6months were evaluated. Bactericidal activity was measured in serum bactericidal assays using human complement (hSBAs). The response rate (RR) represents the percentage of subjects with an hSBA titer ⩾1:4., Results: The six MnB outbreak isolates expressed diverse FHbp variants: A22, B03, B24 (two isolates), B44, and B228. FHbp expression levels ranged from 1309 to 8305 (mean fluorescence intensity units). The RR of preimmune sera from subjects was 7% to 27%. RRs increased for all isolates after each vaccine dose. After two doses, RRs ranged from 40% to 93%. After dose 3, RRs were ⩾73% for all isolates (range, 73%-100%)., Conclusions: Each of the representative French outbreak isolates was killed by sera from subjects vaccinated with bivalent rLP2086. Vaccination elicited an immune response with bactericidal activity against these diverse isolates in a large proportion of subjects at risk. These results provide additional support for the licensure strategy of testing MnB strains expressing vaccine-heterologous FHbp variants in hSBAs and further illustrate the breadth of efficacy of this protein-based MnB vaccine., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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19. Neisseria meningitidis Serogroup B Vaccine, Bivalent rLP2086, Induces Broad Serum Bactericidal Activity Against Diverse Invasive Disease Strains Including Outbreak Strains.
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Harris SL, Donald RG, Hawkins JC, Tan C, O'Neill R, McNeil LK, Perez JL, Anderson AS, Jansen KU, and Jones TR
- Subjects
- Adolescent, Adult, Antibodies, Bacterial immunology, Child, Clinical Trials, Phase II as Topic, Cohort Studies, Disease Outbreaks statistics & numerical data, Humans, Meningococcal Infections epidemiology, Meningococcal Infections microbiology, Meningococcal Vaccines administration & dosage, Meningococcal Vaccines chemistry, Young Adult, Antigens, Bacterial immunology, Bacterial Proteins immunology, Disease Outbreaks prevention & control, Meningococcal Infections prevention & control, Meningococcal Vaccines immunology, Neisseria meningitidis, Serogroup B immunology
- Abstract
Background: Bivalent rLP2086 (Trumenba), 1 of 2 meningococcal serogroup B (MnB) vaccines recently approved in the United States for the prevention of MnB disease in individuals 10-25 years of age, is composed of 2 lipidated factor H binding proteins from subfamilies A and B. This study evaluated the breadth of MnB strain coverage elicited by bivalent rLP2086 measured with serum bactericidal assays using human complement (hSBAs)., Methods: hSBA responses to diverse MnB clinical strains circulating in the United States and Europe (n = 23), as well as recent US university outbreak strains (n = 4), were evaluated. Individual prevaccination and postvaccination sera from adolescents and young adults previously enrolled in phase 2 clinical studies of bivalent rLP2086 were assessed. Responders were defined by an hSBA titer ≥1:8, which is more stringent than the accepted correlate of protection (hSBA titer ≥1:4)., Results: Baseline hSBA response rates were generally low; robust increases were observed after 2 and 3 doses of bivalent rLP2086, with hSBA responses to all test strains ranging from 31.8% to 100% and 55.6% to 100%, respectively. hSBA responses to strains expressing prevalent subfamily A and B factor H binding protein variants in the United States and Europe, A22 and B24, ranged from 88.0% to 95.0% and 81.0% to 100.0%, respectively, after dose 3. Substantial responses were also observed for recent US outbreak strains., Conclusions: Bivalent rLP2086 elicits robust hSBA responses to MnB strains expressing 14 factor H binding protein variants representing approximately 80% of MnB invasive isolates and different from vaccine antigens, suggesting that bivalent rLP2086 confers broad protection against diverse MnB disease-causing strains.
- Published
- 2017
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20. Safety, tolerability, and immunogenicity of a single dose 4-antigen or 3-antigen Staphylococcus aureus vaccine in healthy older adults: Results of a randomised trial.
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Creech CB, Frenck RW Jr, Sheldon EA, Seiden DJ, Kankam MK, Zito ET, Girgenti D, Severs JM, Immermann FW, McNeil LK, Cooper D, Jansen KU, Gruber W, Eiden J, Anderson AS, and Baber J
- Subjects
- Adjuvants, Immunologic metabolism, Aged, Aged, 80 and over, Antibodies, Bacterial blood, Bacterial Proteins immunology, Bacterial Proteins metabolism, Cytokines analysis, Double-Blind Method, Drug-Related Side Effects and Adverse Reactions epidemiology, Female, Humans, Male, Opsonin Proteins blood, Phagocytosis, Placebos administration & dosage, Polysaccharides, Bacterial immunology, Staphylococcal Vaccines administration & dosage, T-Lymphocytes immunology, Treatment Outcome, Vaccines, Conjugate administration & dosage, Vaccines, Conjugate immunology, Antigens, Bacterial immunology, Staphylococcal Vaccines adverse effects, Staphylococcal Vaccines immunology, Staphylococcus aureus immunology
- Abstract
Background: The decline in immune function with age is a challenge to vaccine development. Following an initial study in adults aged 18-64years, this study evaluated the safety and immunogenicity of Staphylococcus aureus (S. aureus) 4-antigen (SA4Ag) and 3-antigen (SA3Ag) vaccine in older adults. SA3Ag included capsular polysaccharide serotypes 5 and 8 (CP5 and CP8) conjugated to the nontoxic mutant form of diphtheria toxin (CRM
197 ) and a recombinant version of clumping factor A (ClfA). SA4Ag included these antigens, with the addition of a recombinant manganese transporter C (rP305A or MntC). Both vaccines were unadjuvanted., Methods: In this double-blind, sponsor-unblinded, placebo-controlled, phase 1/2 study, 284 healthy adults (aged 65-85years) were randomised to receive a single dose of one of three formulations of SA4Ag with escalating dose levels of rP305A, SA3Ag, or placebo. Functional immune responses were measured using opsonophagocytic activity (OPA) killing and fibrinogen-binding inhibition (FBI) assays; immunogenicity was also assessed using a competitive Luminex® immunoassay (cLIA). T-cell responses were measured in a small subgroup of subjects using intracellular cytokine staining (ICS) assays., Results: The results demonstrated rapid and robust functional immune responses to all antigens in healthy older adults. A high proportion of active vaccine recipients met the pre-defined antibody thresholds for each antigen at Day 29. SA4Ag elicited a dose-level response to rP305A with up to a 13-fold rise in cLIA titres at Day 29. Opsonophagocytic activity (OPA) assays showed >50- and >20-fold rises in functional titres using S. aureus strains expressing CP5 and CP8, respectively, at Day 29. T-cell cytokine responses were not substantially above background levels. There were no safety concerns in this study population and no increases in adverse events with higher rP305A dose levels., Conclusions: Single-dose vaccination of SA4Ag and SA3Ag in healthy adults aged 65-85years safely induced rapid and robust functional immune responses, supporting further development of SA4Ag for the prevention of S. aureus disease in adults up to age 85years., Trial Registration Number: NCT01643941., (Copyright © 2016 Elsevier Ltd. All rights reserved.)- Published
- 2017
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21. Approach to the Discovery, Development, and Evaluation of a Novel Neisseria meningitidis Serogroup B Vaccine.
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Green LR, Eiden J, Hao L, Jones T, Perez J, McNeil LK, Jansen KU, and Anderson AS
- Subjects
- Antibodies, Bacterial immunology, Antigens, Bacterial immunology, Bacterial Vaccines genetics, Complement System Proteins metabolism, Genomics, Humans, Immunization, Neisseria meningitidis, Serogroup B genetics, Neisseria meningitidis, Serogroup B growth & development, Safety, Staining and Labeling, Bacterial Vaccines immunology, Drug Discovery methods, Neisseria meningitidis, Serogroup B immunology
- Abstract
In this chapter, we describe a research and development pathway to identify and demonstrate the efficacy of a Neisseria meningitidis non-capsular vaccine, the recently licensed N. meningitidis serogroup B (MnB) vaccine, Trumenba(®). While other approaches have been followed in the identification of a MnB vaccine (Pizza et al. Science 287:1816-1820, 2000), the methods described here reflect the distinctive approach and experiences in discovering and developing Trumenba(®). In contrast to the development and licensure of polysaccharide-conjugate vaccines against meningococcal serotypes A, C, W, and Y, the development of a vaccine to produce broadly protective antibodies against meningococcal serogroup B has proved difficult, due to the antigenic mimicry of the serogroup B polysaccharide capsule, which is composed of polysialic acid structures similar to those expressed on human neuronal cells. Early development efforts for these vaccines failed because the MnB polysaccharide structures resemble autoantigens and thus were poorly immunogenic. The development of an MnB vaccine has therefore focused on non-polysaccharide approaches. It was critical to identify MnB cell surface-exposed antigens capable of inducing a protective response against diverse, circulating strains of invasive MnB to ensure global coverage. Once candidate antigens were identified, it was important to characterize antigenic variation and expression levels, and subsequently to assure that antigens were expressed broadly among diverse clinical isolates. Prior to the initiation of clinical trials in humans, candidate vaccine antigens were tested in functional immunogenicity assays and yielded responses that were correlated with protection from meningococcal disease. These functional immunogenicity assays (serum bactericidal assays using human complement, hSBAs) measure the titer of complement-dependent bactericidal antibodies in serum from immunized test animals using diverse clinical MnB isolates as targets. Following optimization of vaccine antigenic components based on hSBA responses in preclinical models, animal toxicology tests were performed. Initial clinical studies (Phase 1 and 2) subsequently provided data to support (1) safety and immunogenicity of the vaccine formulation, and (2) the dose and schedule. Phase 3 clinical trials were carried out in the target populations to provide the clinical confirmation of safety and efficacy required for vaccine licensure.
- Published
- 2016
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22. Comparison of Phenotypic and Genotypic Approaches to Capsule Typing of Neisseria meningitidis by Use of Invasive and Carriage Isolate Collections.
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Jones CH, Mohamed N, Rojas E, Andrew L, Hoyos J, Hawkins JC, McNeil LK, Jiang Q, Mayer LW, Wang X, Gilca R, De Wals P, Pedneault L, Eiden J, Jansen KU, and Anderson AS
- Subjects
- Adolescent, Adult, Bacterial Capsules genetics, Bacterial Capsules immunology, Epidemiologic Studies, Female, Humans, Male, Neisseria meningitidis genetics, Neisseria meningitidis immunology, Young Adult, Bacterial Capsules classification, Carrier State microbiology, Genotyping Techniques methods, Neisseria meningitidis classification, Neisseriaceae Infections microbiology, Serotyping methods
- Abstract
Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis; however, MnB is most commonly associated with asymptomatic carriage in the nasopharyngeal cavity, as opposed to the disease state. Two vaccines are now licensed for the prevention of MnB disease; a possible additional benefit of these vaccines could be to protect against disease indirectly by disrupting nasopharyngeal carriage (e.g., herd protection). To investigate this possibility, accurate diagnostic approaches to characterize MnB carriage isolates are required. In contrast to invasive meningococcal disease (IMD) isolates, which can be readily serogrouped, carriage isolates often lack capsule expression, making standard phenotypic assays unsuitable for strain characterization. Several antibody-based methods were evaluated for their abilities to serogroup isolates and were compared with two genotyping methods (real-time PCR [rt-PCR] and whole-genome sequencing [WGS]) to identify which approach would most accurately ascertain the polysaccharide groups associated with carriage isolates. WGS and rt-PCR were in agreement for 99% of IMD isolates, including those with coding sequences for MnB, MnC, MnW, and MnY, and the phenotypic methods correctly identified serogroups for 69 to 98% of IMD isolates. In contrast, only 47% of carriage isolates were groupable by genotypic methods, due to mutations within the capsule operon; of the isolates identified by genotypic methods, ≤43% were serogroupable with any of the phenotypic methods tested. These observations highlight the difficulties in the serogrouping and capsular genogrouping of meningococcal carriage isolates. Based on our findings, WGS is the most suitable approach for the characterization of meningococcal carriage isolates., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
- Published
- 2016
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23. Demonstration of the preclinical correlate of protection for Staphylococcus aureus clumping factor A in a murine model of infection.
- Author
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Scully IL, Timofeyeva Y, Keeney D, Matsuka YV, Severina E, McNeil LK, Nanra J, Hu G, Liberator PA, Jansen KU, and Anderson AS
- Subjects
- Animals, Antibodies, Bacterial blood, Antibodies, Bacterial immunology, Coagulase genetics, Coagulase metabolism, Disease Models, Animal, Fibrinogen metabolism, Humans, Immunization, Lactococcus lactis immunology, Lactococcus lactis metabolism, Mice, Protein Binding, Recombinant Proteins administration & dosage, Recombinant Proteins immunology, Staphylococcal Infections immunology, Staphylococcal Infections microbiology, Staphylococcus aureus genetics, Staphylococcus aureus pathogenicity, Virulence genetics, Coagulase immunology, Staphylococcal Infections prevention & control, Staphylococcus aureus immunology
- Abstract
The Staphylococcus aureus virulence factor clumping factor A (ClfA) is a component of an investigational S. aureus prophylactic vaccine. ClfA enables S. aureus to bind to fibrinogen and platelets during the initial stages of invasive disease. Here we demonstrate that ectopic expression of ClfA is sufficient to render nonpathogenic Lactococcus lactis lethal in a murine model of systemic infection. In contrast, L. lactis expressing ClfAY338A, which cannot bind fibrinogen, did not cause death in the mice. Pathogenicity was also prevented by immunization with ClfA. This model was then used to define a preclinical correlate of protection by measuring functional antibody in a S. aureus fibrinogen binding inhibition assay (FBI) and correlating that titer with protective outcomes. Although many humans have pre-existing antibodies that bind to ClfA, only sera with a threshold functional titer in the FBI were protective in this preclinical model. This confirms that fibrinogen binding is critical for ClfA-mediated pathogenesis and demonstrates that functional antibodies against ClfA are sufficient to protect against ClfA-mediated pathogenesis in vivo, enabling the definition of a preclinical correlate of protection for ClfA-containing vaccines based on FBI titer., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2015
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24. IL-4 Knock Out Mice Display Anxiety-Like Behavior.
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Moon ML, Joesting JJ, Blevins NA, Lawson MA, Gainey SJ, Towers AE, McNeil LK, and Freund GG
- Subjects
- Animals, Exploratory Behavior, Male, Maze Learning, Mice, Mice, Inbred C57BL, Mice, Knockout, Social Behavior, Swimming, Anxiety genetics, Behavior, Animal, Inflammation, Interleukin-4 genetics
- Abstract
Inflammation is a recognized antecedent and coincident factor when examining the biology of anxiety. Little is known, however, about how reductions in endogenous anti-inflammatory mediators impact anxiety. Therefore, mood- cognition- and anxiety-associated/like behaviors were examined in IL-4 knock out (KO) mice and wild-type (WT) mice. In comparison to WT mice, IL-4 KO mice demonstrated decreased burrowing and increased social exploration. No differences were seen in forced swim or saccharine preference testing. IL-4 KO mice had similar performance to WT mice in the Morris water maze and during object location and novel object recognition. In the elevated zero-maze, IL-4 KO mice, in comparison to WT mice, demonstrated anxiety-like behavior. Anxiety-like behavior in IL-4 KO mice was not observed, however, during open-field testing. Taken together, these data indicate that IL-4 KO mice display state, but not trait, anxiety suggesting that reductions in endogenous anti-inflammatory bioactives can engender subtypes of anxiety.
- Published
- 2015
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25. The discovery and development of a novel vaccine to protect against Neisseria meningitidis Serogroup B Disease.
- Author
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Zlotnick GW, Jones TR, Liberator P, Hao L, Harris S, McNeil LK, Zhu D, Perez J, Eiden J, Jansen KU, and Anderson AS
- Subjects
- Humans, Neisseria meningitidis, Meningitis, Meningococcal microbiology, Meningitis, Meningococcal prevention & control, Meningococcal Vaccines immunology, Meningococcal Vaccines isolation & purification, Neisseria meningitidis, Serogroup B immunology
- Abstract
Vaccines have had a major impact on the reduction of many diseases globally. Vaccines targeted against invasive meningococcal disease (IMD) due to serogroups A, C, W, and Y are used to prevent these diseases. Until recently no vaccine had been identified that could confer broad protection against Neisseria meningitidis serogroup B (MnB). MnB causes IMD in the very young, adolescents and young adults and thus represents a significant unmet medical need. In this brief review, we describe the discovery and development of a vaccine that has the potential for broad protection against this devastating disease.
- Published
- 2015
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26. A harmonized approach to intracellular cytokine staining gating: Results from an international multiconsortia proficiency panel conducted by the Cancer Immunotherapy Consortium (CIC/CRI).
- Author
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McNeil LK, Price L, Britten CM, Jaimes M, Maecker H, Odunsi K, Matsuzaki J, Staats JS, Thorpe J, Yuan J, and Janetzki S
- Subjects
- CD4-Positive T-Lymphocytes metabolism, CD8-Positive T-Lymphocytes metabolism, Flow Cytometry methods, Humans, Immunotherapy, International Cooperation, Laboratories standards, Laboratory Proficiency Testing, Neoplasms immunology, Neoplasms pathology, Reproducibility of Results, Staining and Labeling, Cytokines metabolism, Flow Cytometry standards, Neoplasms therapy
- Abstract
Previous results from two proficiency panels of intracellular cytokine staining (ICS) from the Cancer Immunotherapy Consortium and panels from the National Institute of Allergy and Infectious Disease and the Association for Cancer Immunotherapy highlight the variability across laboratories in reported % CD8+ or % CD4+ cytokine-positive cells. One of the main causes of interassay variability in flow cytometry-based assays is due to differences in gating strategies between laboratories, which may prohibit the generation of robust results within single centers and across institutions. To study how gating strategies affect the variation in reported results, a gating panel was organized where all participants analyzed the same set of Flow Cytometry Standard (FCS) files from a four-color ICS assay using their own gating protocol (Phase I) and a gating protocol drafted by consensus from the organizers of the panel (Phase II). Focusing on analysis removed donor, assay, and instrument variation, enabling us to quantify the variability caused by gating alone. One hundred ten participating laboratories applied 110 different gating approaches. This led to high variability in the reported percentage of cytokine-positive cells and consequently in response detection in Phase I. However, variability was dramatically reduced when all laboratories used the same gating strategy (Phase II). Proximity of the cytokine gate to the negative population most impacted true-positive and false-positive response detection. Recommendations are provided for the (1) placement of the cytokine-positive gate, (2) identification of CD4+ CD8+ double-positive T cells, (3) placement of lymphocyte gate, (4) inclusion of dim cells, (5) gate uniformity, and 6) proper adjustment of the biexponential scaling., (© 2013 International Society for Advancement of Cytometry.)
- Published
- 2013
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27. Mouse short- and long-term locomotor activity analyzed by video tracking software.
- Author
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York JM, Blevins NA, McNeil LK, and Freund GG
- Subjects
- Animals, Behavior, Animal drug effects, Lipopolysaccharides pharmacology, Locomotion drug effects, Mice, Video Recording instrumentation, Behavior, Animal physiology, Locomotion physiology, Software, Video Recording methods
- Abstract
Locomotor activity (LMA) is a simple and easily performed measurement of behavior in mice and other rodents. Improvements in video tracking software (VTS) have allowed it to be coupled to LMA testing, dramatically improving specificity and sensitivity when compared to the line crossings method with manual scoring. In addition, VTS enables high-throughput experimentation. While similar to automated video tracking used for the open field test (OFT), LMA testing is unique in that it allows mice to remain in their home cage and does not utilize the anxiogenic stimulus of bright lighting during the active phase of the light-dark cycle. Traditionally, LMA has been used for short periods of time (mins), while longer movement studies (hrs-days) have often used implanted transmitters and biotelemetry. With the option of real-time tracking, long-, like short-term LMA testing, can now be conducted using videography. Long-term LMA testing requires a specialized, but easily constructed, cage so that food and water (which is usually positioned on the cage top) does not obstruct videography. Importantly, videography and VTS allows for the quantification of parameters, such as path of mouse movement, that are difficult or unfeasible to measure with line crossing and/or biotelemetry. In sum, LMA testing coupled to VTS affords a more complete description of mouse movement and the ability to examine locomotion over an extended period of time.
- Published
- 2013
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28. Role of factor H binding protein in Neisseria meningitidis virulence and its potential as a vaccine candidate to broadly protect against meningococcal disease.
- Author
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McNeil LK, Zagursky RJ, Lin SL, Murphy E, Zlotnick GW, Hoiseth SK, Jansen KU, and Anderson AS
- Subjects
- Antigens, Bacterial chemistry, Antigens, Bacterial immunology, Bacterial Proteins chemistry, Bacterial Proteins immunology, Humans, Meningococcal Infections immunology, Meningococcal Vaccines metabolism, Neisseria meningitidis immunology, Neisseria meningitidis pathogenicity, Protein Conformation, Virulence immunology, Antigens, Bacterial metabolism, Bacterial Proteins metabolism, Meningococcal Infections prevention & control, Meningococcal Vaccines immunology, Neisseria meningitidis metabolism
- Abstract
Neisseria meningitidis is a Gram-negative microorganism that exists exclusively in humans and can cause devastating invasive disease. Although capsular polysaccharide-based vaccines against serogroups A, C, Y, and W135 are widely available, the pathway to a broadly protective vaccine against serogroup B has been more complex. The last 11 years has seen the discovery and development of the N. meningitidis serogroup B (MnB) outer membrane protein factor H binding protein (fHBP) as a vaccine component. Since the initial discovery of fHBP, a tremendous amount of work has accumulated on the diversity, structure, and regulation of this important protein. fHBP has proved to be a virulence factor for N. meningitidis and a target for functional bactericidal antibodies. fHBP is critical for survival of meningococci in the human host, as it is responsible for the primary interaction with human factor H (fH). Binding of hfH by the meningococcus serves to downregulate the host alternative complement pathway and helps the organism evade host innate immunity. Preclinical studies have shown that an fHBP-based vaccine can elicit serum bactericidal antibodies capable of killing MnB, and the vaccine has shown very encouraging results in human clinical trials. This report reviews our current knowledge of fHBP. In particular, we discuss the recent advances in our understanding of fHBP, its importance to N. meningitidis, and its potential role as a vaccine for preventing MnB disease.
- Published
- 2013
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29. Capsular polysaccharides are an important immune evasion mechanism for Staphylococcus aureus.
- Author
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Nanra JS, Buitrago SM, Crawford S, Ng J, Fink PS, Hawkins J, Scully IL, McNeil LK, Aste-Amézaga JM, Cooper D, Jansen KU, and Anderson AS
- Subjects
- Animals, Antibodies, Bacterial immunology, Complement System Proteins immunology, Macaca mulatta, Opsonin Proteins immunology, Staphylococcal Protein A immunology, Staphylococcus aureus pathogenicity, Bacterial Capsules immunology, Immune Evasion, Phagocytosis, Staphylococcus aureus immunology, Virulence Factors immunology
- Abstract
Staphylococcus aureus can cause severe life threatening invasive diseases. The principal immune effector mechanism by which humans are protected from Gram positive bacteria such as S. aureus is antigen specific antibody- and complement-dependent opsonophagocytosis. This process can be measured in vitro using the opsonophagocytic antibody assay (OPA), which is a complex assay composed of live S. aureus bacteria, a complement source, phagocytic effector cells such as differentiated HL-60 cells, and test serum. In this report, we investigated the impact on the OPA of S. aureus surface antigens capsular polysaccharides (CP) and protein A (SpA). We demonstrated that higher CP expression renders bacteria more resistant to non-specific opsonophagocytic killing than increased SpA expression, suggesting that the expression of capsular polysaccharides may be the more important immune evasion strategy for S. aureus. Bacteria that were not fully encapsulated were highly susceptible to non-specific killing in the assay in the absence of immune serum. This non-specific killing was prevented by growing the bacteria under conditions that increased capsular polysaccharide levels on the surface of the bacteria. In contrast, the level of SpA expression had no detectable effect on non-specific killing in OPA. Using anti-CP antibodies we demonstrated type-specific killing in OPA of both MRSA and MSSA clinical isolates. SpA expression on the cell surface did not interfere with OPA activity, providing evidence that despite the role of SpA in sequestering antibodies by their Fc region, killing is easily accomplished in the presence of high titered anti-capsular polysaccharide antibodies. This highlights the role of CP as an important immune evasion mechanism and supports the inclusion of capsular polysaccharide antigens in the formulation of multi-component prophylactic vaccines against S. aureus.
- Published
- 2013
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30. Non-propagating, recombinant vesicular stomatitis virus vectors encoding respiratory syncytial virus proteins generate potent humoral and cellular immunity against RSV and are protective in mice.
- Author
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Johnson JE, McNeil LK, Megati S, Witko SE, Roopchand VS, Obregon JH, Illenberger DM, Kotash CS, Nowak RM, Braunstein E, Yurgelonis I, Jansen KU, Kalyan NK, and Sidhu MK
- Subjects
- Animals, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Disease Models, Animal, Female, Gene Order, Genetic Vectors administration & dosage, Humans, Immunization, Immunologic Memory, Mice, Respiratory Syncytial Virus Infections prevention & control, Th1 Cells immunology, Viral Fusion Proteins genetics, Viral Fusion Proteins immunology, Genetic Vectors genetics, Genetic Vectors immunology, Immunity, Cellular, Immunity, Humoral, Respiratory Syncytial Virus Infections immunology, Respiratory Syncytial Viruses genetics, Respiratory Syncytial Viruses immunology, Vesiculovirus genetics
- Abstract
Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract illness in infants, the elderly, and other high-risk individuals. Despite years of research in this field, there is no effective licensed vaccine to prevent RSV infection. We have generated candidate RSV vaccines using a recombinant vesicular stomatitis virus (rVSV) replicon in which the attachment and fusion domains of the VSV glycoprotein (G) have been deleted (rVSV-Gstem), rendering the virus propagation-defective except in the presence of complementing VSV G provided in trans. A form of this vector encoding the RSV fusion protein (F) gene expressed high levels of F in vitro and elicited durable neutralizing antibody responses as well as complete protection against RSV challenge in vivo. Mice vaccinated with rVSV-Gstem-RSV-F replicons also developed robust cellular responses characterized by both primary and memory Th1-biased CD8+ and CD4+ T cells. Furthermore, a single high dose of the Gstem-RSV-F replicon was effective against challenge with both RSV A and B subgroup viruses. Finally, addition of an RSV glycoprotein (G)-expressing Gstem vector significantly improved the incomplete protection achieved with a single low dose of Gstem-RSV-F vector alone., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
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31. A recombinant clumping factor A-containing vaccine induces functional antibodies to Staphylococcus aureus that are not observed after natural exposure.
- Author
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Hawkins J, Kodali S, Matsuka YV, McNeil LK, Mininni T, Scully IL, Vernachio JH, Severina E, Girgenti D, Jansen KU, Anderson AS, and Donald RG
- Subjects
- Animals, Antibodies, Bacterial blood, Coagulase metabolism, Humans, Mice, Mice, Inbred BALB C, Protein Binding, Staphylococcal Infections immunology, Staphylococcal Infections prevention & control, Staphylococcus aureus pathogenicity, Bacterial Adhesion, Coagulase immunology, Fibrinogen metabolism, Staphylococcal Vaccines immunology, Staphylococcus aureus immunology
- Abstract
Staphylococcus aureus is a Gram-positive pathogen that causes devastating disease and whose pathogenesis is dependent on interactions with host cell factors. Staphylococcal clumping factor A (ClfA) is a highly conserved fibrinogen (Fg)-binding protein and virulence factor that contributes to host tissue adhesion and initiation of infection. ClfA is being investigated as a possible component of a staphylococcal vaccine. We report the development of an Fg-binding assay that is specific for ClfA-mediated binding. Using the assay, we show that despite the presence of anti-ClfA antibodies, human sera from unvaccinated subjects are unable to prevent the binding of S. aureus to an Fg-coated surface. In contrast, antibodies elicited by a recombinant ClfA-containing vaccine were capable of blocking the ClfA-dependent binding of a diverse and clinically relevant collection of staphylococcal strains to Fg. These functional antibodies were also able to displace S. aureus already bound to Fg, suggesting that the ligand-binding activity of ClfA can be effectively neutralized through vaccination.
- Published
- 2012
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32. Staphylococcus aureus manganese transport protein C is a highly conserved cell surface protein that elicits protective immunity against S. aureus and Staphylococcus epidermidis.
- Author
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Anderson AS, Scully IL, Timofeyeva Y, Murphy E, McNeil LK, Mininni T, Nuñez L, Carriere M, Singer C, Dilts DA, and Jansen KU
- Subjects
- Animals, Antibodies, Bacterial blood, Antibodies, Bacterial immunology, Bacteremia immunology, Bacteremia prevention & control, Bacteremia therapy, Bacterial Load, Bacterial Proteins genetics, Carrier Proteins genetics, Disease Models, Animal, Female, Immunization, Passive, Membrane Proteins genetics, Mice, Rabbits, Rats, Rats, Sprague-Dawley, Staphylococcal Infections immunology, Staphylococcal Infections therapy, Staphylococcal Vaccines administration & dosage, Staphylococcal Vaccines genetics, Treatment Outcome, Bacterial Proteins immunology, Carrier Proteins immunology, Membrane Proteins immunology, Staphylococcal Infections prevention & control, Staphylococcal Vaccines immunology, Staphylococcus aureus immunology, Staphylococcus epidermidis immunology
- Abstract
Staphylococcus aureus and other staphylococci cause severe human disease, and there are currently no vaccines available. We evaluated whether manganese transport protein C (MntC), which is conserved across the staphylococcal species group, could confer protection against S. aureus and Staphylococcus epidermidis. In vivo analysis of S. aureus MntC expression revealed that expression occurs very early during the infectious cycle. Active immunization with MntC was effective at reducing the bacterial load associated with S. aureus and S. epidermidis infection in an acute murine bacteremia model. Anti-MntC monoclonal antibodies have been identified that can bind S. aureus and S. epidermidis cells and are protective in an infant rat passive protection model and induce neutrophil respiratory burst activity. This is the first description of a protein that has the potential to provide protection across the staphylococcal species group.
- Published
- 2012
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33. Macrophages make me sick: how macrophage activation states influence sickness behavior.
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Moon ML, McNeil LK, and Freund GG
- Subjects
- Animals, Humans, Inflammation immunology, Macrophage Activation immunology, Macrophages immunology, Macrophages physiology, Models, Biological, Wit and Humor as Topic, Illness Behavior physiology, Macrophage Activation physiology
- Abstract
The macrophage (MΦ) is an essential cellular first responder in the innate immune system, sensing, alerting, removing and destroying intrinsic and extrinsic pathogens. While congenital aplasia of granulocytes, T or B lymphocytes leads to serious disease, lack of MΦs is incompatible with life. The MΦ, however, is not a monomorphic entity. These constructers, repairers and defenders of the body are diverse in form and function. What controls MΦ phenotype is beginning to be understood and involves a complex interplay of origination, location and microenvironment. Common to all MΦ developmental pathways are pro-inflammatory and anti-inflammatory cytokines. MΦs respond to these bioactives in distinct ways developing recently recognized activation phenotypes that canonically support bacterial clearance (classical activation), parasite defense/tissue repair (alternative activation) and anti-inflammation (deactivation). Critically, the same cytokines which orchestrate immune defense and homeostasis dramatically impact sense of well being and cognition by eliciting sickness symptoms. Such behaviors are the manifestation of pro/anti-inflammatory cytokine action in the brain and are a direct consequence of MΦ function. This review describes the "new" archetypal MΦ activation states, delineates microglia phenotypic plasticity and explores the importance of these macrophage activation states to sickness behavior., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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34. Preclinical evidence for the potential of a bivalent fHBP vaccine to prevent Neisseria meningitidis Serogroup C Disease.
- Author
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Harris SL, Zhu D, Murphy E, McNeil LK, Wang X, Mayer LW, Harrison LH, Jansen KU, and Anderson AS
- Subjects
- Animals, Antibodies, Bacterial blood, Antigens, Bacterial analysis, Antigens, Bacterial genetics, Bacterial Proteins analysis, Bacterial Proteins genetics, Base Sequence, Blood Bactericidal Activity, Cluster Analysis, Complement System Proteins immunology, DNA, Bacterial chemistry, DNA, Bacterial genetics, Female, Flow Cytometry, Genotype, Humans, Macaca fascicularis, Male, Membrane Proteins analysis, Membrane Proteins genetics, Membrane Proteins immunology, Meningococcal Infections microbiology, Meningococcal Vaccines administration & dosage, Models, Molecular, Molecular Sequence Data, Neisseria meningitidis, Serogroup C chemistry, Neisseria meningitidis, Serogroup C genetics, Rabbits, Sequence Analysis, DNA, Antigens, Bacterial immunology, Bacterial Proteins immunology, Meningococcal Infections prevention & control, Meningococcal Vaccines immunology, Neisseria meningitidis, Serogroup C immunology
- Abstract
A bivalent factor H binding protein (fHBP) vaccine for the prevention of disease caused by Neisseria meningitidis serogroup B is currently in clinical development. Since fHBP is also expressed by other meningococcal serogroups, anti-fHBP antibodies may have bactericidal activity against meningococci independent of serogroup. To begin examining the susceptibility of other meningococcal serogroups to anti-fHBP antibodies, meningococcal serogroup C invasive isolates (n = 116) were collected from the Centers for Disease Control and Prevention's Active Bacterial Core surveillance (ABCs) sites during 2000-2001. These isolates were analyzed for the presence of the fhbp gene. All serogroup C isolates contained the gene, and sequence analysis grouped the proteins into two subfamilies, A and B. Flow cytometry analysis demonstrated that fHBP was expressed on the surface of ~70% of isolates in vitro with varying levels of expression. fHBP was accessible to antibodies on the cell surface even in the presence of the polysaccharide capsule. Nine isolates from different geographic regions were identified which harboured an identical single nucleotide deletion that could result in a truncated subfamily B fHBP. Analysis by flow cytometry using a polyclonal fHBP antibody preparation revealed that a subpopulation of each of these isolates expressed fHBP. Rabbit and non-human primate immune sera generated with bivalent fHBP vaccine were tested for bactericidal activity against a panel of diverse serogroup C clinical isolates using human complement. Sera from both species demonstrated serum bactericidal antibody activity against the serogroup C isolates tested. These promising findings suggest that a bivalent fHBP vaccine may be capable of providing protection against meningococcal disease caused by both serogroup C and B.
- Published
- 2011
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35. Human antibody responses to the meningococcal factor H binding protein (LP2086) during invasive disease, colonization and carriage.
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Ala'aldeen DA, Flint M, Oldfield NJ, Omer SA, McNeil LK, Jiang Q, Murphy E, Giardina PC, Novikova EG, Dodge-Scully IL, Bayliss CD, Turner DP, Neal KR, Hoiseth SK, Jansen KU, and Anderson AS
- Subjects
- Adolescent, Adult, Animals, Antibodies, Bacterial blood, Antibody Specificity, Carrier State microbiology, Female, Humans, Immunoglobulin G blood, Longitudinal Studies, Meningococcal Infections prevention & control, Middle Aged, Neisseria meningitidis, Serogroup B immunology, Rabbits, Young Adult, Antibody Formation, Antigens, Bacterial immunology, Bacterial Proteins immunology, Carrier State immunology, Meningococcal Infections immunology
- Abstract
Recombinant forms of Neisseria meningitidis factor H binding protein (fHBP) are undergoing clinical trials in candidate vaccines against serogroup B meningococcal disease. Little is known, however, about the host response to fHBP during natural carriage and disease. Here we report a longitudinal study of the antibody response to fHBP in healthy meningococcal carriers and non-carriers, and in patients with invasive meningococcal disease. Using a highly sensitive quantitative immunoassay, anti-fHBP antibodies were detected in sera from all healthy carriers and non-carriers. Carriers had significantly higher anti-fHBP antibody concentrations than non-carriers. Antibody responses similar to those seen in non-carrier subjects were detected in the sera of patients with invasive disease upon their admission to the hospital. The serum anti-fHBP antibody concentrations in these patients generally rose to reach levels similar to those seen in carriers. No correlation between levels of surface fHBP expressed in vitro by the infecting N. meningitidis strain and the magnitude of antibody responses was observed. These data suggest that fHBP is expressed in vivo during both carriage and invasive disease at levels high enough to elicit a robust antibody response., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
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36. Broad vaccine coverage predicted for a bivalent recombinant factor H binding protein based vaccine to prevent serogroup B meningococcal disease.
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Jiang HQ, Hoiseth SK, Harris SL, McNeil LK, Zhu D, Tan C, Scott AA, Alexander K, Mason K, Miller L, DaSilva I, Mack M, Zhao XJ, Pride MW, Andrew L, Murphy E, Hagen M, French R, Arora A, Jones TR, Jansen KU, Zlotnick GW, and Anderson AS
- Subjects
- Animals, Female, Humans, Meningococcal Infections immunology, Neisseria meningitidis, Serogroup B genetics, Rabbits, Recombinant Proteins immunology, Serum Bactericidal Test, Species Specificity, Antigens, Bacterial immunology, Bacterial Proteins immunology, Meningococcal Infections prevention & control, Meningococcal Vaccines immunology, Neisseria meningitidis, Serogroup B immunology
- Abstract
Factor H binding proteins (fHBP), are bacterial surface proteins currently undergoing human clinical trials as candidate serogroup B Neisseria meningitidis (MnB) vaccines. fHBP protein sequences segregate into two distinct subfamilies, designated A and B. Here, we report the specificity and vaccine potential of mono- or bivalent fHBP-containing vaccines. A bivalent fHBP vaccine composed of a member of each subfamily elicited substantially broader bactericidal activity against MnB strains expressing heterologous fHBP than did either of the monovalent vaccines. Bivalent rabbit immune sera tested in serum bactericidal antibody assays (SBAs) against a diverse panel of MnB clinical isolates killed 87 of the 100 isolates. Bivalent human immune sera killed 36 of 45 MnB isolates tested in SBAs. Factors such as fHBP protein variant, PorA subtype, or MLST were not predictive of whether the MnB strain could be killed by rabbit or human immune sera. Instead, the best predictor for killing in the SBA was the level of in vitro surface expression of fHBP. The bivalent fHBP vaccine candidate induced immune sera that killed MnB isolates representing the major MLST complexes, prevalent PorA subtypes, and fHBP variants that span the breadth of the fHBP phylogenetic tree. Importantly, epidemiologically prevalent fHBP variants from both subfamilies were killed., (Copyright 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
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37. NMR dynamics and antibody recognition of the meningococcal lipidated outer membrane protein LP2086 in micellar solution.
- Author
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Mascioni A, Moy FJ, McNeil LK, Murphy E, Bentley BE, Camarda R, Dilts DA, Fink PS, Gusarova V, Hoiseth SK, Malakian K, Mininni T, Novikova E, Lin S, Sigethy S, Zlotnick GW, and Tsao DH
- Subjects
- Animals, Antibodies, Bacterial immunology, Antibodies, Monoclonal immunology, Antigens, Bacterial immunology, Bacterial Proteins immunology, Humans, Lipopolysaccharides immunology, Mice, Micelles, Neisseria meningitidis immunology, Nuclear Magnetic Resonance, Biomolecular, Protein Structure, Tertiary physiology, Antibodies, Bacterial chemistry, Antibodies, Monoclonal chemistry, Antigens, Bacterial chemistry, Bacterial Proteins chemistry, Lipopolysaccharides chemistry, Models, Molecular, Neisseria meningitidis chemistry
- Abstract
Neisseria meningitidis is a major cause of meningitis. Although protective vaccination is available against some pathogenic serogroups, serogroup B meningococci have been a challenge for vaccinologists. A family of outer membrane lipoproteins, LP2086 (or factor H binding proteins, fHbp), has been shown to elicit bactericidal antibodies and is currently part of a cocktail vaccine candidate. The NMR structure of the variant LP2086-B01 in micellar solution provided insights on the topology of this family of proteins on the biological membrane. Based on flow cytometry experiments on whole meningococcal cells, binding experiments with monoclonal antibodies, and the NMR structure in micellar solution, we previously proposed that LP2086-B01 anchors the outer bacterial membrane through its lipidated N-terminal cysteine, while a flexible 20 residue linker positions the protein above the layer of lipo-oligosaccharides that surrounds the bacteria. This topology was suggested to increase the antigen exposure to the immune system. In the present work, using micellar solution as a membrane mimicking system, we characterized the backbone dynamics of the variant LP2086-B01 in both its lipidated and unlipidated forms. In addition, binding experiments with a Fab fragment derived from the monoclonal MN86-1042-2 were also performed. Our data suggests that due to the length and flexibility of the N-terminal linker, the antigen is not in contact with the micelle, thus making both N- and C-domains highly available to the host immune system. This dynamic model, combined with the binding data obtained with MN86-1042-2, supports our previously proposed arrangement that LP2086-B01 exposes one face to the extracellular space. Binding of MN86-1042-2 antibody shows that the N-domain is the primary target of this monoclonal, providing further indication that this domain is immunologically important for this family of proteins., (Copyright 2009 Elsevier B.V. All rights reserved.)
- Published
- 2010
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38. Detection of LP2086 on the cell surface of Neisseria meningitidis and its accessibility in the presence of serogroup B capsular polysaccharide.
- Author
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McNeil LK, Murphy E, Zhao XJ, Guttmann S, Harris SL, Scott AA, Tan C, Mack M, DaSilva I, Alexander K, Mason K, Jiang HQ, Zhu D, Mininni TL, Zlotnick GW, Hoiseth SK, Jones TR, Pride MW, Jansen KU, and Anderson AS
- Subjects
- Animals, Antibodies, Monoclonal immunology, Antigens, Bacterial immunology, Bacterial Proteins immunology, Blood Bactericidal Activity, Female, Humans, Neisseria meningitidis chemistry, Rabbits, Antigens, Bacterial analysis, Bacterial Capsules immunology, Bacterial Proteins analysis, Neisseria meningitidis immunology, Neisseria meningitidis, Serogroup B immunology
- Abstract
The outer membrane protein LP2086, a human factor H binding protein, is undergoing clinical trials as a vaccine against invasive serogroup B meningococcal (MnB) disease. As LP2086 is a surface protein, expression of capsular polysaccharide could potentially limit accessibility of anti-LP2086 antibodies to LP2086 expressed on the surface of bacteria. To determine whether variability in expression levels of the serogroup B capsule (Cap B) might interfere with accessibility of anti-LP2086 antibody binding to LP2086, we evaluated the ability of anti-Cap B and anti-LP2086 antibodies to bind to the surface of 1263 invasive clinical MnB strains by flow cytometry. One of the anti-LP2086 monoclonal antibodies used recognizes virtually all LP2086 sequence variants. Our results show no correlation between the amount of Cap B expressed and the binding of anti-LP2086 antibodies. Furthermore, the susceptibility of MnB bacteria to lysis by anti-LP2086 immune sera was independent of the level of Cap B expressed. The data presented in this paper demonstrates that Cap B does not interfere with the binding of antibodies to LP2086 expressed on the outer membrane of MnB clinical isolates.
- Published
- 2009
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39. Structural Basis for the Immunogenic Properties of the Meningococcal Vaccine Candidate LP2086.
- Author
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Mascioni A, Bentley BE, Camarda R, Dilts DA, Fink P, Gusarova V, Hoiseth SK, Jacob J, Lin SL, Malakian K, McNeil LK, Mininni T, Moy F, Murphy E, Novikova E, Sigethy S, Wen Y, Zlotnick GW, and Tsao DH
- Subjects
- Animals, Antibodies, Bacterial immunology, Antigens, Bacterial genetics, Antigens, Bacterial immunology, Bacterial Proteins genetics, Bacterial Proteins immunology, Base Sequence, Humans, Lipid Bilayers immunology, Meningococcal Vaccines genetics, Meningococcal Vaccines immunology, Mice, Molecular Sequence Data, Neisseria meningitidis genetics, Neisseria meningitidis immunology, Nuclear Magnetic Resonance, Biomolecular methods, Peptide Mapping methods, Protein Structure, Tertiary, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins immunology, Antibodies, Bacterial chemistry, Antigens, Bacterial chemistry, Bacterial Proteins chemistry, Lipid Bilayers chemistry, Meningococcal Vaccines chemistry, Micelles, Neisseria meningitidis chemistry
- Abstract
LP2086 is a family of outer membrane lipoproteins from Neisseria meningitidis, which elicits bactericidal antibodies and are currently undergoing human clinical trials in a bivalent formulation where each antigen represents one of the two known LP2086 subfamilies. Here we report the NMR structure of the recombinant LP2086 variant B01, a representative of the LP2086 subfamily B. The structure reveals a novel fold composed of two domains: a "taco-shaped" N-terminal beta-sheet and a C-terminal beta-barrel connected by a linker. The structure in micellar solution is consistent with a model of LP2086 anchored to the outer membrane bilayer through its lipidated N terminus. A long flexible chain connects the folded part of the protein to the lipid anchor and acts as spacer, making both domains accessible to the host immune system. Antibodies broadly reactive against members from both subfamilies have been mapped to the N terminus. A surface of subfamily-defining residues was identified on one face of the protein, offering an explanation for the induction of subfamily-specific bactericidal antibodies.
- Published
- 2009
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40. In silico Reconstruction of the Metabolic and Pathogenic Potential of Bacterial Genomes Using Subsystems.
- Author
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McNeil LK and Aziz RK
- Subjects
- Computational Biology, Computer Simulation, Databases, Genetic, Genome, Genomics, Genome, Bacterial, Software
- Abstract
Whole genome sequencing has revolutionized biological sciences, and is leading to a paradigm shift in microbiology. As more microbial genomes are sequenced, and more bioinformatics tools are developed, it has become possible to predict the metabolism of an organism from genomic data. In contrast, predicting the pathogenic potential of parasitic microbes and their interactions with their hosts is still a challenge, especially as the definition of pathogenesis itself is still evolving. In this review, we introduce the subsystem-based technology for genome annotation and analysis, and we discuss some subsystem-based tools available in the National Microbial Pathogen Data Resource (NMPDR, http://www.nmpdr.org) and their potential application in comparative genomics and pathogenomics., (Copyright © 2009 S. Karger AG, Basel.)
- Published
- 2009
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41. The RAST Server: rapid annotations using subsystems technology.
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Aziz RK, Bartels D, Best AA, DeJongh M, Disz T, Edwards RA, Formsma K, Gerdes S, Glass EM, Kubal M, Meyer F, Olsen GJ, Olson R, Osterman AL, Overbeek RA, McNeil LK, Paarmann D, Paczian T, Parrello B, Pusch GD, Reich C, Stevens R, Vassieva O, Vonstein V, Wilke A, and Zagnitko O
- Subjects
- Databases, Nucleic Acid, Genes, rRNA genetics, Genome, Archaeal, Genome, Bacterial, Open Reading Frames genetics, Phylogeny, Proteins genetics, RNA, Transfer genetics, Reproducibility of Results, Sensitivity and Specificity, Time Factors, User-Computer Interface, Computational Biology methods
- Abstract
Background: The number of prokaryotic genome sequences becoming available is growing steadily and is growing faster than our ability to accurately annotate them., Description: We describe a fully automated service for annotating bacterial and archaeal genomes. The service identifies protein-encoding, rRNA and tRNA genes, assigns functions to the genes, predicts which subsystems are represented in the genome, uses this information to reconstruct the metabolic network and makes the output easily downloadable for the user. In addition, the annotated genome can be browsed in an environment that supports comparative analysis with the annotated genomes maintained in the SEED environment. The service normally makes the annotated genome available within 12-24 hours of submission, but ultimately the quality of such a service will be judged in terms of accuracy, consistency, and completeness of the produced annotations. We summarize our attempts to address these issues and discuss plans for incrementally enhancing the service., Conclusion: By providing accurate, rapid annotation freely to the community we have created an important community resource. The service has now been utilized by over 120 external users annotating over 350 distinct genomes.
- Published
- 2008
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42. The National Microbial Pathogen Database Resource (NMPDR): a genomics platform based on subsystem annotation.
- Author
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McNeil LK, Reich C, Aziz RK, Bartels D, Cohoon M, Disz T, Edwards RA, Gerdes S, Hwang K, Kubal M, Margaryan GR, Meyer F, Mihalo W, Olsen GJ, Olson R, Osterman A, Paarmann D, Paczian T, Parrello B, Pusch GD, Rodionov DA, Shi X, Vassieva O, Vonstein V, Zagnitko O, Xia F, Zinner J, Overbeek R, and Stevens R
- Subjects
- Bacteria drug effects, Bacteria metabolism, Bacteria pathogenicity, Bacterial Proteins genetics, Bacterial Proteins physiology, DNA, Bacterial chemistry, Drug Delivery Systems, Genes, Bacterial, Genes, Essential, Genomics, Internet, Sequence Homology, Nucleic Acid, Software, User-Computer Interface, Databases, Nucleic Acid, Genome, Bacterial
- Abstract
The National Microbial Pathogen Data Resource (NMPDR) (http://www.nmpdr.org) is a National Institute of Allergy and Infections Disease (NIAID)-funded Bioinformatics Resource Center that supports research in selected Category B pathogens. NMPDR contains the complete genomes of approximately 50 strains of pathogenic bacteria that are the focus of our curators, as well as >400 other genomes that provide a broad context for comparative analysis across the three phylogenetic Domains. NMPDR integrates complete, public genomes with expertly curated biological subsystems to provide the most consistent genome annotations. Subsystems are sets of functional roles related by a biologically meaningful organizing principle, which are built over large collections of genomes; they provide researchers with consistent functional assignments in a biologically structured context. Investigators can browse subsystems and reactions to develop accurate reconstructions of the metabolic networks of any sequenced organism. NMPDR provides a comprehensive bioinformatics platform, with tools and viewers for genome analysis. Results of precomputed gene clustering analyses can be retrieved in tabular or graphic format with one-click tools. NMPDR tools include Signature Genes, which finds the set of genes in common or that differentiates two groups of organisms. Essentiality data collated from genome-wide studies have been curated. Drug target identification and high-throughput, in silico, compound screening are in development.
- Published
- 2007
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43. A requirement for sustained ERK signaling during thymocyte positive selection in vivo.
- Author
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McNeil LK, Starr TK, and Hogquist KA
- Subjects
- Animals, Cells, Cultured, DNA-Binding Proteins immunology, Early Growth Response Protein 1, Immediate-Early Proteins immunology, Inhibitor of Differentiation Proteins, Mice, Mice, Transgenic, Proteins immunology, Receptors, Antigen, T-Cell immunology, Thymus Gland cytology, Transcription Factors immunology, CD8-Positive T-Lymphocytes immunology, Cell Differentiation immunology, Extracellular Signal-Regulated MAP Kinases immunology, MAP Kinase Signaling System immunology, T-Lymphocyte Subsets immunology, Thymus Gland immunology
- Abstract
It is unknown how the contrasting events of positive and negative selection can lead to the distinct biological outcomes of life or death. An increasing body of evidence suggests that the duration of extracellular signal-regulated kinase (ERK) signaling plays a role in thymocyte selection. However, it remains unclear what the kinetics of ERK activation are during positive selection in vivo. In this study, we examined the magnitude and duration of ERK signaling in intact murine thymic tissues cultured under conditions of negative or positive selection. We found that negative selection induced a rapid and robust ERK activation that is associated with death, whereas positive selection stimulated a lower intensity and brief ERK activation that quickly declined and then gradually increased and was sustained over several days. The expression pattern of Egr-1 (early growth response-1), a downstream ERK effector, correlates with the biphasic kinetics of ERK during positive selection. Id3 (inhibitor of differentiation/DNA binding 3) also exhibits biphasic kinetics but appeared to be independent of ERK signaling. Furthermore, inhibitors of T cell receptor ligation and ERK activation block maturation of CD8 single-positive thymocytes even when added after 24 h. These results demonstrate that the in vivo duration of ERK signaling must be sustained to support positive selection.
- Published
- 2005
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44. The regulated expression of a diverse set of genes during thymocyte positive selection in vivo.
- Author
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Mick VE, Starr TK, McCaughtry TM, McNeil LK, and Hogquist KA
- Subjects
- Animals, Cell Adhesion genetics, Cell Adhesion immunology, Cell Death genetics, Cell Death immunology, Cell Lineage genetics, Cell Lineage immunology, Cell Movement genetics, Cell Movement immunology, Cell Survival genetics, Cell Survival immunology, Gene Rearrangement, T-Lymphocyte, Kinetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Oligonucleotide Array Sequence Analysis methods, Receptors, Antigen, T-Cell biosynthesis, Receptors, Antigen, T-Cell genetics, Receptors, Antigen, T-Cell metabolism, Recombination, Genetic immunology, Reverse Transcriptase Polymerase Chain Reaction, T-Lymphocyte Subsets immunology, Thymus Gland immunology, Transcription Factors biosynthesis, Transcription Factors genetics, Cell Differentiation genetics, Cell Differentiation immunology, Gene Expression Profiling methods, T-Lymphocyte Subsets cytology, T-Lymphocyte Subsets metabolism, Thymus Gland cytology, Thymus Gland metabolism
- Abstract
A signal initiated by the newly formed Ag receptor is integrated with microenvironmental cues during T cell development to ensure positive selection of CD4+CD8+ progenitors into functionally mature CD4+ or CD8+ T lymphocytes. During this transition, a survival program is initiated, TCR gene recombination ceases, cells migrate into a new thymic microenvironment, the responsiveness of the Ag receptor is tuned, and the cells commit to a specific T lineage. To determine potential regulators of these processes, we used mRNA microarray analysis to compare gene expression changes in CD4+CD8+ thymocytes from TCR transgenic mice that have received a TCR selection signal with those that had not received a signal. We found 129 genes with expression that changed significantly during positive selection, the majority of which were not previously appreciated. A large number of these changes were confirmed by real-time PCR or flow cytometry. We have combined our findings with gene changes reported in the literature to provide a comprehensive report of the genes regulated during positive selection, and we attempted to assign these genes to positive selection process categories.
- Published
- 2004
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45. Modification of peptide interaction with MHC creates TCR partial agonists.
- Author
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Ryan KR, McNeil LK, Dao C, Jensen PE, and Evavold BD
- Subjects
- Amino Acid Sequence, Animals, Cytochromes c genetics, Dose-Response Relationship, Immunologic, Epitopes, T-Lymphocyte, Genes, MHC Class II, Hemoglobins genetics, Insect Proteins genetics, Major Histocompatibility Complex genetics, Major Histocompatibility Complex immunology, Molecular Structure, Moths, Peptides genetics, Peptides immunology, Receptors, Antigen, T-Cell metabolism, T-Lymphocyte Subsets metabolism, T-Lymphocytes metabolism, Lymphocyte Activation, Major Histocompatibility Complex physiology, Peptides metabolism, Receptors, Antigen, T-Cell agonists
- Abstract
We report the creation of TCR partial agonists by the novel approach of manipulating the interaction between immunogenic peptide and MHC. Amino acids at MHC anchor positions of the I-E(k)-restricted hemoglobin (64-76) and moth cytochrome c (88-103) peptides were exchanged with MHC anchor residues from the low affinity class II invariant chain peptide (CLIP), resulting in antigenic peptides with altered affinity for MHC class II. Several low affinity peptides were identified as TCR partial agonists, as defined by the ability to stimulate cytolytic function but not proliferation. For example, a peptide containing methionine substitutions at positions one and nine of the I-E(k) binding motif acted as a partial agonist for two hemoglobin-reactive T cell clones (PL.17 and 3.L2). The identical MHC anchor substitutions in moth cytochrome c (88-103) also created a partial agonist for a mCC-reactive T cell (A.E7). Thus, peptides containing MHC anchor modifications mediated similar T cell responses regardless of TCR fine specificity or antigen reactivity. This data contrasts with the unique specificity among individual clones demonstrated using traditional altered peptide ligands containing substitutions at TCR contact residues. In conclusion, we demonstrate that altering the MHC anchor residues of the immunogenic peptide can be a powerful method to create TCR partial agonists.
- Published
- 2004
- Full Text
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46. TCR reserve: a novel principle of CD4 T cell activation by weak ligands.
- Author
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McNeil LK and Evavold BD
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Blocking pharmacology, Antigens, CD biosynthesis, Antigens, Differentiation, T-Lymphocyte biosynthesis, CD4-Positive T-Lymphocytes cytology, Cytochrome c Group immunology, Cytochrome c Group pharmacology, Dose-Response Relationship, Immunologic, Down-Regulation genetics, Down-Regulation immunology, Growth Inhibitors antagonists & inhibitors, Growth Inhibitors biosynthesis, Growth Inhibitors genetics, Growth Inhibitors immunology, Immunoglobulin Fab Fragments pharmacology, Lectins, C-Type, Ligands, Mice, Mice, Inbred A, Mice, Inbred C57BL, Mice, Transgenic, Molecular Sequence Data, Moths enzymology, Receptors, Antigen, T-Cell, alpha-beta antagonists & inhibitors, Receptors, Antigen, T-Cell, alpha-beta genetics, Receptors, Antigen, T-Cell, alpha-beta immunology, T-Lymphocyte Subsets cytology, T-Lymphocyte Subsets immunology, T-Lymphocyte Subsets metabolism, Thymus Gland cytology, Thymus Gland immunology, Up-Regulation immunology, CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes metabolism, Lymphocyte Activation genetics, Receptors, Antigen, T-Cell, alpha-beta biosynthesis
- Abstract
Some ligand-receptor systems have a receptor reserve where a maximal response can be achieved by occupation of a fraction of available receptors. An implication of a receptor reserve is the expansion of the number of ligands for response. To determine whether T cells follow receptor reserve, we have characterized the effect of reducing TCR levels on CD4 T cell responses elicited by altered peptide ligands that vary in potency. Agonist peptide is unaffected by a 90% reduction in TCR level while proliferation to weak agonists is significantly inhibited when TCR expression is reduced by 40%. Thymocyte-negative selection similarly demonstrates a differential requirement of TCR for response to agonist, weak agonist, and partial agonist. Therefore, our data demonstrate receptor reserve as a novel principle of T cell activation in which excess TCRs expand the antigenic repertoire to include less potent ligands.
- Published
- 2003
- Full Text
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47. Dissociation of peripheral T cell responses from thymocyte negative selection by weak agonists supports a spare receptor model of T cell activation.
- Author
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McNeil LK and Evavold BD
- Subjects
- Animals, Female, Histocompatibility Antigens metabolism, Ligands, Male, Mice, Mice, Transgenic, Peptides metabolism, CD4-Positive T-Lymphocytes immunology, Lymphocyte Activation, Models, Immunological, Receptors, Antigen, T-Cell physiology
- Abstract
We have focused on stability of the peptide-MHC complex as a determining factor of ligand potency for thymocytes and peripheral CD4+ T cell responses. MHC variant peptides that have low affinities and fast dissociation rates are different in that they stimulate proliferation and cytolysis of mature T cells (classifying the variant peptides as weak agonists) but do not induce thymocyte negative selection. The MHC variant weak agonists require significant receptor reserve, because decreasing the level of T cell receptor on mature T cells blocks the proliferative response. These results demonstrate that peripheral T cells are more sensitive to MHC variant ligands by virtue of increased T cell receptor expression; in addition, the data support a T cell model of the spare receptor theory.
- Published
- 2002
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48. Archaeal RecA homologues: different response to DNA-damaging agents in mesophilic and thermophilic Archaea.
- Author
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Reich CI, McNeil LK, Brace JL, Brucker JK, and Olsen GJ
- Subjects
- Archaea metabolism, DNA Damage, Gene Expression Regulation, Archaeal, Genes, Archaeal, Rec A Recombinases analysis, Rec A Recombinases metabolism, Recombination, Genetic, Archaea genetics, Rec A Recombinases genetics
- Abstract
Two archaeal proteins, RadA and RadB, share similarity with the RecA/Rad51 family of recombinases, with RadA being the functional homologue. We have studied and compared the RadA and RadB proteins of mesophilic and thermophilic Archaea. In growing cells, RadA levels are similar in mesophilic Methanococcus species and the hyperthermophile Methanococcus jannaschii. Treatment of cells with mutagenic agents (methylmethane sulfonate or UV light) increased the expression of RadA (as evidenced by higher levels of both mRNA and protein) in all organisms tested, but the increase was greater in the mesophiles than in the thermophiles M. jannaschii and Sulfolobus solfataricus. Recombinantly expressed RadA proteins from the mesophile M. voltae and the thermophile M. jannaschii were similar in their ATPase- and DNA-binding activities. All the data are consistent with proposals that RadA plays the same role as eukaryotic Rad51. Surprisingly, the data also suggested that the thermophiles do not need more RadA protein or activity than the mesophiles. On the other hand, RadB is not coregulated with RadA, and its role remains unclear. Neither RadA nor RadB from a mesophile or from a thermophile rescued the UV-sensitive phenotype of an Escherichia coli recA- host.
- Published
- 2001
- Full Text
- View/download PDF
49. Phylogenomic analysis of the alpha proteasome gene family from early-diverging eukaryotes.
- Author
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Bouzat JL, McNeil LK, Robertson HM, Solter LF, Nixon JE, Beever JE, Gaskins HR, Olsen G, Subramaniam S, Sogin ML, and Lewin HA
- Subjects
- Base Sequence, DNA Primers, Eukaryotic Cells, Polymerase Chain Reaction, Proteasome Endopeptidase Complex, Cysteine Endopeptidases genetics, Multienzyme Complexes genetics, Multigene Family, Phylogeny
- Abstract
We employed a phylogenomic approach to study the evolution of alpha subunits of the proteasome gene family from early diverging eukaryotes. BLAST similarity searches of the Giardia lamblia genome identified all seven alpha proteasome genes characteristic of eukaryotes from the crown group. In addition, a PCR strategy for the amplification of multiple alpha subunit sequences generated single alpha proteasome products for representatives of the Kinetoplastida (Leishmania major), the Parabasalia (Trichomonas vaginalis), and the Microsporidia (Vairimorpha sp., Nosema sp., Endoreticulata sp., and Spraguea lophii). The kinetoplastid Trypanosoma cruzi and the eukaryote crown group Acanthamoeba castellanii yielded two distinct alpha proteasome genes each. The presence of seven distinct alpha proteasome genes in G. lamblia, one of the earliest-diverging eukaryotes, indicates that the alpha proteasome gene family evolved rapidly from a minimum of one gene in Archaea to seven or more in Eukarya. Results from the phylogenomic analysis are consistent with the idea that the Diplomonida (as represented by G. lamblia), the Kinetoplastida, the Parabasalia, and the Microsporidia diverged after the duplication events that originated the alpha proteasome gene family. A model for the early origin and evolution of the proteasome gene family is presented.
- Published
- 2000
- Full Text
- View/download PDF
50. Cutting edge: Role of C-C chemokine receptor 5 in organ-specific and innate immunity to Cryptococcus neoformans.
- Author
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Huffnagle GB, McNeil LK, McDonald RA, Murphy JW, Toews GB, Maeda N, and Kuziel WA
- Subjects
- Animals, Cell Movement genetics, Cell Movement immunology, Cryptococcosis genetics, Cryptococcosis mortality, Cryptococcosis pathology, Cryptococcus neoformans growth & development, Immunity, Innate, Lung Diseases, Fungal genetics, Lung Diseases, Fungal immunology, Lung Diseases, Fungal mortality, Lung Diseases, Fungal pathology, Meningitis, Cryptococcal genetics, Meningitis, Cryptococcal immunology, Meningitis, Cryptococcal mortality, Meningitis, Cryptococcal pathology, Mice, Mice, Inbred C57BL, Mice, Inbred Strains, Mice, Knockout, Organ Specificity genetics, Organ Specificity immunology, Receptors, CCR5 biosynthesis, Receptors, CCR5 deficiency, Receptors, CCR5 genetics, Th1 Cells immunology, Th1 Cells metabolism, Cryptococcosis immunology, Cryptococcus neoformans immunology, Receptors, CCR5 physiology
- Abstract
After intratracheal inoculation of the AIDS-associated pathogen Cryptococcus neoformans, 12-wk survival was >90% for CCR5+/+ mice but <25% for CCR5-/- mice. There were no defects in lung leukocyte recruitment (wk 5), pulmonary clearance, or delayed-type hypersensitivity in CCR5-/- mice. However, CCR5-/- mice had defects in leukocyte recruitment into the brain and, strikingly, in elimination of cryptococcal polysaccharide from the brain. In nonimmune CCR5-/- mice, there was a significant defect in macrophage recruitment after challenge with shed cryptococcal products (C. neoformans filtrate Ag) but not other nonspecific stimuli. Thus, CCR5 plays specific roles in innate immunity and organ-specific leukocyte trafficking during host defense against C. neoformans.
- Published
- 1999
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