101 results on '"Steeber DA"'
Search Results
2. Development of a Novel, Small-Molecule Brain-Penetrant Histone Deacetylase Inhibitor That Enhances Spatial Memory Formation in Mice.
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Belayet JB, Beamish S, Rahaman M, Alanani S, Virdi RS, Frick DN, Rahman AFMT, Ulicki JS, Biswas S, Arnold LA, Roni MSR, Cheng EY, Steeber DA, Frick KM, and Hossain MM
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- Animals, Cell Line, Tumor, Histone Deacetylase Inhibitors pharmacokinetics, Histone Deacetylase Inhibitors pharmacology, Mice, Mice, Inbred BALB C, Brain metabolism, Histone Deacetylase Inhibitors chemical synthesis, Spatial Memory drug effects
- Abstract
Histone acetylation is a prominent epigenetic modification linked to the memory loss symptoms associated with neurodegenerative disease. The use of existing histone deacetylase inhibitor (HDACi) drugs for treatment is precluded by their weak blood-brain barrier (BBB) permeability and undesirable toxicity. Here, we address these shortcomings by developing a new class of disulfide-based compounds, inspired by the scaffold of the FDA-approved HDACi romidepsin (FK288). Our findings indicate that our novel compound MJM-1 increases the overall level of histone 3 (H3) acetylation in a prostate cancer cell line. In mice, MJM-1 injected intraperitoneally (i.p.) crossed the BBB and could be detected in the hippocampus, a brain region that mediates memory. Consistent with this finding, we found that the post-training i.p. administration of MJM-1 enhanced hippocampus-dependent spatial memory consolidation in male mice. Therefore, MJM-1 represents a potential lead for further optimization as a therapeutic strategy for ameliorating cognitive deficits in aging and neurodegenerative diseases.
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- 2022
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3. Neutrophils Recirculate through Lymph Nodes to Survey Tissues for Pathogens.
- Author
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Bogoslowski A, Wijeyesinghe S, Lee WY, Chen CS, Alanani S, Jenne C, Steeber DA, Scheiermann C, Butcher EC, Masopust D, and Kubes P
- Subjects
- Animals, Endothelium immunology, Endothelium microbiology, Female, L-Selectin immunology, Lymph Nodes microbiology, Lymphatic Vessels immunology, Lymphatic Vessels microbiology, Lymphocytes immunology, Lymphocytes microbiology, Male, Mice, Mice, Inbred C57BL, Microbiota immunology, Sphingosine-1-Phosphate Receptors immunology, Staphylococcal Infections microbiology, Venules immunology, Venules microbiology, Lymph Nodes immunology, Neutrophil Infiltration immunology, Neutrophils immunology, Staphylococcal Infections immunology
- Abstract
The adaptive immune function of lymph nodes is dependent on constant recirculation of lymphocytes. In this article, we identify neutrophils present in the lymph node at steady state, exhibiting the same capacity for recirculation. In germ-free mice, neutrophils still recirculate through lymph nodes, and in mice cohoused with wild microbiome mice, the level of neutrophils in lymph nodes increases significantly. We found that at steady state, neutrophils enter the lymph node entirely via L-selectin and actively exit via efferent lymphatics via an S1P dependent mechanism. The small population of neutrophils in the lymph node can act as reconnaissance cells to recruit additional neutrophils in the event of bacterial dissemination to the lymph node. Without these reconnaissance cells, there is a delay in neutrophil recruitment to the lymph node and a reduction in swarm formation following Staphylococcus aureus infection. This ability to recruit additional neutrophils by lymph node neutrophils is initiated by LTB4. This study establishes the capacity of neutrophils to recirculate, much like lymphocytes via L-selectin and high endothelial venules in lymph nodes and demonstrates how the presence of neutrophils at steady state fortifies the lymph node in case of an infection disseminating through lymphatics., (Copyright © 2020 by The American Association of Immunologists, Inc.)
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- 2020
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4. Calcium-oligochitosan-pectin microcarrier for colonic drug delivery.
- Author
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Stealey S, Guo X, Majewski R, Dyble A, Lehman K, Wedemeyer M, Steeber DA, Kaltchev MG, Chen J, and Zhang W
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- Chemistry, Pharmaceutical methods, Chitin chemistry, Chitosan, Drug Delivery Systems methods, Hydrogen-Ion Concentration, Oligosaccharides, Solubility drug effects, Calcium chemistry, Chitin analogs & derivatives, Colon drug effects, Drug Carriers chemistry, Pectins chemistry, Pharmaceutical Preparations administration & dosage, Pharmaceutical Preparations chemistry
- Abstract
Pectin-based hydrogel microcarriers have shown promise for drug delivery to the colonic region. Microcarriers must remain stable throughout the upper gastrointestinal tract for effective colonic delivery, an issue that traditional pectin-based microcarriers have faced. The positively-charged natural biopolymer oligochitosan and divalent cation Ca
2+ were used to dually cross-link pectin-based hydrogel microcarriers to improve carrier stability through simulated gastric and intestinal environments. Microcarriers were characterized with Scanning Electron Microscope and Fourier-Transform Infrared analysis. An optical microscope was used to observe the change of microcarrier size and morphology over time in the simulated gastrointestinal environments. Fluorescently-labeled Dextran was used as a model drug for this system. Calcium-Oligochitosan-Pectin microcarriers exhibited relatively small drug release in the upper gastrointestinal regions and were responsive to the high pH and enzymatic activity of simulated colonic environment (over 94% release after 2 h), suggesting great potential for colonic drug delivery.- Published
- 2020
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5. Correction to "A Novel Orally Available Asthma Drug Candidate That Reduces Smooth Muscle Constriction and Inflammation by Targeting GABA A Receptors in the Lung".
- Author
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Forkuo GS, Nieman AN, Kodali R, Zahn NM, Li G, Roni MSR, Stephen MR, Harris TW, Jahan R, Guthrie ML, Yu OB, Fisher JL, Yocum GT, Emala CW, Steeber DA, Stafford DC, Cook JM, and Arnold LA
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- 2019
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6. MIDD0301 - A first-in-class anti-inflammatory asthma drug targets GABA A receptors without causing systemic immune suppression.
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Zahn NM, Huber AT, Mikulsky BN, Stepanski ME, Kehoe AS, Li G, Schussman M, Rashid Roni MS, Kodali R, Cook JM, Stafford DC, Steeber DA, and Arnold LA
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- Adjuvants, Immunologic administration & dosage, Administration, Oral, Animals, Anti-Inflammatory Agents adverse effects, Asthma blood, Asthma immunology, Azepines pharmacology, Disease Models, Animal, Drug Evaluation, Preclinical, Drugs, Investigational adverse effects, Female, GABA-A Receptor Agonists adverse effects, Hemocyanins administration & dosage, Hemocyanins immunology, Heterocyclic Compounds, 3-Ring adverse effects, Humans, Imidazoles pharmacology, Leukocyte Count, Male, Mice, Prednisone administration & dosage, Prednisone adverse effects, Weight Loss, Anti-Inflammatory Agents administration & dosage, Asthma drug therapy, Azepines administration & dosage, Drugs, Investigational administration & dosage, GABA-A Receptor Agonists administration & dosage, Heterocyclic Compounds, 3-Ring administration & dosage, Imidazoles administration & dosage, Immune Tolerance drug effects
- Abstract
We report a 28-day repeat dose immunotoxicity evaluation of investigational drug MIDD0301, a novel oral asthma drug candidate that targets gamma amino butyric acid type A receptors (GABA
A R) in the lung. The study design employed oral administration of mice twice daily throughout the study period with 100 mg/kg MIDD0301 mixed in peanut butter. Compound dosing did not reveal signs of general toxicity as determined by animal weight, organ weight or haematology. Peanut butter plus test drug (in addition to ad libitum standard rodent chow) did not affect weight gain in the adult mice, in contrast to weight loss in 5 mg/kg prednisone-treated mice. Spleen and thymus weights were unchanged in MIDD0301-treated mice, but prednisone significantly reduced the weight of those organs over the 28-day dosing. Similarly, no differences in spleen or thymus histology were observed following MIDD0301 treatment, but prednisone treatment induced morphological changes in the spleen. The number of small intestine Peyer's patches was not affected by MIDD0301 treatment, an important factor for orally administered drugs. Circulating lymphocyte, monocyte and granulocyte numbers were unchanged in the MIDD0301-treated animals, whereas differential lymphocyte numbers were reduced in prednisone-treated animals. MIDD0301 treatment did not alter IgG antibody responses to dinitrophenyl following dinitrophenyl-keyhole limpet haemocyanin immunization, indicating that systemic humoral immune function was not affected. Taken together, these studies show that repeated daily administration of MIDD0301 is safe and not associated with adverse immunotoxicological effects in mice., (© 2019 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)- Published
- 2019
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7. A Novel Orally Available Asthma Drug Candidate That Reduces Smooth Muscle Constriction and Inflammation by Targeting GABA A Receptors in the Lung.
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Forkuo GS, Nieman AN, Kodali R, Zahn NM, Li G, Rashid Roni MS, Stephen MR, Harris TW, Jahan R, Guthrie ML, Yu OB, Fisher JL, Yocum GT, Emala CW, Steeber DA, Stafford DC, Cook JM, and Arnold LA
- Subjects
- Animals, Asthma metabolism, Brain drug effects, Brain metabolism, Bronchoalveolar Lavage Fluid chemistry, CD4-Positive T-Lymphocytes drug effects, CD4-Positive T-Lymphocytes metabolism, Constriction, Cytokines metabolism, Eosinophils drug effects, Eosinophils metabolism, Female, Guinea Pigs, Inflammation metabolism, Ligands, Lung metabolism, Macrophages drug effects, Macrophages metabolism, Male, Mice, Mice, Inbred BALB C, Muscle, Smooth metabolism, Ovalbumin metabolism, Respiratory Hypersensitivity metabolism, Asthma drug therapy, Inflammation drug therapy, Lung drug effects, Muscle, Smooth drug effects, Receptors, GABA-A metabolism
- Abstract
We describe lead compound MIDD0301 for the oral treatment of asthma based on previously developed positive allosteric α
5 β3 γ2 selective GABAA receptor (GABAA R) ligands. MIDD0301 relaxed airway smooth muscle at single micromolar concentrations as demonstrated with ex vivo guinea pig tracheal rings. MIDD0301 also attenuated airway hyperresponsiveness (AHR) in an ovalbumin murine model of asthma by oral administration. Reduced numbers of eosinophils and macrophages were observed in mouse bronchoalveolar lavage fluid without changing mucous metaplasia. Importantly, lung cytokine expression of IL-17A, IL-4, and TNF-α were reduced for MIDD0301-treated mice without changing antiinflammatory cytokine IL-10 levels. Automated patch clamp confirmed amplification of GABA induced current mediated by α1-3,5 β3 γ2 GABAA Rs in the presence of MIDD0301. Pharmacodynamically, transmembrane currents of ex vivo CD4+ T cells from asthmatic mice were potentiated by MIDD0301 in the presence of GABA. The number of CD4+ T cells observed in the lung of MIDD0301-treated mice were reduced by an oral treatment of 20 mg/kg b.i.d. for 5 days. A half-life of almost 14 h was demonstrated by pharmacokinetic studies (PK) with no adverse CNS effects when treated mice were subjected to sensorimotor studies using the rotarod. PK studies also confirmed very low brain distribution. In conclusion, MIDD0301 represents a safe and improved oral asthma drug candidate that relaxes airway smooth muscle and attenuates inflammation in the lung leading to a reduction of AHR at a dosage lower than earlier reported GABAA R ligands.- Published
- 2018
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8. Alleviation of Multiple Asthmatic Pathologic Features with Orally Available and Subtype Selective GABA A Receptor Modulators.
- Author
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Forkuo GS, Nieman AN, Yuan NY, Kodali R, Yu OB, Zahn NM, Jahan R, Li G, Stephen MR, Guthrie ML, Poe MM, Hartzler BD, Harris TW, Yocum GT, Emala CW, Steeber DA, Stafford DC, Cook JM, and Arnold LA
- Subjects
- Animals, Bronchoalveolar Lavage Fluid, Disease Models, Animal, Eosinophils metabolism, Flow Cytometry, Humans, Lung, Male, Mice, Mice, Inbred BALB C, Ovalbumin metabolism, Receptors, GABA metabolism, Respiratory Hypersensitivity metabolism, Swine, Asthma pathology
- Abstract
We describe pharmacokinetic and pharmacodynamic properties of two novel oral drug candidates for asthma. Phenolic α
4 β3 γ2 GABAA R selective compound 1 and acidic α5 β3 γ2 selective GABAA R positive allosteric modulator compound 2 relaxed airway smooth muscle ex vivo and attenuated airway hyperresponsiveness (AHR) in a murine model of asthma. Importantly, compound 2 relaxed acetylcholine contracted human tracheal airway smooth muscle strips. Oral treatment of compounds 1 and 2 decreased eosinophils in bronchoalveolar lavage fluid in ovalbumin sensitized and challenged mice, thus exhibiting anti-inflammatory properties. Additionally, compound 1 reduced the number of lung CD4+ T lymphocytes and directly modulated their transmembrane currents by acting on GABAA Rs. Excellent pharmacokinetic properties were observed, including long plasma half-life (up to 15 h), oral availability, and extremely low brain distribution. In conclusion, we report the selective targeting of GABAA Rs expressed outside the brain and demonstrate reduction of AHR and airway inflammation with two novel orally available GABAA R ligands.- Published
- 2017
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9. Tumor-induced MDSC act via remote control to inhibit L-selectin-dependent adaptive immunity in lymph nodes.
- Author
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Ku AW, Muhitch JB, Powers CA, Diehl M, Kim M, Fisher DT, Sharda AP, Clements VK, O'Loughlin K, Minderman H, Messmer MN, Ma J, Skitzki JJ, Steeber DA, Walcheck B, Ostrand-Rosenberg S, Abrams SI, and Evans SS
- Subjects
- Animals, Cell Line, Tumor, Disease Models, Animal, Female, Gene Expression Regulation, Neoplastic, Lymphocytes metabolism, Male, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Transgenic, Neoplasms immunology, RNA Interference, Transplantation, Heterologous, Adaptive Immunity, Immune Tolerance, L-Selectin biosynthesis, Lymph Nodes immunology, Lymphocytes immunology, Myeloid-Derived Suppressor Cells physiology, Neoplasms physiopathology
- Abstract
Myeloid-derived suppressor cells (MDSC) contribute to an immunosuppressive network that drives cancer escape by disabling T cell adaptive immunity. The prevailing view is that MDSC-mediated immunosuppression is restricted to tissues where MDSC co-mingle with T cells. Here we show that splenic or, unexpectedly, blood-borne MDSC execute far-reaching immune suppression by reducing expression of the L-selectin lymph node (LN) homing receptor on naïve T and B cells. MDSC-induced L-selectin loss occurs through a contact-dependent, post-transcriptional mechanism that is independent of the major L-selectin sheddase, ADAM17, but results in significant elevation of circulating L-selectin in tumor-bearing mice. Even moderate deficits in L-selectin expression disrupt T cell trafficking to distant LN. Furthermore, T cells preconditioned by MDSC have diminished responses to subsequent antigen exposure, which in conjunction with reduced trafficking, severely restricts antigen-driven expansion in widely-dispersed LN. These results establish novel mechanisms for MDSC-mediated immunosuppression that have unanticipated implications for systemic cancer immunity., Competing Interests: The authors declare that no competing interests exist.
- Published
- 2016
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10. Nickel oxide hollow microsphere for non-enzyme glucose detection.
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Ci S, Huang T, Wen Z, Cui S, Mao S, Steeber DA, and Chen J
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- Electrochemical Techniques methods, Humans, Limit of Detection, Microspheres, Oxidation-Reduction, Biosensing Techniques methods, Blood Glucose analysis, Nickel chemistry
- Abstract
A facile strategy has been developed to fabricate nickel oxide hollow microspheres (NiO-HMSs) through a solvothermal method by using a mixed solvent of ethanol and water with the assistance of sodium dodecyl sulfate (SDS). Various techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD), were used to characterize the morphology and the structure of as-prepared samples. It was confirmed that the products possess a hollow microsphere structure that is constructed by interconnecting porous nanoplate framework. Electrochemical studies indicate that the NiO-HMS exhibits excellent stability and high catalytic activity for electrocatalytic oxidation of glucose in alkaline solutions, which enables the NiO-HMS to be used in enzyme-free amperometric sensors for glucose determination. It was demonstrated that the NiO-HMS-based glucose biosensor offers a variety of merits, such as a wide linear response window for glucose concentrations of 1.67 μM-6.87 mM, short response time (3 s), a lower detection limit of 0.53 μM (S/N=3), high sensitivity (~2.39 mA mM(-1) cm(-2)) as well as good stability and repeatability., (© 2013 Published by Elsevier B.V.)
- Published
- 2014
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11. Vascular endothelial growth factor receptor inhibitor SU5416 suppresses lymphocyte generation and immune responses in mice by increasing plasma corticosterone.
- Author
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Grailer JJ and Steeber DA
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- Animals, Immunity, Active drug effects, Lymphocytes cytology, Mice, Mice, Inbred C57BL, Transforming Growth Factor beta metabolism, Corticosterone blood, Indoles pharmacology, Lymphocytes drug effects, Pyrroles pharmacology, Receptors, Vascular Endothelial Growth Factor antagonists & inhibitors
- Abstract
Inhibitors of vascular endothelial growth factor and its receptors (VEGFRs) are attractive therapeutic candidates for cancer treatment. One such small molecule VEGFR inhibitor, SU5416, limits angiogenesis in vivo and is widely used for investigating VEGFR signaling in tumor pathophysiology. Herein, we describe novel actions of SU5416 on the immune system. Treatment of mice with SU5416 for 3 days induced significant reductions in size and cellularity of peripheral lymph nodes. Interestingly, SU5416 did not affect initial lymphocyte localization to peripheral lymph nodes but did reduce lymphocyte accumulation during long-term migration assays. Treatment with SU5416 also induced severe loss of double-positive thymocytes resulting in thymic atrophy and a reduction in peripheral B cells. Furthermore, immune responses following immunization were reduced in mice treated with SU5416. Findings of thymic atrophy and reduced weight gain during SU5416 treatment suggested elevated corticosterone levels. Indeed, a significant 5-fold increase in serum corticosterone was found 4 hours after treatment with SU5416. Importantly, adrenalectomy negated the effects of SU5416 treatment on primary immune tissues, and partial reversal of SU5416-induced changes was observed following blockade of glucocorticoid receptors. SU5416 has been reported to inhibit the activation of latent transforming growth factor (TGF)-β, a cytokine involved in the regulation of glucocorticoid release by the adrenal glands. Interestingly, treatment with a TGF-β receptor inhibitor, showed a similar phenotype as SU5416 treatment, including elevated serum corticosterone levels and thymic atrophy. Therefore, these results suggest that SU5416 induces glucocorticoid release directly from the adrenal glands, possibly by inhibition of TGF-β activation.
- Published
- 2013
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12. Single-walled carbon nanotube field-effect transistors with graphene oxide passivation for fast, sensitive, and selective protein detection.
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Chang J, Mao S, Zhang Y, Cui S, Steeber DA, and Chen J
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- Biosensing Techniques instrumentation, Biosensing Techniques methods, Biotin chemistry, Electronics, Gold chemistry, Proteins chemistry, Transistors, Electronic, Graphite chemistry, Nanotubes, Carbon chemistry, Proteins isolation & purification
- Abstract
We report a novel technique to design an insulating membrane with attachment sites on top of single-walled carbon nanotubes (SWNTs) for achieving high sensitivity and selectivity in an SWNT field-effect transistor (FET) biosensor. Because electronic properties of SWNTs are extremely sensitive to the surface state, direct immobilization of proteins or DNAs onto SWNTs will generate surface defects through chemical reactions or physical adsorption, resulting in degradation of performance and instability of SWNT-FET biosensor devices. Here we demonstrate fabrication of novel FET biosensor devices using SWNTs as semiconducting channels, and a monolayer of graphene oxide (GO) membrane covered on the SWNTs as a passivating layer to avoid direct attachment of biomaterials on SWNTs, thereby preserving intrinsic electrical properties of SWNTs. Gold nanoparticles (Au NPs) are decorated on the GO layer for the covalent attachment of biotin, which is then used to selectively detect the target avidin. The passivation with GO layers can effectively lead to enhanced sensitivity of biosensor devices through increasing the on/off ratio of FET sensors., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
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13. Direct growth of vertically-oriented graphene for field-effect transistor biosensor.
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Mao S, Yu K, Chang J, Steeber DA, Ocola LE, and Chen J
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- Equipment Design, Equipment Failure Analysis, Biosensing Techniques instrumentation, Conductometry instrumentation, Gold chemistry, Graphite chemistry, Immunoassay instrumentation, Metal Nanoparticles chemistry, Transistors, Electronic
- Abstract
A sensitive and selective field-effect transistor (FET) biosensor is demonstrated using vertically-oriented graphene (VG) sheets labeled with gold nanoparticle (NP)-antibody conjugates. VG sheets are directly grown on the sensor electrode using a plasma-enhanced chemical vapor deposition (PECVD) method and function as the sensing channel. The protein detection is accomplished through measuring changes in the electrical signal from the FET sensor upon the antibody-antigen binding. The novel biosensor with unique graphene morphology shows high sensitivity (down to ~2 ng/ml or 13 pM) and selectivity towards specific proteins. The PECVD growth of VG presents a one-step and reliable approach to prepare graphene-based electronic biosensors.
- Published
- 2013
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14. Signaling through L-selectin mediates enhanced chemotaxis of lymphocyte subsets to secondary lymphoid tissue chemokine.
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Subramanian H, Grailer JJ, Ohlrich KC, Rymaszewski AL, Loppnow JJ, Kodera M, Conway RM, and Steeber DA
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- Animals, Antibodies, Monoclonal pharmacology, Cells, Cultured cytology, Cells, Cultured drug effects, Endothelial Cells cytology, Immunologic Memory, Intracellular Signaling Peptides and Proteins antagonists & inhibitors, Intracellular Signaling Peptides and Proteins physiology, L-Selectin genetics, L-Selectin immunology, Lymph Nodes cytology, Mesentery immunology, Mice, Mice, Inbred C57BL, Mice, Knockout, Protein Kinase Inhibitors pharmacology, Protein-Tyrosine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases physiology, Receptors, CCR7 biosynthesis, Receptors, CCR7 genetics, Receptors, CCR7 physiology, Receptors, CXCR4 biosynthesis, Receptors, CXCR4 genetics, Signal Transduction, Specific Pathogen-Free Organisms, Stilbenes pharmacology, Syk Kinase, Chemokine CCL21 physiology, Chemotaxis, Leukocyte physiology, L-Selectin physiology, T-Lymphocyte Subsets cytology
- Abstract
L-selectin functions as an important adhesion molecule that mediates tethering and rolling of lymphocytes by binding to high endothelial venule (HEV)-expressed ligands during recirculation. Subsequent lymphocyte arrest and transmigration require activation through binding of HEV-decorated homeostatic chemokines such as secondary lymphoid tissue chemokine (SLC; CCL21) to its counterreceptor, CCR7. Importantly, L-selectin also functions as a signaling molecule. In this study, signaling induced by ligation of L-selectin using mAb or endothelial cell-expressed ligand significantly enhanced the chemotaxis of murine T cells and B cells to SLC but not to other homeostatic chemokines. Consistent with the expression levels of L-selectin in different lymphocyte subsets, L-selectin-mediated enhancement of chemotaxis to SLC was observed for all naive lymphocytes and effector/memory CD8(+) T cells, whereas only a subpopulation of effector/memory CD4(+) T cells responded. During in vivo mesenteric lymph node migration assays, the absence of L-selectin on lymphocytes significantly attenuated both their ability to migrate out of the HEV and their chemotaxis away from the vessel wall. Notably, ligation of L-selectin and/or CCR7 did not result in increased CCR7 expression levels, internalization, or re-expression. Pharmacologic inhibitor studies showed that L-selectin-mediated enhanced chemotaxis to SLC required intact intracellular kinase function. Furthermore, treatment of lymphocytes with the spleen tyrosine kinase family inhibitor piceatannol reduced their ability to migrate across the HEV in peripheral lymph nodes. Therefore, these results suggest that "cross-talk" in the signaling pathways initiated by L-selectin and CCR7 provides a novel mechanism for functional synergy between these two molecules during lymphocyte migration.
- Published
- 2012
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15. Gold Nanorods Conjugated with Doxorubicin and cRGD for Combined Anticancer Drug Delivery and PET Imaging.
- Author
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Xiao Y, Hong H, Matson VZ, Javadi A, Xu W, Yang Y, Zhang Y, Engle JW, Nickles RJ, Cai W, Steeber DA, and Gong S
- Abstract
A multifunctional gold nanorod (GNR)-based nanoplatform for targeted anticancer drug delivery and positron emission tomography (PET) imaging of tumors was developed and characterized. An anti-cancer drug (i.e., doxorubicin (DOX)) was covalently conjugated onto PEGylated (PEG: polyethylene glycol) GNR nanocarriers via a hydrazone bond to achieve pH-sensitive controlled drug release. Tumor-targeting ligands (i.e., the cyclo(Arg-Gly-Asp-D-Phe-Cys) peptides, cRGD) and (64)Cu-chelators (i.e., 1,4,7-triazacyclononane-N, N', N''-triacetic acid (NOTA)) were conjugated onto the distal ends of the PEG arms to achieve active tumor-targeting and PET imaging, respectively. Based on flow cytometry analysis, cRGD-conjugated nanocarriers (i.e., GNR-DOX-cRGD) exhibited a higher cellular uptake and cytotoxicity than non-targeted ones (i.e., GNR-DOX) in vitro. However, GNR-DOX-cRGD and GNR-DOX nanocarriers had similar in vivo biodistribution according to in vivo PET imaging and biodistribution studies. Due to the unique optical properties of GNRs, this multifunctional GNR-based nanoplatform can potentially be optimized for combined cancer therapies (chemotherapy and photothermal therapy) and multimodality imaging (PET, optical, X-ray computed tomography (CT), etc.).
- Published
- 2012
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16. Cell individuality: the bistable gene expression of the type III secretion system in Dickeya dadantii 3937.
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Zeng Q, Laiosa MD, Steeber DA, Biddle EM, Peng Q, and Yang CH
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- Genes, Reporter, Gram-Negative Bacteria genetics, Models, Genetic, Mutation, Plasmids, Promoter Regions, Genetic genetics, RNA, Bacterial genetics, Virulence Factors genetics, Bacterial Proteins genetics, Bacterial Secretion Systems genetics, Enterobacteriaceae genetics, Gene Expression Regulation, Bacterial genetics
- Abstract
Dickeya dadantii 3937 is a gram-negative phytopathogenic bacterium that expresses genes encoding a type III secretion system (T3SS) in a bistable pattern when cultured in a homogeneous minimal media. In this work, we further characterized the bistable gene expression of T3SS at the single-cell level. We demonstrated that bistable expression of the HrpL-regulon genes, such as hrpA and hrpN, is controlled by the same regulatory mechanism. We also showed that the expression level of the T3SS master regulatory gene hrpL plays an important role in the development of the bistable expression of hrpA. A high expression level of hrpL is required but unable to guarantee the high-state expression of hrpA in a cell. In addition, bistable expression patterns of T3SS genes in other gram-negative pathogens of the Enterobacteriaceae and Pseudomonadaceae families were also described in this study. This suggests that the T3SS bistability might be a conserved population behavior in several gram-negative bacterial pathogens.
- Published
- 2012
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17. cRGD-functionalized, DOX-conjugated, and ⁶⁴Cu-labeled superparamagnetic iron oxide nanoparticles for targeted anticancer drug delivery and PET/MR imaging.
- Author
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Yang X, Hong H, Grailer JJ, Rowland IJ, Javadi A, Hurley SA, Xiao Y, Yang Y, Zhang Y, Nickles RJ, Cai W, Steeber DA, and Gong S
- Subjects
- Animals, Contrast Media chemistry, Drug Delivery Systems, Female, Humans, Hydrogen-Ion Concentration, Integrin alphaVbeta3 metabolism, Magnetic Resonance Imaging, Magnetite Nanoparticles, Malonates chemical synthesis, Mice, Mice, Nude, Models, Animal, Nanomedicine methods, Neoplasms drug therapy, Particle Size, Peptides, Cyclic chemistry, Positron-Emission Tomography, Tissue Distribution, Dextrans chemical synthesis, Diagnostic Imaging methods, Doxorubicin pharmacokinetics, Drug Carriers chemical synthesis
- Abstract
Multifunctional and water-soluble superparamagnetic iron oxide (SPIO) nanocarriers were developed for targeted drug delivery and positron emission tomography/magnetic resonance imaging (PET/MRI) dual-modality imaging of tumors with integrin α(v)β₃ expression. An anticancer drug was conjugated onto the PEGylated SPIO nanocarriers via pH-sensitive bonds. Tumor-targeting ligands, cyclo(Arg-Gly-Asp-d-Phe-Cys) (c(RGDfC)) peptides, and PET ⁶⁴Cu chelators, macrocyclic 1,4,7-triazacyclononane-N, N', N″-triacetic acid (NOTA), were conjugated onto the distal ends of the PEG arms. The effectiveness of the SPIO nanocarriers as an MRI contrast agent was evaluated via an in vitro r₂ MRI relaxivity measurement. cRGD-conjugated SPIO nanocarriers exhibited a higher level of cellular uptake than cRGD-free ones in vitro. Moreover, cRGD-conjugated SPIO nanocarriers showed a much higher level of tumor accumulation than cRGD-free ones according to non-invasive and quantitative PET imaging, and ex vivo biodistribution studies. Thus, these SPIO nanocarriers demonstrated promising properties for combined targeted anticancer drug delivery and PET/MRI dual-modality imaging of tumors., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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18. Multifunctional SPIO/DOX-loaded wormlike polymer vesicles for cancer therapy and MR imaging.
- Author
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Yang X, Grailer JJ, Rowland IJ, Javadi A, Hurley SA, Steeber DA, and Gong S
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- Cell Death drug effects, Doxorubicin pharmacology, Drug Delivery Systems, Flow Cytometry, Folic Acid pharmacology, HeLa Cells, Humans, Hydrophobic and Hydrophilic Interactions drug effects, Magnetic Resonance Spectroscopy, Microscopy, Confocal, Nanoparticles ultrastructure, Polymers chemical synthesis, Dextrans chemistry, Doxorubicin therapeutic use, Drug Carriers chemistry, Magnetic Resonance Imaging, Magnetite Nanoparticles chemistry, Neoplasms drug therapy, Polymers chemistry
- Abstract
Stable and tumor-targeting multifunctional wormlike polymer vesicles simultaneously loaded with superparamagnetic iron oxide (SPIO) nanoparticles (NPs) as magnetic resonance imaging (MRI) contrast agent and anticancer drug doxorubicin (DOX) were developed for targeted cancer therapy and ultrasensitive MR imaging. These multifunctional wormlike polymer vesicles were formed by heterobifunctional amphiphilic triblock copolymers R (R = methoxy or folate (FA))-PEG(114)-PLA(x)-PEG(46)-acrylate using a double emulsion method. The long PEG segments bearing methoxy/folate groups (CH(3)O/FA-PEG(114)) were mostly segregated to the outer hydrophilic PEG layers of the wormlike vesicles thereby providing active tumor-targeting ability, while the short PEG segments bearing acrylate groups (PEG(46)-acrylate) were mostly segregated onto the inner hydrophilic PEG layers of the wormlike vesicles thereby allowing the inner PEG layers to be crosslinked via free radical polymerization for enhanced in vivo stability. The hydrophobic anticancer drug, DOX, was loaded into the hydrophobic membrane of the wormlike vesicles. Meanwhile, a cluster of hydrophilic SPIO NPs was encapsulated into the aqueous cores of the stable wormlike vesicles with crosslinked inner PEG layers for ultrasensitive MRI detection. Cellular uptake of the FA-conjugated wormlike vesicles facilitated by the folate receptor-mediated endocytosis process was higher than that of the FA-free vesicles thereby leading to high cytotoxicity against the HeLa human cervical tumor cell line. Moreover, the SPIO/DOX-loaded wormlike vesicles with crosslinked inner PEG layers demonstrated a much higher r(2) relaxivity value than Feridex, a commercially available T(2) agent, which can be attributed to the high SPIO NPs loading level as well as the SPIO clustering effect. These unique stable and tumor-targeting multifunctional SPIO/DOX-loaded wormlike polymer vesicles would make targeted cancer theranostics possible thereby paving the road for personalized medicine., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
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19. α4β7 Integrin is essential for contact hypersensitivity by regulating migration of T cells to skin.
- Author
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Ohmatsu H, Kadono T, Sugaya M, Tomita M, Kai H, Miyagaki T, Saeki H, Tamaki K, Steeber DA, Tedder TF, and Sato S
- Subjects
- Adoptive Transfer, Animals, Antibodies, Blocking administration & dosage, Cell Movement drug effects, Cell Movement genetics, Cells, Cultured, Dermatitis, Contact drug therapy, Dermatitis, Contact genetics, Immunity, Mucosal drug effects, Integrins antagonists & inhibitors, Integrins genetics, Integrins immunology, Lymphocyte Activation drug effects, Lymphocyte Activation genetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Skin drug effects, Skin pathology, T-Lymphocytes drug effects, T-Lymphocytes immunology, T-Lymphocytes pathology, Dermatitis, Contact immunology, Integrins metabolism, Skin immunology, T-Lymphocytes metabolism
- Abstract
Background: β7 Integrin, a cell adhesion molecule, is present in the form of α4β7 integrin or αEβ7 integrin. α4β7 Integrin is expressed on most leucocytes and is essential for their migration to gut-associated lymphoid tissues by interacting with its primary ligand, mucosal addressin cell adhesion molecule-1, which is preferentially expressed in gut-associated lymphoid tissues. Although the importance of α4β7 integrin in intestinal inflammation has been established, its role in cutaneous inflammation remains to be elucidated., Objective: We sought to investigate the role of β7 integrin in cutaneous inflammation., Methods: We used a murine contact hypersensitivity model and examined the role of β7 integrin by using β7 integrin-deficient and αE integrin-deficient mice., Results: β7 Integrin-deficient mice, not αE integrin-deficient mice, are defective in contact hypersensitivity responses. β7 Integrin deficiency does not affect irritant contact dermatitis. The distribution, migration, and function of antigen presenting cells from β7 integrin-deficient mice are comparable to those from wild-type mice. Moreover, sensitized β7 integrin-deficient T cells are able to respond to antigen stimuli in vitro and elicit contact hypersensitivity responses when directly injected into the skin. However, they are defective in reaching the skin under inflammatory conditions, resulting in reduced contact hypersensitivity responses when intravenously injected. Furthermore, intraperitoneal injection of anti-α4β7 integrin neutralizing antibody elicit impaired contact hypersensitivity responses., Conclusion: α4β7 Integrin contributes to contact hypersensitivity responses by regulating T-cell migration to inflammatory skin., (Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)
- Published
- 2010
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20. Multifunctional stable and pH-responsive polymer vesicles formed by heterofunctional triblock copolymer for targeted anticancer drug delivery and ultrasensitive MR imaging.
- Author
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Yang X, Grailer JJ, Rowland IJ, Javadi A, Hurley SA, Matson VZ, Steeber DA, and Gong S
- Subjects
- Antineoplastic Agents pharmacology, Biological Transport, Contrast Media chemistry, Doxorubicin metabolism, Doxorubicin pharmacology, Drug Carriers chemical synthesis, Drug Carriers metabolism, Drug Carriers pharmacokinetics, Ferric Compounds chemistry, Folic Acid Transporters metabolism, HeLa Cells, Humans, Hydrogen-Ion Concentration, Hydrophobic and Hydrophilic Interactions, Nanoparticles chemistry, Polymers chemical synthesis, Polymers metabolism, Polymers pharmacokinetics, Sensitivity and Specificity, Antineoplastic Agents metabolism, Drug Carriers chemistry, Magnetic Resonance Imaging methods, Polymers chemistry
- Abstract
A multifunctional stable and pH-responsive polymer vesicle nanocarrier system was developed for combined tumor-targeted delivery of an anticancer drug and superparamagnetic iron oxide (SPIO) nanoparticles (NPs). These multifunctional polymer vesicles were formed by heterofunctional amphiphilic triblock copolymers, that is, R (folate (FA) or methoxy)-poly(ethylene glycol)(M(w):5000)-poly(glutamate hydrozone doxorubicin)-poly(ethylene glycol) (M(w):2000)-acrylate (i.e., R (FA or methoxy)-PEG(114)-P(Glu-Hyd-DOX)-PEG(46)-acrylate). The amphiphilic triblock copolymers can self-assemble into stable vesicles in aqueous solution. It was found that the long PEG segments were mostly segregated into the outer hydrophilic PEG layers of the vesicles, thereby providing active tumor targeting via FA, while the short PEG segments were mostly segregated into the inner hydrophilic PEG layer of the vesicles, thereby making it possible to cross-link the inner PEG layer via the acrylate groups for enhanced in vivo stability. The therapeutic drug, DOX, was conjugated onto the polyglutamate segment, which formed the hydrophobic membrane of the vesicles using a pH-sensitive hydrazone bond to achieve pH-responsive drug release, while the hydrophilic SPIO NPs were encapsulated into the aqueous core of the stable vesicles, allowing for ultrasensitive magnetic resonance imaging (MRI) detection. The SPIO/DOX-loaded vesicles demonstrated a much higher r(2) relaxivity value than Feridex, a commercially available SPIO-based T(2) contrast agent, which was attributed to the high SPIO NPs loading level and the SPIO clustering effect in the aqueous core of the vesicles. Results from flow cytometry and confocal laser scanning microscopy (CLSM) analysis showed that FA-conjugated vesicles exhibited higher cellular uptake than FA-free vesicles which also led to higher cytotoxicity. Thus, these tumor-targeting multifunctional SPIO/DOX-loaded vesicles will provide excellent in vivo stability, pH-controlled drug release, as well as enhanced MRI contrast, thereby making targeted cancer therapy and diagnosis possible.
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- 2010
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21. Multifunctional polymeric vesicles for targeted drug delivery and imaging.
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Yang X, Grailer JJ, Pilla S, Steeber DA, Gong S, and Shuai X
- Subjects
- Animals, Cell Line, Tumor, Doxorubicin chemistry, Doxorubicin pharmacokinetics, Flow Cytometry, Folic Acid chemistry, Mice, Microscopy, Confocal, Microscopy, Electron, Transmission, Drug Delivery Systems methods, Micelles, Polyesters chemistry, Polyethylene Glycols chemistry
- Abstract
Multifunctional polymeric vesicles were developed for targeted drug delivery and imaging. To fabricate this system, a biodegradable amphiphilic diblock copolymer, folate-poly(ethylene glycol)-poly(D,L-lactide) was designed and synthesized through sequential anionic polymerization in a well-controlled manner. Hydrophobic superparamagnetic iron oxide nanoparticles were loaded into the hydrophobic membrane for ultra-sensitive magnetic resonance imaging. Meanwhile, the anticancer drug, doxorubicin was encapsulated in the aqueous core of the vesicles. Cell culture experiments demonstrated the potential of polymeric vesicles as an effective targeting nanoplatform for the delivery of anticancer drugs due to the folate attached to the surface of the vesicles.
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- 2010
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22. Tumor-targeting, pH-responsive, and stable unimolecular micelles as drug nanocarriers for targeted cancer therapy.
- Author
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Yang X, Grailer JJ, Pilla S, Steeber DA, and Gong S
- Subjects
- Antineoplastic Agents chemistry, Cell Line, Tumor, Cell Survival drug effects, Dose-Response Relationship, Drug, Drug Carriers chemical synthesis, Drug Screening Assays, Antitumor, Folic Acid metabolism, Humans, Hydrogen-Ion Concentration, Molecular Structure, Particle Size, Polyesters chemical synthesis, Polyesters chemistry, Structure-Activity Relationship, Surface Properties, Antineoplastic Agents administration & dosage, Antineoplastic Agents pharmacology, Drug Carriers chemistry, Folic Acid chemistry, Micelles, Nanostructures chemistry, Polyesters pharmacology, Polymers chemistry
- Abstract
A new type of multifunctional unimolecular micelle drug nanocarrier based on amphiphilic hyperbranched block copolymer for targeted cancer therapy was developed. The core of the unimolecular micelle was a hyperbranched aliphatic polyester, Boltorn H40. The inner hydrophobic layer was composed of random copolymer of poly(ε-caprolactone) and poly(malic acid) (PMA-co-PCL) segments, while the outer hydrophilic shell was composed of poly(ethylene glycol) (PEG) segments. Active tumor-targeting ligands, i.e., folate (FA), were selectively conjugated to the distal ends of the PEG segments. An anticancer drug, i.e., doxorubicin (DOX) molecules, was conjugated onto the PMA segments with pH-sensitive drug binding linkers for pH-triggered drug release. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis showed that the unimolecular micelles were uniform with a mean hydrodynamic diameter around 25 nm. The drug loading content was determined to be 14.2%. The drug release profile, cell uptake and distribution, and cytotoxicity of the unimolecular micelles were evaluated in vitro. The folate-conjugated micelles can be internalized by the cancer cells via folate-receptor-mediated endocytosis; thus, they exhibited enhanced cell uptake and cytotoxicity. At pH 7.4, the physiological condition of bloodstream, DOX conjugated onto the unimolecular micelles exhibited excellent stability; however, once the micelles were internalized by the cancer cells, the pH-sensitive hydrazone linkages were cleavable by the intracellular acidic environment, which initially caused a rapid release of DOX. These findings indicate that these unique unimolecular micelles may offer a very promising approach for targeted cancer therapy.
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- 2010
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23. L-selectin: role in regulating homeostasis and cutaneous inflammation.
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Grailer JJ, Kodera M, and Steeber DA
- Subjects
- Animals, Cell Adhesion immunology, Cell Adhesion Molecules immunology, Cell Adhesion Molecules metabolism, Cell Movement immunology, Endothelium, Vascular metabolism, Homeostasis immunology, Humans, Integrins metabolism, L-Selectin metabolism, Leukocytes metabolism, Signal Transduction immunology, Skin immunology, Skin metabolism, T-Lymphocytes, Regulatory metabolism, Dermatitis immunology, Endothelium, Vascular immunology, Integrins immunology, L-Selectin immunology, Leukocytes immunology, T-Lymphocytes, Regulatory immunology
- Abstract
The maintenance of immune surveillance and the generation of normal immune responses are dependent on leukocyte migration to appropriate lymphoid and non-lymphoid tissues. The process of leukocyte migration occurs through complex and highly regulated interactions between the circulating leukocytes and the vascular endothelium. Multiple families of adhesion molecules as well as specific chemoattractants and their cognate receptors function to stabilize these interactions and induce migration into the tissue. L-selectin is a key adhesion molecule that regulates both the migration of leukocytes at sites of inflammation and the recirculation of lymphocytes between blood and lymphoid tissues. L-selectin-mediated lymphocyte recirculation is required for maintaining the appropriate tissue distribution of lymphocyte subpopulations including naïve and effector subsets such as regulatory T cells. In addition, L-selectin-mediated entry into peripheral lymph nodes is required for optimal induction of lymphocyte homeostatic proliferation during lymphopenia. Importantly, L-selectin has been shown to have both adhesive and signaling functions during leukocyte migration. Specifically, L-selectin is highly efficient at capturing free-flowing leukocytes from the blood and supporting subsequent fast rolling interactions along the vascular endothelium. During rolling, synergistic interactions between L-selectin and integrin functions slow leukocyte rolling velocities allowing for chemoattractant-induced activation and eventual firm adhesion of the leukocyte to the vascular endothelium. Engagement of L-selectin by ligand generates transmembrane signals leading to activation of intracellular signaling pathways, increased integrin binding affinity, and enhanced chemotaxis. L-selectin has also been shown to mediate leukocyte recruitment during chronic inflammatory and autoimmune diseases and thus is a potential therapeutic target for drug development.
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- 2009
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24. Biodegradable hydrogels based on novel photopolymerizable guar gum-methacrylate macromonomers for in situ fabrication of tissue engineering scaffolds.
- Author
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Tiwari A, Grailer JJ, Pilla S, Steeber DA, and Gong S
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- Biocompatible Materials chemistry, Cell Proliferation, Cells, Cultured, Humans, Materials Testing, Molecular Structure, Molecular Weight, Nuclear Magnetic Resonance, Biomolecular, Viscosity, Galactans chemistry, Hydrogels chemical synthesis, Hydrogels chemistry, Hydrogels metabolism, Mannans chemistry, Methacrylates chemistry, Photochemical Processes, Plant Gums chemistry, Tissue Engineering methods, Tissue Scaffolds
- Abstract
Guar gum (GG) is a non-ionic polysaccharide that is found abundantly in nature and has many properties desirable for biomedical applications. In the present work GG with molecular weights ranging from 74 to 210 kDa was modified with glycidyl methacrylate (GMA) to produce a series of water-soluble photopolymerizable guar gum-methacrylate (GG-MA) macromonomers of different molecular weights. We investigated the effects of molecular weight of GG-MA macromonomers from 102 to 216 kDa and with percent degree of methacrylation (%DM) ranging from 14% to 56% on the properties of GG-MA hydrogels. GG-MA hydrogels exhibited a three-dimensional open cell microstructure with an average pore size ranging from approximately 10 to 55 microm and an average pore density of from approximately 2.4 x 10(6) to 8.6 x 10(7) pores cm(-3). The hydrogels exhibited equilibrium swelling ratios ranging from approximately 22% to 63%. The degree of in vitro enzymatic biodegradation of the hydrogels decreased linearly with increasing gel content and the degree of methacrylation of the respective macromonomers. The human endothelial cell line EA.hy926 was photo-encapsulated in the GG-MA hydrogels. Cells remained viable at low macromonomer concentrations, but cell viability decreased sequentially as the macromonomer concentration increased. GG-MA hydrogels with a 0.05 wt.% GG-MA macromonomer concentration revealed excellent endothelial cell proliferation, similar to that of the Matrigel control.
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- 2009
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25. Gold nanoparticles with a monolayer of doxorubicin-conjugated amphiphilic block copolymer for tumor-targeted drug delivery.
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Prabaharan M, Grailer JJ, Pilla S, Steeber DA, and Gong S
- Subjects
- Animals, Cell Line, Tumor, Drug Delivery Systems, Endocytosis, Folic Acid chemistry, Hydrogen-Ion Concentration, Hydrophobic and Hydrophilic Interactions, Mice, Micelles, NIH 3T3 Cells, Polymers chemistry, Doxorubicin administration & dosage, Gold chemistry, Metal Nanoparticles chemistry, Nanotechnology methods, Neoplasms drug therapy
- Abstract
Gold (Au) nanoparticles (NPs) stabilized with a monolayer of folate-conjugated poly(L-aspartate-doxorubicin)-b-poly(ethylene glycol) copolymer (Au-P(LA-DOX)-b-PEG-OH/FA) was synthesized as a tumor-targeted drug delivery carrier. The Au-P(LA-DOX)-b-PEG-OH/FA NPs consist of an Au core, a hydrophobic poly(l-aspartate-doxorubicin) (P(LA-DOX)) inner shell, and a hydrophilic poly(ethylene glycol) and folate-conjugated poly(ethylene glycol) outer shell (PEG-OH/FA). The anticancer drug, doxorubicin (DOX), was covalently conjugated onto the hydrophobic inner shell by acid-cleavable hydrazone linkage. The DOX loading level was determined to be 17 wt%. The Au-P(LA-DOX)-b-PEG-OH/FA NPs formed stable unimolecular micelles in aqueous solution. The size of the Au-P(LA-DOX)-b-PEG-OH/FA micelles were determined as 24-52 and 10-25 nm by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The conjugated DOX was released from the Au-P(LA-DOX)-b-PEG-OH/FA micelles much more rapidly at pH 5.3 and 6.6 than at pH 7.4, which is a desirable characteristic for tumor-targeted drug delivery. Cellular uptake of the Au-P(LA-DOX)-b-PEG-OH/FA micelles facilitated by the folate-receptor-mediated endocytosis process was higher than that of the micelles without folate. This was consistent with the higher cytotoxicity observed with the Au-P(LA-DOX)-b-PEG-OH/FA micelles against the 4T1 mouse mammary carcinoma cell line. These results suggest that Au-P(LA-DOX)-b-PEG-OH/FA NPs could be used as a carrier with pH-triggered drug releasing properties for tumor-targeted drug delivery.
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- 2009
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26. Amphiphilic multi-arm-block copolymer conjugated with doxorubicin via pH-sensitive hydrazone bond for tumor-targeted drug delivery.
- Author
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Prabaharan M, Grailer JJ, Pilla S, Steeber DA, and Gong S
- Subjects
- Animals, Cell Line, Tumor, Cell Survival drug effects, Doxorubicin chemistry, Female, Hydrogen-Ion Concentration, Hydrophobic and Hydrophilic Interactions, Materials Testing, Mice, Breast Neoplasms metabolism, Breast Neoplasms physiopathology, Doxorubicin administration & dosage, Doxorubicin pharmacokinetics, Drug Carriers chemical synthesis, Hydrazones chemistry, Polyethylene Glycols chemistry
- Abstract
Folate-conjugated unimolecular micelles based on amphiphilic hyperbranched block copolymer, Boltorn H40-poly(l-aspartate-doxorubicin)-b-poly(ethylene glycol)/FA-conjugated poly(ethylene glycol) (H40-P(LA-DOX)-b-PEG-OH/FA), were synthesized as a carrier for tumor-targeted drug delivery. The anticancer drug DOX was covalently conjugated onto the hydrophobic segments of the amphiphilic block copolymer arms by pH-sensitive hydrazone linkage. The size of the unimolecular micelles was determined as approximately 17-36 and 10-20 nm by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The release profiles of the DOX from the H40-P(LA-DOX)-b-PEG-OH/FA micelles showed a strong dependence on the environmental pH values. The DOX release rate increased in the acidic medium due to the acid-cleavable hydrazone linkage between the DOX and micelles. Cellular uptake of the H40-P(LA-DOX)-b-PEG-OH/FA micelles was found to be higher than that of the H40-P(LA-DOX)-b-PEG-OH micelles because of the folate-receptor-mediated endocytosis, thereby providing higher cytotoxicity against the 4T1 mouse mammary carcinoma cell line. Degradation studies showed that the H40-P(LA-DOX)-b-PEG-OH/FA copolymer hydrolytically degraded into polymer fragments within six weeks. These results suggest that H40-P(LA-DOX)-b-PEG-OH/FA micelles could be a promising nanocarrier with excellent in vivo stability for targeting the drugs to cancer cells and releasing the drug molecules inside the cells by sensing the acidic environment of the endosomal compartments.
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- 2009
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27. Thermosensitive micelles based on folate-conjugated poly(N-vinylcaprolactam)-block-poly(ethylene glycol) for tumor-targeted drug delivery.
- Author
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Prabaharan M, Grailer JJ, Steeber DA, and Gong S
- Subjects
- Animals, Caprolactam chemistry, Caprolactam therapeutic use, Cell Line, Tumor, Drug Carriers chemistry, Drug Carriers pharmacokinetics, Endocytosis, Folic Acid pharmacokinetics, Folic Acid therapeutic use, Humans, Mice, Micelles, Polyethylene Glycols therapeutic use, Polymers therapeutic use, Species Specificity, Temperature, Antineoplastic Agents administration & dosage, Caprolactam analogs & derivatives, Drug Delivery Systems methods, Folic Acid chemistry, Polyethylene Glycols chemistry, Polymers chemistry
- Abstract
Thermosensitive PNVCL-b-PEG block copolymer coupled with folic acid was prepared as an anti-cancer drug carrier. This polymer self-assembled into stable micelles in aqueous solutions at above 33 degrees C. At 37 degrees C, the release profile of PNVCL-b-PEG-FA micelles showed a slower and more controlled release of the entrapped 5-FU than that at 25 degrees C. The blank and 5-FU-loaded PNVCL-b-PEG-FA micelles did not induce remarkable cytotoxicity against the EA.hy 926 human endothelial cell line; however, 5-FU-loaded PNVCL-b-PEG-FA micelles showed a cytotoxicity effect against 4T1 mouse mammary carcinoma cells due to the availability of loaded anti-cancer drugs delivered to the inside of the cancer cells by the folate-receptor-mediated endocytosis process.
- Published
- 2009
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28. Folate-conjugated amphiphilic hyperbranched block copolymers based on Boltorn H40, poly(L-lactide) and poly(ethylene glycol) for tumor-targeted drug delivery.
- Author
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Prabaharan M, Grailer JJ, Pilla S, Steeber DA, and Gong S
- Subjects
- Antineoplastic Agents chemistry, Antineoplastic Agents therapeutic use, Dendrimers therapeutic use, Doxorubicin chemistry, Doxorubicin therapeutic use, Drug Carriers therapeutic use, Folic Acid chemistry, Folic Acid therapeutic use, Materials Testing, Micelles, Molecular Structure, Polyesters therapeutic use, Polyethylene Glycols therapeutic use, Polymers therapeutic use, Solutions, Time Factors, Water chemistry, Dendrimers chemistry, Drug Carriers chemistry, Drug Delivery Systems, Polyesters chemistry, Polyethylene Glycols chemistry, Polymers chemistry
- Abstract
Folate-conjugated amphiphilic hyperbranched block copolymer (H40-PLA-b-MPEG/PEG-FA) with a dendritic Boltorn H40 core, a hydrophobic poly(l-lactide) (PLA) inner shell and a hydrophilic methoxy poly(ethylene glycol) (MPEG) and folate-conjugated poly(ethylene glycol) (PEG-FA) outer shell was synthesized as a carrier for tumor-targeted drug delivery. The block copolymer was characterized using (1)H NMR and gel permeation chromatography (GPC) analysis. Due to its core-shell structure, this block polymer forms unimolecular micelles in aqueous solutions. The micellar properties of H40-PLA-b-MPEG/PEG-FA block copolymer were extensively studied by dynamic light scattering (DLS), fluorescence spectroscopy, and transmission electron microscopy (TEM). An anticancer drug, doxorubicin in the free base form (DOX) was encapsulated into H40-PLA-b-MPEG/PEG-FA micelles. The DOX-loaded micelles provided an initial burst release (up to 4h) followed by a sustained release of the entrapped DOX over a period of about 40 h. Cellular uptake of the DOX-loaded H40-PLA-b-MPEG/PEG-FA micelles was found to be higher than that of the DOX-loaded H40-PLA-b-MPEG micelles because of the folate-receptor-mediated endocytosis, thereby providing higher cytotoxicity against the 4T1 mouse mammary carcinoma cell line. In vitro degradation studies revealed that the H40-PLA-b-MPEG/PEG-FA block copolymer hydrolytically degraded into polymer fragments within six weeks. These results indicated that the micelles prepared from the H40-PLA-b-MPEG/PEG-FA block copolymer have great potential as tumor-targeted drug delivery nanocarriers.
- Published
- 2009
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29. Amphiphilic multi-arm block copolymer based on hyperbranched polyester, poly(L-lactide) and poly(ethylene glycol) as a drug delivery carrier.
- Author
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Prabaharan M, Grailer JJ, Pilla S, Steeber DA, and Gong S
- Subjects
- Biocompatible Materials chemistry, Cell Line, Drug Carriers pharmacology, Endothelial Cells cytology, Endothelial Cells drug effects, Humans, Materials Testing, Micelles, Molecular Structure, Particle Size, Polyesters pharmacology, Polyethylene Glycols pharmacology, Polymers pharmacology, Drug Carriers chemistry, Drug Delivery Systems, Polyesters chemistry, Polyethylene Glycols chemistry, Polymers chemistry
- Abstract
A novel type of biodegradable/biocompatible amphiphilic hyperbranched copolymer (H40-PLA-b-MPEG) was synthesized. Its micellar properties were studied by DLS, fluorescence spectroscopy and TEM. The drug release profile showed that the H40-PLA-b-MPEG micelles provide an initial burst release, followed by a sustained release of the entrapped hydrophobic model drug over a period of 4 to 58 h. The copolymer degraded hydrolytically within 6 weeks under physiological conditions. The MTT assay showed no obvious cytotoxicity against a human endothelial cell line at a concentration range of 0-400 microg x mL(-1). These results indicate that the H40-PLA-b-MPEG micelles have great potential as hydrophobic drug delivery carriers.
- Published
- 2009
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30. Stimuli-responsive chitosan-graft-poly(N-vinylcaprolactam) as a promising material for controlled hydrophobic drug delivery.
- Author
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Prabaharan M, Grailer JJ, Steeber DA, and Gong S
- Subjects
- Caprolactam chemistry, Chitosan chemistry, Delayed-Action Preparations, Endothelial Cells drug effects, Humans, Hydrophobic and Hydrophilic Interactions, Ketoprofen administration & dosage, Caprolactam analogs & derivatives, Chitosan analogs & derivatives, Drug Carriers chemistry, Polymers chemistry
- Abstract
A novel type of pH- and thermo-responsive copolymer, chitosan-graft-poly(N-vinylcaprolactam) (chitosan-g-PNVCL), was prepared by grafting carboxyl-terminated poly(N-vinylcaprolactam) (PNVCL-COOH) chains onto a chitosan backbone as a drug-delivery carrier. The formation of chitosan-g-PNVCL was confirmed by FT-IR and 1H NMR techniques. Chitosan-g-PNVCL showed a definite phase transition at 32 degrees C as occurs in pure PNVCL. The swelling degree of the chitosan-g-PNVCL beads was found to be higher at pH 2.2 than at pH 7.4. Moreover, the swelling degree of the beads decreased with increased environmental temperature. Compared to the chitosan beads, the release profile of chitosan-g-PNVCL beads showed a slower and more controlled release of the entrapped ketoprofen. The release behavior of the chitosan-g-PNVCL beads was influenced by both the pH and temperature of the medium. The MTT assay showed no obvious cytotoxicity of chitosan-g-PNVCL against a human endothelial cell line over a concentration range of 0-400 microg x mL(-1). These results suggest that chitosan-g-PNVCL could be a potential stimuli-responsive material for controlled drug delivery, and it may improve the bioavailability, efficacy, and compliance of the encapsulated drugs. [Reaction: see text].
- Published
- 2008
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31. The loss of MCP-1 attenuates cutaneous ischemia-reperfusion injury in a mouse model of pressure ulcer.
- Author
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Saito Y, Hasegawa M, Fujimoto M, Matsushita T, Horikawa M, Takenaka M, Ogawa F, Sugama J, Steeber DA, Sato S, and Takehara K
- Subjects
- Animals, Apoptosis, Chemokine CCL2 blood, Female, HSP90 Heat-Shock Proteins genetics, Macrophages physiology, Mice, Mice, Inbred C57BL, Neutrophil Infiltration, Nitric Oxide biosynthesis, Nitric Oxide Synthase Type II genetics, RNA, Messenger analysis, Reperfusion Injury pathology, Skin pathology, Tumor Necrosis Factor-alpha blood, Tumor Necrosis Factor-alpha genetics, Wound Healing, Chemokine CCL2 physiology, Pressure Ulcer etiology, Reperfusion Injury prevention & control, Skin blood supply
- Abstract
The formation of pressure ulcers is dependent on multiple factors including ischemia-reperfusion (IR). This study assessed the mechanism of a previously reported murine model of cutaneous IR injury. Three cycles of IR (days 1-3) by external application of two magnetic plates were performed to induce pressure ulcer formation. Increased infiltration of neutrophils and macrophages, and augmented expression of proinflammatory cytokines and inducible nitric oxide synthase (iNOS), were observed during IR cycles. In this model, monocyte chemoattractant protein-1 (MCP-1) was remarkably increased at day 1 in the skin followed by inflammatory cell infiltration. Therefore, IR cycles were performed in MCP-1-deficient (MCP-1(-/-)) mice to evaluate the role of this chemokine in pressure ulcer development. MCP-1(-/-) mice showed reduced macrophage infiltration and expression of tumor-necrosis factor-alpha (TNF)-alpha and iNOS during IR cycles leading to attenuated apoptosis and skin injury. Importantly, MCP-1 played a role in apoptosis and injury via inducing iNOS during the reperfusion rather than the ischemic period. These findings indicate that MCP-1 may be a critical factor for macrophage recruitment and subsequent skin inflammation and injury during IR cycles. We propose that this is a useful model for investigating the mechanism of pressure ulcer formation using various transgenic mice.
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- 2008
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32. T lymphocyte migration to lymph nodes is maintained during homeostatic proliferation.
- Author
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Kodera M, Grailer JJ, Karalewitz AP, Subramanian H, and Steeber DA
- Subjects
- Animals, Cell Movement immunology, Cell Proliferation, Chemokine CCL21 pharmacology, Chemokine CXCL12 pharmacology, Chemotaxis, Leukocyte drug effects, Genes, RAG-1, Homeostasis, Immunologic Memory, In Vitro Techniques, Lymph Nodes cytology, Lymphatic Vessels cytology, Lymphopenia immunology, Lymphopenia pathology, Mice, Mice, Inbred C57BL, Mice, Knockout, Microscopy, Fluorescence, Phenotype, Receptors, CCR7 metabolism, T-Lymphocytes drug effects, T-Lymphocytes immunology, Cell Movement physiology, T-Lymphocytes cytology, T-Lymphocytes physiology
- Abstract
The immune system maintains appropriate cell numbers through regulation of cell proliferation and death. Normal tissue distribution of lymphocytes is maintained through expression of specific adhesion molecules and chemokine receptors such as L-selectin and CCR7, respectively. Lymphocyte insufficiency or lymphopenia induces homeostatic proliferation of existing lymphocytes to increase cell numbers. Interestingly, homeostatic proliferation of T lymphocytes induces a phenotypic change from naïve- to memory-type cell. Naïve T cells recirculate between blood and lymphoid tissues whereas memory T cells migrate to nonlymphoid sites such as skin and gut. To assess effects of homeostatic proliferation on migratory ability of T cells, a murine model of lymphopenia-induced homeostatic proliferation was used. Carboxyfluorescein diacetate, succinimidyl ester-labeled wild-type splenocytes were adoptively transferred into recombination activation gene-1-deficient mice and analyzed by flow cytometry, in vitro chemotactic and in vivo migration assays, and immunofluorescence microscopy. Homeostatically proliferated T cells acquired a mixed memory-type CD44high L-selectinhigh CCR7low phenotype. Consistent with this, chemotaxis to secondary lymphoid tissue chemokine in vitro was reduced by 22%-34%. By contrast, no differences were found for migration or entry into lymph nodes during in vivo migration assays. Therefore, T lymphocytes that have undergone homeostatic proliferation recirculate using mechanisms similar to naïve T cells.
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- 2008
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33. Fabrication and characterization of microwave immunosensors based on organic semiconductors with nanogold-labeled antibody.
- Author
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Li F, Klemer DP, Kimani JK, Mao S, Chen J, and Steeber DA
- Subjects
- Electric Impedance, Equipment Design, Gold, Antibodies chemistry, Biosensing Techniques instrumentation, Metal Nanoparticles chemistry, Microwaves, Semiconductors instrumentation
- Abstract
Microelectronic biosensors hold great promise for rapid, sensitive and specific in vitro point-of-care immunodiagnostics. In particular, sensors fabricated using organic semiconductors have attractive advantages-such as ease of manufacture and low cost-in the design and implementation of such devices. Furthermore, immobilization of an antibody or protein antigen as a biorecognition element onto an organic semiconducting film allows for direct transduction of biomolecular binding events into an electronic signal which is readily measured and processed. In previous work, we have demonstrated that an antigen can be bound to organic semiconducting films while retaining enzymatic activity after immobilization. The present work considers organic semiconducting films which are spin-cast onto an interdigitated electrode; antibodies labeled with gold-nanoparticles are applied to the organic semiconducting film and serve as a biorecognition element. The sensor geometry includes a high-frequency coplanar waveguide contact metallization to facilitate direct measurement using microwave wafer probes. Equivalent circuit models are derived from microwave measurements over the frequency range 0.3 MHz to 8.5 GHz.
- Published
- 2008
- Full Text
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34. Endothelial selectins regulate skin wound healing in cooperation with L-selectin and ICAM-1.
- Author
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Yukami T, Hasegawa M, Matsushita Y, Fujita T, Matsushita T, Horikawa M, Komura K, Yanaba K, Hamaguchi Y, Nagaoka T, Ogawa F, Fujimoto M, Steeber DA, Tedder TF, Takehara K, and Sato S
- Subjects
- Animals, Cell Movement, Collagen genetics, Collagen metabolism, Cytokines metabolism, E-Selectin genetics, Female, Fibroblast Growth Factor 2, Granulation Tissue pathology, Intercellular Adhesion Molecule-1 genetics, L-Selectin genetics, Macrophages cytology, Macrophages metabolism, Male, Mast Cells cytology, Mast Cells metabolism, Mice, Mice, Knockout, Neovascularization, Physiologic, Neutrophil Infiltration, P-Selectin genetics, P-Selectin metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Skin cytology, E-Selectin metabolism, Intercellular Adhesion Molecule-1 physiology, L-Selectin physiology, Skin metabolism, Wound Healing physiology
- Abstract
Skin wound healing is mediated by inflammatory cell infiltration that is highly regulated by various adhesion molecules. Mice lacking intercellular adhesion molecule-1 (ICAM-1) delayed skin wound healing and mice lacking both L-selectin and ICAM-1 (L-selectin/ICAM-1(-/-)) show more delayed wound healing. Deficiency of both endothelial selectins (E-selectin or P-selectin) also delays wound healing. However, the relative contribution and interaction of selectins and ICAM-1 to the wound healing remain unknown. To clarify them, repair of excisional wounds was examined in L-selectin/ICAM-1(-/-) mice, wild-type mice with both E- and P-selectin blockade, and L-selectin/ICAM-1(-/-) mice with both E- and P-selectin blockade. Wild-type mice with both E- and P-selectin blockade showed delayed wound healing that was comparable with that in L-selectin/ICAM-1(-/-) mice. Combined E- and P-selectin blockade in L-selectin/ICAM-1(-/-) mice resulted in more significant delay. Mice lacking or blocked for adhesion molecules also showed suppressed keratinocyte migration, angiogenesis, granulation tissue formation, leukocyte infiltration, and cytokine expression, including transforming growth factor-beta and interleukin-6. Application of basic fibroblast growth factor (bFGF) but not platelet-derived growth factor to the wounds significantly improved wound healing in L-selectin/ICAM-1(-/-) mice with both E- and P-selectin blockade. bFGF significantly increased the leukocyte infiltration and subsequent fibrogenic cytokine production, as well as keratinocyte migration, angiogenesis, and collagen synthesis despite the loss of four kinds of adhesion molecules. These results indicate that skin wound healing is regulated cooperatively by all selectins and ICAM-1 and may provide critical information for the therapy of skin wounds.
- Published
- 2007
- Full Text
- View/download PDF
35. B cell depletion delays collagen-induced arthritis in mice: arthritis induction requires synergy between humoral and cell-mediated immunity.
- Author
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Yanaba K, Hamaguchi Y, Venturi GM, Steeber DA, St Clair EW, and Tedder TF
- Subjects
- Animals, Antibodies, Monoclonal immunology, Antigens, CD20 immunology, Arthritis, Experimental prevention & control, Autoantibodies immunology, Disease Progression, Enzyme-Linked Immunosorbent Assay, Mice, Mice, Inbred C57BL, Mice, Inbred DBA, Antibody Formation, Arthritis, Experimental immunology, B-Lymphocytes immunology, Immunity, Cellular, Lymphocyte Depletion
- Abstract
Rheumatoid arthritis is a systemic autoimmune disease. B cells are likely to play a critical role in arthritis pathogenesis, although it is unclear whether they are necessary for disease induction, autoantibody production, or disease progression. To assess the role of B cells in inflammatory arthritis, B cells were depleted using mouse anti-mouse CD20 mAbs in a mouse model of collagen-induced arthritis. CD20 mAbs effectively depleted mature B cells from adult DBA-1 mice. When B cells were depleted using CD20 mAbs before collagen immunization, there was a delay in disease onset and autoantibody production, with significantly diminished severity of arthritis both clinically and histologically. B cell depletion further delayed disease onset if initiated before, as well as after, collagen immunization. However, in both cases, the eventual reappearance of peripheral B cells triggered autoantibody production and the subsequent development of arthritis in collagen-sensitized mice. By contrast, B cell depletion after collagen immunizations did not have a significant effect on arthritis progression or severity. Thus, disease symptoms were only induced when peripheral B cells and their autoantibody products were present in collagen-immunized mice, documenting a critical role for B cells during the elicitation phase of collagen-induced arthritis. These studies suggest that B cell depletion strategies will be most effective when initiated early in the development of inflammatory arthritis, with sustained B cell depletion required to inhibit the production of isotype-switched pathogenic Abs and the evolution of joint inflammation and destruction.
- Published
- 2007
- Full Text
- View/download PDF
36. Intercellular adhesion molecule-1 deficiency attenuates the development of skin fibrosis in tight-skin mice.
- Author
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Matsushita Y, Hasegawa M, Matsushita T, Fujimoto M, Horikawa M, Fujita T, Kawasuji A, Ogawa F, Steeber DA, Tedder TF, Takehara K, and Sato S
- Subjects
- Animals, CD3 Complex biosynthesis, Cell Migration Inhibition, Cells, Cultured, Coculture Techniques, Collagen antagonists & inhibitors, Collagen biosynthesis, Collagen genetics, Cytokines antagonists & inhibitors, Cytokines biosynthesis, Cytokines genetics, Down-Regulation immunology, Female, Fibroblasts immunology, Fibroblasts metabolism, Fibroblasts pathology, Fibrosis, Intercellular Adhesion Molecule-1 biosynthesis, Intercellular Adhesion Molecule-1 physiology, Intracellular Fluid immunology, Intracellular Fluid metabolism, L-Selectin genetics, L-Selectin physiology, Mice, Mice, Inbred C57BL, Mice, Knockout, Skin immunology, Skin metabolism, T-Lymphocyte Subsets immunology, T-Lymphocyte Subsets metabolism, T-Lymphocyte Subsets pathology, Th2 Cells immunology, Th2 Cells metabolism, Transforming Growth Factor beta antagonists & inhibitors, Transforming Growth Factor beta biosynthesis, Transforming Growth Factor beta genetics, Up-Regulation immunology, Intercellular Adhesion Molecule-1 genetics, Skin pathology
- Abstract
The tight-skin (TSK/+) mouse, a genetic model for systemic sclerosis, develops cutaneous fibrosis. Although a fibrillin 1 gene mutation and immunological abnormalities have been demonstrated, the roles of adhesion molecules have not been investigated. To directly assess roles of adhesion molecules in skin fibrosis, TSK/+ mice lacking L-selectin and/or ICAM-1 were generated. The deficiency of ICAM-1, but not L-selectin, significantly suppressed ( approximately 48%) the development of skin sclerosis in TSK/+ mice. Similarly, ICAM-1 antisense oligonucleotides inhibited skin fibrosis in TSK/+ mice. Although T cell infiltration was modest into the skin of TSK/+ mice, ICAM-1 deficiency down-regulated this migration, which is consistent with the established roles of endothelial ICAM-1 in leukocyte infiltration. In addition, altered phenotype or function of skin fibroblasts was remarkable and dependent on ICAM-1 expression in TSK/+ mice. ICAM-1 expression was augmented on TSK/+ dermal fibroblasts stimulated with IL-4. Although growth or collagen synthesis of TSK/+ fibroblasts cultured with IL-4 was up-regulated, it was suppressed by the loss or blocking of ICAM-1. Collagen expression was dependent on the strain of fibroblasts, but not on the strain of cocultured T cells. Thus, our findings indicate that ICAM-1 expression contributes to the development of skin fibrosis in TSK/+ mice, especially via ICAM-1 expressed on skin fibroblasts.
- Published
- 2007
- Full Text
- View/download PDF
37. Polymer semiconductors as a biosensing platform: peroxidase activity of enzyme bound to organic semiconducting films.
- Author
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Omari EA, Klemer DP, Steeber DA, and Gaertner WF
- Subjects
- 3,3'-Diaminobenzidine chemistry, Colorimetry methods, Furans chemistry, Photometry methods, Semiconductors, Biosensing Techniques methods, Enzymes, Immobilized chemistry, Horseradish Peroxidase chemistry, Polyvinyls chemistry
- Abstract
Organic polymer semiconductors have unique electronic properties which make them attractive for use in microelectronic and optoelectronic devices fabricated using inexpensive manufacturing processes. In addition, novel chemical and biological sensors have been proposed which make use of the photophysical and electrical properties of conjugated polymer semiconducting films. The work described herein illustrates one such biosensing application by demonstrating successful immobilization of horseradish peroxidase enzyme onto a thin film of the semiconducting polymer MDMO-PPV. Validation of bound peroxidase activity is accomplished through the use of a substrate solution of 3,3'-diaminobenzidine and hydrogen peroxide, which yields a dark brown precipitate in the presence of peroxidase. Photometric measurements are used to derive a quantitative assay of bound peroxidase concentration. This work supports the feasibility of organic semiconducting polymer films as a biosensing platform in microelectronic sensor devices.
- Published
- 2007
- Full Text
- View/download PDF
38. CD25+CD4+ regulatory T cell migration requires L-selectin expression: L-selectin transcriptional regulation balances constitutive receptor turnover.
- Author
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Venturi GM, Conway RM, Steeber DA, and Tedder TF
- Subjects
- Animals, Antigens, CD metabolism, CD4 Antigens analysis, Integrin alpha Chains metabolism, Interleukin-2 Receptor alpha Subunit analysis, L-Selectin analysis, Lymph Nodes cytology, Lymph Nodes immunology, Lymphocyte Activation, Mice, Mice, Mutant Strains, Receptors, Immunologic metabolism, T-Lymphocytes, Regulatory chemistry, Transcription, Genetic, Cell Movement genetics, Gene Expression Regulation, L-Selectin genetics, L-Selectin metabolism, T-Lymphocytes, Regulatory immunology
- Abstract
The molecular mechanisms controlling regulatory CD25(+)Foxp3(+)CD4(+) T cell (T(reg)) migration are central to in vivo immune responses. T(reg) cell subsets differentially express L-selectin, an adhesion molecule mediating lymphocyte migration to peripheral LNs (PLNs) and leukocyte rolling during inflammation. In this study, L-selectin was essential for T(reg) cell migration and normal tissue distribution. Specifically, there was a 90% reduction in PLN T(reg) cells in L-selectin(-/-) mice with a compensatory increase in spleen T(reg) cell numbers. Unexpectedly, however, 40% of the CD4(+) T cells remaining within PLNs of L-selectin(-/-) mice were T(reg) cells. The migratory properties of T(reg) cells were nonetheless markedly different from those of naive CD4(+) T cells, with 3- to 9-fold lower migration of T(reg) cells into PLNs and approximately 2-fold lower migration into the spleen. T(reg) cells also turned over cell surface L-selectin at a faster rate than CD25(-)CD4(+) T cells, but maintained physiologically appropriate L-selectin densities for optimal migration. Specifically, T(reg) cells expressed 30-40% more cell surface L-selectin when its endoproteolytic cleavage was blocked genetically, which resulted in a 2-fold increase in T(reg) cell migration into PLNs. However, increased L-selectin cleavage by T(reg) cells in wild-type mice was accompanied by 2-fold higher L-selectin mRNA levels, which resulted in equivalent cell surface L-selectin densities on T(reg) and naive T cells. Thus, T(reg) cells and CD25(-)CD4(+) T cells share similar requirements for L-selectin expression during migration, although additional molecular mechanisms constrain T(reg) cell migration beyond what is required for naive CD4(+) T cell migration.
- Published
- 2007
- Full Text
- View/download PDF
39. E- and P-selectins synergistically inhibit bleomycin-induced pulmonary fibrosis.
- Author
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Horikawa M, Fujimoto M, Hasegawa M, Matsushita T, Hamaguchi Y, Kawasuji A, Matsushita Y, Fujita T, Ogawa F, Takehara K, Steeber DA, and Sato S
- Subjects
- Animals, Antibiotics, Antineoplastic pharmacology, Antibodies, Monoclonal immunology, Antibodies, Monoclonal pharmacology, Bleomycin pharmacology, Collagen immunology, Collagen metabolism, Cytokines biosynthesis, Cytokines genetics, Cytokines immunology, Disease Models, Animal, E-Selectin genetics, E-Selectin immunology, Gene Expression Regulation drug effects, Gene Expression Regulation genetics, Gene Expression Regulation immunology, Killer Cells, Natural immunology, Killer Cells, Natural metabolism, Killer Cells, Natural pathology, Lung immunology, Lung pathology, Mice, Mice, Knockout, P-Selectin genetics, P-Selectin immunology, Pulmonary Fibrosis chemically induced, Pulmonary Fibrosis genetics, Pulmonary Fibrosis immunology, Pulmonary Fibrosis pathology, RNA, Messenger biosynthesis, RNA, Messenger genetics, RNA, Messenger immunology, Receptors, CXCR3, Receptors, Chemokine biosynthesis, Receptors, Chemokine immunology, T-Lymphocytes immunology, T-Lymphocytes metabolism, T-Lymphocytes pathology, Antibiotics, Antineoplastic toxicity, Bleomycin toxicity, E-Selectin metabolism, Lung metabolism, P-Selectin metabolism, Pulmonary Fibrosis metabolism
- Abstract
The development of bleomycin-induced lung injury, which is a model of pulmonary fibrosis, results from inflammatory cell infiltration, a process highly regulated by the expression of multiple adhesion molecules. Therefore, bleomycin-induced lung fibrosis was examined in E-selectin-/- mice, P-selectin-/- mice, and E-selectin-/- mice treated with anti-P-selectin monoclonal antibody (mAb) in comparison of wild-type mice. E-selectin-/- mice treated with anti-P-selectin mAb exhibited augmented lung fibrosis histologically, increased lung collagen deposition, and increased mortality compared to wild-type mice. Furthermore, lung interferon-gamma mRNA expression decreased in E-selectin-/- mice treated with anti-P-selectin mAb relative to wild-type mice, while tumor necrosis factor-alpha and interleukin-6 mRNA expression increased in these mice. Similar changes were observed in E-selectin-/- mice, albeit to a lesser extent than those treated with anti-P-selectin mAb. Remarkably, flow cytometric analysis revealed that the frequency of interferon-gamma-producing natural killer T (NKT) cells in the bronchoalveolar lavage was decreased in E-selectin-/- mice and E-selectin-/- mice treated with anti-P-selectin mAb compared with wild-type mice. Moreover, the majority of NKT cells expressed high levels of CXCR3, suggesting that NKT cell infiltration is also dependent on CXCR3 expression. These results suggest that E- and P-selectins synergistically inhibit lung fibrosis by promoting the recruitment of NKT cells.
- Published
- 2006
- Full Text
- View/download PDF
40. Population behavior analysis of dspE and pelD regulation in Erwinia chrysanthemi 3937.
- Author
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Peng Q, Yang S, Charkowski AO, Yap MN, Steeber DA, Keen NT, and Yang CH
- Subjects
- Brassica microbiology, Plant Tubers microbiology, Polysaccharide-Lyases genetics, Promoter Regions, Genetic, Solanum tuberosum microbiology, Bacterial Proteins genetics, Bacterial Proteins metabolism, Dickeya chrysanthemi genetics, Dickeya chrysanthemi physiology, Gene Expression Regulation, Bacterial, Polysaccharide-Lyases metabolism
- Abstract
Erwinia chrysanthemi 3937 (Ech3937) is a phytopathogenic bacterium with a wide host range. The pectinolytic enzymes secreted by the bacterium and the type III secretion system (T3SS) are essential for full virulence. We used the green fluorescent protein gene as a reporter to investigate the expression of dspE (a putative T3SS effector) and pelD (a major pectin-degrading enzyme) in populations of Ech3937 under different conditions. Gene expression was analyzed by measuring the fluorescence intensity of individual cells with a fluorescence-activated cell sorter. Ech3937 dspE was induced in minimal medium (MM) with only a portion of Ech3937 cells (43.03%) expressing dspE after 12 h of culture. The nutrient-rich King's medium B did not fully eliminate the expression of dspE; a small percentage of Ech3937 cells (5.55%) was able to express dspE after 12 h of culture in this medium. In all, 68.95% of Ech3937 cells expressed pelD after 12 h of culture in MM supplemented with polygalacturonic acid (PGA). However, 96.34% of Echl31 cells (an hrpL deletion mutant of Ech3937) expressed pelD after 12 h of culture in MM supplemented with PGA. In potato tubers, 6.32% of the bacterial cells expressed dspE 2 h after inoculation, whereas only 0.25% of the cells expressed pelD. However, after 24 h, the percentage of cells expressing pelD (68.48%) was approximately 3.5 times that of cells expressing dspE (19.39%). In contrast to potato tubers, similar proportion of Ech3937 cells expressing dspE (39.34%) and pelD (40.30%) were observed in Chinese cabbage 24 h after inoculation. From promoter activity and real-time quantitative results, the expression of pelD in Ech3937 was demonstrated to be downregulated by HrpL in MM supplemented with PGA.
- Published
- 2006
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- View/download PDF
41. L-selectin and intercellular adhesion molecule-1 regulate the development of Concanavalin A-induced liver injury.
- Author
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Kawasuji A, Hasegawa M, Horikawa M, Fujita T, Matsushita Y, Matsushita T, Fujimoto M, Steeber DA, Tedder TF, Takehara K, and Sato S
- Subjects
- Animals, Chemical and Drug Induced Liver Injury metabolism, Chemical and Drug Induced Liver Injury pathology, Cytokines biosynthesis, Disease Models, Animal, Intercellular Adhesion Molecule-1 biosynthesis, Intercellular Adhesion Molecule-1 genetics, L-Selectin genetics, Leukocytes drug effects, Leukocytes metabolism, Liver drug effects, Mice, Mice, Knockout, RNA, Messenger metabolism, Time Factors, Transforming Growth Factors biosynthesis, Chemical and Drug Induced Liver Injury immunology, Concanavalin A toxicity, Intercellular Adhesion Molecule-1 immunology, L-Selectin immunology, Liver immunology, Liver injuries
- Abstract
Concanavalin A (Con A)-induced hepatitis is a model for human T cell-mediated hepatitis. We evaluated the role of L-selectin and intercellular adhesion molecule-1 (ICAM-1) in this model by injecting Con A intravenously in mice lacking L-selectin (L-selectin-/-), ICAM-1 (ICAM-1-/-), or both (L-selectin/ICAM-1-/-). Blood and liver samples were collected 0, 8, 24, and 48 h after Con A treatment. Increases in plasma transaminase levels, which peaked 8 h after injection, were reduced significantly in L-selectin-/-, ICAM-1-/-, and L-selectin/ICAM-1-/- mice compared with wild-type mice. Liver necrosis was more strongly inhibited in ICAM-1-/- mice than in L-selectin-/- mice but was most prominently reduced in L-selectin/ICAM-1-/- mice, in parallel with decreased plasma transaminase levels. The reduced severity of hepatitis in the mutant mice correlated with decreases in numbers of liver CD4+ T cells but not numbers of CD8+ T cells or neutrophils. Following Con A treatment, L-selectin deficiency reduced liver mRNA expression of tumor necrosis factor-alpha, and ICAM-1 deficiency reduced expression of interleukin-4. By contrast, reductions in liver macrophage inhibitor protein-1alpha mRNA occurred in all mutant mice. These results indicate that L-selectin and ICAM-1 contribute cooperatively to the development of Con A-induced hepatitis by regulating leukocyte infiltration and subsequent cytokine production.
- Published
- 2006
- Full Text
- View/download PDF
42. Neonate-primed CD8+ memory cells rival adult-primed memory cells in antigen-driven expansion and anti-viral protection.
- Author
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Fadel SA, Cowell LG, Cao S, Ozaki DA, Kepler TB, Steeber DA, and Sarzotti M
- Subjects
- Animals, Animals, Newborn, Antibodies, Viral immunology, Antigens, Viral immunology, CD8-Positive T-Lymphocytes virology, Cytotoxicity, Immunologic, Immunity, Cellular, Immunization, Secondary, Interleukin-4 physiology, Leukemia, Experimental immunology, Leukemia, Experimental prevention & control, Mice, Retroviridae Infections immunology, Retroviridae Infections prevention & control, Tumor Virus Infections immunology, Tumor Virus Infections prevention & control, CD8-Positive T-Lymphocytes immunology, Immunologic Memory, Leukemia Virus, Murine immunology
- Abstract
Immunizations early in life, when the host is most susceptible to infection, allow protective immunological memory to develop. Decreasing the dose of Cas-Br-E murine leukemia virus when priming neonatal mice results in adult-like, Type 1 protective responses, but the resulting memory cell populations are smaller than after adult priming. After secondary challenge, virus-specific CD8+ memory cell populations expand twice as much in neonate-primed mice as in adult-primed mice. We found that when equivalent numbers of virus-specific cells were transferred into virus-susceptible mice, protection from disease was similar whether donor, immune mice were primed as neonates or adults, and IL-4 did not alter in vivo virus-specific CD8+ memory cell effector function. Hence, neonate-primed CD8+ cells develop into memory cells that rival adult-primed cells in proliferation and effector function.
- Published
- 2006
- Full Text
- View/download PDF
43. Regulation of local and metastatic host-mediated anti-tumour mechanisms by L-selectin and intercellular adhesion molecule-1.
- Author
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Yamada M, Yanaba K, Hasegawa M, Matsushita Y, Horikawa M, Komura K, Matsushita T, Kawasuji A, Fujita T, Takehara K, Steeber DA, Tedder TF, and Sato S
- Subjects
- Animals, Cell Survival immunology, Cytokines immunology, Cytotoxicity, Immunologic immunology, Immunohistochemistry methods, Killer Cells, Natural immunology, Leukocytes immunology, Lung Neoplasms secondary, Mice, Mice, Inbred Strains, RNA, Messenger immunology, T-Lymphocytes immunology, Tumor Cells, Cultured, Intercellular Adhesion Molecule-1 immunology, L-Selectin immunology, Melanoma, Experimental immunology
- Abstract
Malignant melanoma is often accompanied by a host response of inflammatory cell infiltration that is highly regulated by multiple adhesion molecules. To assess the role of adhesion molecules, including L-selectin and intercellular adhesion molecule-1 (ICAM-1), in this process, subcutaneous primary growth and metastasis to the lung of B16 melanoma cells not expressing L-selectin, ICAM-1 or their ligands were examined in mice lacking L-selectin, ICAM-1 or both. Primary subcutaneous growth of B16 melanoma was augmented by loss of L-selectin, ICAM-1 or both, while pulmonary metastasis was enhanced by the loss of L-selectin or combined loss of L-selectin and ICAM-1. In both situations, the combined loss of L-selectin and ICAM-1 exhibited the greatest effect. This enhancement was associated generally with a reduced accumulation of natural killer (NK) cells, CD4+ T cells and CD8+ T cells and also with a diminished release of interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha but not interleukin (IL)-6. Cytotoxicity against melanoma was not defective by the absence of ICAM-1, L-selectin or both, suggesting that the enhancement of tumour growth and metastasis caused by the loss of adhesion molecules results from an impaired migration of effector cells into the tissue rather than from a suppression of the cytotoxic response. The results indicate that L-selectin and ICAM-1 contribute co-operatively to the anti-tumour reaction by regulating lymphocyte infiltration to the tumour.
- Published
- 2006
- Full Text
- View/download PDF
44. B-1a and B-1b cells exhibit distinct developmental requirements and have unique functional roles in innate and adaptive immunity to S. pneumoniae.
- Author
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Haas KM, Poe JC, Steeber DA, and Tedder TF
- Subjects
- Animals, Antibodies, Bacterial genetics, Cell Differentiation, Immunity, Innate genetics, Immunization, Mice, Mice, Transgenic, Mutation, Pneumococcal Infections prevention & control, Antibodies, Bacterial immunology, Antigens, CD19 genetics, B-Lymphocyte Subsets immunology, Immunity, Innate immunology, Pneumococcal Infections immunology, Polysaccharides, Bacterial immunology, Streptococcus pneumoniae immunology
- Abstract
B-1a and B-1b lymphocytes were found to exhibit specialized roles in providing immunity to Streptococcus pneumoniae and differ dramatically in their developmental requirements. Transgenic mice overexpressing CD19 (hCD19Tg) generated B-1a cells and natural antibodies that provided protection during infection, while CD19-deficient (CD19(-/-)) mice lacked B-1a cells, lacked natural antibodies, and were more susceptible to infection. By contrast, pneumococcal polysaccharide (PPS) immunization protected CD19(-/-) mice during lethal challenge, whereas hCD19Tg mice remained unprotected. This resulted from differences in the B-1b subset: the key population found to produce protective PPS-specific antibody in both wild-type and CD19(-/-) mice. Thus, CD19(-/-) mice generated B-1b cells and protective adaptive PPS-specific antibody responses, whereas hCD19Tg mice lacked B-1b cells and adaptive PPS-specific antibody responses. This reciprocal contribution of B-1a and B-1b subsets to innate and acquired immunity reveals an unexpected division of labor within the B-1 compartment that is normally balanced by their coordinated development.
- Published
- 2005
- Full Text
- View/download PDF
45. A new twist to the leukocyte adhesion cascade: intimate cooperation is key.
- Author
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Steeber DA, Venturi GM, and Tedder TF
- Subjects
- Animals, Cell Adhesion immunology, Humans, Hyaluronan Receptors immunology, Hyaluronan Receptors physiology, Integrin alpha4beta1 immunology, Integrin alpha4beta1 physiology, Leukocytes immunology, Models, Biological, Cell Adhesion physiology, Leukocytes physiology
- Abstract
Leukocyte migration from blood into lymphoid and non-lymphoid tissues requires a highly orchestrated series of adhesive and signaling events. A network of adhesion molecules with overlapping functions mediate the capture, rolling and firm adhesion of leukocytes to the vascular endothelium. A new study adds a novel twist to this paradigm by demonstrating that two adhesion molecules, CD44 and VLA-4, must be physically associated with each other on activated T cells to mediate efficient rolling and firm adhesion.
- Published
- 2005
- Full Text
- View/download PDF
46. Mouse CD20 expression and function.
- Author
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Uchida J, Lee Y, Hasegawa M, Liang Y, Bradney A, Oliver JA, Bowen K, Steeber DA, Haas KM, Poe JC, and Tedder TF
- Subjects
- Animals, B-Lymphocytes cytology, Calcium metabolism, Cell Differentiation immunology, Cell Line, Fluorescent Antibody Technique, Humans, Hybridomas, Immunoglobulin M immunology, Immunoglobulin M metabolism, Lymphocyte Activation immunology, Antibodies, Monoclonal immunology, Antigens, CD20 immunology, Antigens, CD20 metabolism, B-Lymphocytes immunology, Mice immunology, Signal Transduction immunology
- Abstract
CD20 plays a role in human B cell proliferation and is an effective target for immunotherapy. In this study, mouse CD20 expression and biochemistry were assessed for the first time using a new panel of CD20-specific mAb, with CD20 function assessed using CD20-deficient (CD20(-/-)) mice. CD20 expression was B cell restricted and was initiated during late pre-B cell development. The frequency and density of CD20 expression increased during B cell maturation in the bone marrow, with a subpopulation of transitional IgM(hi) B cells expressing higher CD20 levels than the majority of mature recirculating B cells. Transitional T1 B cells in the spleen also expressed high CD20 levels, providing a useful new marker for this B cell subset. In CD20(-/-) mice, immature and mature B cell IgM expression was approximately 20-30% lower relative to B cells from wild-type littermates. In addition, CD19-induced intracellular calcium responses were significantly reduced in CD20(-/-) B cells, with a less dramatic effect on IgM-induced responses. These results reveal a role for CD20 in transmembrane Ca(2+) movement in mouse primary B cells that complements previous results obtained using human CD20 cDNA-transfected cell lines. Otherwise, B cell development, tissue localization, signal transduction, proliferation, T cell-dependent antibody responses and affinity maturation were normal in CD20(-/-) mice. Thus, mouse and human CD20 share similar patterns of expression and function. These studies thereby provide an animal model for studying CD20 function in vivo and the molecular mechanisms that influence anti-CD20 immunotherapy.
- Published
- 2004
- Full Text
- View/download PDF
47. Leukocyte migration is regulated by L-selectin endoproteolytic release.
- Author
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Venturi GM, Tu L, Kadono T, Khan AI, Fujimoto Y, Oshel P, Bock CB, Miller AS, Albrecht RM, Kubes P, Steeber DA, and Tedder TF
- Subjects
- Animals, Gene Targeting, L-Selectin blood, L-Selectin genetics, Mice, Organ Specificity, Cell Movement physiology, Endopeptidases metabolism, L-Selectin metabolism, Leukocytes metabolism
- Abstract
L-selectin mediates lymphocyte migration to peripheral lymph nodes and leukocyte rolling on vascular endothelium during inflammation. One unique feature that distinguishes L-selectin from other adhesion molecules is that it is rapidly cleaved from the cell surface after cellular activation. The biological significance of L-selectin endoproteolytic release was determined by generating gene-targeted mice expressing a modified receptor that was not cleaved from the cell surface. Blocking L-selectin cleavage on antigen-stimulated lymphocytes allowed their continued migration to peripheral lymph nodes and inhibited their short-term redirection to the spleen. Blocking homeostatic L-selectin cleavage also resulted in a constitutive 2-fold increase in overall L-selectin expression by leukocytes. As a result, neutrophils entered the inflamed peritoneum in greater numbers or for a longer duration. Thus, endoproteolytic cleavage regulates both homeostatic and activation-induced changes in cell surface L-selectin density, which directs the migration patterns of activated lymphocytes and neutrophils in vivo.
- Published
- 2003
- Full Text
- View/download PDF
48. Ultraviolet light exposure suppresses contact hypersensitivity by abrogating endothelial intercellular adhesion molecule-1 up-regulation at the elicitation site.
- Author
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Komura K, Hasegawa M, Hamaguchi Y, Saito E, Kaburagi Y, Yanaba K, Kawara S, Takehara K, Seki M, Steeber DA, Tedder TF, and Sato S
- Subjects
- Animals, Antibodies, Monoclonal administration & dosage, Cytotoxicity, Immunologic genetics, Cytotoxicity, Immunologic radiation effects, Dermatitis, Contact immunology, Endothelium, Vascular immunology, Endothelium, Vascular metabolism, Endothelium, Vascular radiation effects, Immunosuppression Therapy, Injections, Intradermal, Intercellular Adhesion Molecule-1 genetics, Intercellular Adhesion Molecule-1 physiology, Intercellular Adhesion Molecule-1 radiation effects, Interleukin-10 immunology, Light, Mice, Mice, Inbred C57BL, Mice, Knockout, Skin immunology, Skin metabolism, Spleen cytology, Spleen immunology, Spleen radiation effects, Spleen transplantation, T-Lymphocytes, Regulatory immunology, T-Lymphocytes, Regulatory metabolism, T-Lymphocytes, Regulatory radiation effects, Tumor Necrosis Factor-alpha administration & dosage, Up-Regulation genetics, Up-Regulation immunology, Dermatitis, Contact metabolism, Dermatitis, Contact prevention & control, Intercellular Adhesion Molecule-1 biosynthesis, Skin radiation effects, Ultraviolet Rays, Up-Regulation radiation effects
- Abstract
Hapten sensitization through UV-exposed skin induces systemic immune suppression, which is experimentally demonstrated by inhibition of contact hypersensitivity (CHS). Although this UV-induced effect has been shown to be mediated by inhibition of the afferent phase of the CHS, the UV effects on the efferent (elicitation) phase remain unknown. In this study, UV effects on endothelial ICAM-1 expression at elicitation sites were first examined. Mice were sensitized by hapten application onto UV-exposed back skin, and ears were challenged 5 days later. ICAM-1 up-regulation at nonirradiated elicitation sites following hapten challenge was eliminated by UV exposure on sensitization sites distant from elicitation sites. To assess whether loss of the ICAM-1 up-regulation at elicitation sites contributed to UV-induced immunosuppression, we examined CHS responses in UV-exposed ICAM-1-deficient (ICAM-1(-/-)) mice that genetically lacked the ICAM-1 up-regulation. ICAM-1(-/-) mice exhibited reduced CHS responses without UV exposure, but UV exposure did not further reduce CHS responses in ICAM-1(-/-) mice. Furthermore, ICAM-1 deficiency did not affect the afferent limb, because ICAM-1(-/-) mice had normal generation of hapten-specific suppressor and effector T cells. This UV-induced immunosuppression was associated with a lack of TNF-alpha production after Ag challenge at elicitation sites. Local TNF-alpha injection before elicitation abrogated the UV-induced CHS inhibition with increased endothelial ICAM-1 expression. TNF-alpha production at elicitation sites was down-regulated by IL-10, a possible mediator produced by hapten-specific suppressor T cells that are generated by UV exposure. These results indicate that UV exposure inhibits CHS by abrogating up-regulation of endothelial ICAM-1 expression after Ag challenge at elicitation sites.
- Published
- 2003
- Full Text
- View/download PDF
49. Relative contributions of selectins and intercellular adhesion molecule-1 to tissue injury induced by immune complex deposition.
- Author
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Yanaba K, Kaburagi Y, Takehara K, Steeber DA, Tedder TF, and Sato S
- Subjects
- Animals, Arthus Reaction genetics, Arthus Reaction pathology, Arthus Reaction physiopathology, Cell Adhesion Molecules physiology, E-Selectin genetics, Edema genetics, Edema pathology, Edema physiopathology, Hemorrhage genetics, Hemorrhage pathology, Hemorrhage physiopathology, Inflammation pathology, Inflammation physiopathology, Intercellular Adhesion Molecule-1 genetics, Mice, Mice, Knockout, P-Selectin genetics, E-Selectin physiology, Immune Complex Diseases pathology, Intercellular Adhesion Molecule-1 physiology, P-Selectin physiology, Selectins physiology
- Abstract
Immune complex-induced tissue injury is mediated by inflammatory cell infiltration that is highly regulated by multiple adhesion molecules. To assess the relative contribution of adhesion molecules, including selectins and ICAM-1, in this pathogenetic process, the cutaneous passive Arthus reaction was examined in mice lacking E-selectin, P-selectin, or both L-selectin and ICAM-1 with anti-P- or E-selectin mAbs. Edema and hemorrhage were significantly reduced in P-selectin(-/-) mice compared with wild-type mice while they were not inhibited in E-selectin(-/-) mice. Combined E- and P-selectin blockade resulted in more significant reduction relative to L-selectin/ICAM-1(-/-) as well as P-selectin(-/-) mice. Remarkably, both E- and P-selectin blockade in L-selectin/ICAM-1(-/-) mice completely abrogated edema and hemorrhage. The inhibited edema and hemorrhage paralleled reduced infiltration of neutrophils and mast cells that expressed significant levels of P-selectin glycoprotein ligand-1. Similarly reduced infiltration of neutrophils and mast cells was observed in the peritoneal Arthus reaction and was associated partly with the decreased production of tumor necrosis factor-alpha and interleukin-6. The results of this study indicate that both endothelial selectins contribute predominantly to the Arthus reaction by regulating mast cell and neutrophil infiltration and that the full development of the Arthus reaction is mediated cooperatively by all selectins and ICAM-1.
- Published
- 2003
- Full Text
- View/download PDF
50. L-selectin or ICAM-1 deficiency reduces an immediate-type hypersensitivity response by preventing mast cell recruitment in repeated elicitation of contact hypersensitivity.
- Author
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Shimada Y, Hasegawa M, Kaburagi Y, Hamaguchi Y, Komura K, Saito E, Takehara K, Steeber DA, Tedder TF, and Sato S
- Subjects
- Administration, Cutaneous, Animals, Antibodies, Monoclonal administration & dosage, Antigens administration & dosage, Antigens immunology, Cell Migration Inhibition, Cell Movement genetics, Dermatitis, Contact blood, Dermatitis, Contact genetics, Dermatitis, Contact pathology, Down-Regulation immunology, Edema genetics, Edema immunology, Edema prevention & control, Hypersensitivity, Immediate blood, Hypersensitivity, Immediate pathology, Immunoglobulin E blood, Injections, Intravenous, Intercellular Adhesion Molecule-1 biosynthesis, Intercellular Adhesion Molecule-1 immunology, Intercellular Adhesion Molecule-1 physiology, L-Selectin blood, L-Selectin immunology, L-Selectin physiology, Mast Cells pathology, Mice, Mice, Inbred C57BL, Mice, Knockout, Oxazolone administration & dosage, Oxazolone immunology, Cell Movement immunology, Dermatitis, Contact immunology, Down-Regulation genetics, Hypersensitivity, Immediate genetics, Hypersensitivity, Immediate prevention & control, Intercellular Adhesion Molecule-1 genetics, L-Selectin genetics, Mast Cells immunology
- Abstract
Repeated Ag exposure results in a shift in the time course of contact hypersensitivity (CH) from a typical delayed-type to an immediate-type response followed by a late phase reaction. Chronic CH responses are clinically relevant to human skin allergic diseases, such as atopic dermatitis, that are usually caused by repeated stimulation with environmental Ags. Chronic inflammatory responses result in part from infiltrating leukocytes. To determine the role of leukocyte adhesion molecules in chronic inflammation, chronic CH responses were assessed in mice lacking L-selectin, ICAM-1, or both adhesion molecules. Following repeated hapten sensitization for 24 days at 2-day intervals, wild-type littermates developed an immediate-type response at 30 min after elicitation, followed by a late phase reaction. By contrast, loss of ICAM-1, L-selectin, or both, eliminated the immediate-type response and inhibited the late phase reaction. Similar results were obtained when wild-type littermates repeatedly exposed to hapten for 22 days were treated with mAbs to L-selectin and/or ICAM-1 before the elicitation on day 24. The lack of an immediate-type response on day 24 paralleled a lack of mast cell accumulation after 30 min of elicitation and decreased serum IgE production. Repeated Ag exposure in wild-type littermates resulted in increased levels of serum L-selectin, a finding also observed in atopic dermatitis patients. The current study demonstrates that L-selectin and ICAM-1 cooperatively regulate the induction of the immediate-type response by mediating mast cell accumulation into inflammatory sites and suggests that L-selectin and ICAM-1 are potential therapeutic targets for regulating human allergic reactions.
- Published
- 2003
- Full Text
- View/download PDF
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