1,351 results
Search Results
252. Analysis of an HIV Model with Immune Responses and Cell-to-Cell Transmission.
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Guo, Ting, Qiu, Zhipeng, and Rong, Libin
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IMMUNE response , *HIV infections , *VIRAL load , *CYTOTOXIC T cells , *DYNAMICAL systems , *T cells , *VIRAL antibodies - Abstract
In this paper, a mathematical model is formulated to investigate the dynamics of HIV infection. The model incorporates two routes of infection (namely cell-to-cell transmission and virus-to-cell infection), two types of adaptive immune responses (i.e., cellular and antibody immune response) and two intracellular delays (viz., the eclipse phase and virus production period). By constructing Lyapunov functionals, we show that the global dynamics of the model can be explicitly determined by five reproduction numbers. Using the uncertainty and sensitivity analyses, we obtain the mean values and standard deviation of the five reproduction numbers and find that the reproduction numbers are most sensitive to the death rate of infected cells, viral clearance rate and immune parameters. We further compare four related HIV models and show that cell-to-cell transmission, immune responses and time delays can substantially affect the dynamical behavior of the system. Specifically, cell-to-cell transmission increases the concentration of infected cells. Inclusion of cytotoxic T lymphocyte and virus production delay can significantly reduce the viral load and infected cell concentration, and generate a higher level of uninfected CD4+ T cells. The analytical and numerical results may help to improve the understanding of HIV dynamics. [ABSTRACT FROM AUTHOR]
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- 2020
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253. Validation of simple prediction algorithms to consistently achieve CD3+ and postselection CD34+ targets with leukapheresis.
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Yoon, Edward J., Zhang, Jiahao, Weinberg, Rona S., Brochstein, Joel A., Nandi, Vijay, Sachais, Bruce S., and Shi, Patricia A.
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STANDARD deviations , *T cells , *PROGENITOR cells , *LEUKAPHERESIS , *HEMATOPOIETIC stem cells , *ALGORITHMS , *ANTIGENS - Abstract
Background: Cellular therapies using engineered T cells, haploidentical transplants, and autologous gene therapy are increasing. Specified CD3+ or high CD34+ doses are typically required for subsequent manufacturing, manipulation, or CD34+ selection. Simple, practical, and reliable lymphocyte and hematopoietic progenitor cell (HPC) collection algorithms accounting for subsequent CD34+ selection have not been published.Study Design and Methods: In this analysis of 15 haploidentical donors undergoing tandem lymphocyte and HPC collections, we validated one-step, practical prediction algorithms (Appendix S1, available as supporting information in the online version of this paper) that use conservative facility-specific collection efficiencies, CD34+ selection efficiency, and donor-specific peripheral counts to reliably achieve the target CD3+ and CD34+ product doses. These algorithms expand on our previously published work regarding predictive HPC collection algorithms.Results: Ninety-three percent of lymphocyte and 93% of CD34+ collections achieved the final target CD3+ and CD34+ product dose when our algorithm-calculated process volumes were used. Linear regression analysis of our algorithms for CD3+, preselection CD34+, and postselection CD34+ showed statistically significant models with R2 of 0.80 (root mean square error [RMSE], 31.3), 0.72 (RMSE, 385.7), and 0.56 (RMSE, 326.0), respectively, all with p values less than 0.001.Conclusion: Because achievement of CD3+ or CD34+ dose targets may be critical for safety and efficacy of cell therapies, these simple, practical, and reliable prediction algorithms for lymphocyte and HPC collections should be very useful for collection facilities. [ABSTRACT FROM AUTHOR]- Published
- 2020
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254. Identification of the best‐suited donor for generating virus‐specific T cells.
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Tasnády, Szabolcs, Karászi, Éva, Szederjesi, Attila, Bihari, György, Juhász, Zsófia, Hardi, Apor, Kriván, Gergely, Kállay, Krisztián, Reményi, Péter, Sinkó, János, Mikala, Gábor, Réti, Marienn, and Masszi, Tamás
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T cells , *LEUKAPHERESIS , *CELL separation , *MAGNETIC separation , *LEWIS basicity , *FLOW cytometry - Abstract
Background and objectives: Administration of virus‐specific T cells (VSTs) is a viable antiviral treatment strategy after allogeneic HSCT, even if conventional therapies fail. Third‐party donors are often chosen for the generation of the VST product. The eligibility of the donor has to be tested in a rigorous donor screening procedure, since the isolation technology only targets pre‐existing VSTs. Materials and methods: In a period of 3 years, we performed 32 VST treatments for 28 patients. Targeting four different viruses, 284 healthy individuals underwent 417 donor screening procedures. VSTs were counted by flow cytometry detecting interferon‐gamma (IFN‐γ) producing T cells. Generation of the VSTs was performed from leukapheresis products in a fully automated and closed system using magnetic cell separation. Results: The mean circulating VST frequencies ranged from 0·006% to 0·328%. The average yield of viable VSTs in the product was 1·83·106 cells, while the average VST dose calculated for the patient's body weight was 4·63·104/kg. The mean purity – percentage of VSTs within the T cells – of all T‐cell products was 62·9%. Correlation was identified between the frequency of the VSTs in the peripheral blood of the donor and the VST numbers of the end product; the strongest correlation was seen for CMV. Conclusion: This paper focuses on the T‐cell donors, highlighting some key points on the donor selection process. Based on the findings in connection with the CMV therapies, peripheral VST seems to be the best predictor of the VST content of the final product administered to the patient. [ABSTRACT FROM AUTHOR]
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- 2020
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255. Discovery of hPRDX5-based peptide inhibitors blocking PD-1/PD-L1 interaction through in silico proteolysis and rational design.
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Zou, Sen, Liu, Juanjuan, Sun, Zhengyang, Feng, Xiao, Wang, Zhongbo, Jin, Yuanyuan, and Yang, Zhaoyong
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PROTEOLYSIS , *PEPTIDOMIMETICS , *RECOMBINANT proteins , *MORPHOGENESIS , *T cells , *PROGRAMMED cell death 1 receptors , *TUMOR growth , *MACROMOLECULAR dynamics - Abstract
Purpose: The human peroxiredoxin-5 (hPRDX5) is a member of the family of antioxidant enzymes, which could resist immunosuppression by promoting immune organs development, lymphocyte proliferation and up-regulation of the levels of serum cytokines. However, being a recombinant protein, the hPRDX5 exhibits some problems including the high production cost and bad tissue penetration. Compared to macromolecular therapeutic agents, synthetic peptides have several advantages as drug candidates, such as lower manufacturing costs, reduced immunogenicity, and better organ or tumor penetration. The purpose of this research was to design the novel peptides come from hPRDX5 that can block the interaction of PD-1 and PD-L1.Methods: Herein in this work, we firstly confirmed the inhibitory activity of hPRDX5 on the binding of PD-L1 to PD-1 based on the previous observation, subsequently, in silico proteolysis and rational design (such as alanine scanning mutagenesis and truncation) were used to automate the design of new peptides derived from hPRDX5 with anti-tumour activity.Results: We found that the most potent peptide could block the PD-1/PD-L1 interaction effectively with an IC50 of 0.646 μM, and could restore the function of Jurkat T cells which had been suppressed by stimulated HCT116 cells. Moreover, experiments with tumor-bearing mice models showed that the peptide IMB-P6-10 could effectively inhibit tumor growth and showed extraordinary low acute toxicity in vivo.Conclusions: The peptides described in this paper may provide novel low-molecular-weight drug candidates for cancer immunotherapy. [ABSTRACT FROM AUTHOR]- Published
- 2020
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256. Development of CAR-T cell therapy for B-ALL using a point-of-care approach.
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de Macedo Abdo, Luiza, Barros, Luciana Rodrigues Carvalho, Saldanha Viegas, Mariana, Vieira Codeço Marques, Luisa, de Sousa Ferreira, Priscila, Chicaybam, Leonardo, and Bonamino, Martín Hernán
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CELLULAR therapy , *GENETIC vectors , *T cells , *ELECTROPORATION , *LOW-income countries , *MANUFACTURING cells , *MAXILLARY expansion - Abstract
Recently approved by the FDA and European Medicines Agency, CAR-T cell therapy is a new treatment option for B-cell malignancies. Currently, CAR-T cells are manufactured in centralized facilities and face bottlenecks like complex scaling up, high costs, and logistic operations. These difficulties are mainly related to the use of viral vectors and the requirement to expand CAR-T cells to reach the therapeutic dose. In this paper, by using Sleeping Beauty-mediated genetic modification delivered by electroporation, we show that CAR-T cells can be generated and used without the need for ex vivo activation and expansion, consistent with a point-of-care (POC) approach. Our results show that minimally manipulated CAR-T cells are effective in vivo against RS4;11 leukemia cells engrafted in NSG mice even when inoculated after only 4 h of gene transfer. In an effort to better characterize the infused CAR-T cells, we show that 19BBz T lymphocytes infused after 24 h of electroporation (where CAR expression is already detectable) can improve the overall survival and reduce tumor burden in organs of mice engrafted with RS4;11 or Nalm-6 B cell leukemia. A side-by-side comparison of POC approach with a conventional 8-day expansion protocol using Transact beads demonstrated that both approaches have equivalent antitumor activity in vivo. Our data suggest that POC approach is a viable alternative for the generation and use of CAR-T cells, overcoming the limitations of current manufacturing protocols. Its use has the potential to expand CAR immunotherapy to a higher number of patients, especially in the context of low-income countries. [ABSTRACT FROM AUTHOR]
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- 2020
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257. Genetic instability as a driver for immune surveillance.
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Aguadé-Gorgorió, Guim and Solé, Ricard
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GENETIC load , *IMMUNE recognition , *CANCER prognosis , *KNOCKOUT mice , *T cells , *DISEASE eradication , *HUMAN carcinogenesis , *HUMAN activity recognition - Abstract
*: BackgroundGenetic instability is known to relate with carcinogenesis by providing tumors with a mechanism for fast adaptation. However, mounting evidence also indicates causal relation between genetic instability and improved cancer prognosis resulting from efficient immune response. Highly unstable tumors seem to accumulate mutational burdens that result in dynamical landscapes of neoantigen production, eventually inducing acute immune recognition. How are tumor instability and enhanced immune response related? An important step towards future developments involving combined therapies would benefit from unraveling this connection. *: MethodsIn this paper we present a minimal mathematical model to describe the ecological interactions that couple tumor adaptation and immune recognition while making use of available experimental estimates of relevant parameters. The possible evolutionary trade-offs associated to both cancer replication and T cell response are analysed, and the roles of mutational load and immune activation in governing prognosis are studied. *: ResultsModeling and available data indicate that cancer-clearance states become attainable when both mutational load and immune migration are enhanced. Furthermore, the model predicts the presence of well-defined transitions towards tumor control and eradication after increases in genetic instability numerically consistent with recent experiments of tumor control after Mismatch Repair knockout in mice. *: ConclusionsThese two main results indicate a potential role of genetic instability as a driver of transitions towards immune control of tumors, as well as the effectiveness of increasing mutational loads prior to adoptive cell therapies. This mathematical framework is therefore a quantitative step towards predicting the outcomes of combined therapies where genetic instability might play a key role. [ABSTRACT FROM AUTHOR]
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- 2019
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258. Transgenerational transfer of gene-modified T cells.
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Cosgrove, Cormac, Dellacecca, Emilia R., van den Berg, Joost H., Haanen, John B., Nishimura, Michael I., Le Poole, I. Caroline, and Bergmans, Hans E. N.
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T cells , *ANKYLOGLOSSIA , *B cell lymphoma , *PREGNANT women , *CO-sleeping , *CELL morphology , *IMMUNOLOGIC memory , *TRANSFER of training - Abstract
Tumor immunotherapy using gene-modified T cells has already met with considerable success in the treatment of metastatic melanoma and B cell lymphoma. With improving patient prognoses, new questions arise. In particular, the long-term consequences of treatment among individuals of childbearing age could now be considered. Former patients can carry a cohort of transgenic memory T cells long after treatment has ceased and the effector T cell population has contracted. When patients become parents well after treatment is completed, expectant mothers may still pass transgenic T cells to their unborn children. Consequences should be more measurable if the mother also breastfeeds the baby. Maternal T cells may shape immune responses in the child, can tolerize the child to maternal antigens, and might cause either beneficial or adverse effects in the offspring. The hypothesis put forth is that transgenic T cells transferred from mother to child during and after pregnancy might have consequences that have not been adequately considered to date. Depending on the targeted antigen and the MHC eventually required to present it, such transfer may be beneficial, uneventful or even damaging. Such potential consequences are addressed in this paper. The transgenic T cells might form a pocket of memory T cells in secondary lymphoid organs of the child, expand upon antigen stimulation, and react. However, simple measures might be devised to avoid any reason for concern. These considerations provide ample incentive to probe transgenerational transfer of transgenic T cells. [ABSTRACT FROM AUTHOR]
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- 2019
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259. IL16 deficiency enhances Th1 and cytotoxic T lymphocyte response against influenza A virus infection.
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Ran Jia, Shuai Liu, Jin Xu, and Xiaozhen Liang
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VIRUS diseases , *CYTOTOXIC T cells , *INFLUENZA A virus , *DENDRITIC cells , *T cells , *CELL physiology , *MAJOR histocompatibility complex - Abstract
Influenza A virus (IAV) is the major cause of seasonal epidemics and flu outbreaks worldwide. Given that interleukin 16 (IL16) can regulate T cell function and is one of the signature markers for virus infection including IAV infection, the impact of IL16 on IAVinduced T cell immune response hasn't been elucidated yet. In this paper, we infected wild type and IL16 knockout (KO) mice with IAV and analyzed the immunity of mice by flow cytometry. We observed an increase in the percentage of T helper (Th) 1 cells in the spleens of IL16 KO mice and elevation of IFN-α and TNF-α secretion from CD8+ T cells in the lungs and spleens of IL16 KO mice in response to IAV infection. Moreover, the expression of major histocompatibility complex II which represents the maturation of dendritic cells (DCs) was upregulated in the lungs of IL16 KO mice. Taken together, our study suggests that IL16 deficiency enhanced Th1 and cytotoxic T lymphocyte response as well as DC maturation upon IAV infection, which provides new insight into the host regulation of T cell immune responses during IAV infection. [ABSTRACT FROM AUTHOR]
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- 2019
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260. How does polyunsaturated fatty acid biosynthesis regulate T‐lymphocyte function?
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Fielding, B. A., Calder, P. C., Irvine, N. A., Miles, E. A., Lillycrop, K. A., von Gerichten, J., and Burdge, G. C.
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T cells , *AGING , *GENES , *IMMUNITY , *INGESTION , *ISOTOPES , *LEUCOCYTES , *UNSATURATED fatty acids , *EICOSANOIDS , *LINOLEIC acid , *EPIGENOMICS , *PHYSIOLOGY - Abstract
Impaired regulation of immune function characterised by chronic inflammation together with a declining protective immune response is a major challenge to healthy ageing. It is therefore important to understand the mechanisms that regulate immune function and the impact of ageing upon such processes. Appropriate induction and resolution of the immune response require adequate availability of polyunsaturated fatty acids (PUFAs) for incorporation into cell membranes. However, humans are unable to synthesise PUFAs de novo and are dependent upon dietary intake for pre‐formed PUFAs or synthesis by the liver from the essential fatty acids, linoleic acid (LA, 18:2n‐6) and alpha‐linolenic acid (aLNA, 18:3n‐3). We have shown that activation of peripheral blood mononuclear cells increases PUFA biosynthesis from essential fatty acids via a mechanism that involves altered epigenetic regulation of a key gene in the pathway. Moreover, induction of PUFA synthesis is directly involved in the regulation of lymphocyte activation and proliferation. The aim of the Biotechnology and Biological Sciences Research Council responsive mode award described in this paper, 'How does polyunsaturated fatty acid biosynthesis regulate T‐lymphocyte function?', is to determine how PUFA biosynthesis regulates T‐cell function and the effect of ageing on this process. The project will identify points of regulation in the biosynthetic pathway and how these might influence the capacity for up‐regulation of PUFA synthesis in older individuals. We will use stable isotope tracers of LA and aLNA to determine whether newly synthesised PUFAs are preferential substrates for synthesis of lipid mediators and whether they are involved in formation of membrane microdomains that mediate cell signalling. [ABSTRACT FROM AUTHOR]
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- 2019
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261. Nonsteroidal anti-inflammatory drugs-induced hypersensitivity reactions: algorithm for the diagnostic and management.
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Vicovan, Andrei Gheorghe, Veres, Liliana, Cucu, Andrei, Turliuc, Dana, and Ghiciuc, Cristina Mihaela
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NEUROSURGEONS , *ALLERGIES , *DRUG side effects , *DRUG allergy , *PAIN management , *T cells , *RADICULOPATHY - Abstract
The role of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in neurosurgical practice is a secondary one, however they are still constantly involved in perioperative management of pain or in nonoperative management of acute radiculopathy. Beside the well-known adverse reactions (ADRs), the neurosurgeon practitioner should also take in account the drug hypersensitivity reactions (DHRs) of NSAIDs and be able to deal with it. The aim of this paper was to review the diagnostic and management steps for NSAIDs-induced Hypersensitivity Reactions. The actual stratification of NSAIDs-induced Hypersensitivity Reactions is based on understanding of the heterogeneity of immunological/non-immunological mechanisms of reactions and complexity of clinical manifestations. Practically, this stratification allows the physician to assess suspicion of DHR, based on anamnesis and clinical analysis, and to consider further practical steps to manage and eventually confirm the diagnosis. Drug allergies are considered only the DHRs for which a definite immunological mechanism (either drug-specific antibody or T cell) is demonstrated. In conclusion, clinical analysis and anamnesis of patient with NSAIDs-induced Hypersensitivity Reactions can be realized by any physician and could be enough to diagnose, but it is not sufficient to confirm the diagnosis. In vitro tests and oral provocation challenges may be necessary to be undertaken by an allergy specialist. [ABSTRACT FROM AUTHOR]
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- 2019
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262. Altered thymic CD4+ T-cell recovery after allogeneic hematopoietic stem cell transplantation is critical for nocardiosis.
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Roussel, Xavier, Daguindau, Etienne, Berceanu, Ana, Desbrosses, Yohan, Saas, Philippe, Ferrand, Christophe, Seilles, Estelle, Pouthier, Fabienne, Deconinck, Eric, and Larosa, Fabrice
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HEMATOPOIETIC stem cell transplantation , *KILLER cells , *ALEMTUZUMAB , *ANTIBIOTIC prophylaxis , *NOCARDIOSIS , *T cells , *CELLULAR immunity - Abstract
Nocardia affects immunocompromised human host exhibiting an altered cell-mediated immunity. Infectious risk after allogeneic hematopoietic cell transplantation (AHCT) is significantly correlated to the recovery status of donor-derived immune system, especially CD4+ T-cells reconstitution and thymopoiesis. The purpose of this paper is to highlight a lack of cell-mediated immunity recovery for patients presenting a nocardiosis compared to a control cohort. This is a case control retrospective monocentric study. We retrospectively analyzed a monocentric cohort of 15 cases of nocardiosis after AHCT and we explored the degree of patients' immunosuppression by phenotyping circulating lymphoid subpopulations, including NK cells, CD8+ T-cells, CD4+ T-cells and CD19+ B-cells. We focused on CD4+ T-cell subsets to appreciate thymic output, especially on naive CD4+ T-cells (NTE, CD45RA+/RO− CD4+ T-cells) and recent thymic emigrants (RTE, CD4+CD45RA+/RO−/CD31+). Infected patients were paired with a control cohort of patients with identical transplantation characteristics screened on hematological disease, AHCT conditioning, primary graft- versus -host disease (GHVD) prophylaxis, graft type, sex, age, and season at the AHCT and data concerning immunological reconstitution were compared. At onset of nocardiosis, circulating lymphocytes and CD4+ T-cells means count were respectively 730/μL and 162/μL. CD8+ T-cells, CD56+ NK cells and CD19+ B-cells means count were respectively 362/μL, 160/μL, 112/μL. CD4+ T-cells subpopulations, naïve CD4+ T-cells production was impaired with NTE and RTE means count at 26/μL and 11/μL respectively. Comparison between nocardiosis cohort and control cohort over time highlight significant lower cellular count for lymphocytes, CD4+ T-cells, NTE and RTE with p = 0.001, p < 0.001, p < 0.001, p < 0.001 respectively. Immune recovery monitoring follow-up after AHCT is of particular importance to identify patients susceptible to develop Nocardiosis. Efficient microbiological investigations toward Nocardia such PCR should be used in case of compatible clinical presentation. [ABSTRACT FROM AUTHOR]
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- 2019
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263. Evaluation of alloreactive T cells based on the degree of MHC incompatibility using flow cytometric mixed lymphocyte reaction assay in dogs.
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Miyamae, Jiro, Yagi, Hayato, Sato, Keita, Okano, Masaharu, Nishiya, Kohei, Katakura, Fumihiko, Sakai, Manabu, Nakayama, Tomohiro, Moritomo, Tadaaki, and Shiina, Takashi
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T cells , *LYMPHOCYTES , *MAJOR histocompatibility complex , *STEM cells , *GRAFT rejection , *BLOOD group incompatibility , *DOG diseases - Abstract
It has become anticipated that regenerative medicine will extend into the field of veterinary medicine as new treatments for various disorders. Although the use of allogeneic stem cells for tissue regeneration is more attractive than that of autologous cells in emergencies, the therapeutic potential of allogeneic transplantation is often limited by allo-immune responses inducing graft rejection. Therefore, a methodology for quantifying and monitoring alloreactive T cells is necessary for evaluating allo-immune responses. The mixed lymphocyte reaction (MLR) is widely used to evaluate T cell alloreactivity. In human, flow cytometric MLR with carboxyfluorescein diacetate succinimidyl ester has been established and used as a more useful assay than conventional MLR with radioisotope labeling. However, the available information about alloreactivity based on the differences of dog major histocompatibility complex (MHC) (dog leukocyte antigen, DLA) is quite limited in dog. In this paper, we describe our established flow cytometric MLR method that can quantify the T cell alloreactivity while distinguishing cell phenotypes in dog, and T cell alloreactivity among DLA-type matched pairs was significantly lower than DLA-mismatched pairs, suggesting that our developed flow cytometric MLR method is useful for quantifying T cell alloreactivity. In addition, we demonstrated the advantage of DLA homozygous cells as a donor (stimulator) for allogeneic transplantation. We also elucidated that the frequency of alloreactive T cell precursors was almost the same as that of mouse and human (1–10%). To our knowledge, this is the first report to focus on the degree of allo-immune responses in dog based on the differences of DLA polymorphisms. [ABSTRACT FROM AUTHOR]
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- 2019
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264. Cross-presentation of Exogenous Antigens.
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Li, B. and Hu, L.
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CYTOTOXIC T cells , *ANTIGEN presenting cells , *CHEMOKINE receptors , *T cells , *MAJOR histocompatibility complex - Abstract
Presentation of exogenous antigens loaded on major histocompatibility complex class I molecules by antigen presenting cells, termed cross-presentation, is essential for the induction of CD8+ T cells and is performed mainly by specialized dendritic cell subsets. Research into this field has described two main mechanisms of cross-presentation, the cytosolic pathway and the vacuolar pathway. As the first step in cross-presentation, surface receptors relating to cross-presentation are required in the recognition and uptake of Ags, which include C-type lectin receptors, immunoglobulin γ Fc region receptor, chemokine receptor, scavenger receptor etc. After uptake by the cells, there are also many molecules that enable Ags to participate in cross-presentation pathways. By this approach, exogenous Ags can induce CD8+ T cells into cytotoxic T lymphocytes, which is of great significance to induce antitumor and antiviral immune responses, and the molecular mechanism would facilitate the development of related adjuvants. However, the detailed mechanisms of cross-presentation still remain unknown. In this paper, some latest researches, including two major pathways, DC surface receptors and application prospects are summarized. [ABSTRACT FROM AUTHOR]
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- 2019
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265. A simulation of the random and directed motion of dendritic cells in chemokine fields.
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Parr, Avery, Anderson, Nicholas R., and Hammer, Daniel A.
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DENDRITIC cells , *CHEMOTAXIS , *CHEMOKINE receptors , *CELL receptors , *ANTIGEN presenting cells , *T cells , *MOTION - Abstract
Dendritic cells (DCs) are the most effective professional antigen-presenting cell. They ferry antigen from the extremities to T cells and are essential for the initiation of an adaptive immune response. Despite interest in how DCs respond to chemical stimuli, there have been few attempts to model DC migration. In this paper, we simulate the motility of DCs by modeling the generation of forces by filopodia and a force balance on the cell. The direction of fliopodial extension is coupled to differential occupancy of cognate chemokine receptors across the cell. Our model simulates chemokinesis and chemotaxis in a variety of chemical and mechanical environments. Simulated DCs undergoing chemokinesis were measured to have a speed of 5.1 ± 0.07 μm·min-1 and a persistence time of 3.2 ± 0.46 min, consistent with experiment. Cells undergoing chemotaxis exhibited a stronger chemotactic response when exposed to lower average chemokine concentrations, also consistent with experiment. We predicted that when placed in two opposing gradients, cells will cluster in a line, which we call the “line of equistimulation;” this clustering has also been observed. We calculated the effect of varying gradient steepness on the line of equistimulation, with steeper gradients resulting in tighter clustering. Moreover, gradients are found to be most potent when cells are in a gradient of chemokine whose mean concentration is close to the binding of the Kd to the receptor, and least potent when the mean concentration is 0.1Kd. Comparing our simulations to experiment, we can give a quantitative measure of the strength of certain chemokines relative to others. Assigning the signal of CCL19 binding CCR7 a baseline strength of 1, we found CCL21 binding CCR7 had a strength of 0.28, and CXCL12 binding CXCR4 had a strength of 0.30. These differences emerge despite both chemokines having virtually the same Kd, suggesting a mechanism of signal amplification in DCs requiring further study. [ABSTRACT FROM AUTHOR]
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- 2019
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266. Variability aware FinFET SRAM cell with improved stability and power for low power applications.
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Birla, Shilpi
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STATIC random access memory , *MICROPROCESSORS , *THRESHOLD voltage , *CELL anatomy , *SOCIAL impact , *T cells - Abstract
Purpose: Major area of a die is consumed in memory components. Almost 60-70% of chip area is being consumed by "Memory Circuits". The dominant memory in this market is SRAM, even though the SRAM size is larger than embedded DRAM, as SRAM does not have yield issues and the cost is not high as compared to DRAM. At the same time, the other attractive feature for the SRAM is speed, and it can be used for low power applications. CMOS SRAM is the crucial component in microprocessor chips and applications, and as the said major portion of the area is dedicated to SRAM arrays, CMOS SRAM is considered to be the stack holders in the memory market. Because of the scaling feature of CMOS, SRAM had its hold in the market over the past few decades. In recent years, the limitations of the CMOS scaling have raised so many issues like short channel effects, threshold voltage variations. The increased thrust for alternative devices leads to FinFET. FinFET is emerging as one of the suitable alternatives for CMOS and in the region of memory circuits. Design/methodology/approach: In this paper, a new 11 T SRAM cell using FinFET technology has been proposed, the basic component of the cell is the 6 T SRAM cell with 4 NMOS access transistors to improve the stability and also makes it a dual port memory cell. The proposed cell uses a header scheme in which one extra PMOS transistor is used which is biased at different voltages to improve the read and write stability thus, helps in reducing the leakage power and active power. Findings: The cell shows improvement in RSNM (read static noise margin) with LP8T by 2.39× at sub-threshold voltage 2.68× with D6T SRAM cell, 5.5× with TG8T. The WSNM (write static noise margin) and HM (hold margin) of the SRAM cell at 0.9 V is 306 mV and 384 mV. It shows improvement at sub-threshold operation also. The leakage power is reduced by 0.125× with LP8T, 0.022× with D6T SRAM cell, TG8T and SE8T. The impact of process variation on cell stability is also discussed. Research limitations/implications: The FinFet has been used in place of CMOS even though the FinFet has been not been a matured technology; therefore, pdk files have been used. Practical implications: SRAM cell has been designed which has good stability and reduced leakage by which we can make an array and which can be used as SRAM array. Social implications: The cell can be used for SRAM memory for low power consumptions. Originality/value: The work has been done by implementing various leakage techniques to design a stable and improved SRAM cell. The advantage of this work is that the cell has been working for low voltage without degrading the stability factor. [ABSTRACT FROM AUTHOR]
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- 2019
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267. Dynamical analysis of tumor-immune-help T cells system.
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Li, Huixia, Wang, Shaoli, and Xu, Fei
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T helper cells , *TUMOR antigens , *HOPF bifurcations , *MATHEMATICAL analysis , *T cells - Abstract
In this paper, we construct a mathematical model to investigate the interaction between the tumor cells, the immune cells and the helper T cells (HTCs). We perform mathematical analysis to reveal the stability of the equilibria of the model. In our model, the HTCs are stimulated by the identification of the presence of tumor antigens. Our investigation implies that the presence of tumor antigens may inhibit the existence of high steady state of tumor cells, which leads to the elimination of the bistable behavior of the tumor-immune system, i.e. the equilibrium corresponding to the high steady state of tumor cells is destabilized. Choosing immune intensity c as bifurcation parameter, there exists saddle-node bifurcation. Besides, there exists a critical value c ∗ , at which a Hopf bifurcation occurs. The stability and direction of Hopf bifurcation are discussed. [ABSTRACT FROM AUTHOR]
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- 2019
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268. Evaluation of binding confirmation method for ligand binding to CD4 receptor in HIV-infected T lymphocytes.
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Babu, P. B. Ramesh and Nursimhan, G. Achuta
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CD4 antigen , *T cells , *LIGAND binding (Biochemistry) , *MOLECULAR interactions , *HIV - Abstract
Aim and Objective: HIV (Human Immunodeficiency Virus) has been reported to weaken the immune system by binding to CD4+ receptor of T lymphocytes, thereby making the affected individual to become more susceptible to several microbial infections leading to life threatening problems. Recent literature indicate there is promsing advancement in identifying drug targets through CD4+ receptor binding capabilities with its ligand. The main purpose of this paper was to study the various molecular interactions of HIV to other molecules like receptors CD4+ and also co-receptors like CCR5 and CXCR4. Materials and Required: The molecules are going to be modeled by using software known as Swiss PDB viewer. The first objective is to get the FASTA sequence from the NCBI website. Then we need to paste the sequence onto the Swiss PDB viewer. Conclusion: The requierd protein/molecule is modeled. We are going to follow this method to obtain templates and modles for the following molecukles: HIV, GP120, CCR5 and CXCR4. [ABSTRACT FROM AUTHOR]
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- 2019
269. Bifurcation analysis of a multidelayed HIV model in presence of immune response and understanding of in‐host viral dynamics.
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Adak, Debadatta and Bairagi, Nandadulal
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HIV , *IMMUNE response , *T cells , *VIRAL replication - Abstract
In this paper, we proposed a multidelayed in‐host HIV model to represent the interaction between human immunodeficiency virus and immune response. One delay was considered to incorporate the time required by the virus for various intracellular events to make a host cell productively infective, and the second delay was introduced to take into account the time required for adaptive immune system to respond against infection. We extensively analyzed this multidelayed model analytically and numerically. We show that delay may have both destabilizing and stabilizing effects even when the system contains a single immune response delay. It happens when there exists two sequences of critical values of this delay. If the system starts with stable state in absence of delay, then the smallest value of these critical delays causes instability and the next higher value causes stability. The system may also show stability switching for different values of the virus replication factor. These results demonstrate the possible reasons of intrapatients and interpatients variability of CD4+ T cells and virus counts in HIV‐infected patients. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
270. A Mathematical Model of the Effects of Aging on Naive T Cell Populations and Diversity.
- Author
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Lewkiewicz, Stephanie, Chuang, Yao-li, and Chou, Tom
- Subjects
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CELL populations , *T cells , *T cell receptors , *MATHEMATICAL models , *VACCINE effectiveness , *POPULATION dynamics - Abstract
The human adaptive immune response is known to weaken in advanced age, resulting in increased severity of pathogen-born illness, poor vaccine efficacy, and a higher prevalence of cancer in the elderly. Age-related erosion of the T cell compartment has been implicated as a likely cause, but the underlying mechanisms driving this immunosenescence have not been quantitatively modeled and systematically analyzed. T cell receptor diversity, or the extent of pathogen-derived antigen responsiveness of the T cell pool, is known to diminish with age, but inherent experimental difficulties preclude accurate analysis on the full organismal level. In this paper, we formulate a mechanistic mathematical model of T cell population dynamics on the immunoclonal subpopulation level, which provides quantitative estimates of diversity. We define different estimates for diversity that depend on the individual number of cells in a specific immunoclone. We show that diversity decreases with age primarily due to diminished thymic output of new T cells and the resulting overall loss of small immunoclones. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
271. Analysis of pattern formation and phase separation in the immunological synapse.
- Author
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Hori, Yuko, Raychaudhuri, Subhadip, and Chakraborty, Arup K.
- Subjects
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IMMUNE response , *T cells , *ANTIGEN presenting cells - Abstract
T lymphocytes (T cells) play an important role in orchestrating an adaptive immune response in complex organisms. Recent experiments have shown that when T cells recognize antigen presenting cells, a complex and large-scale reorganization of intercellular membrane proteins and cell shape occurs. The resulting motif is implicated in information transfer between T cells and antigen presenting cells, and has been labeled the immunological synapse. Numerical solutions of a mathematical model that incorporates binding kinetics, protein mobility, and down regulation, and membrane mechanics has proven successful in describing some of these observations. In this paper, we analyze the equations that describe this model, and this sheds light on the origins of pattern formation in the immunological synapse. In particular, the thermodynamic considerations and dynamic instabilities that lead to pattern formation in and out of equilibrium are elucidated. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
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272. Evaluation of antigen-induced synovitis in a porcine model: Immunological, arthroscopic and kinetic studies.
- Author
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Vela, Francisco-Javier, Sánchez-Margallo, Francisco-Miguel, Blázquez, Rebeca, Álvarez, Verónica, Tarazona, Raquel, Teresa Mangas-Ballester, M., Cristo, Alejandro, and Casado, Javier G.
- Subjects
- *
SYNOVITIS , *ANIMAL models in research , *INFLAMMATION , *T cells , *IMMUNITY - Abstract
Background: Synovitis is an inflammation-related disease linked to rheumatoid arthritis, osteoarthritis, infections and trauma. This inflammation is accompanied by immune cells infiltration which initiates an inflammatory response causing pain, discomfort and affecting the normal joint function. The treatment of synovitis is based on the administration of anti-inflammatory drugs or biological agents such as platelet rich plasma and mesenchymal stem cells. However, the evaluation and validation of more effective therapies of synovitis requires the establishment of clinically relevant animal models. Results: In this study, Large White pigs were pre-immunized to evaluate an antigen-induced synovitis. The immune monitoring of synovial fluids in this model allowed us the identification of IL-12p40 and T cell subsets as immune biomarkers. Moreover, the evolution of synovitis was performed by arthroscopic procedures and kinetic analysis. In summary, this paper describes an animal model of antigen-induced synovitis to be used in the evaluation of anti-inflammatory therapies. Conclusions: The novelty of this paper lies in the development of a clinically relevant model of synovitis which permits the simultaneous evaluation of synovitis from an immunological, surgical and kinetic point of view. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
273. Promissory identities: Sociotechnical representations & innovation in regenerative medicine.
- Author
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Gardner, John, Higham, Ruchi, Faulkner, Alex, and Webster, Andrew
- Subjects
- *
BIOTECHNOLOGY , *DIFFUSION of innovations , *REGENERATION (Biology) , *T cells - Abstract
The field of regenerative medicine (RM) is championed as a potential source of curative treatments and economic wealth, and initiatives have been launched in several countries to facilitate innovation within the field. As a way of examining the social dimensions of innovation within regenerative medicine, this paper explores the sociotechnical representations of RM technologies in the UK, and the tensions, affordances and complexities these representations present for actors within the field. Specifically, the paper uses the Science and Technology Studies-inspired notions of ‘technology identity’ and ‘development space’ to examine how particular technologies are framed and positioned by actors, and how these positionings subsequently shape innovation pathways. Four developing RM technologies are used as case studies: bioengineered tracheas; autologous chondrocyte implantation; T-cell therapies; and a ‘point-of-care’ cell preparation device. Using these case studies we argue that there are particular identity aspects that have powerful performative effects and provide momentum to innovation projects, and we argue that there are particular stakeholders in the UK RM landscape who appear to have considerable power in shaping these technology identities and thus innovation pathways. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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274. Developments in the field of allergy mechanisms in 2015 through the eyes of Clinical & Experimental Allergy.
- Author
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Roberts, G., Boyle, R., Bryce, P. J., Crane, J., Hogan, S. P., Saglani, S., Wickman, M., and Woodfolk, J. A.
- Subjects
- *
ALLERGIES , *ALLERGENS , *IMMUNE system , *T cells , *PATHOLOGICAL physiology , *IMMUNOLOGICAL tolerance , *IMMUNOTHERAPY , *DIAGNOSIS of food allergies - Abstract
In the first of two papers we described the development in the field of allergy mechanisms as described by Clinical and Experimental Allergy in 2015. Experimental models of allergic disease, basic mechanisms, clinical mechanisms and allergens are all covered. A second paper will cover clinical aspects. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
275. Immune-mediated processes in neurodegeneration: where do we stand?
- Author
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Fakhoury, Marc
- Subjects
- *
NEURODEGENERATION , *NEURONS , *ALZHEIMER'S disease , *PARKINSON'S disease , *MULTIPLE sclerosis - Abstract
Neurodegeneration is a pathological condition that predominantly affects neurons. It represents a large spectrum of disorders with heterogeneous symptoms and distinct clinical features. In addition to the devastating effects it can have on the affected individual, it constitutes a heavy burden to the society in terms of health care costs. Although the exact cause of neurodegeneration is not known, there are plenty of evidences supporting the notion that the immune system is strongly associated with various forms of neurodegenerative diseases. Given the numerous functions of immune cells, a change in their expression can either be beneficial or deleterious to the host. A better understanding of the molecular and cellular processes in neurodegeneration is therefore needed. This could facilitate the development of new therapeutic targets and provide effective means to dampen the progression of neurodegenerative disorders. The overarching aim of this paper is to provide an overview of the roles that the innate and adaptive immune systems play in the central nervous system, and to discuss their beneficial or detrimental effects during neurodegeneration. This paper also critically examines the contribution of immune and inflammatory-mediated responses in the development of neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and amyloid lateral sclerosis by illustrating key findings from animal and human studies. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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276. Delivery of self-amplifying RNA vaccines in in vitro reconstituted virus-like particles.
- Author
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Biddlecome, Adam, Habte, Habtom H., McGrath, Katherine M., Sambanthamoorthy, Sharmila, Wurm, Melanie, Sykora, Martina M., Knobler, Charles M., Lorenz, Ivo C., Lasaro, Marcio, Elbers, Knut, and Gelbart, William M.
- Subjects
- *
DENDRITIC cells , *RNA replicase , *VIRUS-like particles , *RNA , *PLANT viruses , *INSECT viruses - Abstract
Many mRNA-based vaccines have been investigated for their specific potential to activate dendritic cells (DCs), the highly-specialized antigen-presenting cells of the immune system that play a key role in inducing effective CD4+ and CD8+ T-cell responses. In this paper we report a new vaccine/gene delivery platform that demonstrates the benefits of using a self-amplifying (“replicon”) mRNA that is protected in a viral-protein capsid. Purified capsid protein from the plant virus Cowpea Chlorotic Mottle Virus (CCMV) is used to in vitro assemble monodisperse virus-like particles (VLPs) containing reporter proteins (e.g., Luciferase or eYFP) or the tandem-repeat model antigen SIINFEKL in RNA gene form, coupled to the RNA-dependent RNA polymerase from the Nodamura insect virus. Incubation of immature DCs with these VLPs results in increased activation of maturation markers – CD80, CD86 and MHC-II – and enhanced RNA replication levels, relative to incubation with unpackaged replicon mRNA. Higher RNA uptake/replication and enhanced DC activation were detected in a dose-dependent manner when the CCMV-VLPs were pre-incubated with anti-CCMV antibodies. In all experiments the expression of maturation markers correlates with the RNA levels of the DCs. Overall, these studies demonstrate that: VLP protection enhances mRNA uptake by DCs; coupling replicons to the gene of interest increases RNA and protein levels in the cell; and the presence of anti-VLP antibodies enhances mRNA levels and activation of DCs in vitro. Finally, preliminary in vivo experiments involving mouse vaccinations with SIINFEKL-replicon VLPs indicate a small but significant increase in antigen-specific T cells that are doubly positive for IFN and TFN induction. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
277. Two-way communication between ex vivo tissues on a microfluidic chip: application to tumor–lymph node interaction.
- Author
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Shim, Sangjo, Belanger, Maura C., Harris, Alexandra R., Munson, Jennifer M., and Pompano, Rebecca R.
- Subjects
- *
TISSUES , *TWO-way communication , *T cells - Abstract
Experimentally accessible tools to replicate the complex biological events of in vivo organs offer the potential to reveal mechanisms of disease and potential routes to therapy. In particular, models of inter-organ communication are emerging as the next essential step towards creating a body-on-a-chip, and may be particularly useful for poorly understood processes such as tumor immunity. In this paper, we report the first multi-compartment microfluidic chip that continuously recirculates a small volume of media through two ex vivo tissue samples to support inter-organ cross-talk via secreted factors. To test on-chip communication, protein release and capture were quantified using well-defined artificial tissue samples and model proteins. Proteins released by one sample were transferred to the downstream reservoir and detectable in the downstream sample. Next, the chip was applied to model the communication between a tumor and a lymph node, to test whether on-chip dual-organ culture could recreate key features of tumor-induced immune suppression. Slices of murine lymph node were co-cultured with tumor or healthy tissue on-chip with recirculating media, then tested for their ability to respond to T cell stimulation. Interestingly, lymph node slices co-cultured with tumor slices appeared more immunosuppressed than those co-cultured with healthy tissue, suggesting that the chip may successfully model some features of tumor-immune interaction. In conclusion, this new microfluidic system provides on-chip co-culture of pairs of tissue slices under continuous recirculating flow, and has the potential to model complex inter-organ communication ex vivo with full experimental accessibility of the tissues and their media. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
278. Bifurcations and Multistability in a Model of Cytokine-Mediated Autoimmunity.
- Author
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Fatehi, Farzad, Kyrychko, Yuliya N., Molchanov, Robert, and Blyuss, Konstantin B.
- Subjects
- *
AUTOIMMUNITY , *T cells , *ACTIVATION energy , *IMMUNE response , *VIRUS diseases - Abstract
This paper investigates the dynamics of immune response and autoimmunity with particular emphasis on the role of regulatory T cells (Tregs), T cells with different activation thresholds, and cytokines in mediating T cell activity. Analysis of the steady states yields parameter regions corresponding to regimes of normal clearance of viral infection, chronic infection, or autoimmune behavior, and the boundaries of stability and bifurcations of relevant steady states are found in terms of system parameters. Numerical simulations are performed to illustrate different dynamical scenarios, and to identify basins of attraction of different steady states and periodic solutions, highlighting the important role played by the initial conditions in determining the outcome of immune interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
279. Functional Medicine for the Brain and Thyroid: A Clinical Conversation with Datis Kharrazian, PhD, DHSc, DC, MS, MMSc, FACN, and Robert Rountree, MD.
- Author
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Kharrazian, Datis and Rountree, Robert
- Subjects
- *
ALZHEIMER'S disease treatment , *TREATMENT of autism , *BRAIN disease treatment , *HYPOTHYROIDISM treatment , *THYROID diseases , *FATIGUE (Physiology) , *COGNITION disorders treatment , *ALTERNATIVE medicine , *AUTOIMMUNE diseases , *CYTOKINES , *ENDOCRINOLOGISTS , *EXERCISE , *HEART diseases , *IMMUNOGLOBULINS , *INFLAMMATION , *T cells , *THYROTROPIN , *THERAPEUTICS - Abstract
An interview with functional medicine healthcare provider Dr. Datis Kharrazian is presented. Topics of the interview include the start of Kharrazian's interest in being a chiropractor and a nutritionist, his stand on the move of some reviewers in medical journals to reject research paper without any useful commentary, and his clinical research fellowship at Harvard University.
- Published
- 2019
- Full Text
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280. Rheumatoid arthritis - a mathematical model.
- Author
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Moise, Nicolae and Friedman, Avner
- Subjects
- *
RHEUMATOID arthritis , *MATHEMATICAL models , *PARTIAL differential equations , *AUTOIMMUNE diseases , *T cells - Abstract
Highlights • This is the first mathematical model of RA which quantitatively describes the progression of the disease. • The model explains the roles of macrophages, inflammatory fibroblasts, and T cells in the degradation of cartilage in a joint. • Example is given how to achieve the same efficacy in stabilization of the cartilage while decreasing negative side-effects. Abstract Rheumatoid arthritis (RA) is a common autoimmune disease that mainly affects the joints. It is characterized by synovial inflammation, which may result in cartilage and bone destruction. The present paper develops a mathematical model of chronic RA. The model is represented by a system of partial differential equations (PDEs) in the synovial fluid, the synovial membrane, and the cartilage. The model characterizes the progression of the disease in terms of the degradation of the cartilage. More precisely, we assume a simplified geometry in which the synovial membrane and the cartilage are planar layers adjacent to each other. We then quantify the state of the disease by how much the cartilage layer has decreased, or, equivalently, how much the synovial layer has increased. The model is used to evaluate treatments of RA by currently used drugs, as well as by experimental drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
281. Influence of CD4-1+, CD4-2+ and CD8+ T lymphocytes subpopulations on the immune response of B lymphocytes in flounder (Paralichthys olivaceus) immunized with thymus-dependent or thymus-independent antigen.
- Author
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Xing, Jing, Luo, Keke, Xiao, Yue'e, Tang, Xiaoqian, and Zhan, Wenbin
- Subjects
- *
FLATFISHES , *IMMUNE response in fishes , *T cells , *THYMUS , *FISH immunology , *IMMUNOSUPPRESSIVE agents - Abstract
Abstract In order to elucidate the influence of T lymphocytes subpopulations on B lymphocytes immune response, in this paper, CD4-1+, CD4-2+, CD8+ T lymphocytes and B lymphocytes responses to thymus-independent (TI) or thymus-dependent (TD) antigen plus immunosuppressant were investigated in flounder (Paralichthys olivaceus). The results showed that in LPS-immunized group, the percentages of CD4-1+, CD4-2+, CD8β+ T (PCD4-1+ T, PCD4-2+ T and PCD8β+ T) lymphocytes in peripheral blood leucocytes (PBLs) had no significant variations, the percentages of IgM+ B (PIgM+ B) lymphocytes and LPS-specific antibodies (LA) significantly increased and peaked at 3rd or 4th week post-injection; CsA had no inhibition on both T/B lymphocytes and LA; RaPa only suppressed the PIgM+ B lymphocytes and LA, and the inhibition maximum (Imax) were about 35% and 20%, respectively. In KLH-immunized group, the PCD4-1+, PCD4-2+ and PCD8β+ T lymphocytes significantly increased and peaked at 3rd or 5th day, successively the PIgM+ B lymphocytes and KLH-specific antibodies (KA) significantly increased to the peak at 5th week; the PCD4-1+, PCD4-2+ T and PIgM+ B lymphocytes and LA were inhibited significantly by both CsA and RaPa, and the Imax on them were 13%–33%, 11%–25%, 19%–34%, 22%–26%, respectively, while the PCD8β+ T lymphocytes showed no significant suppression. The results indicated that the suppression of PIgM+ B lymphocytes in KLH + CsA group was not directly derived from CsA, but due to the suppression of T lymphocytes, especially CD4+ T lymphocytes subpopulations. The results showed for the first time that, similar to higher vertebrates, T lymphocytes didn't respond to TI antigen, moreover, T lymphocyte subpopulations had a regulation on the immune response of B lymphocyte for TD antigen in flounder. Highlights • KLH activated CD4-1+, CD4-2+, CD8+ T and B lymphocytes responses. • LPS only induced B lymphocytes response and antibodies production. • Cyclosporine A (CsA) specifically inhibited T lymphocytes. • CD4-1+, CD4-2+ T lymphocytes influenced the response of B lymphocytes for TD antigen. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
282. Numerical inversion of Laplace transform based on Bernstein operational matrix.
- Author
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Rani, Dimple, Mishra, Vinod, and Cattani, Carlo
- Subjects
- *
LAPLACE transformation , *NUMERICAL analysis , *PLASMA Bernstein waves , *T cells , *WAVELET transforms - Abstract
This paper provides a technique to investigate the inverse Laplace transform by using orthonormal Bernstein operational matrix of integration. The proposed method is based on replacing the unknown function through a truncated series of Bernstein basis polynomials and the coefficients of the expansion are obtained using the operational matrix of integration. This is an alternative procedure to find the inversion of Laplace transform with few terms of Bernstein polynomials. Numerical tests on various functions have been performed to check the applicability and efficiency of the technique. The root mean square error between exact and numerical results is computed, which shows that the method produces the satisfactory results. A rough upper bound for errors is also estimated. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
283. Modelling the suppression of autoimmunity after pathogen infection.
- Author
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Oliveira, Bruno M. P. M., Trinchet, Ricard, Otero Espinar, María Victoria, Pinto, Alberto, and Burroughs, Nigel
- Subjects
- *
AUTOIMMUNITY , *PATHOGENIC microorganisms , *INFECTION , *T cells , *IMMUNE response - Abstract
We study a mathematical model of immune response by T cells where the regulatory T cells (Treg) inhibit interleukin 2 (IL‐2) secretion. We model the suppression of the autoimmune line of T cells after a different line of T cells responded to a pathogen infection. In this paper, we show that if the population of the pathogen responding line of T cells becomes large enough, the competition for IL‐2 and the increase in the death rates may lead to a depletion in the concentration of autoimmune T cells. Provided this lasts for a sufficiently long time, the concentration of autoimmune T cells can be brought down to values inside the basin of attraction of the controlled state, and autoimmunity can be suppressed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
284. Cluster of differentiation 8 T-cell population in the laryngeal mucosa of smokers with laryngeal cancer.
- Author
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Elwany, S, Radi, S, Khalil, H, Talaat, I, and Belasy, K
- Subjects
- *
ANTIGENS , *CANCER , *CYTOCHEMISTRY , *LARYNGECTOMY , *LARYNX , *MUCOUS membranes , *SMOKING , *T cells ,LARYNGEAL tumors - Abstract
Objective: To study the cluster of differentiation 8 population in the laryngeal mucosa of patients with laryngeal carcinoma. To our knowledge this is the first paper to address this issue. Methods: The study group included 40 patients with known laryngeal cancer who were scheduled for laryngectomy. The control groups included 10 smokers and 10 non-smokers who were scheduled for microlaryngeal surgery. Specimens from the three groups were processed for histopathological and histochemical evaluation. Results: In patients without cancer of the larynx, the number of cluster of differentiation 8 lymphocytes was greater in smokers than non-smokers. The number of cluster of differentiation 8 lymphocytes was greatest in smokers with laryngeal cancer, and the difference between this group and the two control groups was statistically significant. Conclusion: The study showed that smoking increased the number of cluster of differentiation 8 T-lymphocytes in the laryngeal mucosa. The increase was greatest in patients who had developed laryngeal cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
285. Impacts of the Cell-Free and Cell-to-Cell Infection Modes on Viral Dynamics.
- Author
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Shu, Hongying, Chen, Yuming, and Wang, Lin
- Subjects
- *
LYAPUNOV functions , *HOPF bifurcations , *T cells , *NUMERICAL analysis , *DIFFERENTIAL equations - Abstract
Virus can disseminate between uninfected target cells via two modes, namely, the diffusion-limited cell-free viral spread and the direct cell-to-cell transfer using virological synapses. To examine how these two viral infection modes impact the viral dynamics, in this paper, we propose and analyze a general viral infection model that incorporates these two viral infection modes. The model also includes nonlinear target-cell dynamics, infinitely distributed intracellular delays, nonlinear incidences, and concentration-dependent clearance rates. It is shown that the numbers of secondly infected cells through the cell-free infection mode and the cell-to-cell infection mode both contribute to the basic reproduction number. Under some reasonable assumptions, the model exhibits a global threshold dynamics: the infection is cleared out if the basic reproduction number is less than one and the infection persists if the basic reproduction number is larger than one. Two specific examples are provided to illustrate that our theoretical results cover and improve some existing ones. When the underlying assumptions are not satisfied, oscillations via global Hopf bifurcation can be observed. A brief simulation of two-parameter bifurcation analysis is given to explore the joint impacts on viral dynamics for the interplay between nonlinear target-cell dynamics and intracellular delays. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
286. Development of a BiTE®-mediated CD8+ cytotoxic T-lymphocyte activity assay to assess immunomodulatory potential of drug candidates in Cynomolgus macaque.
- Author
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Frank, Brendon, Wei, Yu-Ling, Kim, Kyung-Hoon, Guerrero, Abraham, Lebrec, Hervé, Balazs, Mercedesz, and Wang, Xiaoting
- Subjects
- *
T cells , *IMMUNE response , *INTERFERONS , *IMMUNOLOGICAL adjuvants , *IMMUNOTOXICOLOGY - Abstract
The immunotoxic potential of drug candidates is assessed through the examination of results from a variety of studies and endpoints. While the functional assessment of CD8+ cytotoxic T-lymphocytes (CTL) is well-characterized in the clinic, the lack of a robust macaque CTL functional assay has been an important hurdle in evaluating and accurately quantifying cell-mediated CD8+ T-cell effector responses in the nonclinical setting. This paper describes the development of an assay to measure CTL activity in peripheral blood mononuclear cells (PBMC) isolated from Cynomolgus macaques. A human EGFR/CD3 Bispecific T-cell Engager (BiTE®) was used to mount a robust CD8+ T-cell response in the presence of target-expressing cells. Upon target engagement, degranulation of CD107a and production of interferon (IFN)-γ both reliably indicated a robust functional response in CD8+ T-cells. The BiTE®-mediated stimulation method proved to be favorable when compared to other methods of stimulation in the absence of target cells. These studies demonstrated acceptable longitudinal variability of the functional assay and sensitivity to dexamethasone-mediated immunosuppression. Taken together, the results indicated an assay leveraging CD3-bispecific antibodies and target-expressing cells can provide a robust approach to the in vitro or ex vivo assessment of CTL function in Cynomolgus macaques. Because the impairment of CTL activity by immunomodulators is recognized to be an important contributor to decreased antiviral defense and increased carcinogenicity risk, we believe that this novel assay to be a valuable addition to the immunotoxicology assessment of therapeutic drug candidates. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
287. Modelling the suppression of autoimmunity after pathogen infection.
- Author
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Oliveira, Bruno M. P. M., Trinchet, Ricard, Otero Espinar, María Victoria, Pinto, Alberto, and Burroughs, Nigel
- Subjects
- *
AUTOIMMUNITY , *PATHOGENIC microorganisms , *INTERLEUKIN-2 , *T cells , *CYTOKINES , *CELLULAR immunity - Abstract
We study a mathematical model of immune response by T cells where the regulatory T cells (Treg) inhibit interleukin 2 (IL‐2) secretion. We model the suppression of the autoimmune line of T cells after a different line of T cells responded to a pathogen infection. In this paper, we show that if the population of the pathogen responding line of T cells becomes large enough, the competition for IL‐2 and the increase in the death rates may lead to a depletion in the concentration of autoimmune T cells. Provided this lasts for a sufficiently long time, the concentration of autoimmune T cells can be brought down to values inside the basin of attraction of the controlled state, and autoimmunity can be suppressed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
288. FMER: An Energy-Efficient Error Recovery Methodology for SRAM-Based FPGA Designs.
- Author
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Agiakatsikas, Dimitris, Cetin, Ediz, and Diessel, Oliver
- Subjects
- *
ELECTRICAL engineering , *FIELD programmable gate arrays , *STATIC random access memory chips , *ENERGY consumption , *T cells - Abstract
This paper introduces frame- and module-based configuration memory error recovery (FMER), that is, a FMER technique targeting triple modular redundant (TMR) designs that are realized on SRAM-based FPGAs. Module-based configuration memory (CM) error recovery (MER) is used to reconfigure on demand the CM of faulty TMR modules, whereas the remaining CM of the device recovers from soft errors with periodic scrubbing. We derive reliability, availability, and power consumption models of TMR designs that incorporate FMER, MER, blind scrubbing, and no recovery at all, and show that FMER is particularly beneficial for missions that require high reliability or availability subject to a low-energy budget. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
289. The Diverse Family of MR1-Restricted T Cells.
- Author
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Gherardin, Nicholas A., McCluskey, James, and Godfrey, Dale I.
- Subjects
- *
T cells , *LYMPHOCYTES , *CD4 antigen , *ANTIBIOTICS , *HETEROGENEITY - Abstract
Mucosal-associated invariant T (MAIT) cells are characterized by a semi-invariant TCR that recognizes vitamin B metabolite Ags presented by the MHC-related molecule MR1. Their Ag restriction determines a unique developmental lineage, imbuing a tissue-homing, preprimed phenotype with antimicrobial function. A growing body of literature indicates that MR1-restricted T cells are more diverse than the MAIT term implies. Namely, it is increasingly clear that TCR a- and TCR b-chain diversity within the MR1-restricted repertoire provides a potential mechanism of Ag discrimination, and context-dependent functional variation suggests a role for MR1-restricted T cells in diverse physiological settings. In this paper, we summarize MR1-restricted T cell biology, with an emphasis on TCR diversity, Ag discrimination, and functional heterogeneity. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
290. Role of Mast Cells and Type 2 Innate Lymphoid (ILC2) Cells in Lung Transplantation.
- Author
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Mortaz, Esmaeil, Amani, Saeede, Mumby, Sharon, Adcock, Ian M., Movassaghi, Mehrnaz, Folkerts, Jelle, Garssen, Johan, and Folkerts, Gert
- Subjects
- *
MAST cells , *INNATE lymphoid cells , *IMMUNE system , *MUCOUS membranes , *NATURAL immunity , *IMMUNE response , *LUNG transplantation , *T cells - Abstract
The multifunctional role of mast cells (MCs) in the immune system is complex and has not fully been explored. MCs reside in tissues and mucous membranes such as the lung, digestive tract, and skin which are strategically located at interfaces with the external environment. These cells, therefore, will encounter external stimuli and pathogens. MCs modulate both the innate and the adaptive immune response in inflammatory disorders including transplantation. MCs can have pro- and anti-inflammatory functions, thereby regulating the outcome of lung transplantation through secretion of mediators that allow interaction with other cell types, particularly innate lymphoid cells (ILC2). ILC2 cells are a unique population of hematopoietic cells that coordinate the innate immune response against a variety of threats including infection, tissue damage, and homeostatic disruption. In addition, MCs can modulate alloreactive T cell responses or assist in T regulatory (Treg) cell activity. This paper outlines the current understanding of the role of MCs in lung transplantation, with a specific focus on their interaction with ILC2 cells within the engrafted organ. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
291. The Role of WNT Signaling in Mature T Cells: T Cell Factor Is Coming Home.
- Author
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van Loosdregt, Jorg and Coffer, Paul J.
- Subjects
- *
T cells , *TRANSCRIPTION factors , *HEMATOPOIESIS , *IMMUNOLOGY , *STEM cells , *CATENINS - Abstract
T cell factor, the effector transcription factor of the WNT signaling pathway, was so named because of the primary observation that it is indispensable for T cell development in the thymus. Since this discovery, the role of this signaling pathway has been extensively studied in T cell development, hematopoiesis, and stem cells; however, its functional role in mature T cells has remained relatively underinvestigated. Over the last few years, various studies have demonstrated that T cell factor can directly influence T cell function and the differentiation of Th1, Th2, Th17, regulatory T cell, follicular helper CD4+ T cell subsets, and CD8+ memory T cells. In this paper, we discuss the molecular mechanisms underlying these observations and place them in the general context of immune responses. Furthermore, we explore the implications and limitations of these findings for WNT manipulation as a therapeutic approach for treating immune-related diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
292. The elevated glutaminolysis of bladder cancer and T cells in a simulated tumor microenvironment contributes to the up-regulation of PD-L1 expression by interferon-γ.
- Author
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Wang, Liping, Yang, Xuecheng, Li, Dan, Liang, Zhijuan, Chen, Yuanbin, Ma, Guofeng, Wang, Yonghua, Li, Yongxin, Liang, Ye, and Niu, Haitao
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CANCER cells , *T cells , *BLADDER cancer , *INTERFERON gamma , *CANCER treatment - Abstract
Background: Metabolic reprogramming occurs in the tumor microenvironment and influences the survival and function of tumor and immune cells. Interferon-γ (IFN-γ) produced by T cells up-regulates PD-L1 expression in tumors. However, reports regarding the relationship between nutrient metabolism and the up-regulation of PD-L1 expression are lacking.Materials and methods: In this paper, we analyzed the metabolic changes in T cells and bladder cancer cells in a simulated tumor microenvironment to provide evidence regarding their relevance to PD-L1 up-regulation.Results: The glutaminolysis was increased in both activated T cells and glucose-deprived T cells. IFN-γ production by T cells was decreased in a glucose-free medium and severely decreased when cells were simultaneously deprived of glutamine. Furthermore, the glutaminolysis of the bladder cancer cells under glucose deprivation exhibited a compensatory elevation. The glucose concentration of T cells co-cultured with bladder cancer cells was decreased and T cell proliferation was reduced, but IFN-γ production and glutaminolysis were increased. However, in bladder cancer cells, the elevation in glutaminolysis under co-culture conditions did not compensate for glucose deprivation because the glucose concentration in the culture medium did not significantly differ between the cultures with and without T cells. Our data also show that inhibiting glutamine metabolism in bladder cancer cells could reduce the elevation in PD-L1 expression induced by IFN-γ.Conclusion: In a simulated tumor microenvironment, elevated glutaminolysis may play an essential role in IFN-γ production by T cells, ultimately improving the high PD-L1 expression, and also directly contributing to producing more PD-L1 in bladder cancer cells. [ABSTRACT FROM AUTHOR]
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- 2018
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293. Syndecan-1 Regulates Psoriasiform Dermatitis by Controlling Homeostasis of IL-17-Producing γδ T Cells.
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Jaiswal, Anil Kumar, Sadasivam, Mohanraj, Archer, Nathan K., Miller, Robert J., Dillen, Carly A., Ravipati, Advaitaa, Park, Pyong Woo, Chakravarti, Shukti, Miller, Lloyd S., and Hamad, Abdel Rahim A.
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SKIN inflammation , *SYNDECANS , *T cells , *HOMEOSTASIS , *APOPTOSIS - Abstract
IL-17 is a potent proinflammatory cytokine that drives pathogenesis of multiple autoimmune diseases, including psoriasis. A major source of pathogenic IL-17 is a subset of γδ T cells (Tγδ17) that acquires the ability to produce IL-17 while developing in the thymus. The mechanisms that regulate homeostasis of Tγδ17 cells and their roles in psoriasis, however, are not fully understood. In this paper, we show that the heparan sulfate proteoglycan syndecan-1 (sdc1) plays a critical role in regulating homeostasis of Tγδ17 cells and modulating psoriasis-like skin inflammation in mice. sdc1 was predominantly expressed by Tγδ17 cells (but not IL-172 Tγδ cells) in the thymus, lymph nodes, and dermis. sdc1 deficiency significantly and selectively increased the frequency and absolute numbers of Tγδ17 cells by mechanisms that included increased proliferation and decreased apoptosis. Adoptive transfer experiments ruled out a significant role of sdc1 expressed on nonhematopoietic cells in halting expansion and proliferation of sdc1-deficient Tγδ17 cells. When subjected to imiquimod-induced psoriasiform dermatitis, Tγδ17 cells in sdc1KO mice displayed heightened responses accompanied by significantly increased skin inflammation than their wild-type counterparts. Furthermore, transferred sdc1-deficient γδ T cells caused more severe psoriasiform dermatitis than their sdc1-sufficient counterparts in TCR-β δ KO hosts. The results uncover a novel role for sdc1 in controlling homeostasis of Tγδ17 cells and moderating host responses to psoriasis-like inflammation. [ABSTRACT FROM AUTHOR]
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- 2018
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294. CD8+CD28+ T cells might mediate injury of cardiomyocytes in acute myocardial infarction.
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Zhang, Lili, Wang, Zhiyan, Wang, Di, Zhu, Jumo, and Wang, Yi
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MYOCARDIAL infarction , *HEART cells , *CD8 antigen , *CD28 antigen , *T cells - Abstract
Highlights • Few paper investigates the role of CD8+CD28+ T cells in patients with AMI. • The frequency of CD8+CD28+ T cells in patients with AMI were significant increased. • In patients with AMI, frequency of CD8+CD28+ T cells was positively correlated with TNI and negatively associated with LVEF. • The CD8+ CD28+ T cell might participate in the process of myocardial damage. Abstract CD8+ T cells accumulate in the necrotic myocardium of acute myocardial infarction (AMI). It is unclear whether CD8+CD28+ T cells, a specific subset of CD8+ T cells, contribute to myocardial injury. In this study, 92 consecutive patients with AMI and 28 healthy control subjects were enrolled. The frequency of CD8+CD28+ T cells in peripheral blood samples was assayed by flow cytometry. Plasma cardiac troponin I (TNI) and left ventricular ejection fraction (LVEF) were determined. Long-term prognosis of the patients was evaluated by major adverse cardiac and cerebrovascular events (MACCE) over a 12-month follow-up period. Our findings indicated that patients with AMI who presented with high numbers of CD8+CD28+ T cells had an increased infarction size and aggravated ventricular function. We proposed that cytotoxic CD8+CD28+ T cell-mediated myocardial necrosis may act as a novel and alternative pathway of AMI. [ABSTRACT FROM AUTHOR]
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- 2018
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295. Stability of latent pathogen infection model with adaptive immunity and delays.
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Elaiw, A. M. and AlShamrani, N. H.
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PATHOGENIC microorganisms , *T cells , *IMMUNE response , *CELL-mediated cytotoxicity , *IMMUNOGLOBULINS - Abstract
In this paper we propose and analyze a pathogen dynamics model with antibody and Cytotoxic T Lymphocyte (CTL) immune responses. We incorporate latently infected cells and three distributed time delays into the model. We show that the solutions of the proposed model are nonnegative and ultimately bounded. We derive four threshold parameters which fully determine the existence and stability of the five steady states of the model. Using Lyapunov functionals, we established the global stability of the steady states of the model. The theoretical results are confirmed by numerical simulations. [ABSTRACT FROM AUTHOR]
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- 2018
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296. Grouped gene selection and multi-classification of acute leukemia via new regularized multinomial regression.
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Li, Juntao, Wang, Yanyan, Jiang, Tao, Xiao, Huimin, and Song, Xuekun
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ACUTE leukemia , *GENE expression , *B cells , *T cells , *MOLECULAR genetics - Abstract
Diagnosing acute leukemia is the necessary prerequisite to treating it. Multi-classification on the gene expression data of acute leukemia is help for diagnosing it which contains B-cell acute lymphoblastic leukemia (BALL), T-cell acute lymphoblastic leukemia (TALL) and acute myeloid leukemia (AML). However, selecting cancer-causing genes is a challenging problem in performing multi-classification. In this paper, weighted gene co-expression networks are employed to divide the genes into groups. Based on the dividing groups, a new regularized multinomial regression with overlapping group lasso penalty (MROGL) has been presented to simultaneously perform multi-classification and select gene groups. By implementing this method on three-class acute leukemia data, the grouped genes which work synergistically are identified, and the overlapped genes shared by different groups are also highlighted. Moreover, MROGL outperforms other five methods on multi-classification accuracy. [ABSTRACT FROM AUTHOR]
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- 2018
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297. CD4+ Regulatory T Cells Exert Differential Functions during Early and Late Stages of the Immune Response to Respiratory Viruses.
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Shafagati, Nazly, Johnson, Monika, Williams, John V., Rogers, Meredith C., Lamens, Kristina D., Joyce, Sebastian, and Oury, Tim D.
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ADULT respiratory distress syndrome , *T cells , *CYTOKINES , *MICE , *PHENOTYPES - Abstract
Acute respiratory virus infection (ARI) induces CD8+ T cells with diminished cytokine production and functional impairment. The role of cellular mediators of immune impairment, specifically CD4+ regulatory T cells (Tregs), is incompletely understood in ARI. Tregs are known suppressors of effector T cell function, but whether they are detrimental or beneficial in ARI remains controversial. We show in this paper that Treg depletion leads to increased CD8+ T cell function and lower virus titer in mice infected with human metapneumovirus. We further demonstrate that Tregs play a temporal role in the immune response to human metapneumovirus and influenza: Treg depletion before infection pathologically reduces virus-specific CD8+ T cell numbers and delays virus clearance, whereas depletion 2 d postinoculation enhances CD8+ T cell functionality without reducing virus-specific CD8+ T cell numbers. Mechanistically, Treg depletion during immune priming led to impaired dendritic cell and CD8+ T cell migration. Further, early Treg depletion was associated with immune skewing toward a type 2 phenotype characterized by increased type 2 innate lymphoid cells and TH2 CD4+ T cells, which was not observed when Treg depletion was delayed until after inoculation. These results indicate that the presence of Tregs at inoculation is critical for efficient priming of the CD8+ T cell response to ARI, whereas later in infection, Tregs are dispensable for virus clearance. [ABSTRACT FROM AUTHOR]
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- 2018
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298. Real-time monitoring of T-cell-secreted interferon-γ for the diagnosis of tuberculosis.
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Wu, Changlin, He, Jianan, Li, Boan, Xu, YunQing, Gu, Dayong, Liu, Houming, Zhao, Dan, and Shao, Chaopeng
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MYCOBACTERIUM tuberculosis , *T cells , *BIOSENSORS , *IMMUNOGLOBULINS , *TUBERCULOSIS , *CD4 antigen , *SURFACE plasmon resonance - Abstract
In this paper, we report the development of a label-free biosensor, based on surface plasmon resonance, for real-time monitoring of captured human CD4+T-cells, and their dynamic cytokine production upon specific antigen stimulation. Microarrays of CD4+T-cells, and interferon gamma (IFN-γ) specific antibody (Ab) spots were printed side by side onto the poly(OEGMA-co-HEMA) matrix. The placement of CD4+ T-cells near the anti IFN-γ Ab-coated spots ensured a high local concentration of secreted IFN-γ for detection. We have demonstrated that this approach enables the detection of tuberculosis (TB) infection in clinical samples, with an overall sensitivity of 85.5% and an overall specificity of 97.7%. [ABSTRACT FROM AUTHOR]
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- 2018
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299. Curcumin attenuates sepsis-induced acute organ dysfunction by preventing inflammation and enhancing the suppressive function of Tregs.
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Chen, Longwang, Lu, Yang, Zhao, Linjun, Hu, Lili, Qiu, Qiaomeng, Zhang, Zhuoling, Li, Mengfang, Hong, Guangliang, Wu, Bing, Zhao, Guangju, and Lu, Zhongqiu
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SEPSIS , *INFLAMMATION prevention , *CURCUMIN , *T cells , *ANTI-inflammatory agents , *IMMUNOREGULATION , *THERAPEUTICS - Abstract
Sepsis is characterized by the extensive release of cytokines and other mediators. It results in a dysregulated immune response and can lead to organ damage and death. Curcumin has anti-inflammatory properties and immunoregulation functions in various disorders such as sepsis, cancer, rheumatoid arthritis, cardiovascular diseases, lung fibrosis, gallstone formation, and diabetes. This paper investigates the effects of curcumin on immune status and inflammatory response in mice subjected to cecal ligation and puncture (CLP). Inflammatory tissue injury was evaluated by histological observation. Magnetic microbeads were used to isolate splenic CD4 + CD25 + regulatory T cells (Tregs), and phenotypes were then analyzed by flow cytometry. The levels of Foxp3 were detected by Western blot and real-time PCR and cytokine levels were determined by enzyme-linked immunosorbent assay. We found that the administration of curcumin significantly alleviated inflammatory injury of the lung and kidney in septic mice. The suppressive function of Treg cells was enhanced and the plasma levels of IL-10 increased after treatment with curcumin. Furthermore, the secretion of plasma TNF-α and IL-6 was notably inhibited in septic mice treated with curcumin and administration with curcumin could improve survival after CLP. These data suggest that curcumin could be used as a potential therapeutic agent for sepsis. [ABSTRACT FROM AUTHOR]
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- 2018
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300. Stability of a CD4+ T cell viral infection model with diffusion.
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Xu, Zhiting and Xu, Youqing
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T cells , *CD4 antigen , *VIRUS diseases , *LYAPUNOV functions , *COMPUTER simulation - Abstract
This paper is devoted to the study of the stability of a CD 4 + T cell viral infection model with diffusion. First, we discuss the well-posedness of the model and the existence of endemic equilibrium. Second, by analyzing the roots of the characteristic equation, we establish the local stability of the virus-free equilibrium. Furthermore, by constructing suitable Lyapunov functions, we show that the virus-free equilibrium is globally asymptotically stable if the threshold value ℛ 0 ≤ 1 ; the endemic equilibrium is globally asymptotically stable if ℛ 0 > 1 and d u ∗ − δ w ∗ ≥ 0. Finally, we give an application and numerical simulations to illustrate the main results. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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