Search results for "Natural killer"
showing 10 items of 153 documents
CD2-mediated autocrine growth of herpes virus saimiri-transformed human T lymphocytes.
1992
Herpes virus saimiri (HVS) immortalizes T lymphocytes from a variety of primates and causes acute T cell lymphomas and leukemias in nonnatural primate hosts. Here we have analyzed the requirements for growth of three HVS-transformed human T cell lines. The cells expressed the phenotype of activated T cells: two were CD4+, and one was CD8+. All three cells responded to all allogeneic human cell lines tested with enhanced proliferation, production of interleukin 2 (IL-2), and increased expression of the IL-2 receptor. Binding of CD2 to its ligand CD58 was the critical event mediating stimulation because: (a) monoclonal antibodies (mAbs) to CD2 and to CD58, but not to a variety of other surfac…
TGF-β signalling is required for CD4⁺ T cell homeostasis but dispensable for regulatory T cell function.
2013
Signalling by the cytokine TGF-β regulates mature CD4+ T cell populations but is not involved in the survival and function of regulatory T cells.
Invariant NKT cells are expanded in peripheral blood but are undetectable in salivary glands of patients with primary Sjögren's syndrome
2016
OBJECTIVES: Invariant NKT (iNKT) cells play a role in regulating the function of autoreactive B cells before their entry into germinal centres. Absence and/or reduction of iNKT cells have been demonstrated in patients with systemic lupus erythematosus (SLE) together with an increase of autoreactive B cell activity. Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease in which lymphocyte infiltration and organisation in lymphoid structures of inflamed salivary glands occurs. The aim of the study was to investigate the percentage and function of iNKT in the salivary glands and peripheral blood of patients with pSS. METHODS: Minor salivary gland biopsies were obtained from patient…
Differences in non-MHC restricted cytotoxic activities of human peripheral blood lymphocytes after transfusion with allogeneic leukocytes or platelet…
1990
Abstract MHC-unrestricted cytotoxic activity of peripheral blood lymphocytes (PBL) from 4–6 healthy donors was investigated before and after transfusion with allogeneic leukocytes or platelets. Natural killer and lectin-dependent cellular cytotoxicity (LDCC) of PBL was tested against K562 and Raji target cells in a 4-h and 16-h 51 Cr-release assay, respectively. After allotransfusion with leukocytes, we found increased cytotoxic activity of each donor's PBL against all the three targets on day 3 or 7. The highest non-specific cytotoxic activity was detected against the relatively NK resistant Raji target cells. The increase of cytotoxic activity was lowest against the LDCC target (PHA-treat…
Anti-GD3 antibodies are potent activators of human gamma/delta and alpha/beta positive T cells.
1995
The ganglioside GD3 has a variety of biological functions. These include stimulatory effects on proliferation, natural killer activity and cytokine production by freshly isolated peripheral T cells. In this study we have characterized anti-GD3 antibody (MoAb Z21) mediated effects on T cell clones. Our data indicate that alpha/beta TCR CD4+ and CD8+ as well as gamma/delta TCR positive T cells can be stimulated resulting in proliferation and cytokine production. This effect could be blocked by cyclosporin A and did not involve the LFA-3 or CD4 molecule. Apart from IFN-gamma and IL-2 production by T helper 1 and T helper 0 cells we have observed production of IL-4 and IL-10 by T helper 2 cells…
LFA-1 Contributes to Signal I of T-Cell Activation and to the Production of Th1 Cytokines
2010
The beta(2) integrins are important for both transendothelial migration of leukocytes and T-cell activation during antigen presentation. In T cells, triggering of leukocyte functional antigen-1 (LFA-1) is required for full activation and T-helper (Th)1/Th2 differentiation. We used CD18-deficient (CD18(-/-)) mice to examine the role of LFA-1 in the activation of T cells. Compared with wild-type controls, CD18(-/-) T cells proliferated normally when stimulated with antibodies against CD3 and CD28, but secreted significantly less IFN-gamma and IL-2 than their wild-type counterparts. However, when T cells were stimulated with dendritic cells (DCs) that provide additional LFA-1 ligation, the pro…
Th9 Cells: A Novel CD4 T-cell Subset in the Immune War against Cancer
2015
Abstract CD4 T cells are key components of the immune system that shape the anticancer immune response in animal models and in humans. The biology of CD4 T cells is complex because naïve T cells can differentiate into various subpopulations with various functions. Recently, a new population called Th9 cells was described. These cells are characterized by their ability to produce IL9 and IL21. They were first described in the context of parasite infections and allergic processes. However, some reports described their presence in the tumor bed in mice and humans. Their high secretion of IL9 and IL21 in the tumor bed contributes to their anticancer functions. Indeed, these cytokines trigger th…
Rapid identification and sorting of viable virus-reactive CD4+ and CD8+ T cells based on antigen-triggered CD137 expression
2008
Abstract Current methods for the detection and isolation of antigen-specific CD4 + and CD8 + T cells require the availability of peptide/MHC multimers or are restricted to cells that produce cytokines after antigen contact. Here we show that de novo cell surface expression of the TNF-receptor family member CD137 (4-1BB) identifies recently activated, but not resting, human CD4 + and CD8 + memory T cells. Maximum CD137 expression level is uniformly observed in both T-cell subsets at 24h after stimulation with antigen. In experiments with CMV and EBV-reactive T cells, we confirmed the specificity of CD137 expression by co-staining with peptide/HLA tetramers. Substantial proportions of CD137 +…
CD4(+) and CD8(+) anergic T cells induced by interleukin-10-treated human dendritic cells display antigen-specific suppressor activity.
2002
Interleukin-10 (IL-10)–treated dendritic cells (DCs) induce an alloantigen- or peptide-specific anergy in various CD4+ and CD8+ T-cell populations. In the present study, we analyzed whether these anergic T cells are able to regulate antigen-specific immunity. Coculture experiments revealed that alloantigen-specific anergic CD4+ and CD8+ T cells suppressed proliferation of syngeneic T cells in a dose-dependent manner. The same effect was observed when the hemagglutinin-specific CD4+T-cell clone HA1.7 or tyrosinase-specific CD8+ T cells were cocultured with anergic T cells of the same specificity. Anergic T cells did not induce an antigen-independent bystander inhibition. Suppression was depe…
Deficiency in the Transcription Factor Interferon Regulatory Factor (Irf)-2 Leads to Severely Compromised Development of Natural Killer and T Helper …
2000
Interferon (IFN) regulatory factor (IRF)-2 was originally described as an antagonist of IRF-1–mediated transcriptional regulation of IFN-inducible genes. IRF-1−/− mice exhibit defective T helper type 1 (Th1) cell differentiation. We have used experimental leishmaniasis to show that, like IRF-1−/− mice, IRF-2−/− mice are susceptible to Leishmania major infection due to a defect in Th1 differentiation. Natural killer (NK) cell development is compromised in both IRF-1−/− and IRF-2−/− mice, but the underlying mechanism differs. NK (but not NK+ T) cell numbers are decreased in IRF-2−/− mice, and the NK cells that are present are immature in phenotype. Therefore, like IRF-1, IRF-2 is required for…