Cytotoxic T cell

About: Cytotoxic T cell is a research topic. Over the lifetime, 92492 publications have been published within this topic receiving 4768477 citations. The topic is also known as: killer T cell & cytotoxic T lymphocyte.

HIV-specific cytotoxic T lymphocytes in seropositive individuals.

Abstract: Virus-specific cytotoxic T lymphocytes (CTL) which kill virus-infected cells are thought to be a major host defence against viral infections. Here we report the existence of human immunodeficiency virus (HIV)-specific CTL in persons infected with this virus, the aetiological agent of AIDS (acquired immunodeficiency syndrome). Recombinant HIV-vaccinia viruses were used to express HIV antigens in B-cell lines established from subjects seropositive for HIV and seronegative controls. Circulating lymphocytes capable of killing HIV env-expressing autologous B cells were detected in eight of eight seropositive subjects; in addition, at least three seropositive subjects demonstrated gag-specific cytotoxic responses. No HIV-specific cytotoxicity was observed in seronegative subjects. Selective inhibition of the env-specific cytotoxicity by a CD3-specific monoclonal antibody indicates that the effectors are T cells. This demonstration of a cytotoxic T-cell immune response to HIV in infected individuals should prove useful in investigating the immunopathogenesis of HIV infection further and in evaluating AIDS vaccine strategies.

Clonotypic structures involved in antigen-specific human T cell function. Relationship to the T3 molecular complex.

Abstract: Monoclonal antibodies were produced against a human cytotoxic T cell clone, CT8III (specificity: HLA-A3), with the view of defining clonally restricted (clonotypic) surface molecules involved in its antigen recognition function. Two individual antibodies, termed anti-Ti1A and anti-Ti1B, reacted exclusively with the CT8III clone when tested on a panel of 80 additional clones from the same donor, resting or activated T cells, B cells, macrophages, thymocytes, or other hematopoietic cells. More importantly, the two antibodies inhibited cell-mediated killing and antigen-specific proliferation of the CT8III clone but did not affect the functions of any other clone tested. This inhibition was not secondary to generalized abrogation of the CT8III clone's function, because interleukin 2 responsiveness was enhanced. To examine the relationship of the structures defined by anti-clonotypic antibodies with known T cell surface molecules, antibody-induced modulation studies and competitive binding assays were performed. The results indicated that the clonotypic structures were associated with, but distinct from, the 20,000-mol wt T3 molecule expressed on all mature T lymphocytes. Moreover, in contrast to anti-T3, anti-Ti1A and anti-Ti1B each immunoprecipitated two molecules of 49,000 and 43,000-mol wt from 131I-labeled CT8III cells under reducing conditions. The development of monoclonal antibodies to such polymorphic T cell surface structures should provide important probes to further define the surface receptor for antigen.

Immunological surveillance against altered self components by sensitised T lymphocytes in lymphocytic choriomeningitis.

Abstract: THE cytotoxic activity1,2 of immune thymus-derived lymphocytes (T cells) for 51Cr-labelled fibroblasts, or macrophages infected with lymphocytic choriomeningitis (LCM) virus is restricted by the H-2 gene complex3,4. Specific lysis of LCM-infected monolayer cultures occurs only when targets and overlaying, sensitised T cells share at least one set of H-2 antigenic specificities.

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Abstract: Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell-mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ-specific autoimmune disease.