The inhibitory T-cell surface-expressed receptor, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), which belongs to the class of cell surface proteins phosphorylated by extrinsic tyrosine kinases that also includes antigen receptors, binds the related ligands, B7-1 and B7-2, expressed on antigen-presenting cells. Conformational changes are commonly invoked to explain ligand-induced "trigge...

It is known that CD28, a positive costimulatory receptor, plays a very important role in inducing the optimal stimulation of T lymphocytes. CTLA-4 (CD152), however, acts as a negative regulator in T lymphocyte activation. The effect of an feline immunodeficiency virus (FIV) infection on the expression of feline CD28 and CTLA-4 was studied with FIV-infected and uninfected peripheral blood mononu...

Cytotoxic T lymphocyte antigen-4 (CTLA-4/CD152) is a member of the CD28 family of T cell effector antigens. Current belief, based primarily on results from gene-deleted mice, is that CTLA-4 promotes suppression of T cell proliferation. In this manuscript, Mark Slifka and colleagues compare antiviral responses of unmanipulated virus-specific CTLA-4 and CTLA-4 T cells. The results of this work su...

  Background: Both genetic and environmental factors are important in pathogenesis of diabetes. Non HLA (Human Leukocyte Antigen) genes such as INS-VNTR and CTLA-4 in addition of HLA genes have influence on genetic susceptibility for diabetes mellitus. In this study the association of +49 A/G CTLA-4 and -23 A/T INS-VNTR polymorphisms with diabetes and their association with islet auto...

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), a potent immunoregulatory molecule, can down-regulate T-cell activation and inhibit anti-tumor immune response. This study showed that LPS-stimulated human dendritic cells (DCs) decreased the expression of HLA-DR, CD83 and costimulatory molecules (CD40, CD80 and CD86) following coculturing with CTLA-4+ breast cancer cells. Moreover, the supp...

Functional impairment of antigen-specific T cells is a defining characteristic of many chronic infections, but the underlying mechanisms of T-cell dysfunction are not well understood. To address this question, we analyzed genes expressed in functionally impaired virus-specific CD8 T cells present in mice chronically infected with lymphocytic choriomeningitis virus (LCMV), and compared these wit...

Cytotoxic T lymphocyte antigen 4 (CTLA-4) is an essential negative regulator of T cell immune responses whose mechanism of action is the subject of debate. CTLA-4 shares two ligands (CD80 and CD86) with a stimulatory receptor, CD28. Here, we show that CTLA-4 can capture its ligands from opposing cells by a process of trans-endocytosis. After removal, these costimulatory ligands are degraded ins...

CTLA-4 is a T cell antigen that is structurally related to CD28 and serves as a high affinity ligand for the B cell antigen B7-1/2. Unlike CD28, the function of CTLA-4 is unclear, although reports have implicated the antigen in the costimulation of T cells. Recently, phosphatidylinositol 3-kinase (PI 3-kinase) has been implicated in the costimulatory function of CD28 by virtue of its ability to...

multiple sclerosis (ms), a chronic inflammatory demyelinating disease of the central nervous system is believed to have a t cell-mediated autoimmune etiology. the cytotoxic t lymphocyte antigen 4 (ctla-4) gene is a strong candidate for the involvement in autoimmune diseases. to examine the genetic association of the ctla-4 gene locus with ms, in a case-control design, we analyzed (-318 c/t) sin...

Similarities in the phenotypes of mice deficient for cytotoxic T lymphocyte antigen-4 (CTLA-4) or transforming growth factor-beta1 (TGF-beta1) and other observations have led to speculation that CTLA-4 mediates its inhibitory effect on T cell activation via costimulation of TGF-beta production. Here, we examine the role of TGF-beta in CTLA-4-mediated inhibition of T cell activation and of CTLA-...