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...

Chronic T cell responses, as they occur in rheumatoid arthritis, are complex and are likely to involve many mechanisms. There is a growing body of evidence that, in concert with the T cell antigen receptor signal, CD28 and cytotoxic T-lymphocyte antigen-4 (CTLA-4; CD152) are the primary regulators of T cell responses. Whereas CD28 primarily activates T cell processes, CTLA-4 inhibits them. The ...

T cell activation through the T cell receptor (TCR) involves partitioning of receptors into discrete membrane compartments known as lipid rafts, and the formation of an immunological synapse (IS) between the T cell and antigen-presenting cell (APC). Compartmentalization of negative regulators of T cell activation such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is unknown. Recent cr...

Evidence indicates that cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) may negatively regulate T cell activation, but the basis for the inhibitory effect remains unknown. We report here that cross-linking of CTLA-4 induces transforming growth factor beta (TGF-beta) production by murine CD4(+) T cells. CD4(+) T helper type 1 (Th1), Th2, and Th0 clones all secrete TGF-beta after antibody cr...

CD4 T cells activated in vitro by anti-CD3/28-coated beads are resistant to infection by CC chemokine receptor 5 (CCR5)-dependent HIV-1 isolates. In vivo, antigen-presenting cells (APCs) activate CD4 T cells in part by signaling through the T cell receptor and CD28, yet cells stimulated in this manner are susceptible to HIV-1 infection. We show that cytotoxic T lymphocyte antigen 4 (CTLA-4) eng...

The generation of an effective immune response involves antigen-specific T cell expansion and differentiation of effector function. T cell activation requires at least two distinct signals, including signaling via the antigen-specific T cell receptor (TCR) and a costimulatory pathway. Antigen stimulation of T cells can lead either to a productive immune response, characterized by proliferation,...

background: immunological factors are important in pregnancy loss because of the interaction between mother and fetus. t-regulatory cells as the component of humeral immune response play important role in the fetu-maternal interface. one of the regulatory mechanisms for these cells is mediated by antigen independent co-stimulatory signals and interaction of cytotoxic t-lymphocyte antigen 4 (b7/...

Recently, "ipilimumab," an anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) monoclonal antibody, has been demonstrated to improve overall survival in metastatic melanoma. "CTLA-4" is an immune-checkpoint molecule that downregulates pathways of T-cell activation. Ipilimumab, by targeting CTLA-4, is able to remove the CTLA-4 inhibitory signal, allowing the immune system to react to cancer cells. Du...

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) modifying agents have been involved in the development of intestinal inflammation, especially therapeutic monoclonal antibodies directed against CTLA-4. Here we report the appearance of a severe stricturing Crohn's disease-like colitis in a patient with a kidney allograft who was treated with belatacept, a recombinant CTLA-4-Ig fusion protein.

Psoriasis is a chronic inflammatory skin disease characterized by hyperplasia of keratinocytes and immune cell infiltration. The IL-17-producing T cells play key role in psoriasis pathogenesis, while regulatory (Treg) are diminished during psoriatic inflammation. Current treatments largely focus on IL-17 IL-23, however, few studies have explored therapeutic drugs targeting an increase Treg to c...