Anti-CTLA4 Antibody Fluoro647 Conjugated

CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4), also known as CD152, is a protein receptor that down regulates the immune system. It is a member of the immunoglobulin superfamily, which is expressed on the surface of Helper T cells and transmits an inhibitory signal to T cells. CTLA4 is similar to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. CTLA4 transmits an inhibitory signal to T cells, whereas CD28 transmits a stimulatory signal. Blockade of CTLA4 expression in vitro augmented HIV-specific CD4-positive T-cell function.

Inhibitory receptor acting as a major negative regulator of T-cell responses. The affinity of CTLA4 for its natural B7 family ligands, CD80 and CD86, is considerably stronger than the affinity of their cognate stimulatory coreceptor CD28 (By similarity) . .

1. Dariavach P, Mattéi MG, Golstein P, Lefranc MP (December 1988) . Human Ig superfamily CTLA-4 gene: chromosomal localization and identity of protein sequence between murine and human CTLA-4 cytoplasmic domains. Eur. J. Immunol. 18 (12) : 1901–5. 2. Magistrelli G, Jeannin P, Herbault N, Benoit De Coignac A, Gauchat JF, Bonnefoy JY, Delneste Y (November 1999) . A soluble form of CTLA-4 generated by alternative splicing is expressed by nonstimulated human T cells.Eur. J. Immunol. 29 (11) : 3596–602. 3. Waterhouse P, Penninger JM, Timms E, Wakeham A, Shahinian A, Lee KP, Thompson CB, Griesser H, Mak TW (November 1995) . Lymphoproliferative disorders with early lethality in mice deficient in Ctla-4. Science 270 (5238) : 985–8.