Anti-Human CD3-APC/CD4-FITC/CD8a-PE [OKT-3,RPA-T4,OKT-8]

This product is a FCM antibody cocktail made up of APC Anti-Human CD3 Antibody [Clone: OKT-3] (Mouse IgG2a, kappa), FITC Anti-Human CD4 Antibody [Clone: RPA-T4] (Mouse IgG1, kappa) and PE Anti-Human CD8a Antibody [Clone: OKT-8] (Mouse IgG2a, kappa). CD3 is a heterotetrameric protein consisting of a CD3gamma, a CDdelta and 2 CD3epsilon. It forms complex with TCR. OKT-3 recognize human CD3epsilon. Human CD3 is expressed on the surface of T cells and NKT cells. CD4 is also called Leu-3 or T4. It's a single-chain type I transmembrane glycoprotein, mainly expressed on the surface of T cells, and monocytes/macrophages. In T cells, CD4 forms complex with TCR/CD3 and play important roles in T cell immunity. The target of HIV is CD4+ T cells. Reduction of CD4+ T cells is the main reason of defected immunity after HIV infection. CD8 is mainly expressed on cytotoxic T cells and also some subpopulations of NK cells. CD8 forms dimer function. In most cells, CD8 is a heterodimer consisting of CD8a and CD8b, but in NK cells nearly all CD8 is homodimer of CD8a. CD8a can form co-receptor with MHC-I restricted TCR to promote T cell antigen recognition and activation. Protein function: Part of the TCR-CD3 complex present on T-lymphocyte cell surface that plays an essential role in adaptive immune response. When antigen presenting cells (APCs) activate T-cell receptor (TCR), TCR- mediated signals are transmitted across the cell membrane by the CD3 chains CD3D, CD3E, CD3G and CD3Z. All CD3 chains contain immunoreceptor tyrosine-based activation motifs (ITAMs) in their cytoplasmic domain. Upon TCR engagement, these motifs become phosphorylated by Src family protein tyrosine kinases LCK and FYN, resulting in the activation of downstream signaling pathways (PubMed:2470098). In addition of this role of signal transduction in T-cell activation, CD3E plays an essential role in correct T-cell development. Initiates the TCR-CD3 complex assembly by forming the two heterodimers CD3D/CD3E and CD3G/CD3E. Participates also in internalization and cell surface down- regulation of TCR-CD3 complexes via endocytosis sequences present in CD3E cytosolic region (PubMed:10384095, PubMed:26507128). [The UniProt Consortium]