Recombinant Human VISTA/B7-H5 Protein (C09-1610-167)

Protein Function:Platelet receptor Gi24, also known as Dies1, VISTA, SISP1 and B7-H5, is a 55-65 kDa transmembrane glycoprotein with homology to B7-like immune costimulatory molecules. Mature human Gi24 contains a 162 amino acid (aa) extracellular domain (ECD) with one V-type Ig-like domain, a 21 aa transmembrane segment, and a 96 aa cytoplasmic domain. Within the ECD, human Gi24 shares 70% and 67% aa sequence identity with mouse and rat Gi24, respectively. The 30 kDa ECD can be shed by MT1-MMP, with a 25-30 kDa fragment remaining in the membrane. Gi24 promotes both MT1-MMP expression and the MT1-MMP mediated activation of MMP-2. Gi24 supports the differentiation of embryonic stem cells (ESC) and enhances BMP-4 induced signaling in ESC, but is also down-regulated following BMP-4 exposure. It binds to BMP-4 directly, and also associates with the type I BMP receptor Activin RIB/ALK-4. Gi24 is expressed on the surface of naïve CD4+ T cells, regulatory T cells, and adipocytes. It is up-regulated in vivo on activated monocytes and dendritic cells. Gi24 inhibits CD4+ and CD8+ T cell proliferation, and their production of IL-2 and IFN-gamma. Its expression on tumor cells attenuates the anti-tumor immune response and enables more rapid tumor progression. In contrast, Gi24 limits disease progression in the autoimmune disease model EAE. Gi24 also acts as a co-inhibitory receptor on alloreactive T cells to regulate T cell tolerance. Specification: Animal Free, Carrier Free, Bioactive, ActiBioPure™, ≥95%(SDS-PAGE)