Recombinant Rat VISTA/B7-H5/PD-1H Fc Chimera Protein, CF

Recombinant Rat VISTA/B7-H5/PD-1H Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: VISTA/B7-H5/PD-1H

V-domain Ig suppressor of T cell activation (VISTA), also known as platelet receptor Gi24, Dies1, SISP1, PD-1H, and B7‑H5, is a 50-60 kDa transmembrane glycoprotein with homology to B7-like immune co-stimulatory molecules (1, 2). Mature rat VISTA contains a 160 amino acid (aa) extracellular domain (ECD) with one Ig-like domain, a 24 aa transmembrane segment, and a 96 aa cytoplasmic domain. The ECD of rat VISTA shares a 78% and 67% aa sequence identity with mouse and human VISTA, respectively. In human VISTA, a 30 kDa ECD can be shed by MT1‑MMP, leaving a 25-30 kDa fragment remaining in the membrane (3). VISTA promotes both MT1‑MMP expression and the MT1-MMP mediated activation of MMP-2 (3). VISTA has been shown to support the differentiation of embryonic stem cells (ESC) and enhances BMP-4 induced signaling in ESC, but it is also down-regulated following BMP-4 exposure (4, 5). Vista can bind directly to BMP-4, but it also associates with the type I BMP receptor Activin RIB/ALK 4 (4, 5). VISTA is highly expressed on mature CD11b high myeloid-derived APCs and to a lesser extent on CD4⁺, CD8⁺, and T regs and is also found on tumor infiltrating lymphocytes (7). It is up-regulated in vivo on activated monocytes and dendritic cells (5). VISTA inhibits CD4⁺ and CD8⁺ T cell proliferation, and their production of IL2 and IFN-gamma (6). Its expression on tumor cells attenuates the antitumor immune response and enables more rapid tumor progression (6). Suppression of VISTA signaling was shown to increase the rate of progression in the mouse autoimmune disease model EAE (6). VISTA-Ig suppressed proliferation of T cells but not B cells and blunted the production of T cell cytokines and activation markers, suggesting that VISTA as a negative checkpoint regulator suppresses T cell activation (8, 9).

Related Research Areas

• Coagulation
• Co-stimulatory and Co-inhibitory Molecules
• Embryonic and Induced Pluripotent Stem Cell Markers
• Metalloproteases and Regulators
• MMPs, TIMPs and Related Molecules
• Search Immune Checkpoint Targets