PRODUCTS

V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA), Fc Tag, His Tag

Human VISTA was expressed from hamster CHO-K1 cells. The protein was purified by affinity and size exclusion chromatography. The protein carries a human IgG1 Fc tag at the C-terminus and His tag. The human IgG1 Fc tag can be digested by Factor X leaving the VISTA protein sequence with digestion site at the C-terminus.

V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA), also known as PD-1H, DD1α, c10orf54, Gi24, Dies1, and SISP1 (3), is 279 amino acids protein, comprising a 162-aa extracellular domain, a 21- aa transmembrane domain and a 96-aa cytoplasmic domain. The VISTA extracellular domain is hyperglycosylated and appears 15 kDa larger than its predicted molecular mass of 20 kDa upon analysis by gel electrophoresis (SDS-PAGE). VISTA is expressed on CD11b monocytes, CD11c+ dendritic cells (2), CD66b+ neutrophils, at low levels on CD4+ and CD8+ T-cells, and in a subset of NK cells. Not detected on B cells (1). VISTA can be both a ligand and a receptor. As a ligand, VISTA is expressed on antigen-presenting cells and binds a receptor on T cells to inhibit downstream T cell activation. As a receptor, VISTA is expressed on T cells and transduces intracellular inhibitory signals after ligand binding to curtail T cell activity. VISTA is implicated in a number of human cancers, including skin (melanoma), prostate, colon, pancreatic, ovarian, endometrial, and lung (1). VISTA in tumour cells suppressed T cell proliferation and cytokine production in vitro, and decreased the tumour-infiltrating CD8+ T cells in vivo (4).

1. Mehta N et al. Structure and Functional Binding Epitope of V-domain Ig Suppressor of T Cell Activation. Cell Reports. 2019 Sep 3;28(10): 2509-2516 e5.
2. Lines JL at al. VISTA is an immune checkpoint molecule for human T cells. Cancer Research. 2014 Apr 1;74(7): 1924-1932.
3. Nowak EC et al. Immunoregulatory Functions of VISTA. Immunological Reviews.   2017 Mar 276(1): 66-79.
4. Mulati K et al. VISTA expressed in tumour cells regulates T cell function. British Journal of Cancer. 2019 Jan 120(1): 115-127.