Anti-VISTA, Rabbit Monoclonal (RM503)

Human VISTA is a 55 to 65kDa type I Ig membrane protein with the extracellular domain homologous to PD-L1. VISTA is mainly expressed on hematopoietic tissues (spleen, thymus and bone marrow) and on myeloid cells with lower expression on CD4+ and CD8+ T cells. VISTA is a new negative checkpoint regulator that potently suppresses T cell activation. Overexpression of VISTA on tumors inhibits the protective anti-tumor immunity and blockade of VISTA enhances antitumor immunity in multiple tumor models. VISTA on APC delivers negative signaling to T cells via a yet-to-identify binding partner on T cells.