About InVivoSIM anti-human VISTA (Onvatilimab Biosimilar) This non-therapeutic biosimilar antibody uses the same variable regions as the therapeutic antibody, Onvatilimab, making it ideal for research use. Onvatilimab is a humanized IgG1 monoclonal antibody that reacts with V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA), also known as VSIR or B7-H5. VISTA is an immunoregulatory receptor that inhibits the T-cell response. VISTA is also involved in the stimulation of MMP14-mediated MMP2 activation. VISTA is suggested to promote embryonic stem cell differentiation through its inhibitory effects on BMP4 signaling. VISTA is a type I transmembrane glycoprotein from the Ig superfamily, and it is expressed in several myeloid cells, including CD11b monocytes, CD66b+ neutrophils, at low levels on CD4+ and CD8+ T-cells, and in a subset of NK cells. VISTA functions as a negative immune-checkpoint protein that suppresses T cell cytokine production and proliferation. VISTA is overexpressed by tumor-infiltrating lymphocytes, such as myeloid cells and regulatory T cells. In tumors, VISTA regulates T cell function, thus promoting antitumor effects. In preclinical mouse models, VISTA blockade with monoclonal antibodies decreases the MDSC infiltration in tumors with concomitant induction of immune effector infiltrates, thereby exerting positive effects on the survival of tumor-bearing mice. InVivoSIM anti-human VISTA (Onvatilimab Biosimilar) Specifications IsotypeHuman IgG1, κ Recommended Isotype Control(s)RecombiMAb human IgG1 isotype control, anti-hen egg lysozyme Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenHuman VISTA Reported Applicationsin vitro blocking of VISTA signaling in vivo blocking of VISTA signaling Functional assays Flow cytometry ELISA FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<0.5EU/mg (<0.0005EU/μg) Determined by LAL gel clotting assay Aggregation<5% Determined by SEC Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtration ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein A Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze.