Human VISTA Antibody - Onvatilimab IgG1fut Isotype

Non-fucosylated human IgG1 monoclonal antibody (mAb) against human VISTA

Anti-hVISTA-hIgG1fut is a recombinant monoclonal antibody (mAb) featuring a variable region that recognizes human VISTA, a member of the CD28/B7 protein superfamily, and a non-fucosylated constant region of the human IgG1 (hIgG1fut) isotype.

V-domain Ig-containing suppressor of T-cell activation (VISTA), also known as programmed death-1 homolog (PH-1H) is a known immune checkpoint, that directly suppresses T cell activation, proliferation, and cytokine production [1]. VISTA can be considered both a ligand and a receptor, whereby it transmits inhibitory signals to T cells, either extrinsically, through expression on myeloid cells (i.e. macrophage and dendritic cells) and binding to an unknown receptor on T cells, or intrinsically, through its expression on T cells (i.e. CD4+, CD8+) [2]. In the context of cancer immunotherapy, VISTA has been found to be heightened on cells that infiltrate the tumor microenvironment (TME) and not the tumor cells themselves, therefore, VISTA-blocking antibodies are of interest. These function to inhibit the engagement of VISTA with its receptor on T cells or by directly targeting VISTA expressed on naïve and effector T cells, preventing it from providing negative signaling [1, 2].

Features of Anti-hVISTA-hIgG1fut:

• Targets specifically human VISTA
• Features the hIgG1fut constant region for enhanced effector function
• Functionally validated by flow cytometry

Anti-hVISTA-hIgG1fut is a non-fucosylated antibody, whereby the absence of fucose residues from N-glycans of the IgG-Fc results in an enhancement of antibody-dependent cellular cytotoxicity (ADCC). This increased ADCC is without any detectable change to complement-dependent cytotoxicity (CDC) or antigen-binding capability. Anti-hVISTA-hIgG1fut was generated by recombinant DNA technology, produced in CHO cells (deficient for fucosylation), and purified by affinity chromatography with protein G.

References:

1. Nowak, E.C. et al. 2017. Immunoregulatory functions of VISTA. Immunol Rev 276, 66-79.
2. Xu, W. et al. 2018. The structure, expression, and multifaceted role of immune-checkpoint protein VISTA as a critical regulator of anti-tumor immunity, autoimmunity, and inflammation. Cell Mol Immunol 15, 438-446.