InVivoSIM anti-human 4-1BB (Urelumab Biosimilar)

About InVivoSIM anti-human 4-1BB (Urelumab Biosimilar)

This non-therapeutic biosimilar antibody uses the same variable regions as the therapeutic antibody, Urelumab, making it ideal for research use. Urelumab reacts with 4-1BB, also known as CD137 antigen, TNF receptor superfamily member 9, or induced by lymphocyte activation. Urelumab has been engineered as a humanized IgG4 monoclonal antibody to reduce its non-specific binding to Fc receptors. Urelumab has a hinge mutation, S228P, which prevents IgG4 Fab exchange, thereby improving stability. CD137 is a type 1 membrane glycoprotein receptor that belongs to the tumor necrosis factor (TNF) superfamily, and it is expressed in lymphoid tissues. Upon activation, CD137 is expressed on the surface of several immune cells, including T cells (CD4+ and CD8+), NKT cells, regulatory T cells, eosinophils, and dendritic cells. Notably, CD137 is not expressed on the surface of resting T and B cells, as well as activated B lymphocytes, rendering it an advantageous biomarker for immunological activation. CD137L is an established ligand of CD137, and the CD137-CD137L signaling pathway augments and prolongs T-cell reactivity to alloantigens. Urelumab is an agonistic antibody that replicates cross-linking by the endogenous ligand (i.e., CD137-CD137L), and this antibody triggers a robust costimulatory signal in antigen-primed T cells, enhances the ADCC of NK cells, and boosts the T cell-mediated antitumor immunity.