The MIH43 monoclonal antibody specifically binds to human B7-H4 (B7 family member, H4) that is encoded by the VTCN1 (V-set domain containing T cell activation inhibitor 1) gene. B7-H4 is a type I membrane glycoprotein with a calculated molecular weight of 30.89 kDa. It is also known as VCTN1, B7h.5, B7S1 (B7 superfamily member 1) or B7X. B7-H4 is a newly discovered member of the B7 family of costimulatory proteins. B7-H4 is not constitutively expressed on peripheral tissues. Its expression can be induced on macrophages, dendritic cells, B cells and T cells. By binding to its putative receptor, the function of B7-H4 was initially reported to be a negative regulator of T cell activation, proliferation and differentiation related to cytokine production and cytotoxic effector cell functions. B7-H4 is reportedly overexpressed in a variety tumors. B7-H4 expression by tumor macrophages appears to play a role in suppression antigen-specific T cell mediated immunity. Recent studies indicate that B7-H4 can also be a positive regulator of T cell responses. B7-H4 can be involved innate immunity as well, eg, by inhibiting neutrophil expansion.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.