Human VSIG4 Recombinant Protein (His Tag)

Background: V-Set and Immunoglobulin Domain-Containing Protein 4 (VSIG4) is a 45-50 kDa macrophage-specific transmembrane glycoprotein that belongs to the B7 family-related protein and an Ig superfamily member. In contrast to the B7 family members which contain two IgG domains; VSIG4 contains one complete V-type Ig domain and a truncated C-type I g domain. VSIG4 is abundantly expressed in several fetal tissues. In adult tissues; the highest expression of VSIG4 is in lung and placenta. It is also expressed in resting macrophages. No VSIG4 expression appears to be present in T and B cells. The specific expression of VSIG4 on resting macrophages in tissue suggests that this inhibitory ligand may be important for the maintenance of T cell unresponsiveness in healthy tissues. VSIG4 functions as a negative regulator of T cell activation; and may be involved in the maintenance of peripheral T cell tolerance; and is also identified as a potent suppressor of established inflammation. VSIG4 is a phagocytic receptor; strong negative regulator of T-cell proliferation and IL2 production. It is a potent inhibitor of the alternative complement pathway convertases. Human VSIG4 is 399 amino acids (aa) in length. It is a type I transmembrane (TM) glycoprotein that contains a 264 aa extracellular domain (ECD) (aa 20 – 283) and a 95 aa cytoplasmic region.