B7-H2/ICOSLG Recombinant Rabbit mAb (S-3306-12)

CD275, also called ICOS ligand (ICOSL) or B7-H2, is a 40–60 kDa glycosylated type-I transmembrane protein encoded by the ICOSLG gene on chromosome 21 and classified within the B7 and immunoglobulin superfamilies; it is expressed on B cells, dendritic cells, macrophages, monocytes, endothelial cells and various non-hematopoietic tissues, can be rapidly up-regulated by IFN-γ, TNF-α or LPS, and serves as the indispensable ligand for the inducible costimulator ICOS on activated T cells, thereby delivering a critical positive co-stimulatory signal that drives T-cell activation, proliferation, Th2 cytokine secretion and the generation of follicular helper T cells and germinal centers while simultaneously promoting B-cell differentiation into plasma cells and antibody production during secondary immune responses, and plays additional roles in reactivating effector/memory T cells on inflamed endothelium to control tissue entry and in skewing maternal immunity toward a protective Th2 phenotype during pregnancy; its dysregulation contributes to infection, hypersensitivity, autoimmune diseases, transplantation immunity and tumor immunity, and alternative splicing yields multiple isoforms with distinct tissue distributions and functions.