Description
B7-H2, also known as ICOSL and B7RP-1, is a transmembrane glycoprotein and member of the B7 family of co-stimulatory molecules related to B7-1 and B7-2. B7-H2 is expressed on B cells and macrophages and binds to ICOS on activated T cells delivering a positive co-stimulatory signal for optimal T cell function (1). The structural features of B7-H2 are crucial for its co-stimulatory function where receptor binding is mediated solely by the IgV domain but requires the IgC domain for maintaining the structural integrity of the protein (2)