Definitions of B7 1 Costimulatory Molecule

  1. The natural ligand for the T- cell antigen CD28; ( ANTIGENS, CD28); mediating T- and B- cell adhesion. CD80 is expressed on activated B- cells and gamma- interferon- stimulated monocytes. The binding of CD80 to CD28 and CTLA- 4 provides a co- stimulatory signal to T- cells and leads to greatly upregulated lymphokine production.