背景资料:CD86 (B7-2) is an 80 kDa type I integral membrane protein and a member of the immunoglobulin superfamily of cell surface receptors. Along with CD80 (B7-1), CD86 participates in T cell costimulation via interaction with CD28 and CD152 (CTLA-4). It is expressed at very low density in normal tissues but is rapidly upregulated on stimulated B cells, monocytes, and dendritic cells. Since CD86 has rapid kinetics of induction, it is believed to be the major CD28 ligand expressed early in the immune response.