Cluster of Differentiation 80 and 86 (CD80/CD86)

CD80 (B7-1) and CD86 (B7-2) are critical costimulatory ligands expressed on the surface of antigen-presenting cells (APCs) that dictate the outcome of T cell receptor signaling (UniProt P33681, P42081). They interact with two competing receptors on T cells: CD28, which provides the essential stimulatory signal for T cell proliferation and survival, and CTLA-4 (CD152), which serves as a high-affinity inhibitory checkpoint (Nature Reviews Immunology, 2011). Regulatory T cells (Tregs) utilize CTLA-4 to maintain peripheral tolerance by outcompeting CD28 for ligand binding and by physically removing CD80/CD86 from the APC surface via a process known as trans-endocytosis (Science, 2011). This competitive axis is a primary therapeutic target in transplantation and autoimmunity, where CTLA-4-Ig fusion proteins like Abatacept mimic Treg-mediated suppression to prevent graft-versus-host disease and tissue destruction (StatPearls, NBK537012). In oncology, the axis is manipulated using checkpoint inhibitors that block CTLA-4, thereby ensuring CD80/CD86 remains available to bind CD28 and enhance anti-tumor effector T cell responses (NEJM, 2010).

Other names

B7-1 (CD80)B7-2 (CD86)B7 moleculesT-lymphocyte activation antigen CD80T-lymphocyte activation antigen CD86B7.1/B7.2

Drugs like Abatacept and Belatacept function as CTLA-4-Ig fusion proteins that bind to CD80/CD86 on antigen-presenting cells, competitively inhibiting their interaction with CD28 on effector T cells to prevent costimulation. Conversely, checkpoint inhibitors like Ipilimumab block the CTLA-4 receptor on T cells to prevent it from sequestering CD80/CD86, thereby maintaining CD28-mediated activation.