CD86 (B7-2) and CD80 (B7-1) are molecules upregulated on Antigen Presenting Cells (APCs) upon activation of Toll-Like Receptor (TLR) pathways, playing a crucial role in T cell activation by binding to the co-stimulatory molecule CD28. CTLA-4 (CD152) is expressed on activated T cells and binds to CD80 and CD86 with higher affinity than CD28, leading to the suppression of T cell activation. Blocking CTLA-4 signaling prolongs T cell activation and enhances anti-tumor responses. CTLA-4 was the first immune checkpoint targeted for cancer treatment.

Abbreviations:

BU63, B7-2/CD86, B7.2, CD28LG2, B70, CTLA-4 counter-receptor B7.2, CD86, T-lymphocyte activation antigen CD86, LAB72, Activation B7-2 antigen.