CD80 antigen and CD86 antigen (CD80 (for B7-1), CD86 (for B7-2))

CD80 antigen (B7-1) and CD86 antigen (B7-2) are closely related type I transmembrane proteins of the immunoglobulin superfamily, belonging to the B7 family and expressed on antigen-presenting cells such as dendritic cells, B cells, monocytes, and activated macrophages. These ligands interact with costimulatory receptors CD28 and CTLA-4 on T cells, providing essential signals for initiation, maintenance, and regulation of T cell-mediated immune responses. While both proteins promote T cell activation by binding CD28, their engagement by CTLA-4 delivers a negative regulatory signal to limit immune activation. CD86 (B7-2) is generally expressed at higher baseline levels and upregulated more quickly than CD80 (B7-1), which shows inducible expression. They differ in structural and biochemical properties—CD80 is predominantly a cell surface dimer, while CD86 is a monomer. Both have significant roles in immunotherapy as targets for T cell modulation, especially in cancer and autoimmune disease treatments. They are also relevant safety markers due to the risk of excessive immune suppression or activation from therapeutic intervention.

Other names

B7-1Cluster of Differentiation 80B7-2Cluster of Differentiation 86

Blockade of CD80/CD86 prevents costimulatory signaling to CD28, reducing T cell activation. Enhances CTLA-4 mediated inhibitory signaling (immune checkpoint inhibition). Immunomodulation, either augmenting or suppressing immune responses depending on context.