CD86 is one of two ligands (the other CD80) for CTLA4 and CD28. CD86 acts as costimulatory molecule in eliciting T-cell help during antigen presentation. Antigen presentation in the absence of sufficient co-stimulation involving CD86/CD80 can induce tolerance. CD80 appears to play a role distinct from CD80 in T helper cell differentiation. CD86 is a type I membrane protein that is a member of the immunoglobulin superfamily. The CD86 protein is expressed by antigen-presenting cells, and it is the ligand for two proteins at the cell surface of T cells, CD28 antigen and cytotoxic T-lymphocyte-associated protein 4. Binding of CD86 with CD28 antigen is a costimulatory signal for activation of the T-cell. Binding of CD86 with cytotoxic T-lymphocyte-associated protein 4 negatively regulates T-cell activation and diminishes the immune response. Alternative splicing results in two transcript variants encoding different isoforms of CD86. Additional transcript variants have been described for CD86, but their full-length sequences have not been determined. Diseases associated with CD86 dysfunction include gallbladder squamous cell carcinoma and myocarditis.
Activation B7-2 antigen; CD86; early T cell costimulatory molecule-1; Early T-cell costimulatory molecule 1; ETC-1; MGC34413; T-lymphocyte activation antigen CD86