T-lymphocyte activation antigen CD86 (CD86)

T-Lymphocyte activation antigen CD86, also known as B7‑2, is a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily. It is primarily expressed on professional antigen-presenting cells such as dendritic cells, macrophages, and activated B cells. CD86 functions as a key costimulatory molecule required for full T cell activation, working alongside its homolog CD80/B7‑1, by binding two major receptors on T cells—CD28 (providing stimulatory signals) and CTLA‑4/CD152 (providing inhibitory signals). The balance between these interactions determines whether an adaptive immune response proceeds toward immunity or tolerance/anergy. The engagement between CD86/CD80 on APCs with CD28/CTLA‐4 on T cells is essential both for initiating effective immunity against pathogens/tumors and maintaining self-tolerance. Dysregulation can contribute to autoimmunity or cancer progression. Therapeutically, this axis is targeted by biologics such as abatacept that modulate co-stimulation in autoimmune disease settings.[3][5][9] Additionally, human/mouse cross-reactivity studies show conservation across species at critical binding sites. Beyond its role in adaptive immunity, CD86 also serves as a cellular receptor for certain adenoviruses, highlighting additional relevance beyond classical immunology.[1][5]

Other names

B7-2Activation B7-2 antigenB70BU63CD28LG2CTLA-4 counter-receptor B7.2Early T-cell costimulatory molecule 1 (ETC‑1)FUN‑1[1][2][4]

Blockade or modulation of the interaction between CD86 and its ligands: Inhibition via binding to CTLA‑4 analogs/fusion proteins prevents costimulatory signaling required for full T cell activation. Immunomodulation by altering balance between stimulatory signals through CD28 and inhibitory signals through CTLA‑4.[3][9]