T-lymphocyte activation antigen CD80 and T-lymphocyte activation antigen CD86 (CD80/CD86)

CD80 (B7-1) and CD86 (B7-2) are essential co-stimulatory molecules primarily expressed on the surface of professional antigen-presenting cells, such as dendritic cells [1, 8]. They belong to the immunoglobulin superfamily and play a pivotal role in the adaptive immune response by providing the necessary second signal for T-cell activation through their interaction with the CD28 receptor [1, 10]. Conversely, they also bind to the inhibitory receptor CTLA-4 with higher affinity, which serves to attenuate T-cell responses and maintain peripheral tolerance [2, 14]. Dysregulation of the CD80/CD86 pathway is implicated in various conditions, including autoimmune diseases like rheumatoid arthritis and the prevention of organ transplant rejection [1, 12]. In oncology, these molecules are often studied for their role in the tumor microenvironment, where their interaction with CTLA-4 can lead to immune evasion by the tumor [5, 13]. Therapeutic strategies involve using fusion proteins like abatacept and belatacept to block these ligands, thereby inhibiting pathological T-cell activation [1, 2]. Monitoring the expression levels of CD80 and CD86 on dendritic cells serves as a valuable biomarker for assessing immune status and therapeutic response [3, 6].

Other names

B7-1B7-2B7.1B7.2BB1B70CD28LG1CD28LG2LAB7LAB72T-lymphocyte activation antigen CD80T-lymphocyte activation antigen CD86

Drugs such as abatacept and belatacept are CTLA-4-Ig fusion proteins that bind directly to CD80 and CD86 on the surface of antigen-presenting cells [1, 2]. This binding competitively inhibits the interaction between these ligands and the CD28 receptor on T-cells, thereby blocking the essential co-stimulatory signal required for T-lymphocyte activation, proliferation, and cytokine production [1, 10]. This mechanism is primarily used to treat autoimmune conditions and prevent transplant rejection by inducing a state of immune unresponsiveness [1, 12].