T-lymphocyte activation antigen CD80 (CD80) (CD80)

T-lymphocyte activation antigen CD80, commonly known as B7-1, is a transmembrane glycoprotein expressed on the surface of professional antigen-presenting cells, including dendritic cells, B cells, and macrophages [1, 5]. It serves as a critical co-stimulatory molecule in the immune system, providing the essential secondary signal required for full T-cell activation upon binding to the CD28 receptor [2, 5]. Conversely, CD80 also binds to CTLA-4 with higher affinity, which transmits inhibitory signals to dampen the immune response and maintain self-tolerance [3, 11]. This dual functionality makes CD80 a central regulator of immune homeostasis and a significant therapeutic target [4, 6]. In disease states, dysregulated CD80 signaling is linked to autoimmune disorders like rheumatoid arthritis and systemic lupus erythematosus, as well as immune evasion in various cancers [2, 4, 14]. Therapeutic interventions include CTLA-4-Ig fusion proteins such as abatacept and belatacept, which block the CD80/CD28 interaction to treat autoimmune conditions and prevent organ transplant rejection [3, 6]. Additionally, novel CD80-based fusion proteins and antibodies are being investigated in clinical trials to enhance T-cell activity against solid tumors and hematologic malignancies [4, 11].

Other names

B7-1B7BB1CD28LGCD28LG1LAB7Activation B7-1 antigen

Co-stimulation blockade via competitive inhibition of CD28 binding and mimicry of CTLA-4 inhibitory signaling.