T-lymphocyte activation antigen CD80 and T-cell-specific surface glycoprotein CD28 interaction (CD80-CD28 interaction)

The CD80-CD28 interaction is a fundamental costimulatory pathway essential for the full activation of T lymphocytes [2, 6]. CD80 (also known as B7-1) is a glycoprotein expressed on the surface of professional antigen-presenting cells, while CD28 is its primary stimulatory receptor constitutively expressed on T cells [2, 8]. When CD80 binds to CD28, it provides a critical "second signal" that complements the primary signal from the T-cell receptor, leading to robust T-cell proliferation, survival, and the production of cytokines like interleukin-2 [4, 6]. This pathway is a major therapeutic target because its dysregulation is central to various pathologies; overactivity is linked to autoimmune diseases and transplant rejection, while its suppression by inhibitory receptors like CTLA-4 allows tumors to evade immune detection [2, 9]. Drugs such as Abatacept and Belatacept utilize CTLA-4-Ig fusion proteins to competitively inhibit CD80/CD86 from binding to CD28, thereby suppressing unwanted immune responses in conditions like rheumatoid arthritis [9]. Conversely, emerging cancer therapies seek to modulate this interaction to restore or enhance anti-tumor T-cell activity [2, 8].

Other names

B7-1/CD28 interactionB7-1-CD28 costimulatory pathwayCD80-CD28 costimulationB7-CD28 interactionCostimulatory signal 2

Competitive inhibition of CD28 binding by blocking CD80/CD86 ligands or direct blockade of the CD28 receptor to prevent costimulatory signaling [2, 9].