Table 2 Summary of the biological and molecular functions of CTLA-4, PD-1 and PD-L1
From: Targeting RNA N6-methyladenosine to synergize with immune checkpoint therapy
Molecule | Ligand(s) | Receptor expression pattern | Biological function | Molecular mechanism | References |
|---|---|---|---|---|---|
CTLA-4 | CD80 (B7-1), CD86 (B7-2) | Activated T cells, Tregs, NK cells | Restrains T cell activity and T-cell co-stimulation | Competitively inhibits CD28 signaling (binding of CD80 and CD86); reduces CD80/CD86 expression | |
PD-1 | PD-L1, PD-L2 | Activated T cells, Tregs, NK cells, NKT cells, B cells, macrophages, DCs, Langerhans’ cells | Inhibits T-cell stimulation and costimulatory signaling | Inhibits TCR signaling and CD28 signaling | |
PD-L1 | PD-1 | DCs, monocytes, macrophages, mast cells, T cells, B cells, NK cells, tumor cells | Suppresses T-cell activity | Inhibits T-cell activity by binding to PD-1 |