Table 2.
T cell associated inhibitory immune checkpoint pathways.
| Molecule | Expression | Ligand/ receptor | Effect |
|---|---|---|---|
| LAG-3 (CD223) | T and NK cells, TILs | MHC II | Negative regulator of T cell function and DC (22, 23) |
| TIM-3 | NK cells, macrophages | Multiple: SCTLACAM-1, galectin | Induction of MDSC, negative regulator of T cell function (24) |
| VISTA (PD-L1H) | Tumor, myeloid cells, T cells, Tregs | T cell suppression (25) | |
| TIGIT | T and NK cells | CD155, CD112 | Immune suppression IFN-γ↓, IL-10↑ (26, 27) |
| B7-H3 (CD276) | Tumors, APC, NK, B and T cells | Receptor not yet analyzed | Activation/suppression of T cell and NK cell function (28) |
| BTLA-4 (CD272) | Tumor cells | HVEM | Inhibition of T and B cell activation |
| A2aR and CD73 | T cells, APC, NK cells, endothelial cells | Adenosine | Attenuation of inflammation, inhibition of T cell activation (29) |
| B7-H4 (B7x) | ACP, DC, macrophages, tumor cells | Receptor not yet identified | Inhibition of T cell function and differentiation (30) |
↑ upregulation, ↓ downregulation.