Fig. 2

Created with BioRender.com. Receptors DNAM-1 and TIGIT cell extrinsic mechanisms: ① DNAM-1+ Tregs exert weak suppressive capacity with significantly increased cytokine IL-10 production. ② TIGIT binding to its ligands expressed on dendritic cells (DCs) inhibits T cell activation by enhancing the production of IL-10 and reducing the production of IL-12 in DCs, which creates an immunosuppressive microenvironment. ③ TIGIT+ Tregs exhibit enhanced suppressive capacity by augmenting Treg suppression and stability with high expression of IL-10, perforin, and TGF-β. ④ The bidirectional arrow represents the interaction between receptors and their ligands. The thickness of the arrow represents affinity between receptors and their common ligand. TIGIT indirectly inhibits T cell activation by directly completing DNAM-1 binding to their common ligand. ⑤ TIGIT inhibits T cell activation by disrupting CD226 cis-homodimerization in human T cells