Fig. 4

Negative regulators of innate anti-tumor immunity. Schematic illustrating receptors and their ligands regulating anti-tumor immunity by NK cells (top) and macrophages (bottom). In NK cells, inhibitory receptors that recognize MHC class 1 molecules are recognized as a potential target to enhance NK cell-mediated cytotoxicity against tumors. Targeting macrophage phagocytosis checkpoints has also emerged as a potential approach in combination with various cancer mAb therapies due to its potential in enhancing the elimination of antibody-coated tumor cells. An immunosuppressive metabolite, adenosine, also potently inhibits innate and adaptive anti-tumor immunity. ADCP, antibody-dependent cellular phagocytosis; ADCC, antibody-dependent cellular cytotoxicity; DNAM-1, DNAX accessory molecule 1; TIGIT, T cell immunoreceptor with Ig and ITIM domains; NKG2A, NK group 2 member A; KIRs, killer-cell immunoglobulin-like receptors; HLA, human leukocyte antigen; MHC, major histocompatibility complex; LILRB1, leukocyte immunoglobulin-like receptor B1; SIRPα, signal regulatory protein α, Siglec-10, Sialic acid-binding Ig-like lectin 10