Figure 1.

Mechanisms underlying the roles of innate and innate-like lymphocytes in the progression of NASH. Hepatic steatosis is induced by diet, chemical or genetic factors, characterized by the presence of hepatocytes with lipid accumulation. Stressed hepatocytes and non-parenchymal hepatic cells trigger the innate immune responses by releasing various signals. NK, ILC2/3, NKT, γδT, and MAIT cells are activated and exert their functions directly, or indirectly by linking the innate and adaptive immune cells including macrophages/monocytes, HSCs, CD4⁺ T and CD8⁺ T cells. NK, natural killer cell; NKT, natural killer T cell; ILC, innate lymphoid cell; MAIT, mucosal-associated invariant T cell; HSC, hepatic stellate cell; MoMF, monocyte-derived macrophage; Hh, hedgehog; OPN, osteopontin; Gal-9, galectin-9; LIGHT, LTβR ligand.