1. Figure 6 Innate lymphoid cells in liver inflammation
Figure 6 | Innate lymphoid cells in liver inflammation. NKT cells constitutively patrol the liver sinusoids and are highly dependent on CXCR6-mediated signalling. Upon activation they secrete several cytokines such as IL-4 but also IFNγ and IL-17, mainly due to glycolipid recognition via CD1d on endothelial cells and Kupffer cells. NKT cells can propagate inflammatory responses, for example, by activating neutrophils and monocyte recruitment. NKT cells subsequently guide T-cell polarization dependent on the cytokine milieu and drive IL-33 production by endothelial cells and hepatocytes. Liver damage can limit NKT-cell responses by transient deletion. In human liver, NKT cells are less frequent, but MAIT cells show similar functions especially in microorganism-initiated reactions. NK cells perform important functions in viral defence and can furthermore limit development of liver fibrosis by deleting activated HSC. CTLA-4, cytotoxic T-lymphocyte protein 4; FasL, Fas ligand; HSC, hepatic stellate cell; LSEC, liver sinusoidal endothelial cell; MAIT, mucosal-associated invariant T cell; MPO, myeloperoxidase; MR1, mannose receptor 1; NK cell, natural killer cell; NKT cell, natural killer T cell; ROS, reactive oxygen species; STAT4, signal transducers and activators of transcription; TLR, Toll-like receptor.
Heymann, F. & Tacke, F. (2016) Immunology in the liver — from homeostasis to disease
Nat. Rev. Gastroenterol. Hepatol. doi: /nrgastro