Figure 2.

IL-17 impact in liver regeneration IL-17 is mainly produced by Th17 - from naïve T cells differentiation upon TGF-β, IL-6 and IL-21 stimulation - and γδ T cells. Inflammatory environment induced by injury sustains Th17 population and controls the balance between Th17 and their counteracting Treg cells to preserve immune homeostasis. Upon injury γδ T cells increase in number to sustain IL-17 levels. IL-17 acts on hepatocyte inducing massive production of IL-6 and IL-8 to trigger pro-inflammatory genes activation. IL-17 induced Kupffer cells produce pro-inflammatory cytokines. IL-17 signalling controls C/EBPβ and A20 regulating in turn IL-6/STAT3 and NF-κB signalling. In proliferating environment high level of IL-17 interferes with NKs activation inducing IL-4-mediated proliferation; reduced IL-17 levels at termination phase promote IFN-γ production by NKs reactivation, inducing apoptosis in hepatocytes and interrupting regenerating process.