Between Scylla and Charybdis: The role of the human immune system in the pathogenesis of hepatitis C

Figure 2 Multiple activities of hepatitis C virus-specific regulatory T cells in chronic hepatitis C. Regulatory T cell (Tregs) inhibit antiviral immunity via release of immunosuppressive factors, such as interleukin 10 (IL-10), transforming growth factor beta (TGF-β) and interleukin 35 (IL-35). Tregs in hepatitis C are also differentiated towards interleukin 8 (IL-8) production. Release of IL-8 binds to its receptors, such as CXCR2 on hepatic stellate cells (HSC), which become activated and produce extracellular matrix (ECM) components. IL-8 down-regulates interferon-stimulated genes in infected cells and induces an interferon (IFN)-refractory state, which also counter-acts antiviral immunity. ISGs: Interferon-stimulated genes.