29 Although Th17 cells participate in inducing proinflammatory responses during viral infection, the antiviral activity of Th17 cells to control HCV replication

appears to be limited. Rather, Th17 cells appear to play a role in the progression of liver fibrosis and cirrhosis.22, 25 Indeed, histological studies show extensive infiltration of Th17 cells in the area of severe hepatic damage. Based on the role of TSLP in inducing differentiation of CD4+ Th17 effector T cells, we speculate a potential mechanism(s) for HCV-induced Th17 differentiation through several stepwise processes of crosstalk between virus-infected cells and local DCs. Liver-resident DCs are conditioned by TSLP released from HCV-infected hepatocytes to favor, either at the

site of viral infection and/or in the draining lymph node, the SRT1720 concentration differentiation of Th17 cells, which then home to liver damage sites and possibly contribute to disease progression by interacting with other immune cells and nonimmune cells. This points out a critical biological role of TSLP secreted by HCV-infected hepatocytes in activating DCs which result in Th17 differentiation. Future studies are necessary to elucidate whether Th17 cells promote liver damage and are directly involved in enhanced virus survival or if they are simply less capable than Th1 cells in the induction of antiviral responses. Nevertheless, our studies point out that blockade of TSLP might be a new strategy for the treatment of chronic HCV patients with severe liver diseases. As TSLP is known for its role in inducing inflammation, efforts check details to block TSLP is being investigated for its potential as a treatment for asthma. The availability of therapeutic agent(s) targeting TSLP could accelerate the translation of these findings into clinical practices such as treatment of HCV-associated chronic liver diseases. In summary, our findings suggest that TSLP produced by HCV-infected hepatocytes

can enhance the development of potential injury-provoking CD4+ Th17 effector T cells through the ability of cytokines to condition DCs to drive the differentiation of CD4+ T cells towards Th17 effector status. If, as we believe, CD4+ Th17 effector T-cell responses medchemexpress in the HCV-infected liver are important regulators of liver injury, then TSLP might represent a novel therapeutic target in HCV-infected liver with the potential to limit tissue injury and possibly promote virus clearance. We thank Susan Landes for excellent technical assistance, Dr. Thomas J. Braciale and Dr. Taeg S. Kim for critical discussion of the article prior to submission, and members of the Hahn laboratory for helpful discussions throughout the course of this work. “
“Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide.