The Role Of Regulatory T Cells And T Helper17Cells In The Development Of HCC With HBV Infection

With persistent HBV (hepatitis B viruses) infection, dysregulation of hepatocyte growth occurs, resulting in progression of regenerative nodules and atypical hyperplasia (AH) then ultimately, development of HCC. Therefore, the inflammatory immune response caused by chronic HBV infection is a key factor of HCC. Lymphocytes are the main body of host immune response, the pro-inflammatory Th17(T helper cell17) and ant-inflammatory Tregs control the immune response balance. Studies have shown that the imbalance between Th17and Tregs is an important factor for progression in several of other human tumors. For HCC, several independent studies have shown that increased Tregs or Th17are associated with progression of HCC and prognosis. However, so far, little is known about the changes in equilibrium between Th17and Tregs in patients with CHB progressing from AH to HCC. In this study, the role of Thl7and Tregs in the immunopathogenesis of HCC in patients with chronic HBV infection was explored.Objective:1. The aim of the present study was to evaluate the expression of Tregs and Thl7in liver tissue and peripheral blood, IL-10and IL-17in plasma from CHB to HCC, and to investigate the role both Tregs and Th17in the development of HBV-related HCC.2. We also explored the roles of Tregs and Thl7in the development of HCC in vitro.3. We analyzed the prognostic value of tumor-infiltrating FoxP3+T cells in HCC by a meta-analysis.Methods:1.56sets of patient-matched tumors and peritumoral surgical specimens from56patient with HCC and136liver biopsies specimens from46patients with CHB,37with atypical hyperplasia (AH) and53with HCC were enrolled. The expression of IL-17and FoxP3in liver tissue was measured by immunochemistry.2. IL-17、IL-10in plasma of HCC patients in each group was detected by ELISA.3. Th17and Tregs in peripheral of HCC patients in each group were detected by Flow cytometry.4. MTT and ELISpot assays were performed to detect the effect of Tregs or Th17on CTL cells.5. The effect of Thl7on HepG2or HepG2.2.15cells was detected by MTT and BrdU/DAPI, and VEGF, IL-6and TGF-β were detected by ELISA.6. Relevant literature was searched, and a meta-analysis was conducted to estimate pooled survival and recurrence ratios.Results:1. In biopsies specimens, the density of liver infiltrated FoxP3+Tregs was increased in a stepwise manner from CHB to AH and HCC, while there was a decreasing trend for the density of IL-17+T cells. In surgical specimens of less differentiated HCC, the quantity of tumor-infiltrating FoxP3+Tregs were significantly lower and tumor-infiltrating IL-17+T cells were significantly higher. Additionally, high intratumoral FoxP3+Treg with high intratumoral IL-17+T cells or peritumoral IL-17+T cells showed a significantly lower OS and DFS compared with other groups (OS, P=0.033; DFS, P=0.004).2. IL-17, IL-10in plasma of HCC patients were no significant correlation with the clinical features and prognosis (P>0.05).3. There was a decreasing trend for Th17/Tregs in peripheral from CHB to HCC, and Thl7/Tregs was correlated with tumor stage (P=0.026).4. Tregs promote proliferation of hepatoma cells by suppressed the activity of secreting IFN-y by HCC specific CTL, but Th17can not affect the secreting IFN-y activity of HCC specific CTL. And when they were co-cultured with HepG2or HepG2.2.15, the more Th17, the more VEGF and IL-6(P<0.05) was secreted, and the more obvious of hepatoma cells proliferation (P<0.05) in the co-cultured system.5. The Meta analysis showed that the overall survival at1,3and5-year in high tumor-infiltrating FoxP3+T patients were lower than that low tumor-infiltrating FoxP3+T patients (P<0.001), and the recurrences at1,3and5-year in high tumor-infiltrating FoxP3+T patients were higher than that low tumor-infiltrating FoxP3+T patients (P<0.001).Conclusions:1. Th17and Tregs cells may cooperate to promote the progression of HCC, high intratumoral FoxP3+Treg with high IL-17+T cells patients showed a poor prognosis.2. Tregs inhibit the development of HCC by suppression of CTL, but Th17can promote the proliferation of HCC by pro-angiogenic and/or IL-6pathway.3. Tumor-infiltrating FoxP3+T cells were a factor for a poor prognosis for HCC.