Fu-Sheng Wang

Impairment of CD4+ cytotoxic T cells predicts poor survival and high recurrence rates in patients with hepatocellular carcinoma.

The role of CD4+ cytotoxic T cells (CTLs) in hepatocellular carcinoma (HCC) remains obscure. This study characterized CD4+ CTLs in HCC patients and further elucidated the associations between CD4+ CTLs and HCC disease progression. In all, 547 HCC patients, 44 chronic hepatitis B (CHB) patients, 86 liver cirrhosis (LC) patients, and 88 healthy individuals were enrolled in the study. CD4+ CTLs were defined by flow cytometry, immunohistochemistry, and lytic granule exocytosis assays. A multivariate analysis of prognostic factors for overall survival was performed using the Cox proportional hazards model. Circulating and liver‐infiltrating CD4+ CTLs were found to be significantly increased in HCC patients during early stage disease, but decreased in progressive stages of HCC. This loss of CD4+ CTLs was significantly correlated with high mortality rates and reduced survival time of HCC patients. In addition, the proliferation, degranulation, and production of granzyme A, granzyme B, and perforin of CD4+ CTLs were inhibited by the increased forkhead/winged helix transcription factor (FoxP3+) regulatory T cells in these HCC patients. Further analysis showed that both circulating and tumor‐infiltrating CD4+ CTLs were independent predictors of disease‐free survival and overall survival after the resection of the HCC. Conclusion: The progressive deficit in CD4+ CTLs induced by increased FoxP3+ regulatory T cells was correlated with poor survival and high recurrence rates in HCC patients. These data suggest that CD4+ CTLs may represent both a potential prognostic marker and a therapeutic target for the treatment of HCC. (HEPATOLOGY 2013)

Increased Th17 cells contribute to disease progression in patients with HBV‐associated liver cirrhosis

Summary.  T helper (Th) 17 cells have been demonstrated to participate in the pathogenesis of HBV‐associated liver damage. However, little is known regarding the immunopathogenic role of liver fibrosis in patients with HBV‐associated liver cirrhosis. The aims of this study were to evaluate whether Th17 cells are related to disease progression in patients and to explore the possible mechanisms. The frequencies of circulating Th17 cells were analysed in 78 patients with hepatitis B and cirrhosis (Child A: 34; Child B: 22; Child C 22) and matched controls. Liver samples were collected from 13 patients with HBV‐associated cirrhosis, 23 patients with chronic hepatitis B and 12 healthy controls for immunohistochemical analysis. IL‐17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL‐17 by flow cytometry. Patients with hepatitis B‐associated cirrhosis with more severe disease displayed significant increases in peripheral numbers of Th17 cells as well as in IL‐17 plasma levels. The increased intrahepatic IL‐17+ cells correlated positively with fibrotic staging scores and clinical progression from CHB to cirrhosis. Moreover, many IL‐17+ cells were located in fibrotic areas in the liver of patients with cirrhosis. In vitro, IL‐17 together with IL‐17‐activated monocytes, could promote the activation of stellate cells, which, in turn, aggravated liver fibrosis and the inflammatory response. In summary, increased peripheral and intrahepatic Th17 cells are enriched in patients with hepatitis B and cirrhosis and contribute further to the severity of disease progression through induction of stellate cell activation.

CD24 polymorphisms affect risk and progression of chronic hepatitis B virus infection

T‐cell immunity to hepatitis B virus (HBV) is involved in both viral clearance and the pathogenesis of cirrhosis and hepatocellular carcinoma following chronic HBV infection. It is therefore of great interest to analyze whether genetic polymorphism of genes involved in the immune response may determine the outcomes of chronic HBV infection. Here we report that CD24 polymorphisms affect the risk and progression of chronic HBV infection. Thus the CD24 P170T allele, which is expressed at a higher level, is associated with an increased risk of chronic HBV infection. Among the chronic HBV patients this allele shows recessive association with more rapid progression to liver cirrhosis and hepatocellular carcinoma in comparison to the P170C allele. In contrast, a dinucleotide deletion at position 1527–1528 (P1527del), which reduces CD24 expression, is associated with a significantly reduced risk of chronic HBV infection. To confirm the role for CD24 in liver carcinogenesis, we compared the size of liver tumor developed in CD24−/− and CD24+/− HBV transgenic mice. Our data demonstrate that targeted mutation of CD24 drastically reduced the sizes of spontaneous liver cancer in the HBV transgenic mice. Conclusion: These data demonstrate that genetic variation of CD24 may be an important determinant for the outcome of chronic HBV infection. (HEPATOLOGY 2009.)

Impaired function of CD4+ T follicular helper (Tfh) cells associated with hepatocellular carcinoma progression.

Background and Aims CD4+ T follicular helper (Tfh) cells, a new subset of immune cells, have been demonstrated to be involved in the development and prognosis of tumors. However, their functional role in human hepatocellular carcinoma (HCC) is relatively unknown, and the detailed mechanisms in HCC development remain to be described. Methods A total of 85 HCC patients with hepatitis B virus (HBV) infection, 25 HBV-relative liver cirrhosis (LC) patients, and 20 healthy controls (HC) were randomly enrolled. Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion, B cell maturation) assays were used to analyze the properties of CXCR5+CD4+ T cells. In addition, the relationship between the frequency of CXCR5+CD4+ T cells and overall survival rates or disease-free survival rates was also analyzed by the Kaplan-Meier method. Results The frequency of circulating CXCR5+CD4+ T cells was significantly decreased in HCC patients compared with HBV-relative liver cirrhosis (LC) patients and healthy controls, and the decrease in circulating CXCR5+CD4+ T cells correlated with disease progression. The proportion of infiltrated CXCR5+CD4+ T cells was significantly decreased in tumor regions compared with nontumor regions. Furthermore, compared with healthy controls, the function of circulating CXCR5+CD4+ T cells in HCC was impaired, with reduced IL-21 secretion and dysfunction in promoting B cell maturation. Importantly, follow-up data indicated that a decreased frequency of circulating CXCR5+CD4+ T cells was also associated with reduced disease-free survival time in HCC patients. Conclusions Impairment of CD4+ T follicular helper cells may influence the development of HBV-associated HCC. Decreased CD4+ T follicular helper cells may represent a potential prognostic marker and serve as a novel therapeutic target for HCC patients.

Myeloid-derived suppressor cells are associated with viral persistence and downregulation of TCR ζ chain expression on CD8(+) T cells in chronic hepatitis C patients.

Myeloid-derived suppressor cells (MDSCs) play an important role in impairing the function of T cells. We characterized MDSCs in two chronic hepatitis C (CHC) cohorts: a cross-sectional group that included 61 treatment-naive patients with CHC, 14 rapid virologic response (RVR) cases and 22 early virologic response (EVR) cases; and a longitudinal group of 13 cases of RVR and 10 cases of EVR after pegylated-interferon-α/ribavirin treatment for genotype 1b HCV infection. Liver samples from 32 CHC patients and six healthy controls were subjected to immunohistochemical analysis. MDSCs frequency in treatment-naive CHC was significantly higher than in RVR, EVR, or healthy subjects and was positively correlated with HCV RNA. Patients infected with HCV genotype 2a had a significantly higher frequency of MDSCs than those infected with genotype 1b. Decreased T cell receptor (TCR) ζ expression on CD8+ T cells was significantly associated with an increased frequency of MDSCs in treatment-naive CHC patients and was restored by L-arginine treatment in vitro. Increased numbers of liver arginase-1+ cells were closely associated with the histological activity index in CHC. The TCR ζ chain was significantly downregulated on hepatic CD8+ T cells in CHC. During antiviral follow up, MDSCs frequency in peripheral blood mononuclear cells was directly correlated with the HCV RNA load in the plasma and inversely correlated with TCR ζ chain expression in CD8+ T cells in both RVR and EVR cases. Notably, the RVR group had a higher frequency of MDSCs at baseline than the EVR group. Collectively, this study provides evidence that MDSCs might be associated with HCV persistence and downregulation of CD8 ζ chain expression.

Association between hepatitis B viral burden in chronic infection and a functional single nucleotide polymorphism of the PDCD1 gene.

BackgroundPD-1, encoded by PDCD1, is highly expressed on virus-specific T cells and plays critical roles in modulating anti-virus immune responses in chronic viral infection. It is unknown, however, whether polymorphisms of the PDCD1 are associated with viral clearance during chronic viral infections.Methodology and principal findingsHere, we used the polymerase chain reaction-restriction fragment length polymorphism method to genotype two single nucleotide polymorphisms (SNPs) of PDCD1 in 502 patients with chronic hepatitis B virus (HBV) infection and 359 healthy controls to determine the association between PDCD1 genotypes and serum viral load as well as the risk of chronic infection. Our results showed that although neither the P7209C/T SNP site nor the P8737A/G site was associated with the risk of chronic HBV infection, the P7209T allele in intron 4 is significantly associated with lower viral burden in the blood. Using a luciferase reporter assay, we demonstrated that the P7209T allele creates a negative cis-element for gene transcription.Conclusions and significanceOur data provide the first evidence that PDCD1 polymorphisms is a genetic factor in pathogenesis of chronic viral infection and reveal the functional significance of the P7209 SNP of the PDCD1.

HCV-specific interleukin-21+CD4+ T cells responses associated with viral control through the modulation of HCV-specific CD8+ T cells function in chronic hepatitis C patients

Interleukin-21 (IL-21)+CD4+ T cells are involved in the immune response against hepatitis B virus (HBV) by secreting IL-21. However, the role of IL-21+CD4+ T cells in the immune response against chronic hepatitis C (CHC) virus infection is poorly understood. This study aimed to investigate the role of IL-21+CD4+ T cells in CHC patients and the potential mechanisms. The study subjects included nineteen CHC patients who were grouped by viral load (low, < 106 RNA copies/ml, n = 8; high, > 106 RNA copies/ml, n = 11). The peripheral frequency of HCV-specific IL-21+CD4+ T cells was higher in the low viral load group and was negatively correlated with the serum HCV RNA viral load in all CHC patients. Meanwhile, IL-21+ cells accumulated in the liver in the low viral load group. In vitro, IL-21 treatment increased the expression of proliferation markers and cytolytic molecules on HCV-specific CD8+ T cells. In summary, these findings suggest that HCV-specific IL-21+CD4+ T cells might contribute to HCV control by rescuing HCV-specific CD8+ T cells in CHC patients.

Regulation of T cell function by microRNA-720

Chronic hepatitis B virus (HBV) infection is a major global health burden. Functional exhaustion and numerical reduction of HBV-specific cytotoxic T lymphocytes (CTLs) in the liver and peripheral blood limit anti-HBV CTL activity in patients with chronic HBV infection (CHB). However, the ongoing anti-HBV CD8+ T cell responses in the lymphoid organs are largely unknown due to the infeasibility of obtaining lymphoid organs from CHB patients. Here we demonstrate that the percentage of HBV-specific CD8+ T cells is higher in the spleen of CHB patients than that from peripheral blood and liver. Although they do respond to TCR stimulation and produce IFNγ, the cells proliferate poorly. Furthermore, miR-720 expression is upregulated in HBV-specific CD8+ T cells. Overexpression of miR-720 in primary human CD8+ T cells inhibits TCR stimulation-induced proliferation. We also demonstrate that TGFβ sustains miR-720 upregulation after TCR stimulation, and blood TGFβ levels are associated with the outcome of type I interferon treatment of CHB patients. Thus, therapies targeting miR-720 may help restore impaired immunity in CHB patients.

Interleukin-21 mediates hepatitis B virus-associated liver cirrhosis by activating hepatic stellate cells.

Interleukin‐21 (IL‐21) is involved in effective primary hepatic immune response against hepatitis B virus (HBV) and profibrotic function. However, the role of IL‐21 in HBV‐associated liver cirrhosis is poorly understood. This study aimed to investigate the role of IL‐21 in HBV‐associated liver cirrhosis and possible mechanisms.

Inflammation-Dependent IL18 Signaling Restricts Hepatocellular Carcinoma Growth by Enhancing the Accumulation and Activity of Tumor-Infiltrating Lymphocytes

Chronic inflammation in liver tissue is an underlying cause of hepatocellular carcinoma. High levels of inflammatory cytokine IL18 in the circulation of patients with hepatocellular carcinoma correlates with poor prognosis. However, conflicting results have been reported for IL18 in hepatocellular carcinoma development and progression. In this study, we used tissue specimens from hepatocellular carcinoma patients and clinically relevant mouse models of hepatocellular carcinoma to evaluate IL18 expression and function. In a mouse model of liver fibrosis that recapitulates a tumor-promoting microenvironment, global deletion of the IL18 receptor IL18R1 enhanced tumor growth and burden. Similarly, in a carcinogen-induced model of liver tumorigenesis, IL18R1 deletion increased tumor burden. Mechanistically, we found that IL18 exerted inflammation-dependent tumor-suppressive effects largely by promoting the differentiation, activity, and survival of tumor-infiltrating T cells. Finally, differences in the expression of IL18 in tumor tissue versus nontumor tissue were more predictive of patient outcome than overall tissue expression. Taken together, our findings resolve a long-standing contradiction regarding a tumor-suppressive role for IL18 in established hepatocellular carcinoma and provide a mechanistic explanation for the complex relationship between its expression pattern and hepatocellular carcinoma prognosis. Cancer Res; 76(8); 2394-405. ©2016 AACR.