| Objective Hepatocellular carcinoma(HCC)is the fifth most common tumor and the third most common cause of cancer-related deaths worldwid.The etiology is complicated and obcure,especially chronic inflammation caused by infection or autoimmune diseases.The chronic inflammation play plays an important role in the proceesses of tumorigenesis,development and outcome and effect the body’s immune monitoring and treatment of the response;most of the tumors can benefit from immune cells,by adjusting the tumor cells,so that make immune cells in a tolerated or defective state,eventually tumor cells escape the body’s immune monitoring.Therefore,the immue mechanism of HCC tumorigenesis will provide important theoretical basis and new lights for tumor development and tumor immune therapy.HCC tumor microenvironment exhibit several mechanisms to escape from the control of the immune system,one major component in the creation of an immunosuppressive microenvironment is the recruitmentof inhibitory Treg cells to the tumor site.Regulatory T cells(Treg)are a class of T lymphocyte subsets with unique immunoregulatory function.In HCC,infiltration by Treg has been observed in the tumor tissue,and tumor infiltration by Treg was clearly associated with poor clinical outcome.But now the reason and the method for aggregation Treg cells in the tumor site is still not entirely clear and needs further exploration.Hepatocellular microenvironment expresses a variety of cytokines,in which macrophage-derived chemokine CCL22 and its receptor CCR4 are expressed in Tregs.HCC tumor microenvironment through CCL22 and its receptor CCR4 binding chemotaxis Tregs migration movement,and then cause local immune escape of liver cancer molecular mechanism has not yet clear.In this study,we investigated the expression of CCL22 / CCR4 signaling pathway in Tregs recruitment and local immune tolerance of hepatocellular carcinoma(HCC)by detecting the expression of CCR4 receptor on CCL22 and CD4 + Foxp3 + Tregs in tumor tissues,adjacent tissues,peripheral blood mononuclear cells.Methods First,bioinformatics were used to download the CCL22 / CCR4 / CD4 chip information in the cancer tissue of HCC patients,the correlation between those gene and the clinical significance of chemokine expression were analyzed in the CBioportal database.The tumor tissues,adjacent tissues and peripheral blood of HCC patients were collected from the First Affiliated Hospital of Zhengzhou University.The expression of chemokine CCL22 in hepatocellular carcinoma and adjacent tissues was detected by QT-PCR,and the expression of CD4 and cytokines Foxp3 and IL-10 were detected at the gene level.Detection of CCL22 expression in cancer tissues and clinical parameters in HCC patients by immunohistochemistry.T lymphocytes and peripheral blood mononuclear lymphocytes(PBMCs)were extracted with lymphocyte separation solution by using density gradient method.T cell subsets were then performed by flow cytometry and chemokine corresponding receptors were tested.Results 1.CCR4 gene in HCC patients may be related to CCL22 and CD4(r=0.2 p<0.0001,r=0.2 p<0.0001).2.The results of RT-PCR showed that the expression of chemokine CCL22 in hepatocellular carcinoma was higher than that in adjacent tissues(0.56±0.06 vs 0.31±0.04),the difference was statistically significant(outcomes).3.The expression of CCL22 in HCC TNM staging I-III was detected by immunohistochemistry.The results showed that the expression of CCL22 in TNM II was higher than that in TNM I(4.231 ± 0.2571 vs 3.326 ± 0.3671,P = 0.04);TNM III expression was significantly higher than that of TNM I(5.100 ± 0.4033 vs 3.326 ± 0.3671,p = 0.0048),the difference was statistically significant;TNM III was not significantly different from TNM II(5.100 ± 0.4033 vs 4.231 ± 0.2571 p = 0.0769).The median survival time was 44 months and 53 months in patients with high expression of CCL22 and those with low expression of CCL22 by Log-rank test.The difference was statistically significant(p = 0.01).There was no significant difference in age,sex,HBe Ag,ALT,AST and AFP between the two groups(P> 0.05),but the tumor size(p = 0.005),tumor size(p = 0.002),tumor number(p = 0.038),and there was a statistically significant difference in cancer cell differentiation(p = 0.031).Therefore,CCL22 may be a predictor of HCC progression and prognosis.4.The correlation analysis showed that chemokine CCL22 was positively correlated with the expression of CD4,Foxp3 and IL10 in cancer tissues(r=0.22,p<0.0001;r=0.24,p<0.0001;r=0.36,p<0.0001).5.Flow cytometry showed that the proportion of total CD4 + T cells in TIL was higher than that in PBMC(35.52 ± 2.064 vs 29.41 ± 1.96,p = 0.03),and the proportion of Treg cell subgroup TIL was 16.60 ± 1.29 higher than that in PBMC The ratio of TIL in CCR4 + Treg cells was also higher than that in PBMC(40.82 ± 2.251 vs 33.85 ± 2.291,p = 0.03).The difference was statistically significant(P <0.05).Conclusion 1.HCC tissue can secrete a large amount of CCl22 that could recruit CD4+CD25+Tregs to tumor tissue by activating CCl22 / CCR4 signaling CD4+CD25+Tregs played an important role in the immune escape of HCC and indicate a poor prognosis.2.CCL22 / CCR4/Treg signaling pathway may be a potential prognostic factor for HCC patients and may serve as a new target for immunotherapy of HCC. |
PDF Full Text Request