Expression Of IL-17~＋CD8~＋T Lymphocytes In Hepatocellular Carcinoma And Its Clinical Significance

Objective In this study, we aimed to investigate the expression of IL-17⁺CD8⁺T lymphocytes (Tc17) in cancer tissues of patients with hepatocellular carcinoma (HCC) and its usage.Methods Immunohistochemisty staining was used to detect the expression of IL-17 in HCC and normal liver tissues, and flow cytometry was carried out to determine the distribution, phenotype and function of Tc17 cells in HCC patients. The expression diversities among different tumor stages were analyzed.Results We found that the positive rate of IL-17 expression was significantly higher in the HCC liver tissues than that in the normal liver tissues (P< 0.05). The frequency of Tc17 cells was significantly increased in tumor-infiltrating lymphocytes (TILs) (2.41±1.45)% compared with peripheral blood from patients (0.71±0.29)% and healthy controls (0.51±0.37)%. Tc17 cells in TILs expressed an activated effector memory phenotype (CD45RA^-CD28⁺CD27^-/+CCR7^-CD69^high) and expressed high levels of proinflammatory factors TNF and IFN-γ, but little granzyme B or perforin. Furthermore, we found no significant changes of Tc17 expression among different tumor stages.Conclusion The results of this present work imply that Tc17 cells with activated effector memory phenotypic features are significantly accumulated in TILs of HCC patients. These cells secreted hardly cytotoxic molecules granzyme B or perforin , but large amounts of proinflammatory factors TNF and IFN-γ, through which they potentially contribute to tumorigenesis and tumor progression in HCC.