The Mechanism Of Decreased Infiltration And Impaired Functions Of Intra-tumor γδ T Cells In Hepatocellular Carcinoma

Tumor microenviroment played an important role in cancer progression, the immune system plays a dual role in cancer:it can not only suppress tumor growth and invasion but also promote caner progression either by immunoselection or establishing an immune inhibition network within the tumor microenviroment that facilitate cancer development. Until now, much works have being focusing on the adaptive immune system, nonetheless, the role of innate system in the tumor microenviroment was not well defined yet. In this study, firstly, we analysis the the relationship between expressions of chemokines and distributions of y8 T cells, which was recognized as subset of innate immune cells accumulating remarkably in the liver, in the microenviroment of hepatocellular carcinoma. Then we evaluated the expression and prognosis value of transcription factors Eomes, which were important mediator of IFN-y function, in hepatocellular carcinoma.Part 1The phenotypes and infiltration of γδ T cells in different location in hepatocellular carcinomay8 T cells, bearing γ-and 8-chain T-cell receptor (TCR) heterodimers and possessing innate properties, mediate tumor-inhibition effects in multiple malignancies.γδ T cells can recognize soluble protein and non-protein antigens that are up-regulated by transformed or otherwise dysregulated host cells, in a manner independent of major histocompatibility complex (MHC) and antigen presentation. Notably, the antigens recognized by γδ T cells are not seen by αβT cells. After activation, y8 T cells boost strong cytotoxic effector activity (using both cytolytic granule pathways and death receptor/death ligand) and prodduce various cytokines (frequently including tumor necrosis factor-a and IFN-y), thereby providing an essential additional pathway with immediate relevance for malignancy immunosurveillance. However, the immune status of y8T cells in the tumor microenviroment was not defined yet.We found that the infiltration of y8 T cells in HCC tissue was significantly decreased compared with paired peritumor tissue as well as IL-18Rb, CD40L mRNA and FasL mRNA. We also found that CCL18mRNA and CD276 mRNA in γδ T cells in HCC tissue was significantly increased compared with paired peritumor tissue. It suggested that y8 T was impairment.Part 2The correlation analysis between the expression of Chemokines and infiltration of γδ T cells in different location in hepatocellular carcinomaThe different infiltration of y8 T cells lead to different Chemokines expression. So we made effort to evaluate the expression of Chemokines. We found that many chemokines were significiantly up or down-regulated between high and low γa T infiltration. This demonstrate why the infiltration of γδ cells in HCC tissue was significantly decreased compared with paired peritumor tissue.Part 3The correlation analysis relationship between TSLP and CCL5 and Foxp3 and γδ T cells in different locations in hepatocellular carcinomaThere was positive correlation with γδT cells and foxp3 in peri-tumor and a negative correlation with TSLP in intra-tumor.TSLP and CCL5 may contribute to infiltration of γδT cells.Part 4The expression status of Eomes in hepatocellular carcinoma and their association with prognosis of HCCIFN-y put great tumor sculpting pressure on tumor cells, which was associated with the expression of Eomes. The expression of transcription factors Eomes played an important role in the differentiation and activation of effector CD8 T cells, NK cells and γδT cells.In this study, immunohistochemistry was used to analyze the nuclear expression of Eomes in a cohort of 331 HCC patients. The expressions of Eomes in infiltration T cells were assesed by Flow Cytometry.We found that high expressions of Eomes were associated with good outcome. High expressions of Granzyme were found in positive staining of Eomes positive cells. The ratio of Eomes+γδT cells and CD3+CD56-T cells was decreased compared with paired peritumor tissues.This study unraveled that Eomes expressions were associated with prognosis of HCC patients.Conclusions1 The infiltration of γδ T cells in HCC tissue was significantly decreased compared with paired peritumor tissue. Ectopic expression of Chemokines were associated with the decreased infiltration of γδT cells displayed immune inhibited phenotype.2 Eomes expressions were associated with prognosis of HCC patients withConsistency predictive power.Novelty1 We firstly demonstrated that the infiltration of γδ T cells were substantially decreased in hepatocellular carcinoma microenviroment due to ectopic expression of Chemokines.2 We firstly evaluated the prognosis value of Eomes in hepatocellular carcinoma.