Distribution of central and effector memory T cells subsets in tumor infiltrating lymphocytes of HCC patients

Abstract

Objective To illustrate the distribution of two memory T cells subsets CD45RO+ CD62L+ CCR7+ T cells (central memory T cells, TCM) and CD45RO+ CD62L-CCR7-T cells (effector memory T cells, TEM) in tumor infiltrating lymphocytes (TILs) of hepatocellular carcinoma (HCC) patients. Methods Polychromatic flow cytometry (PFC) was used to test the cell surface molecules of infiltrating lymphocytes in liver, including CD3, CD4, CD8, CD45RO, CD62L and CCR7. Results The proportions of CD4+ TCM subsets in CD4+ CD45RO+ Tm in HCC tissues, adjacent liver tissues and normal liver tissues were (0.25±0.17)%, (0.29±0.22)% and (0.37±0.33)%, and there were no significant differences (P>0.05). The proportions of CD4+ TEM subsets in CD4+ CD45RO+ Tm in HCC tissues, adjacent liver tissues and normal liver tissues were (89.7±7.4)%, (98.7±0.6)% and (95.5±3.7)%, respectively. Paired comparison showed that the proportions of CD4+ TEM subsets in HCC tissues were significantly lower than those in adjacent liver tissues and normal liver tissues (P<0.05). The proportions of CD8+ TCM subsets in CD8+ CD45RO+ Tm in HCC tissues, adjacent liver tissues and normal liver tissues were (0.41±0.31)%, (0.55±0.60)% and (0.26±0.25)%. Paired comparison showed that the proportions of CD8+ TCM subsets in adjacent liver tissues were significantly higher than those in normal liver tissues (P<0.05). The proportions of CD8+ TEM subsets in CD8+ CD45RO+ Tm from HCC tissues, adjacent liver tissues and normal liver tissues were (92.4±4.3)%, (98.1±0.7)% and (98.2±1.1)%. Paired comparison showed that the proportions of CD8+ TEM subsets in HCC tissues were significantly lower than those in adjacent liver tissues and in normal tissues (P<0.05). Conclusions Comparing to the TCM,TEM subsets including CD4+ and CD8+ , accounted for the majority of tumor infiltrating CD45RO+ Tm in HCC patients. The proportions of CD4+ TEM and CD8+ TEM subsets in CD45RO+ Tm from tumor tissues were significantly lower than those in non-cancerous tissues. However, the proportions of CD4+ TCM and CD8+ TCM subsets in CD45RO+ Tm from tumor tissues were the same as those from non-cancerous tissues. Key words: Central memory T cells; Effector memory T cells; Tumor infiltrating lymphocytes; Hepatocellular carcinoma