Single-Cell Analysis Reveals Characterization of Infiltrating T Cells in Moderately Differentiated Colorectal Cancer
Xi Yang, Qi Quan, Yuefen Pan, Qing Zhou, Wu Yinhang, Jing Zhuang, Jiamin Xu, Mingyue Pan, Shuwen Han
Abstract
Objective This study aimed to characterize the tumor-infiltrating T cells in moderately differentiated colorectal cancer. Methods Using single-cell RNA sequencing data of isolated 1632 T cells from tumor tissue and 1252 T cells from the peripheral blood of CRC patients, unsupervised clustering analysis was performed to identify functionally distinct T cell populations, followed by correlations and ligand-receptor interactions across cell types. Finally, differential analysis of the tumor-infiltrating T cells between colon cancer and rectal cancer were carried out. Results A total of eight distinct T cell populations were identified from tumor tissue. Tumor-Treg showed a strong correlation with Th17 cells. CD8 + T RM was positively correlated with CD8 + IEL. Seven distinct T cell populations were identified from peripheral blood. There was a strong correlation between CD4+T N and CD4+blood-T CM . Colon cancer and rectal cancer showed differences in the composition of tumor-infiltrating T cell populations. Tumor-infiltrating CD8 + IEL cells were found in rectal cancer but not in colon cancer, while CD8 + T N cells were found in the peripheral blood of colon cancer but not in that of rectal cancer. A larger number of tumor-infiltrating CD8 + Tex (88.94%) cells were found in the colon cancer than in the rectal cancer (11.06%). The T cells of the colon and rectal cancers showed changes in gene expression pattern. Conclusions We characterized the T cell populations in the CRC tumor tissue and peripheral blood.