Characteristics and anatomic location of PD-1+TCF1+ stem-like CD8 T cells in chronic viral infection and cancer
CD8 T cells play an essential role in anti-tumor immunity and chronic viral infections. Recent findings have delineated the differentiation pathway of CD8 T cells in accordance with the progenitor-progeny relationship of TCF1+ stem-like and Tim-3+TCF1- more differentiated T cells. Here we investigated the characteristics of stem-like and differentiated CD8 T cells isolated from several murine tumor models and human lung cancer samples in terms of phenotypic and transcriptional features as well as their location compared to virus-specific CD8 T cells in the chronically LCMV-infected mice. We found that CD8 tumor-infiltrating lymphocytes (TILs) in both murine and human tumors exhibited overall similar phenotypic and transcriptional characteristics compared to corresponding subsets in the spleen of chronically infected mice. Overall design: Primary and metastatic tumors in lung tissues were obtained from 19 patients with stage I-IV. Stem-like (Tim-3-CD28+ PD-1+) and exhausted (Tim-3+ PD-1+) human CD8 T cells were sorted from frozen TIL samples isolated from NSCLC patients.  And naive (CCR7+CD45RA+CD58-CD95-) CD8 T cells from a healthy subject.