Accumulation of tissue-resident natural killer cells, innate lymphoid cells, and CD8+T cells towards the center of human lung tumors

ABSTRACTLung cancer is a leading cause of cancer-related death worldwide. Despite recent advances in tissue immunology, little is known about the spatial distribution of tissue-resident lymphocyte subsets in lung tumors. Using high-parameter flow cytometry, we identified an accumulation of tissue-resident lymphocytes including tissue-resident NK (trNK) cells and CD8+tissue-resident memory T (TRM) cells toward the center of human non-small cell lung carcinomas (NSCLC). Chemokine receptor expression patterns indicated different modes of tumor-infiltration and/or residency between trNK cells and CD8+TRMcells. In contrast to CD8+TRMcells, trNK cells and ILCs generally expressed low levels of immune checkpoint receptors independent of location in the tumor. Additionally, granzyme expression in trNK cells and CD8+TRMcells was highest in the tumor center, and intratumoral CD49a+CD16−NK cells were functional and responded stronger to target cell stimulation than their CD49a−counterparts, indicating functional relevance of trNK cells in lung tumors.In summary, the present spatial mapping of lymphocyte subsets in human NSCLC provides novel insights into the composition and functionality of tissue-resident immune cells, suggesting a role for trNK cells and CD8+TRMcells in lung tumors and their potential relevance for future therapeutic approaches.