Phenotypic Differences of CD103+ Tissue-Resident Memory T Cells Associated with Various Cancers

Abstract

Background/Aims: The presence and clinical importance of tissue-resident memory T (T_RM) cells have been recently described in association with various cancer types. However, the frequency and the traditional naïve–effector–memory phenotypic characteristics of T_RM cells are largely unknown. Methods: We analyzed single-cell populations of colorectal cancer (CC, n = 18), stomach cancer (SC, n = 13), renal cell carcinoma (RCC, n = 19), and breast cancer (BC, n = 16) by dissociation of tumor tissue with collagenase/hyaluronidase. We investigated populations of naïve, effector, and memory T and T_RM cells by flow cytometry. Results: Among CD8⁻ cells, CC was associated with a significantly higher proportion of CD103⁺ T cells than other tumor types (p < 0.001). Among CD8⁺ cells, CC and SC were associated with higher CD103⁺ T-cell proportions than RCC and BC (p < 0.001). Significantly more CD8⁺ than CD8⁻ cells expressed CD103 (p < 0.001). In association with SC, RCC, and BC, CD8⁺ T cells had a similar T-cell phenotype composition pattern: fewer effector T cells and more memory-type T cells among CD103⁺ cells compared with CD103⁻ cells (p < 0.05). Tumors with higher proportion of CD103⁺ cells had no specific clinicopathologic characteristics than those with lower proportion of CD103⁺ cells. Conclusion: T_RM cell abundance and phenotypes varied among CC, SC, RCC, and BC. Further studies regarding the functional differences of T_RM associated with various tumors are warranted.