Tissue-resident memory T cell signatures from single-cell analysis associated with better melanoma prognosis

Tissue-resident memory T cells (T_RM) are a specialized T cell population residing in peripheral tissues. The presence and potential impact of T_RM in the tumor immune microenvironment (TIME) remain to be elucidated. Here, we systematically investigated the relationship between T_RM and melanoma TIME based on multiple clinical single-cell RNA-seq datasets and developed signatures indicative of T_RM infiltration. T_RM infiltration is associated with longer overall survival and abundance of T cells, NK cells, M1 macrophages, and memory B cells in the TIME. A 22-gene T_RM-derived risk score was further developed to effectively classify patients into low- and high-risk categories, distinguishing overall survival and immune activation, particularly in T cell-mediated responses. Altogether, our analysis suggests that T_RM abundance is associated with melanoma TIME activation and patient survival, and the T_RM-based machine learning model can potentially predict prognosis in melanoma patients.