Specific ablation of BFAR on CD8+ T cells promotes CD8+T cell antitumor immunity

To investigate the role of aging in the regulation of CD8+ T cell anti-tumor function, we sorted CD8+T cells from Rag1-/- mice that were received intravenously injection of young/old mice-derived CD8+ T cells on the same day with tumor cell inoculation and carried out single-cell RNA sequencing, and the young group showed increased highly cytotoxic TRM and reduced exhausted CD8+ T cells in tumor microenvironment. Our study also found that BFAR deficiency reinvigorates tumor infiltrating CD8+ T cells into a more young state, as reflected by increased TRM. Young/aged tumor infiltrating CD8+T cells were isolated from Rag1-/- mice that were received intravenously injection of young (8-weeks)/old mice (18-months-old)-derived CD8+ T cells on the same day with MB49 tumor cell inoculation and and analyzed by single-cell RNA sequencing technology, and WT/BFAR-deficient CD8+ T cells isolated from subcutaneous MB49 tumors in WT or BFAR-CD8-KO mice. Each sample contains CD45+ CD8+ T cells combined from 3 mice.