RNA-seq of Ctrl and NaBu-treated CD8+ T cells in vitro

Recent studies in both mice and human have suggested that the gut microbiota could modulate tumor response to chemotherapeutic agents or immunotherapies. However, the underlying mechanism has not been well characterized. Here, we found that disruption of the intestinal microbiota with antibiotics impaired the anti-cancer efficacy of oxaliplatin, which was correlated with the reduction of lots of the intestinal microbial metabolites including butyrate, one of the short chain fatty acids. Re-supplementation of either the whole intestinal microbial metabolites or butyrate could rescue the therapeutic responses of oxaliplatin in the microbiota-destroyed tumor-bearing mice by modulating CD8+ T cell function in the tumor microenvironment. Further experiments showed butyrate boosted the anti-tumor cytotoxic CD8+ T cell responses through ID2, a key transcription regulator highly expressed by tumor-infiltrating CD8+ T cells. Butyrate induced ID2 expression in CD8+ T cells, while ID2 further promoted the proliferation and function of CD8+ T cells through IL-12 signaling. Together, our findings suggest that gut microbial metabolite butyrate could promote the anti-tumor therapeutic efficacy through the ID2-dependent regulation of CD8+ T cell immunity. 4 samples: 2 Ctrl CD8+ T cells, 2 NaBu-treated CD8+ T cells