Nature：肠道菌群驱动T细胞可塑性，增强癌症免疫治疗效果

Core Viewpoint - Cancer immunotherapy, particularly immune checkpoint blockade (ICB) therapy, has transformed cancer treatment, but a significant proportion of patients do not respond, highlighting the need to understand factors affecting ICB efficacy [2][3]. Group 1: Research Findings - The study published by Dan R. Littman's team indicates that gut microbiota-induced T cell plasticity enables immune-mediated tumor control, suggesting that targeting gut microbiota could enhance ICB therapy effectiveness [3][7]. - The research utilized segmented filamentous bacteria (SFB) to investigate how its colonization in the small intestine influences the efficacy of ICB therapy against tumors expressing SFB antigens [5][6]. - It was found that effective anti-PD-1 treatment in mice only occurred when SFB was present in the gut, leading to the identification of SFB-specific T H 1-like cells that produce high levels of pro-inflammatory cytokines, enhancing tumor control [6][7]. Group 2: Mechanistic Insights - The study elucidates a cellular pathway where a specific gut symbiotic bacterium enhances the efficacy of PD-1 blockade therapy by imparting T cell plasticity [7]. - Conditional removal of IL-17A+ CD4+ T cells, which are precursors to tumor-associated T H 1-like cells, completely abolished the tumor control mediated by anti-PD-1 therapy, indicating their critical role in the tumor microenvironment [6].