Clostridium leptum Attenuates Allergic Airway Inflammation via tDC‒Treg Axis Activation in a Murine Model of Gut Dysbiosis-Associated Asthma

To investigate whether oral CL administration restores gut–lung immune homeostasis and suppresses allergic inflammation via tDC/Treg induction in a dysbiosis-asthma comorbidity model, adult BALB/c mice were subjected to ovalbumin (OVA) sensitization/challenge and antibiotic-induced gut dysbiosis. The gut microbiota (16S rRNA sequencing), metabolome (untargeted LC‒MS), and immune parameters were assessed via histopathology, flow cytometry (tDCs: CD11c+CD80-CD86-; Tregs: CD4+CD25+FoxP3+), cytokine profiling (ELISA), and analyses of the TLR/NF-κB pathway (IHC/qPCR/WB).为探究口服CL制剂是否可通过诱导致耐受性树突状细胞（tolerogenic dendritic cell, tDC）/调节性T细胞（regulatory T cell, Treg），在菌群失调-哮喘共病模型中恢复肠-肺免疫稳态（gut-lung immune homeostasis）并抑制过敏性炎症，本研究对成年BALB/c小鼠实施卵清蛋白（OVA）致敏/激发，并通过抗生素诱导其肠道菌群失调。随后采用组织病理学、流式细胞术（tDCs表型：CD11c+CD80-CD86-；Tregs表型：CD4+CD25+FoxP3+）、细胞因子谱分析（酶联免疫吸附试验，ELISA）以及Toll样受体/核因子-κB（TLR/NF-κB）通路分析（免疫组织化学/实时定量聚合酶链反应/蛋白质印迹，IHC/qPCR/WB），对肠道菌群（16S核糖体RNA测序，16S rRNA sequencing）、代谢组（非靶向液相色谱-质谱联用，untargeted LC-MS）及免疫指标进行评估。