Tissue immunity and responses to injury depend on the coordinated action and communication among physiological systems. Here, we show that, upon injury, adaptive responses to the microbiota directly promote sensory neuron regeneration. At homeostasis, tissue-resident commensal-specific T cells colocalize with sensory nerve fibers within the dermis, express a transcriptional program associated with neuronal interaction and repair, and promote axon growth and local nerve regeneration following injury. Mechanistically, our data reveal that the cytokine interleukin-17A (IL-17A) released by commensal-specific Th17 cells upon injury directly signals to sensory neurons via IL-17 receptor A, the transcription of which is specifically upregulated in injured neurons. Collectively, our work reveals that in the context of tissue damage, preemptive immunity to the microbiota can rapidly bridge biological systems by directly promoting neuronal repair, while also identifying IL-17A as a major determinant of this fundamental process.

组织免疫和对损伤的反应取决于生理系统之间的协调作用和交流。在这里，我们表明，在受伤后，对微生物群的适应性反应直接促进感觉神经元再生。在体内平衡时，组织驻留的共生特异性 T 细胞与真皮内的感觉神经纤维共定位，表达与神经元相互作用和修复相关的转录程序，并促进轴突生长和损伤后局部神经再生。从机制上讲，我们的数据表明，共生特异性 Th17 细胞在损伤后释放的细胞因子白细胞介素 17A (IL-17A) 通过 IL-17 受体 A 直接向感觉神经元发出信号，其转录在受损神经元中特异性上调。总的来说，我们的工作表明，在组织损伤的情况下，