Key aspects of intestinal T cells, including their antigen specificity and their selection by the microbiota and other intestinal antigens, as well as the contribution of individual T cell clones to regulatory and effector functions, remain unresolved. Here we tracked adoptively transferred T cell populations to specify the interrelation of T cell receptor repertoire and the gut antigenic environment. We show that dominant TCRα clonotypes were shared between interferon-γ- and interleukin-17-producing but not regulatory Foxp3⁺ T cells. Identical TCRα clonotypes accumulated in the colon of different individuals, whereas antibiotics or defined colonization correlated with the expansion of distinct expanded T cell clonotypes. Our results demonstrate key aspects of intestinal CD4⁺ T cell activation and suggest that few microbial species exert a dominant effect on the intestinal T cell repertoire during colitis. We speculate that dominant proinflammatory T cell clones might provide a therapeutic target in human inflammatory bowel disease.

肠道 T 细胞的关键方面，包括它们的抗原特异性和微生物群和其他肠道抗原的选择，以及单个 T 细胞克隆对调节和效应功能的贡献，仍未得到解决。在这里，我们跟踪过继转移的 T 细胞群，以指定 T 细胞受体库与肠道抗原环境的相互关系。我们表明主要的 TCRα 克隆型在产生干扰素-γ-和白细胞介素-17 的细胞之间共享，但不是调节性 Foxp3 ⁺ T 细胞。在不同个体的结肠中积累了相同的 TCRα 克隆型，而抗生素或确定的定植与不同扩增的 T 细胞克隆型的扩增相关。我们的结果证明了肠道 CD4 ^{+ 的}关键方面T 细胞活化，并表明在结肠炎期间，很少有微生物物种对肠道 T 细胞库产生显着影响。我们推测显性促炎性 T 细胞克隆可能为人类炎症性肠病提供治疗靶点。