Department of Pediatrics, Division of Hematology, Oncology, Stem Cell Transplantation and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
Sci Transl Med. 2023 Dec 20;15(727):eadg6822. doi: 10.1126/scitranslmed.adg6822.
Studies of the monogenic autoimmune disease immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX) have elucidated the essential function of the transcription factor FOXP3 and thymic-derived regulatory T cells (T) in controlling peripheral tolerance. However, the presence and the source of autoreactive T cells in IPEX remain undetermined. Here, we investigated how FOXP3 deficiency affects the T cell receptor (TCR) repertoire and T stability in vivo and compared T cell abnormalities in patients with IPEX with those in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED). To study T independently of their phenotype and to analyze T cell autoreactivity, we combined T-specific demethylation region analyses, single-cell multiomic profiling, and bulk TCR sequencing. We found that patients with IPEX, unlike patients with APECED, have expanded autoreactive T cells originating from both autoreactive effector T cells (T) and T. In addition, a fraction of the expanded T from patients with IPEX lost their phenotypic and functional markers, including CD25 and FOXP3. Functional experiments with CRISPR-Cas9-mediated FOXP3 knockout T and T from patients with IPEX indicated that the patients' T gain a T2-skewed T-like function, which is consistent with immune dysregulation observed in these patients. Analyses of mutation-carrier mothers and a patient with IPEX after hematopoietic stem cell transplantation indicated that T expressing nonmutated prevent the accumulation of autoreactive T and unstable T. These findings could be directly used for diagnostic and prognostic purposes and for monitoring the effects of immunomodulatory treatments.
对单基因自身免疫性疾病免疫调节多内分泌腺病肠病性外胚层发育不良 X 连锁综合征（IPEX）的研究阐明了转录因子 FOXP3 和胸腺来源的调节性 T 细胞（Treg）在控制外周耐受中的重要功能。然而，IPEX 中自身反应性 T 细胞的存在和来源仍未确定。在这里，我们研究了 FOXP3 缺陷如何影响体内 T 细胞受体（TCR）库和 T 细胞的稳定性，并比较了 IPEX 患者与自身免疫性多内分泌腺病-念珠菌病-外胚层发育不良综合征（APECED）患者的 T 细胞异常。为了研究 T 细胞而不考虑其表型，并分析 T 细胞自身反应性，我们结合了 T 细胞特异性去甲基化区分析、单细胞多组学分析和批量 TCR 测序。我们发现，与 APECED 患者不同，IPEX 患者存在源自自身反应性效应 T 细胞（Teff）和 Treg 的扩增自身反应性 T 细胞。此外，IPEX 患者扩增的 T 细胞中有一部分失去了其表型和功能标志物，包括 CD25 和 FOXP3。使用 CRISPR-Cas9 介导的 FOXP3 敲除 T 细胞和来自 IPEX 患者的 T 细胞进行的功能实验表明，这些患者的 T 细胞获得了 T2 偏向的 T 样功能，这与这些患者中观察到的免疫失调一致。对携带 突变的母亲和接受造血干细胞移植的 IPEX 患者的分析表明，表达非突变 的 Treg 可防止自身反应性 T 细胞和不稳定 T 细胞的积累。这些发现可直接用于诊断和预后目的，并用于监测免疫调节治疗的效果。
