Rejection is a primary cause of allograft dysfunction after kidney transplantation. The diversity of immune subpopulations involved in the different endotypes of rejection remains to be delineated at single-cell resolution. In a cohort of 76 kidney transplant recipients, we conducted high-dimensional immune phenotyping of blood CD4 T and B cells, single-cell RNA and T/B cell receptor sequencing, and plasma cytokine profiling. Phenotypic, transcriptional, and clonal states of CD4T and B cells could significantly distinguish stable allograft states from rejection. Patients undergoing T cell-mediated rejection displayed accumulation of clonally expanded cytotoxic T helper (Th)1 cells and Th17-like cells, associated with predominant naive B cell responses. In contrast, antibody-mediated rejection was characterized by clonal expansion of Th1-polarized T follicular helper cells and effector T-bet+ memory B cells, both of which strongly expressed interleukin 12 and tumor necrosis factor-signaling pathways. Plasma cytokine analysis confirmed mixed Th1/Th17 and Th1/T follicular helper cell-driven inflammatory profiles distinguishing T cell-mediated rejection and antibody-mediated rejection, respectively. CD4T and B cell subpopulations and signatures were validated using bulk RNA-seq analysis of matched kidney allografts and using an independent single-cell RNA-seq data set. These data improve mechanistic understanding of the immune pathogenesis of rejection and support the development of more specific immunosuppressive therapies to treat allograft rejection.

中文翻译：

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对肾移植免疫反应的高维分析揭示了与排斥反应相关的异质性辅助性 T 细胞 1 和 B 细胞效应子


排斥反应是肾移植术后同种异体移植物功能障碍的主要原因。参与不同排斥反应内型的免疫亚群的多样性仍有待在单细胞分辨率下描述。在 76 名肾移植受者的队列中，我们进行了血液 CD4 T 和 B 细胞的高维免疫表型、单细胞 RNA 和 T/B 细胞受体测序以及浆细胞因子分析。CD4T 和 B 细胞的表型、转录和克隆状态可以显着区分稳定的同种异体移植物状态和排斥反应。接受 T 细胞介导的排斥反应的患者表现出克隆扩增的细胞毒性辅助性 T 细胞 （Th） 1 细胞和 Th17 样细胞的积累，这与主要的幼稚 B 细胞反应有关。相比之下，抗体介导的排斥反应的特征是 Th1 极化 T 滤泡辅助细胞和效应 T-bet+ 记忆 B 细胞的克隆扩增，这两者都强烈表达白细胞介素 12 和肿瘤坏死因子信号通路。浆细胞因子分析证实了混合的 Th1/Th17 和 Th1/T 滤泡辅助细胞驱动的炎症特征，分别区分 T 细胞介导的排斥反应和抗体介导的排斥反应。使用匹配的肾同种异体移植物的大量 RNA-seq 分析和独立的单细胞 RNA-seq 数据集来验证 CD4T 和 B 细胞亚群和特征。这些数据提高了对排斥反应免疫发病机制的机制理解，并支持开发更特异性的免疫抑制疗法来治疗同种异体移植物排斥反应。