Department of Rheumatology and Immunology, Southern Medical University, Nanfang Hospital, Guangzhou, China.
Department of Rheumatology and Immunology, Department of Clinical Medical Research Center, Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, The First Affiliated Hospital Southern University of Science and Technology), Shenzhen, China.
Front Immunol. 2021 Feb 2;11:594658. doi: 10.3389/fimmu.2020.594658. eCollection 2020.
Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease, and its pathogenetic mechanism is far from being understood. In this study, we aimed to explore the cellular and molecular mechanisms that lead to pathogenesis of this disease.
We applied single-cell RNA sequencing (scRNA-seq) to 57,288 peripheral blood mononuclear cells (PBMCs) from five patients with pSS and five healthy controls. The immune cell subsets and susceptibility genes involved in the pathogenesis of pSS were analyzed. Flow cytometry was preformed to verify the result of scRNA-seq.
We identified two subpopulations significantly expand in pSS patients. The one highly expressing cytotoxicity genes is named as CD4 CTLs cytotoxic T lymphocyte, and another highly expressing T cell receptor (TCR) variable gene is named as CD4 TRAV13-2+ T cell. Flow cytometry results showed the percentages of CD4 CTLs, which were profiled with CD4 and GZMB staining; the total T cells of 10 patients with pSS were significantly higher than those of 10 healthy controls (= 0.008). The expression level of IL-1β in macrophages, TCL1A in B cells, as well as interferon (IFN) response genes in most cell subsets was upregulated in the patients with pSS. Susceptibility genes including HLA-DRB5, CTLA4, and AQP3 were highly expressed in patients with pSS.
Our data revealed disease-specific immune cell subsets and provided some potential new targets of pSS. Specific expansion of CD4 CTLs may be involved in the pathogenesis of pSS, which might give valuable insights for therapeutic interventions of pSS.
原发性干燥综合征（pSS）是一种系统性自身免疫性疾病，其发病机制尚不清楚。本研究旨在探讨导致该病发病的细胞和分子机制。
我们应用单细胞 RNA 测序（scRNA-seq）技术对 5 名 pSS 患者和 5 名健康对照者的 57288 个外周血单个核细胞（PBMCs）进行分析。分析了参与 pSS 发病机制的免疫细胞亚群和易感基因。采用流式细胞术验证 scRNA-seq 的结果。
我们鉴定出两种在 pSS 患者中明显扩增的亚群。一种高度表达细胞毒性基因的亚群命名为 CD4 CTLs 细胞毒性 T 淋巴细胞，另一种高度表达 T 细胞受体（TCR）可变基因的亚群命名为 CD4 TRAV13-2+T 细胞。流式细胞术结果显示，10 例 pSS 患者的 CD4 CTLs 细胞百分比，通过 CD4 和 GZMB 染色进行分析；10 例健康对照者的总 T 细胞明显高于 pSS 患者（=0.008）。巨噬细胞中白细胞介素 1β（IL-1β）、B 细胞中 TCL1A 以及大多数细胞亚群中的干扰素（IFN）反应基因的表达水平在 pSS 患者中上调。易感基因包括 HLA-DRB5、CTLA4 和 AQP3 在 pSS 患者中高表达。
我们的数据揭示了疾病特异性免疫细胞亚群，并为 pSS 提供了一些潜在的新靶点。CD4 CTLs 的特异性扩增可能参与了 pSS 的发病机制，这可能为 pSS 的治疗干预提供有价值的见解。
