Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
J Autoimmun. 2018 Jan;86:19-28. doi: 10.1016/j.jaut.2017.09.011. Epub 2017 Oct 20.
The goal of this study was to comprehensively characterize CD4+CD28+ T cells overexpressing CD11a and KIR genes, and examine the relationship between this T cell subset, genetic risk, and disease activity in lupus.
The size of the CD4+CD28+KIR+CD11a T cell subset was determined by flow cytometry, and total genetic risk for lupus was calculated in 105 female patients using 43 confirmed genetic susceptibility loci. Primary CD4+CD28+KIR+CD11a T cells were isolated from lupus patients or were induced from healthy individuals using 5-azacytidine. Genome-wide DNA methylation was analyzed using an array-based approach, and the transcriptome was assessed by RNA sequencing. Transcripts in the CDR3 region were used to assess the TCR repertoire. Chromatin accessibility was determined using ATAC-seq.
A total of 31,019 differentially methylated sites were identified in induced KIR+CD11a T cells with >99% being hypomethylated. RNA sequencing revealed a clear pro-inflammatory transcriptional profile. TCR repertoire analysis suggests less clonotype diversity in KIR+CD11a compared to autologous KIR-CD11a T cells. Similarly, primary KIR+CD11a T cells isolated from lupus patients were hypomethylated and characterized by a pro-inflammatory chromatin structure. We show that the genetic risk for lupus was significantly higher in African-American compared to European-American lupus patients. The demethylated CD4+CD28+KIR+CD11a T cell subset size was a better predictor of disease activity in young (age ≤ 40) European-American patients independent of genetic risk.
CD4+CD28+KIR+CD11a T cells are demethylated and characterized by pro-inflammatory epigenetic and transcriptional profiles in lupus. Eliminating these cells or blocking their pro-inflammatory characteristics might present a novel therapeutic approach for lupus.
本研究旨在全面描述 CD4+CD28+T 细胞中 CD11a 和 KIR 基因的过度表达，并研究该 T 细胞亚群与遗传风险和狼疮疾病活动之间的关系。
通过流式细胞术确定 CD4+CD28+KIR+CD11a T 细胞亚群的大小，并使用 43 个已确认的遗传易感性基因座计算 105 名女性患者的狼疮总遗传风险。使用 5-氮杂胞苷从狼疮患者中分离或从健康个体中诱导产生原代 CD4+CD28+KIR+CD11a T 细胞。使用基于阵列的方法分析全基因组 DNA 甲基化，并通过 RNA 测序评估转录组。使用 CDR3 区的转录本评估 TCR 库。使用 ATAC-seq 确定染色质可及性。
在诱导的 KIR+CD11a T 细胞中鉴定出 31,019 个差异甲基化位点，其中 99%以上为低甲基化。RNA 测序显示出明显的促炎转录谱。TCR 库分析表明，与自体 KIR-CD11a T 细胞相比，KIR+CD11a 中的克隆型多样性较少。同样，从狼疮患者中分离的原代 KIR+CD11a T 细胞呈低甲基化状态，表现出促炎染色质结构。我们表明，与欧洲裔美国狼疮患者相比，非洲裔美国狼疮患者的狼疮遗传风险明显更高。年轻（≤40 岁）欧洲裔美国患者的疾病活动度与遗传风险无关，CD4+CD28+KIR+CD11a T 细胞亚群大小的去甲基化是更好的预测指标。
狼疮患者的 CD4+CD28+KIR+CD11a T 细胞呈去甲基化状态，表现出促炎的表观遗传和转录特征。消除这些细胞或阻断其促炎特性可能为狼疮提供一种新的治疗方法。
