在这项研究中，我们旨在调查Breg对Th17/Treg细胞平衡的调节作用以及在低密度脂蛋白受体（LDLr）-/-  + Pristane小鼠模型中下游炎症因子的释放情况。在建立SLE合并动脉粥样硬化（AS）的小鼠模型后，将8周龄的LDLr-/-  + Pristane小鼠（n = 10）纳入SLE + AS组。此外，以8周龄的MRL/lpr小鼠和C57小鼠分别作为SLE和正常对照组（每组n = 10）。饲喂高脂饮食14周后，收集小鼠的外周血和脾脏，通过流式细胞术、酶联免疫吸附法和逆转录聚合酶链反应检测Breg、Th17和Treg细胞以及相关的炎性因子。SLE + AS小鼠脾淋巴细胞中Breg和Treg的数量显著下降，而Th17细胞的数量显著增加，与C57组相比（p <.05）。此外，Breg的比例与Th17/Treg比值呈负相关（p =.03）。SLE + AS组的小鼠血清中IL-10、IL-17和肿瘤坏死因子-α的水平较SLE和C57组显著升高（p <.05）。此外，SLE + AS组中IL-35和转化生长因子（TGF）-β的表达相对于C57组减少（p <.05）。Breg减少的比例与Th17/Treg增加呈负相关，这在SLE + AS小鼠中增加了，表明Breg可能通过产生IL-35和TGF-β来调节Th17/Treg细胞的平衡和细胞因子的释放。©2023亚太风湿病协会联合会和Wiley&Sons Australia，有限公司。

In this study, we aimed to investigate Bregs, their regulatory effects on Th17/Treg cell balance, and the release of downstream inflammatory factors in a mouse model of low-density lipoprotein receptor (LDLr)-/-  + Pristane.After the establishment of the mouse model of systemic lupus erythematosus (SLE) complicated with atherosclerosis (AS), 8-week-old LDLr-/-  + Pristane mice (n = 10) were included in the SLE + AS group. Furthermore, 8-week-old MRL/lpr and C57 mice were used as the SLE and normal control groups, respectively (n = 10 per group). After feeding the mice a high-fat diet for 14 weeks, peripheral blood and spleen of mice were collected, and Bregs, Th17, and Treg cells and related inflammatory factors were detected by flow cytometry, enzyme-linked immunosorbent assay, and reverse-transcription polymerase chain reaction.The number of Bregs and Tregs in spleen lymphocytes of SLE + AS mice significantly decreased compared with the C57 group (p < .05), whereas the number of Th17 cells significantly increased (p = .000). Furthermore, the proportion of Bregs showed a negative correlation with the Th17/Treg ratio (p = .03). Mice in the SLE + AS group showed higher serum interleukin (IL)-10, IL-17, and tumor necrosis factor-α levels than those in the SLE and C57 groups (p < .05). Furthermore, IL-35 and transforming growth factor (TGF)-β expression was reduced in the SLE + AS group compared with the C57 group (p < .05).The proportion of Breg decreases was negatively associated with increased Th17/Treg which was increased in SLE + AS mice, indicating that Bregs may regulate Th17/Treg cell homeostasis and cytokine release via IL-35 and TGF-β production.© 2023 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.