Role of CD19+CD5+CD1d+ Bregs in maintaining the Th17/Treg balance in mice with systemic lupus erythematosus complicated with atherosclerosis

Objective 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. Methods 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. Results The number of Bregs and Tregs in spleen lymphocytes of SLE + AS mice significantly decreased compared with the C57 group (p