Abstract Systemic lupus erythematosus (SLE) is an autoimmune disease associated with abnormal activation of immune cells. Regulatory B (Breg) cells are a cell subset that negatively regulate responses via secretion immunoregulatory cytokines interleukin (IL)-10, IL-35, and transforming growth factor (TGF)-β. We had previously shown in lupus-prone MRL/lpr mice, pre-disease Breg were more potent ...