[The identification and advances of regulatory B cells]

B cells are typically characterized by their ability to regulate the immune responses through presenting antigens and producing antibodies. However, a novel B cell subset, named regulatory B cells (Bregs), has been identified. As Tregs, the Bregs are capable of performing both pathogenic and regulatory functions by production of suppressive cytokines, such as IL-10 or TGF-beta1, or by interaction with pathogen T cells or other immune cells. Recent studies indicate that the Bregs play a critical role in the development and resolution of multiple chronic diseases, including inflammatory bowel disease, rheumatoid arthritis, and experimental autoimmune encephalomyelitis. The identification and the clarification of action mechanisms of the Bregs will greatly contribute to understanding the mechanisms of immune tolerance comprehensively and deeply, and to develop the rational therapeutic strategies for arthritis, diabetes, multiple sclerosis, infectious diseases and cancer, etc. In this review, we summarized the recent insights of identification, characterizations, development, and regulation mechanisms of Bregs and these cells' contribution to the pathogenesis of inflammatory diseases.