[Regulatory B cell and autoimmune disease].

Regulatory B cells that produce IL-10 are now recognized as an important component of the immune system. Hallmark papers from a number of distinguished laboratories have identified phenotypically diverse B cell subsets with regulatory functions during distinct autoimmune diseases, including IL-10-producing B cells, CD5(+) B-1a cells, CD1d(+) marginal zone B cells, and transitional 2-marginal zone precursor B cells. Most recently, a numerically rare and phenotypically unique CD1d(hi)CD5(+)CD19(hi) subset of regulatory B cells has been identified in the spleens of both normal and autoimmune mice. Remarkably, regulatory B cells are potent negative regulators of inflammation and autoimmunity in mouse models of disease in vivo. Herein, our current understanding of regulatory B cell function is reviewed in the context of previous studies that have identified and characterized regulatory B cells.