To B or not to B--pathogenic and regulatory B cells in autoimmune diabetes

B cells have a vitally important function to produce antibodies which are directly pathogenic in some autoimmune diseases. However, it is clear that a number of other B cell functions are also critical in the pathogenesis of organ-specific autoimmune diseases that were previously thought to be mainly T cell mediated. Therapeutic agents that target B cells and their functions may therefore be of considerable importance in these autoimmune diseases. In this review, we will focus on B cell characteristics and functions that contribute to type 1 diabetes (T1D) and discuss why anti-B cell treatment may be effective in T1D, a disease that was previously considered to be primarily T cell mediated.