AID was originally thought to be made only by mature B cells and, as previously discovered by Imanishi-Kari and colleagues, in the developing B cells of transgenic mice. In the current article, Imanishi-Kari and colleagues reveal that AID is also made by developing B cells in wild-type, or normal, mice which implies that AID plays a larger role in the immune system than previously thought. Building upon what is already known about B cells, Imanishi-Kari hypothesizes that AID plays a role during B cell development by mutating B cell antibodies and, thereby, preventing B cells from mistaking some healthy human cells as disease pathogens, which is what occurs in autoimmune diseases such as systemic lupus erythematosus (SLE or lupus). Uncovering the presence of AID in developing B cells may offer a new direction for research into autoimmunity and other diseases. -Tufts University, Health Sciences
