Researchers have for the first time described a method that Staphylococcus aureus (staph) infection uses to inactivate the body’s immune system. A protein produced by the staph bacteria causes previously healthy B cells — a specialized cell of the immune system — to commit suicide, a process called apoptosis. “By the targeted elimination of disease-causing B cells, properly dosed injections of SpA may have the potential to control the over-activity of the immune system that causes damage in autoimmune diseases like lupus and in certain cancers,” said Gregg Silverman, M.D., UCSD professor of medicine and senior author of the paper.