Superantigens are secreted toxins from some kinds of bacteria that stimulate a massive and damaging immune response in the body, causing a number of diseases. For example, TSST-1 is a superantigen that can cause toxic shock syndrome which may lead to multiple organ failure and often death. Shirin Kalyan is studying how the immune system responds to superantigens at the cellular level. Superantigens activate between 5 to 30 percent of all T cells (white blood cells involved in fighting infection). This ability to stimulate such a large pool of immune cells leads to a massive inflammatory response. In contrast, conventional antigens activate less than .01 per cent of T cells. Shirin is investigating whether a particular type of primodial innate T cell can influence the immune response that causes toxic shock syndrome. The findings could lead to more effective treatments for toxic shock syndrome and other immune disorders caused by superantigens.