NKT cells are a subset of white blood cells that regulate immune response to bacterial, viral and parasitic infections. They also prevent unwanted immune responses that cause autoimmune diseases such as type I diabetes and multiple sclerosis. Therefore, the objective of the experiments described here is to gain insight into the mechanism(s) by which NKT cells regulate immune responses to infections such as Francisella spp. including Francisella tularensis, F. holarctica, and F. novicida, a relative of F. tularensis which causes tularemic-like disease in mice, Mycobacterium tublerculosis the eitiological agent of tuberculosis, and Listeria monocytogenes (Lm), a common intestinal pathogen that causes food poisoning.

All of these bacteria survive in cells of the immune system and are thereby protected from much of the immune response. In order to eliminate this infection, small molecules of the immune system called cytokines must be released into the system to activate the cells where these bacteria survive. NKT cells are capable of releasing numerous cytokines as well as causing or preventing the release of cytokines from other cells. Over-production of cytokines is detrimential to the host so fine control over cytokines is necessary for health. NKT cells appear to be central to this level of control.