Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Smith Building Room 516C, One Jimmy Fund Way, Boston, MA 02115, USA.
Group 1 and group 2 CD1 present both self and microbial lipid antigens to T cells. While group 1 CD1-restricted T cells are known for their ability to recognize mycobacterial glycolipid antigens, group 2 CD1-restricted T cells are recognized as regulatory T cells that can influence the outcome of innate and adaptive immune responses. The evidence that these T cells contribute to host defense against infectious diseases is reviewed.