Submitted on July 26, 2007
Accepted on August 20, 2007
Role of NKT cells in Intestinal Immunity
Sebastian Zeissig1, Arthur Kaser2, Stephanie K. Dougan1, Edward E.S. Nieuwenhuis3, and Richard S. Blumberg4*
1 Department of Medicine, Division of Gastroenterology, Boston, Massachusetts, United States
2 Department of Medicine, Division of Gastroenterology, Innsbruck, Massachusetts, Austria
3 Department of Pediatric Gastroenterology, Laboratory of Pediatrics, Rotterdam, Netherlands
4 Gastroenterology Division, Brigham and Women's Hospital, Boston, Massachusetts, United States
* To whom correspondence should be addressed. E-mail: rblumberg{at}partners.org.
Natural Killer T (NKT) cells are a small subset of unconventional T cells which recognize lipid antigens presented by the non-classical MHC class I molecule CD1d. NKT cells are involved in the host response to a variety of microbial pathogens and likely commensals. In the intestine, invariant and non-invariant NKT cells can be found among intraepithelial lymphocytes and in the lamina propria. Activation of intestinal NKT cells by CD1d-expressing intestinal epithelial cells (IECs) and professional antigen presenting cells (APCs) may contribute to induction of oral tolerance and protection from mucosal infections. On the other hand, sustained and uncontrolled activation of NKT cells may play a pivotal role in the pathogenesis of inflammatory bowel disease. Here, we review the current literature on intestinal NKT cells and their function in the intestine in health and disease.
