A novel lymphocyte lineage, V alpha 14 NKT cells, has recently been identified and appears to be distinct from conventional alphabeta T cells. V alpha 14 NKT cells express a single invariant V alpha 14 antigen receptor that is essential for their development. They recognize a glycolipid antigen (alpha -galactosylceramide) or parasitic glycophosphatidylinositols (GPI) in association with a monomorphic class Ib, CD1d, and perform various functions such as Th1 and Th2 cytokine production as well as perforin/granzyme B-mediated cytotoxicity. Although the precise physiological function of V alpha 14 NKT cells remains to be elucidated, emerging experimental evidence suggests their intriguing regulatory features in the immune system.
Copyright 2000 Academic Press.