Negative modulation of invariant natural killer T cell responses to glycolipid antigens by p38 MAP kinase.

Invariant natural killer T (iNKT) cells are CD1d-restricted, glycolipid-reactive lymphocytes with potent immunoregulatory characteristics. Although recent years have witnessed intensified interest in iNKT cells, little is known about intracellular signaling pathways that control iNKT cell responses, including those mediated by mitogen-activated protein kinases (MAPKs). We employed selective inhibitors of ERK1/2, JNK and p38 to examine the importance of these MAPKs in iNKT cell responses to the prototype glycolipid antigen alpha-galactosylceramide (alpha GC).