Widespread natural variation in murine natural killer T-cell number and function.

Natural killer T (NKT) cells comprise a novel T-lymphocyte subset that can influence a wide variety of immune responses through their ability to secrete large amounts of a variety of cytokines. Although variation in NKT-cell number and function has been extensively studied in autoimmune disease-prone mice, in which it has been linked to disease susceptibility, relatively little is known of the natural variation of NKT-cell number and function among normal inbred mouse strains. Here, we demonstrate strain-dependent variation in the susceptibility of C57BL/6J and BALB/cJ mice to NKT-mediated airway hyperreactivity, which correlated with significant increases in serum interleukin-4 (IL-4) and IL-13 elicited by the synthetic glycosphingolipid alpha-galactosylceramide.