Expansion of lung V alpha 14 NKT cells by administration of alpha-galactosylceramide-pulsed dendritic cells.

NKT cells, a novel murine lymphoid lineage bearing an invariant T cell receptor encoded by V alpha 14 and J alpha 281 gene segments, recognize a specific ligand glycolipid, alpha-galactosylceramide (alpha-GalCer) in a CD1d-dependent manner. Recent research has revealed that activated V alpha 14 NKT cells have dramatic antitumor effects against a wide variety of tumor cell lines in vivo and in vitro. Here, we demonstrate strong in vivo antitumor effects brought about by treatment with alpha-GalCer-pulsed dendritic cells in comparison with in vitro-activated V alpha 14 NKT cells. Furthermore, we show a significant expansion of endogenous V alpha 14 NKT cells in the lung following the administration of alpha-GalCer-pulsed dendritic cells. The feasibility of immunotherapy with alpha-GalCer-pulsed dendritic cells is discussed.