Expansion of lung Vα14 NKT cells by administration of α-galactosylceramide-pulsed dendritic cells

NKT cells, a novel murine lymphoid lineage bearing an invariant T cell receptor encoded by Valpha14 and Jalpha281 gene segments, recognize a specific ligand glycolipid, alpha-galactosylceramide (alpha-GalCer) in a CD1d-dependent manner. Recent research has revealed that activated Valpha14 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 Valpha14 NKT cells. Furthermore, we show a significant expansion of endogenous Valpha14 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.