Synthesis of NBD-alpha-galactosylceramide and its immunologic properties

[GRAPHICS] A representative alpha-galactosylceramide (alpha-GalCer), KRN7000, can acti vate NKT cells through CD1d molecules, which play an essential role in the generation of the strong antitumor activity of KRN7000, Our previous study has demonstrated that alpha-GalCer binds directly to CD1d molecules. Howeve r, it is controversial whether Cold binds a-GalCer in endosomal compartment s, To address this question, we synthesized NBD-alpha-GalCer, which has str ong fluorescent properties. We found that the NBD-alpha-GalCer has immunost imulatory activity that is stronger than that of KRN7000.