Synthesis and human NKT cell stimulating properties of 3-O-sulfo-α/β-galactosylceramides Original Research Article

Two novel hybrid molecules 3-O-sulfo-α/β-galactosylceramide 3 and 4, which are derived from an immunostimulatory agent α-GalCer 1 and self-glycolipid ligand sulfatide 2, were designed and synthesized. Compound 3 was shown to efficiently stimulate human NKT cells to secret IL-4 and IFN-γ, with activities similar to 1, suggesting that modification of the 3″-OH position of the galactose moiety with sulfate has no significant effect on NKT cell stimulation. As a comparison, the β-isomer 4 has no affinity to NKT cells, which demonstrates that the α-glycosidic bond of galactosylceramide is crucial to the NKT cells activation.