Synthesis and Th1-immunostimulatory activity of α-galactosylceramide analogues bearing a halogen-containing or selenium-containing acyl chain

A novel series of CD1d ligand alpha-galactosylceramides (alpha-GalCers) were synthesized by incorporation of the heavy atoms Br and Se in the acyl chain backbone of alpha-galactosyl-N-cerotoylphytosphingosine. The synthetic analogues are potent CD1d ligands and stimulate mouse invariant natural killer T (iNKT) cells to selectively enhance Th1 cytokine production. These synthetic analogues would be efficient X-ray crystallographic probes to disclose precise atomic positions of alkyl carbons and lipid-protein interactions in KRN7000/CD1d complexes. (C) 2016 Elsevier Ltd. All rights reserved.