NKT cells, a unique subset of T cells
that recognizes glycolipid
antigens presented by CD1d molecules, are believed to produce key
cytokines of both Th1 and Th2 T cells and are thus involved in the
control of several types of immune response. As an active glycolipid
antigen having α-galactosyl ceramide core structure, KRN7000
showed promising immunostimulation activity and was selected as an
anticancer drug candidate for further clinical application. In this
report, three new KRN7000 structural analogues were designed and synthesized,
in which the ring oxygen of the galactopyranose residue is replaced
by a sulfur atom along with the variation on the lipid chain. Their
abilities for stimulating mouse NKT cells to produce IFN-γ and
IL-4 were evaluated both <i>in vivo</i> and <i>in vitro</i>