Boosting innate immunity in cancer

Mature DCs and the NKT cell ligand α-galactosyl ceramide (α-GalCer) are a promising combination for boosting immunity in humans, according to a study on page 1503. Chang and colleagues used α-GalCer–pulsed DCs to immunize cancer patients and showed that the treatment resulted in long-term expansion of both NKT cells and virus-specific CD8⁺ T cells.α-GalCer, a glycolipid derived from marine sponges, was identified based on its antitumor properties. This foreign glycolipid was later found to be presented to NKT cells by DCs. NKT cells activated by this glycolipid can promote tumor regression in mice. Attempts to extend this work to humans, however, have met with limited success. α-GalCer treatment alone decreased NKT cell numbers in patients with solid tumors, and vaccination with α-GalCer–pulsed immature DCs induced only modest and transient...