Non-reducing end α-mannosylated glycolipids as potent activators for invariant Vα19 TCR-bearing natural killer T cells

Attempts have been made to find specific antigens for a novel NKT cell subset bearing invariant Vα19-Jα33 TCR α chains (Vα19 NKT cell). Comprehensive examinations revealed substantial antigenic activity in certain α-mannosyl sphingolipids and phosphatidylinositols that were presented by MR1. Structural modification of the sphingosine moiety of α-ManCer improved antigenic activity to enhance either Th1- or Th2-promoting cytokine production by Vα19 NKT cells. Such glycolipids will be useful for developing new therapies as immunomodulators.