Adjuvants that Enhance Th2 or Tr Responses

It is well-known that many isoforms of toll-like receptors (TLRs) function as Th1 adjuvant receptors. Thus, the ligands induce Th1 differentiation in an antigen non-specific manner. During the past few years, not only Th1, but also Th2 adjuvants have been reported. Allergy-inducing materials, such as parasites, first stimulate dendritic cells (DCs) to change their character as professional antigen-presenting cells. Such a DC population (DC2) can stimulate naive CD4T cells to induce differentiation into Th2. In some instances, DCs that can stimulate regulatory T cells are also induced. Interestingly, many of such substances are glycolipids or phospholipids that mammalian species do not usually carry. In this paper, we show a cellular and molecular basis for Th2 adjuvants.