Prostaglandin D2 selectively induces chemotaxis in T helper type 2 cells, eosinophils, and basophils via seven-transmembrane receptor CRTH2

Prostaglandin (PG)D-2, which has long been implicated in allergic diseases, is currently considered to elicit its biological actions through the DP receptor (DP). Involvement of DP in the formation of allergic asthma was recently demonstrated with DP-deficient mice. However, proinflammatory functions of PGD, cannot be explained by DP alone. We show here that a seven-transmembrane receptor, CRTH2, which is preferentially expressed in T helper type 2 (Th2) cells, eosinophils, and basophils in humans, serves as the novel receptor for PGD(2). In response to PGD(2), CRTH2 induces intracellular Ca2+ mobilization and chemotaxis in Th2 cells in a G alphai-dependent manner. In addition, CRTH2, but not DP, mediates PGD(2)-dependent cell migration of blood eosinophils and basophils. Thus, PGD(2) is likely involved in multiple aspects of allergic inflammation through its dual receptor systems, DP and CRTH2.