Prostaglandin D(2) and T(H)2 Inflammation in the Pathogenesis of Bronchial Asthma

Prostaglandin D(2) (PGD(2)) is a major prostanoid, produced mainly by mast cells, in allergic diseases, including bronchial asthma. PGD(2)-induced vasodilatation and increased permeability are well-known classical effects that may be involved in allergic inflammation. Recently, novel functions of PGD(2) have been identified. To date, D prostanoid receptor (DP) and chemoattractant receptor homologous molecule expressed on T(H)2 cells (CRTH2) have been shown to be major PGD(2)-related receptors. These two receptors have pivotal roles mediating allergic diseases by regulating the functions of various cell types, such as T(H)2 cells, eosinophils, basophils, mast cells, dendritic cells, and epithelial cells. This review will focus on the current understanding of the roles of PGD(2) and its metabolites in T(H)2 inflammation and the pathogenesis of bronchial asthma.