Prostaglandin D2 receptor 2 (PTGDR2) (PTGDR2)

Prostaglandin D2 receptor 2 (PTGDR2), commonly referred to as CRTH2 (Chemoattractant receptor-homologous molecule expressed on Th2 cells), is a G protein-coupled receptor that plays a central role in mediating allergic inflammation (Source: UniProt P24823). It is predominantly expressed on Th2 lymphocytes, eosinophils, and basophils, where it acts as a high-affinity receptor for prostaglandin D2 (PGD2), a major mediator released by mast cells (Source: PubMed PMID: 11359911). Activation of PTGDR2 leads to the chemotaxis of these immune cells and the production of type 2 cytokines such as IL-4, IL-5, and IL-13, which are critical in the pathogenesis of asthma and allergic rhinitis (Source: NIH/NCBI Gene ID 11251). Because of its involvement in the recruitment and activation of inflammatory cells, PTGDR2 has been a major target for drug development in respiratory and allergic diseases. Several small-molecule antagonists, including Fevipiprant and Setipiprant, have been investigated in clinical trials to block the PGD2-PTGDR2 axis (Source: PubChem). While these drugs aim to reduce eosinophilic inflammation, some high-profile candidates have failed to demonstrate sufficient clinical efficacy in late-stage trials, suggesting that patient selection based on specific biomarkers may be necessary for therapeutic success (Source: ClinicalTrials.gov). Despite these setbacks, the receptor remains a significant point of interest for understanding the mechanisms of Th2-driven diseases.

Other names

CRTH2Chemoattractant receptor-homologous molecule expressed on Th2 cellsGPR44CD294DL1RG protein-coupled receptor 44

PTGDR2 antagonists competitively bind to the receptor, preventing prostaglandin D2 from inducing Gi protein-mediated signaling, which inhibits the migration and activation of Th2 cells and eosinophils (Source: PubMed PMID: 29124383).