Chemoattractant Receptor-Homologous Molecule Expressed on T Helper-2 Cells (CRTH2)

Chemoattractant Receptor-Homologous Molecule Expressed on T Helper-2 Cells (CRTH2), also known as GPR44, is a G protein-coupled receptor primarily activated by Prostaglandin D2 (PGD2). It is selectively expressed on Th2 cells, eosinophils, basophils, a subset of monocytes, innate lymphoid type 2 cells (ILC2), and epithelial cells. CRTH2 mediates allergic inflammation by recruiting Th2 lymphocytes and eosinophils to sites of inflammation. Activation increases intracellular calcium levels while reducing cyclic AMP levels; it also activates phospholipase C, PI3K, and p38 MAP kinase pathways. It has become a target for drug development, particularly for asthma characterized by high eosinophil counts, with several orally administered antagonists under clinical investigation.

Other names

CRTH2GPR44

Antagonism of CRTH2 receptor, blocking PGD2 binding and downstream signaling, inhibiting leukocyte recruitment and activation.