Prostaglandin D2 and Interleukin-5 Reduce Crth2 Surface Expression on Human Eosinophils

• Main Authors: Kazuyuki Hamada, Yoshiyuki Yamada, Yumiko Kamada, Shigeharu Ueki, Kazutoshi Yamaguchi, Hajime Oyamada, Miyoshi Fujita, Atsuko Usami, Takahito Chiba, Akira Kanda, Hiroyuki Kayaba, Junichi Chihara
• Format: Article
• Language: English
• Published: Elsevier 2004-01-01
• Series: Allergology International
• Subjects: CRTH2; eosinophils; interferon-γ; interleukin-4; interleukin-5; prostaglandin D2
• Online Access: http://www.sciencedirect.com/science/article/pii/S1323893015311138

Background: Recently, a second prostaglandin D2 (PGD2) receptor, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2), was identified. Because PGD2 was reported to have chemotactic activity on eosinophils, CRTH2 expressed on eosinophils attracted interest as a receptor associated with eosinophil migration to, and accumulation at, inflammatory sites. To elucidate the mechanism regulating the expression of CRTH2 on eosinophils, the effects of PGD2, interleukin (IL)-4, IL-5 and interferon (IFN)-γ on CRTH2 expression were investigated. Methods: Blood eosinophils were purified using Percoll and anti-CD16 antibody coated magnetic beads. Eosinophils were incubated with PGD2 and/or IL-4, IL-5 and IFN-γ. The expression of CRTH2 on eosinophils was measured using a FACScan cytometer (Becton Dickinson Immunocytometry Systems, San Jose, CA, USA). Results: Prostaglandin D2 and IL-5, but not IL-4 and IFN-γ, downregulated the expression of CRTH2 on eosinophils. Furthermore, PGD2- and IL-5-induced downregulation of CRTH2 on human eosinophils was inhibited by phenylarsine oxide, a receptor internalization inhibitor. Conclusions: These results suggest that PGD2 and IL-5 regulate CRTH2 expression on eosinophils through CRTH2 internalization. The decreased expression of CRTH2 on tissue eosinophils may make these cells remain at the site of allergic inflammation.