title: Chemotactic responses of peripheral blood eosinophils to prostaglandin D2 in atopic keratoconjunctivitis.
abstract: BACKGROUND
  Eosinophils appear to be key cells in the pathogenesis of conjunctival inflammation in atopic keratoconjunctivitis (AKC). Chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2) mediates prostaglandin D2 (PGD2)-dependent migration of eosinophils. However, it is unclear whether CRTH2/PGD2-dependent eosinophil migration is upregulated in allergic diseases.
  
  
  OBJECTIVE
  To compare the chemotactic responses of peripheral blood eosinophils to prostaglandin D2 in patients with severe AKC and healthy individuals.
  
  
  METHODS
  We used an enzyme immunoassay system to measure PGD2 levels in tears and blood samples from healthy individuals and patients with AKC. CRTH2 expression on peripheral blood eosinophils was determined using reverse-transcriptase polymerase chain reaction (RT-PCR), flow cytometry, and an oligonucleotide array system. Chemotaxis experiments were performed using a modified Boyden chamber technique and an optical assay system.
  
  
  RESULTS
  The PGD2 concentrations were higher in tears from patients with severe AKC compared with healthy individuals. RT-PCR (severe and mild cases), flow cytometry (mild cases), and GeneChip analyses revealed a significantly higher expression of CRTH2 on peripheral blood eosinophils in patients with AKC than in healthy individuals. PGD2 and its stable metabolite 13,14-dihydro-15-keto-PGD2, a CRTH2 agonist, induced chemotaxis of eosinophils from patients with AKC; chemotaxis was significantly enhanced in eosinophils from patients with severe AKC compared with those from healthy individuals.
  
  
  CONCLUSIONS
  CRTH2 is more abundantly expressed on eosinophils from patients with AKC and promoted PGD2-dependent migration to a greater extent than in healthy individuals.
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. fujishima117@gmail.com
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujishima
authors.forename: Kazumi
authors.initials: K
authors.lastname: Fukagawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Okada
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hirai
authors.forename: Kinya
authors.initials: K
authors.lastname: Nagata
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Hashida
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Saito
mesh_terms: D000293:Adolescent; D000328:Adult; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D004804:Eosinophils / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006967:Hypersensitivity / Q000378:metabolism*; D007637:Keratoconjunctivitis / Q000378:metabolism*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D015230:Prostaglandin D2 / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000096:biosynthesis; D011982:Receptors, Prostaglandin / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D011971:Receptors, Immunologic; D011982:Receptors, Prostaglandin; D015230:Prostaglandin D2; C036293:prostaglandin D2 receptor