title: In situ hybridization analysis of ICAM-1 (CD54) mRNA on conjunctival epithelium during allergic inflammation.
abstract: BACKGROUND
  The intercellular adhesion molecule ICAM-1 has been detected by immunohistochemical methods on epithelial cells of the conjunctiva and nose during allergic inflammation.
  
  
  OBJECTIVE
  The aim of the present study was to evaluate whether ICAM-1 expression on conjunctival epithelium derives from endogenous synthesis or is merely due to passive uptake of soluble ICAM-1 released from inflammatory cells.
  
  
  METHODS
  In situ hybridization was performed using a 3' end dygoxygenin-labelled specific DNA oligonucleotide probe on fixed conjunctival smears from allergic subjects challenged with, or naturally exposed to the allergen, and from healthy subjects. Immunocytochemistry for ICAM-1 was performed by alkaline phosphatase antialkaline phosphatase.
  
  
  RESULTS
  In allergic patients, both naturally exposed to the allergen and after specific challenge, a clear hybridization pattern on epithelial cells was apparent. Out of allergen exposure, some symptomfree pollinosic subjects, as well as a few healthy volunteers showed mild ICAM-1 mRNA cytoplasmic staining in the absence of immunohistochemically detectable ICAM-1. This finding may explain the very early appearance of ICAM-1 on conjunctival epithelium following specific challenge in allergic individuals.
  
  
  CONCLUSIONS
  These results indicate that the presence of ICAM-1 on conjunctival epithelium during allergic inflammation derives from endogenous synthesis and not from uptake of soluble ICAM-1.
authors.affiliation: Allergy and Clinical Immunology Service, Department of Internal Medicine, University of Genoa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bagnasco
authors.forename: G
authors.initials: G
authors.lastname: Pesce
authors.forename: N
authors.initials: N
authors.lastname: Fiorino
authors.forename: A M
authors.initials: AM
authors.lastname: Riccio
authors.forename: G
authors.initials: G
authors.lastname: Ciprandi
authors.forename: S
authors.initials: S
authors.lastname: Buscaglia
authors.forename: G W
authors.initials: GW
authors.lastname: Canonica
mesh_terms: D016475:3T3 Cells; D000328:Adult; D000818:Animals; D002460:Cell Line; D003228:Conjunctiva / Q000276:immunology*; D003233:Conjunctivitis, Allergic / Q000276:immunology*; D004848:Epithelium / Q000276:immunology; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D008297:Male; D051379:Mice; D008875:Middle Aged; D009296:Nasal Cavity / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1