title: Microarray-based in vitro test system for the discrimination of contact allergens and irritants: identification of potential marker genes.
abstract: BACKGROUND
  Animal tests have been used to characterize the potential of chemicals to produce allergic contact dermatitis, but this approach is increasingly a matter of public and political concern. Our aim was to develop and validate an alternative in vitro test that can identify contact allergens.
  
  
  METHODS
  We developed a targeted microarray containing oligonucleotide probes for 66 immune-relevant genes and analyzed gene expression in monocyte-derived dendritic cells (Mo-DCs) treated with 1 irritant (SDS) and 2 prominent contact allergens, nickel and Bandrowski's base (BB), which is the oxidation product of the most important hair dye allergen, p-phenylenediamine.
  
  
  RESULTS
  Comparing RNA amounts in chemical-treated and solvent-treated cells, we identified significant changes in the expression of 21 genes and 10 genes after exposure of immature DCs (iDCs) to nickel and BB, respectively, but not after exposure to SDS. Eight genes were differentially expressed after application of both nickel and BB. Real-time PCR was used to confirm the results for selected genes.
  
  
  CONCLUSIONS
  We propose a microarray-based in vitro test that might allow the identification of contact allergens. Independently from donor variability, several immune-relevant genes were up- or downregulated after the application of the tested sensitizers to iDCs, therefore presenting potential marker genes. While reducing the number of laboratory animals used, this test would also enable reliable analysis of chemicals using a human system.
authors.affiliation: Molecular Diagnostics, Austrian Research Centers GmbH, ARC, Seibersdorf, Austria. Sandra.Szameit@arcs.ac.at
authors.forename: Sandra
authors.initials: S
authors.lastname: Szameit
authors.forename: Klemens
authors.initials: K
authors.lastname: Vierlinger
authors.forename: Letizia
authors.initials: L
authors.lastname: Farmer
authors.forename: Helga
authors.initials: H
authors.lastname: Tuschl
authors.forename: Christa
authors.initials: C
authors.lastname: Noehammer
mesh_terms: D000485:Allergens / Q000276:immunology / Q000494:pharmacology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects / Q000378:metabolism; D003877:Dermatitis, Contact / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006202:Hair Dyes / Q000494:pharmacology; D006801:Humans; D007509:Irritants / Q000494:pharmacology*; D009532:Nickel / Q000276:immunology / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010655:Phenylenediamines / Q000276:immunology / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology
chemical_list: D000485:Allergens; D006202:Hair Dyes; D007509:Irritants; D010655:Phenylenediamines; C051597:Bandrowski's base; D012967:Sodium Dodecyl Sulfate; C029938:nickel sulfate; D009532:Nickel