title: Primary nasal epithelium exposed to house dust mite extract shows activated expression in allergic individuals.
abstract: Nasal epithelial cells form the outermost protective layer against environmental factors. However, this defense is not just physical; it has been shown that epithelial cells respond by the production of inflammatory mediators that may affect local immune responses. In this research we set out to characterize potential differences between the responses of nasal epithelium from healthy and allergic individuals to house dust mite (HDM) allergen. These differences will help us to define local mechanisms that could contribute to allergic disease expression. Epithelial cells were cultured from nasal biopsies taken from five healthy and five allergic individuals. These cultures were exposed for 24 hours to culture medium containing HDM allergen, or to culture medium alone. Isolated RNA was used for microarray analysis. Gene-ontology of the response in healthy epithelium revealed mainly up-regulation of chemokines, growth factors, and structural proteins. Moreover, we saw increased expression of two transcription factors (NF-kappaB and AP-1) and their regulatory members. The expression pattern of epithelium from allergic individuals in the absence of the HDM stimulus suggests that it is already in an activated state. Most striking is that, while the already activated NF-kappaB regulatory pathway remained unchanged in allergic epithelium, the AP-1 pathway is down-regulated upon exposure to HDM allergen; this is contrary to what we see in healthy epithelium. Clear differences in the expression pattern exist between epithelial cells isolated from healthy and allergic individuals at baseline and between their responses to allergen exposure; these differences may contribute to the inflammatory response.
authors: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, The Netherlands. a.b.vroling@amc.uva.nl
authors: Aram B
authors: AB
authors: Vroling
authors: Martijs J
authors: MJ
authors: Jonker
authors: Silvia
authors: S
authors: Luiten
authors: Timo M
authors: TM
authors: Breit
authors: Wytske J
authors: WJ
authors: Fokkens
authors: Cornelis M
authors: CM
authors: van Drunen
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D016022:Case-Control Studies; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D016000:Cluster Analysis; D015536:Down-Regulation / Q000187:drug effects; D004847:Epithelial Cells / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D008875:Middle Aged; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D009297:Nasal Mucosa / Q000166:cytology*; D009299:Nasal Provocation Tests; D020411:Oligonucleotide Array Sequence Analysis; D025341:Principal Component Analysis; D039981:Pyroglyphidae / Q000276:immunology*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D015203:Reproducibility of Results; D012882:Skin Tests; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000276:immunology / Q000378:metabolism
chemical_list: D000485:Allergens; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D012313:RNA