title: Lack of transient receptor potential vanilloid-1 enhances Th2-biased immune response of the airways in mice receiving intranasal, but not intraperitoneal, sensitization.
abstract: BACKGROUND
  Transient receptor potential vanilloid-1 (TRPV1) may modulate allergic airway inflammation because it is expressed not only on the nerve endings but also on several cells of the immune system. We wanted to know the characteristics of airway and systemic responses against sensitization and challenge with allergens in TRPV1 receptor gene knockout mice (TRPV1(-/-)).
  
  
  METHODS
  TRPV1(-/-) and their wild-type counterparts (TRPV1(+/+)) were sensitized with either house dust mite (HDM) or ovalbumin (OVA) via intranasal (i.n.) or intraperitoneal (i.p.) route before the final i.n. challenge with the corresponding allergen. One day after the final challenge, serum IgE levels, cytokine levels in the bronchoalveolar lavage fluid (BALF), and the number of BALF cells were examined after measuring bronchial hyperresponsiveness against methacholine.
  
  
  RESULTS
  Compared to TRPV1(+/+), TRPV1(-/-) showed enhanced Th2-biased response after i.n. HDM or OVA sensitization, including increased levels of serum IgE, interleukin 4 (IL-4) and eosinophils in the BALF. By contrast, when sensitized via i.p. route, the response against OVA or HDM was almost similar between TRPV1(+/+) and TRPV1(-/-).
  
  
  CONCLUSIONS
  TRPV1 receptor may downregulate Th2-biased immune response when sensitized via airways, although this was not the case when sensitized systemically.
authors: Laboratory of Allergy and Immunology, Faculty of Pharmacy, Takasaki University of Health and Welfare, Takasaki, Japan. tmori@takasaki-u.ac.jp
authors: Tetsuya
authors: T
authors: Mori
authors: Katsuyo
authors: K
authors: Saito
authors: Yasushi
authors: Y
authors: Ohki
authors: Hirokazu
authors: H
authors: Arakawa
authors: Makoto
authors: M
authors: Tominaga
authors: Kenichi
authors: K
authors: Tokuyama
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001249:Asthma / Q000276:immunology; D016535:Bronchial Hyperreactivity / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D016207:Cytokines / Q000097:blood / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007274:Injections, Intraperitoneal; D008168:Lung / Q000276:immunology; D016210:Methacholine Chloride / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010047:Ovalbumin / Q000276:immunology*; D039981:Pyroglyphidae / Q000276:immunology*; D012130:Respiratory Hypersensitivity / Q000097:blood / Q000276:immunology; D050916:TRPV Cation Channels / Q000235:genetics* / Q000378:metabolism*; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D016207:Cytokines; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D016210:Methacholine Chloride; D007073:Immunoglobulin E; D010047:Ovalbumin