Mucosal sensitization to German cockroach involves protease-activated receptor-2

<p>Abstract</p> <p>Background</p> <p>Allergic asthma is on the rise in developed countries. A common characteristic of allergens is that they contain intrinsic protease activity, and many have been shown to activate protease-activated receptor (PAR)-2 <it>in vitro...

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Main Authors: Dienger Krista, Zhou Ping, Ledford John R, Page Kristen, Wills-Karp Marsha
Format: Article
Language:English
Published: BMC 2010-05-01
Series:Respiratory Research
Online Access:http://respiratory-research.com/content/11/1/62
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author Dienger Krista
Zhou Ping
Ledford John R
Page Kristen
Wills-Karp Marsha
author_facet Dienger Krista
Zhou Ping
Ledford John R
Page Kristen
Wills-Karp Marsha
author_sort Dienger Krista
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Allergic asthma is on the rise in developed countries. A common characteristic of allergens is that they contain intrinsic protease activity, and many have been shown to activate protease-activated receptor (PAR)-2 <it>in vitro</it>. The role for PAR-2 in mediating allergic airway inflammation has not been assessed using a real world allergen.</p> <p>Methods</p> <p>Mice (wild type or PAR-2-deficient) were sensitized to German cockroach (GC) feces (frass) or protease-depleted GC frass by either mucosal exposure or intraperitoneal injection and measurements of airway inflammation (IL-5, IL-13, IL-17A, and IFNγ levels in the lung, serum IgE levels, cellular infiltration, mucin production) and airway hyperresponsiveness were performed.</p> <p>Results</p> <p>Following systemic sensitization, GC frass increased airway hyperresponsiveness, Th2 cytokine release, serum IgE levels, cellular infiltration and mucin production in wild type mice. Interestingly, PAR-2-deficient mice had similar responses as wild type mice. Since these data were in direct contrast to our finding that mucosal sensitization with GC frass proteases regulated airway hyperresponsiveness and mucin production in BALB/c mice (Page et. al. 2007 Resp Res 8:91), we backcrossed the PAR-2-deficient mice into the BALB/c strain. Sensitization to GC frass could now occur via the more physiologically relevant method of intratracheal inhalation. PAR-2-deficient mice had significantly reduced airway hyperresponsiveness, Th2 and Th17 cytokine release, serum IgE levels, and cellular infiltration compared to wild type mice when sensitization to GC frass occurred through the mucosa. To confirm the importance of mucosal exposure, mice were systemically sensitized to GC frass or protease-depleted GC frass via intraperitoneal injection. We found that removal of proteases from GC frass had no effect on airway inflammation when administered systemically.</p> <p>Conclusions</p> <p>We showed for the first time that allergen-derived proteases in GC frass elicit allergic airway inflammation via PAR-2, but only when allergen was administered through the mucosa. Importantly, our data suggest the importance of resident airway cells in the initiation of allergic airway disease, and could make allergen-derived proteases attractive therapeutic targets.</p>
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spelling doaj.art-e7be18cd573c4b1bb6b4329b62d33ba52022-12-22T00:57:21ZengBMCRespiratory Research1465-99212010-05-011116210.1186/1465-9921-11-62Mucosal sensitization to German cockroach involves protease-activated receptor-2Dienger KristaZhou PingLedford John RPage KristenWills-Karp Marsha<p>Abstract</p> <p>Background</p> <p>Allergic asthma is on the rise in developed countries. A common characteristic of allergens is that they contain intrinsic protease activity, and many have been shown to activate protease-activated receptor (PAR)-2 <it>in vitro</it>. The role for PAR-2 in mediating allergic airway inflammation has not been assessed using a real world allergen.</p> <p>Methods</p> <p>Mice (wild type or PAR-2-deficient) were sensitized to German cockroach (GC) feces (frass) or protease-depleted GC frass by either mucosal exposure or intraperitoneal injection and measurements of airway inflammation (IL-5, IL-13, IL-17A, and IFNγ levels in the lung, serum IgE levels, cellular infiltration, mucin production) and airway hyperresponsiveness were performed.</p> <p>Results</p> <p>Following systemic sensitization, GC frass increased airway hyperresponsiveness, Th2 cytokine release, serum IgE levels, cellular infiltration and mucin production in wild type mice. Interestingly, PAR-2-deficient mice had similar responses as wild type mice. Since these data were in direct contrast to our finding that mucosal sensitization with GC frass proteases regulated airway hyperresponsiveness and mucin production in BALB/c mice (Page et. al. 2007 Resp Res 8:91), we backcrossed the PAR-2-deficient mice into the BALB/c strain. Sensitization to GC frass could now occur via the more physiologically relevant method of intratracheal inhalation. PAR-2-deficient mice had significantly reduced airway hyperresponsiveness, Th2 and Th17 cytokine release, serum IgE levels, and cellular infiltration compared to wild type mice when sensitization to GC frass occurred through the mucosa. To confirm the importance of mucosal exposure, mice were systemically sensitized to GC frass or protease-depleted GC frass via intraperitoneal injection. We found that removal of proteases from GC frass had no effect on airway inflammation when administered systemically.</p> <p>Conclusions</p> <p>We showed for the first time that allergen-derived proteases in GC frass elicit allergic airway inflammation via PAR-2, but only when allergen was administered through the mucosa. Importantly, our data suggest the importance of resident airway cells in the initiation of allergic airway disease, and could make allergen-derived proteases attractive therapeutic targets.</p>http://respiratory-research.com/content/11/1/62
spellingShingle Dienger Krista
Zhou Ping
Ledford John R
Page Kristen
Wills-Karp Marsha
Mucosal sensitization to German cockroach involves protease-activated receptor-2
Respiratory Research
title Mucosal sensitization to German cockroach involves protease-activated receptor-2
title_full Mucosal sensitization to German cockroach involves protease-activated receptor-2
title_fullStr Mucosal sensitization to German cockroach involves protease-activated receptor-2
title_full_unstemmed Mucosal sensitization to German cockroach involves protease-activated receptor-2
title_short Mucosal sensitization to German cockroach involves protease-activated receptor-2
title_sort mucosal sensitization to german cockroach involves protease activated receptor 2
url http://respiratory-research.com/content/11/1/62
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AT pagekristen mucosalsensitizationtogermancockroachinvolvesproteaseactivatedreceptor2
AT willskarpmarsha mucosalsensitizationtogermancockroachinvolvesproteaseactivatedreceptor2