Linked Life Data

19864598

Source:http://linkedlifedata.com/resource/pubmed/id/19864598

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-11-5
pubmed:abstractText
Eosinophils are multifunctional leukocytes implicated in the pathogenesis of asthma and in immunity to certain organisms. Associations between exposure to an environmental fungus, such as Alternaria, and asthma have been recognized clinically. Protease-activated receptors (PARs) are G protein-coupled receptors that are cleaved and activated by serine proteases, but their roles in innate immunity remain unknown. We previously found that human eosinophils respond vigorously to Alternaria organisms and to the secretory product(s) of Alternaria with eosinophils releasing their proinflammatory mediators. In this study, we investigated the roles of protease(s) produced by Alternaria and of PARs expressed on eosinophils in their immune responses against fungal organisms. We found that Alternaria alternata produces aspartate protease(s) and that human peripheral blood eosinophils degranulate in response to the cell-free extract of A. alternata. Eosinophils showed an increased intracellular calcium concentration in response to Alternaria that was desensitized by peptide and protease ligands for PAR-2 and inhibited by a PAR-2 antagonistic peptide. Alternaria-derived aspartate protease(s) cleaved PAR-2 to expose neo-ligands; these neo-ligands activated eosinophil degranulation in the absence of proteases. Finally, treatment of Alternaria extract with aspartate protease inhibitors, which are conventionally used for HIV-1 and other microbes, attenuated the eosinophils' responses to Alternaria. Thus, fungal aspartate protease and eosinophil PAR-2 appear critical for the eosinophils' innate immune response to certain fungi, suggesting a novel mechanism for pathologic inflammation in asthma and for host-pathogen interaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
183
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6708-16
pubmed:dateRevised
2010-12-3
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Recognition of fungal protease activities induces cellular activation and eosinophil-derived neurotoxin release in human eosinophils.
pubmed:affiliation
Department of Medicine and Immunology, Mayo Clinic, Rochester, MN 55905, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural