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Degranulation status of airway tissue eosinophils in mouse models of allergic airway inflammation

Malm-Erjefält, Monika LU ; Persson, Carl LU and Erjefält, Jonas LU (2001) In American Journal of Respiratory Cell and Molecular Biology 24(3). p.352-359
Abstract
Eosinophil degranulation is a characteristic feature of asthma and allergic rhinitis. However, degranulated eosinophils have not been convincingly demonstrated in the common mouse models of these airway diseases. This study uses eosinophil peroxidase (EPO) histochemistry and transmission electron microscopy (TEM) analysis to assess eosinophil degranulation in the airways of ovalbumin (OVA)-sensitized and challenged BALB/c and C57BL/6 mice. Using TEM we also examined mouse and human blood eosinophils after in vitro incubation with formyl-Met-Leu-Phe (fMLP) or phorbol myristate acetate (PMA). Although OVA exposure induced significant nasal and lung eosinophilia, we did not observe any of the known cellular processes by which eosinophils... (More)
Eosinophil degranulation is a characteristic feature of asthma and allergic rhinitis. However, degranulated eosinophils have not been convincingly demonstrated in the common mouse models of these airway diseases. This study uses eosinophil peroxidase (EPO) histochemistry and transmission electron microscopy (TEM) analysis to assess eosinophil degranulation in the airways of ovalbumin (OVA)-sensitized and challenged BALB/c and C57BL/6 mice. Using TEM we also examined mouse and human blood eosinophils after in vitro incubation with formyl-Met-Leu-Phe (fMLP) or phorbol myristate acetate (PMA). Although OVA exposure induced significant nasal and lung eosinophilia, we did not observe any of the known cellular processes by which eosinophils release their granule products, i.e., eosinophil cytolysis, piecemeal degranulation, and exocytosis. The occurrence of other allergen-induced degranulation events was ruled out because no difference in granule morphology was observed between lung-tissue eosinophils and blood or bone-marrow eosinophils from control animals. Accordingly, there was no detectable extracellular EPO in lung tissues of allergic mice. Similarly, mouse blood eosinophils remained nondegranulated in vitro in the presence of fMLP and PMA, whereas the same treatment of human eosinophils resulted in extensive degranulation. This investigation indicates that OVA-induced airway inflammation in the present mouse strains does not involve significant eosinophil degranulation. It is speculated that this dissimilarity from the human disease may be due to a fundamental difference in the regulation of mouse and human eosinophils. (Less)
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Contribution to journal
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published
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in
American Journal of Respiratory Cell and Molecular Biology
volume
24
issue
3
pages
352 - 359
publisher
American Thoracic Society
external identifiers
  • pmid:11245636
  • scopus:0035091256
ISSN
1535-4989
language
English
LU publication?
yes
id
82ab0e6f-3700-494a-9e1c-544d3e232899 (old id 1122938)
alternative location
http://ajrcmb.atsjournals.org/cgi/content/full/24/3/352
date added to LUP
2008-07-04 13:43:59
date last changed
2018-01-07 05:23:45
@article{82ab0e6f-3700-494a-9e1c-544d3e232899,
  abstract     = {Eosinophil degranulation is a characteristic feature of asthma and allergic rhinitis. However, degranulated eosinophils have not been convincingly demonstrated in the common mouse models of these airway diseases. This study uses eosinophil peroxidase (EPO) histochemistry and transmission electron microscopy (TEM) analysis to assess eosinophil degranulation in the airways of ovalbumin (OVA)-sensitized and challenged BALB/c and C57BL/6 mice. Using TEM we also examined mouse and human blood eosinophils after in vitro incubation with formyl-Met-Leu-Phe (fMLP) or phorbol myristate acetate (PMA). Although OVA exposure induced significant nasal and lung eosinophilia, we did not observe any of the known cellular processes by which eosinophils release their granule products, i.e., eosinophil cytolysis, piecemeal degranulation, and exocytosis. The occurrence of other allergen-induced degranulation events was ruled out because no difference in granule morphology was observed between lung-tissue eosinophils and blood or bone-marrow eosinophils from control animals. Accordingly, there was no detectable extracellular EPO in lung tissues of allergic mice. Similarly, mouse blood eosinophils remained nondegranulated in vitro in the presence of fMLP and PMA, whereas the same treatment of human eosinophils resulted in extensive degranulation. This investigation indicates that OVA-induced airway inflammation in the present mouse strains does not involve significant eosinophil degranulation. It is speculated that this dissimilarity from the human disease may be due to a fundamental difference in the regulation of mouse and human eosinophils.},
  author       = {Malm-Erjefält, Monika and Persson, Carl and Erjefält, Jonas},
  issn         = {1535-4989},
  language     = {eng},
  number       = {3},
  pages        = {352--359},
  publisher    = {American Thoracic Society},
  series       = {American Journal of Respiratory Cell and Molecular Biology},
  title        = {Degranulation status of airway tissue eosinophils in mouse models of allergic airway inflammation},
  volume       = {24},
  year         = {2001},
}