Alpha-1-antitrypsin is present in the specific granules of human eosinophilic granulocytes
Författare
Summary, in English
Eosinophils may be found at sites of inflammation, for example in asthma, allergy and helminthic infestation, but their role in human inflammatory disease is unclear. In the present study, we investigated the presence of alpha-1-antitrypsin (AAT), a serine proteinase inhibitor, in human eosinophils. When lysates of highly purified eosinophils were subjected to Western blotting, with a chemiluminescent substrate, immunoreactive bands were seen. An ELISA was developed to measure the AAT content, which was found to be about 100 ng/5 x 106 eosinophils, about 50 ng/5 x 106 neutrophils, and about 25 ng/5 x 106 monocytes. Immunoelectron microscopy showed localization of AAT to the specific granules of eosinophils. During prolonged incubation of eosinophils, no significant increase in the total amount of AAT could be detected by ELISA. However, there was an increased level of AAT in the medium, in parallel with a decrease in the intracellular AAT content, suggesting release of preformed AAT. Apparent complex formation between iodinated elastase and AAT in eosinophil lysates provided evidence that the AAT is functionally active. On the basis of these findings it is suggested that by releasing AAT, eosinophils may, in a microenvironment, play a role in counteracting the tissue damage caused by serine proteinases released by neutrophils in inflammatory conditions.
Avdelning/ar
- Teknisk mikrobiologi
- Klinisk kemi, Malmö
- Chronic Inflammatory and Degenerative Diseases Research Unit
- Lungmedicin, allergologi och palliativ medicin
Publiceringsår
2001
Språk
Engelska
Sidor
379-386
Publikation/Tidskrift/Serie
Clinical and Experimental Allergy
Volym
31
Issue
3
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley
Ämne
- Respiratory Medicine and Allergy
Nyckelord
- granules
- inflammation
- eosinophils
- alpha-1-antitrypsin
- serpins
- asthma
Status
Published
Forskningsgrupp
- Clinical Chemistry, Malmö
- Chronic Inflammatory and Degenerative Diseases Research Unit
ISBN/ISSN/Övrigt
- ISSN: 1365-2222