Premium
Organic dust exposure increases mast cell tryptase in bronchoalveolar lavage fluid and airway epithelium of heaves horses
Author(s) -
Dacre K. J.,
McGorum B. C.,
Marlin D. J.,
Bartner L. R.,
Brown J. K.,
Shaw D. J.,
Robinson N. E.,
Deaton C.,
Pemberton A. D.
Publication year - 2007
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2007.02857.x
Subject(s) - tryptase , bronchoalveolar lavage , degranulation , mast cell , horse , immunology , medicine , chymase , lung , pathology , biology , receptor , paleontology
Summary Background Mast cell degranulation is believed to act as a key event in initiating and maintaining airway response to allergen challenge in human asthma. It is hypothesized that the mast cell may play a similar role in equine heaves, which shares many similarities with occupational dust‐induced asthma. Objective The aim of this study was to quantify the mast cell proteinase tryptase in bronchoalveolar lavage fluid (BALF) from control and heaves‐susceptible horses and to investigate tryptase mRNA and protein expression in pulmonary mast cells. Methods Equine BALF tryptase concentrations were determined by ELISA from control and heaves‐susceptible horses pre and post 24 h hay/straw challenge (HSC). Tryptase mRNA and protein expression were investigated by quantitative PCR and immunohistochemistry in bronchial and bronchiolar tissue samples of control and heaves‐susceptible horses. Results Both control and heaves‐susceptible horses had significantly increased BALF tryptase concentrations following HSC ( P =0.003 and 0.034, respectively). Increased numbers of tryptase‐expressing intra‐epithelial mast cells were demonstrated in heaves horses, but not controls, following challenge ( P =0.02). Bronchiolar tissue from heaves horses removed from challenge contained significantly lower tryptase transcripts than that from control horses ( P =0.02). Conclusion Mast cell degranulation and tryptase release into the airways occur following HSC of control and heaves‐susceptible horses. The greater number of mast cells available in the bronchiolar epithelium of heaves horses may be clinically significant in the pulmonary inflammatory response of heaves.