Staphylococcus aureus and influenza A virus stimulate human bronchoalveolar cells to release histamine and leukotrienes

Abstract
Mediator release was examined from superficially lying cells in the airway epithelium obtained by bronchoalveolar lavage (BAL) in 13 non-atopic individuals. The BAL-cells were incubated (20 min, 37°C) withStaphylococcus (Staph.) aureus or with human influenza A virus.Staph. aureus was found to release histamine from cells from 7 of the 13 individuals and influenza A virus in 3 of 5 persons. Furthermore,Staph. aureus stimulated the BAL-cells to release leukotriene B4 in 7 of 11 subjects, whereas no release was found by influenza A virus in 7 examined persons. When cells from 4 persons were stimulated withStaph. aureus no release of leukotriene C4 was found. The mediator release caused by bacteria and virus might be of importance for the exacerbation of bronchial asthma in upper respiratory tract infections, since histamine is assumed to increase the epithelial permeability with entrance of allergens and other insulting particles, and leukotriene B4 facilitates airway inflammation.