ABSTRACT
In rooms with moisture damage, the indoor air can be enriched with microorganisms causing a variety of symptoms. Due to the highly diverse composition of bioaerosols and the multiple effects on humans, an assessment of the health risk is not sufficiently possible. The aim of this study was to characterize the features of innate immunity using blood from subjects exposed to moisture damage compared to control subjects living in houses without visible moisture damage. We investigated the expression of TLR-2, TLR-4 and dectin-1 on the surface of monocytes from both fresh blood and after in vitro stimulation with the model substances E. coli endotoxin, zymosan A, Pam3Cys and Aspergillus versicolor in 25 exposed subjects and 25 control subjects. In vitro stimulation of whole blood with the same components was performed for 20 h and the release of inflammatory mediators IL-8 and IL-1ß were quantified. In addition to an enhanced number of blood leucocytes, the expression of the receptors TLR-2, TLR-4 and dectin-1 on blood monocytes was significantly enhanced in exposed subjects. In contrast, no different alteration in expression was detected between exposed and control group after in vitro stimulation with the model substances. The release of IL-8 and IL-1ß after stimulation of whole blood with A. versicolor was increased in subjects exposed to moisture damage. Furthermore, in the exposed subjects the IL-1ß release was significantly enhanced after in vitro stimulation with E. coli endotoxin (1000 pg/mL). In conclusion, features of the innate immune system (receptor expression and mediator release of monocytes) are altered in subjects exposed to moisture damage which may be a potential explanation for the increased incidence of respiratory health diseases observed in these populations.
Subject(s)
Aspergillus , Gene Expression Regulation/immunology , Humidity/adverse effects , Interleukin-1beta/immunology , Interleukin-8/immunology , Lectins, C-Type/immunology , Monocytes/immunology , Toll-Like Receptor 2/immunology , Toll-Like Receptor 4/immunology , Adult , Cells, Cultured , Female , Humans , Interleukin-1beta/biosynthesis , Lectins, C-Type/biosynthesis , Male , Middle Aged , Monocytes/metabolism , Monocytes/pathology , Pilot Projects , Respiratory Tract Diseases/etiology , Respiratory Tract Diseases/immunology , Respiratory Tract Diseases/metabolism , Respiratory Tract Diseases/pathology , Toll-Like Receptor 2/biosynthesis , Toll-Like Receptor 4/biosynthesisABSTRACT
The aim of this study was to characterize the mediator release in the whole blood assay induced by stimulation with an extract of the indoor mold A. versicolor. In addition, the effect of concomitant stimulation with E. coli endotoxin and A. versicolor, and the involvement of the relevant Toll-like receptors were investigated. The stimulation of cryo-preserved whole blood with 400pg/ml E. coli endotoxin induced a significant IL-1ß release (976±133pg/ml), whereas, none of the tested A. versicolor concentrations (10-1000mg/ml) caused IL-1ß release. However, stimulation with A. versicolor resulted in a maximum IL-8 release of 6200pg/ml. The simultaneous stimulation with 5pg/ml E. coli endotoxin and A. versicolor induced a synergistic effect on both IL-1ß and IL-8 release. Addition of anti-TLR-4 reduced the release of IL-1ß and IL-8 up to 56% and 43%, respectively. In summary, the whole blood assay is useful to characterize the inflammatory potential of A. versicolor, especially when the release of the pro-inflammatory chemokine IL-8 is included. Additionally, it is also possible to study the influence of cell-surface receptors of the innate immunity involved in the effects of specific microbial stimuli.