Subpollen Particles May Be Cause of Seasonal Asthma
Particles from ragweed are of breathable size and induce airway inflammation in mouse asthma model
MONDAY, Oct. 30 (HealthDay News) -- Subpollen particles of breathable size released by ragweed contain allergenic proteins and induce allergic airway inflammation in a mouse model of asthma, possibly explaining some severe symptoms of seasonal asthma, according to a study in the October issue of the Journal of Allergy and Clinical Immunology.
Istvan Boldogh, Ph.D., and colleagues from the University of Texas Medical Branch in Galveston examined the size of subpollen particles released from ragweed pollen grains, their protein components and their redox properties and oxidative effects on cells. The particles were also tested for their allergenic properties using a mouse model of asthma.
The researchers found that 0.5 to 4.5 micron particles were released from ragweed pollen grains. The particles contained allergenic proteins and oxidase activity mediated by reduced nicotinamide adenine dinucleotide phosphate, or NAD(P)H. Subpollen particles also led to significantly higher levels of reactive oxygen species in epithelial cells and caused allergic airway inflammation in the mouse model.
"The allergenic potency of subpollen particles released from ragweed pollen grains is mediated in tandem by reactive oxygen species generated by intrinsic NAD(P)H oxidases and antigenic proteins," Boldogh and colleagues conclude. "Severe clinical symptoms associated with seasonal asthma might be explained by immune responses to inhaled subpollen particles carrying allergenic proteins and reactive oxygen species-producing NAD(P)H oxidases."