College of Food, Ag & Nat Res Sci
Exposure of human airway epithelial cells to fungal aeroallergens induces an innate immune response that involves the release of nuclear and mitochondrial DNA. Comet assays have demonstrated that allergens derived from the common saprophyte Alternaria alternata produce rapid DNA fragmentation resulting from activation of caspase 3 by a non-canonical mechanism. A portion of this DNA is released into the extracellular fluid along with specific histone (H1, H2A, and H3) proteins which function to ampify allergic inflammation of the airways. The fragmented DNA that remains in the cell is repaired over a period of 12 hours and the epithelial cells not only survive, but also maintain both barrier function and ion transport activity. These researchers have isolated and sequenced the nuclear DNA that is released in response to Alternaria exposure and are interested in determining whether specific regions of the genome are selctively mobilized and released in response to allergen exposure.