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THE ALLERGENIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS
Citation:
Ward, MDW, M. E. Viana, Y. Chung, N. H. HaykalCoates, L B. Copeland, S H. Gavett, AND MJK Selgrade. THE ALLERGENIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS. Presented at Indoor Air Quality Problems and Engineering Solutions Symposia, Research Triangle Park, NC, July 21-23, 2003.
Description:
The Allergenic Potential of Indoor Air Fungal Contaminants
Marsha D W Ward1, Michael E Viana2, Yongjoo Chung3, Najwa Haykal-Coates1, Lisa B Copeland1, Steven H Gavett1, and MaryJane K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA, 3 UNC, SPH, Chapel Hill, NC, USA.
The indoor environment has increased in importance to children's health with children now spending more than 90% of their time indoors. Molds are an important component of this environment and have been associated with exacerbation of asthma. Their contribution to the induction of allergic asthma is less certain.
We have assessed extracts from 3 fungal strains, 1) Metarhizium anisopliae (MACA), 2) Stachybotrys chartarum (SCE-1) and 3) Penicillium chrysogenum (PC) for the capacity to induce responses typical of allergic asthma in a female BALB/c mouse model. In a series of studies mice were subjected to 4 aspiration (ASP) exposures to 10 g of MACA or SCE-1. Serum and bronchoalveolar lavage fluid (BALF) were collected before (D0), and at 1 (D1) and 3 (D3) days following the final ASP exposure. Whole-body plethysmography (Buxco) was used to assess pulmonary resistance and bronchoconstriction. Mice were assessed for immediate responses following each aspiration exposure and for airway hyperresponsiveness to methacholine. In other similarly designed experiments, mice were exposed with up to 100 ?g of PC by ASP.
Exposure to both MACA and SCE-1 extracts resulted in increased levels of BALF total protein, LDH (indicative of edema and non-specific cell damage) and BALF IL-5, total IgE, eosinophil influx, and serum total IgE (endpoints indicative of allergy). Additionally, these extracts caused significant increases in Buxco measures. Furthermore, the specific proteins in MACA responsible for IgE induction have been identified. Current data indicate that only the mice exposed to 100 ?g of PC demonstrate levels of the BALF parameters comparable to or higher than those levels in mice exposed to 10 ?g of MACA.
The PC extract may not be as potent at inducing allergic responses as are MACA and SCE-1. Multiple respiratory exposures to either MACA or SCE-1 cause responses similar to those observed in human allergic lung disease suggesting that these two molds may have a role in the induction of asthma.
(Supported by NCSU/EPA Cooperative Training Agreement CT826512010 and UNC/EPA Cooperative Training Agreement CT829471.) (This abstract does not reflect EPA policy.)