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ASSESSMENT OF A CRUDE FUNGAL (METARHIZIUM ANISOPLIAE) EXTRACT AND IT'S COMPONENTS FOR ALLERGENICITY
Citation:
Ward, MDW, M. E. Viana, L B. Copeland, AND MJK Selgrade. ASSESSMENT OF A CRUDE FUNGAL (METARHIZIUM ANISOPLIAE) EXTRACT AND IT'S COMPONENTS FOR ALLERGENICITY. Presented at American Thoracic Society, Atlanta, GA, May 17-22, 2002.
Description:
ASSESSMENT OF A CRUDE FUNGAL (METARHIZIUM ANISOPLIAE) EXTRACT AND IT'S COMPONENTS FOR ALLERGENICITY. M D W Ward1, M E Viana2, L B Copeland1, and MJ K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, College of Veterinary Medicine, Raleigh, NC, USA.
Metarhizium anisopliae is a microbial pesticide licensed for cockroach mitigation. Crude antigen (MACA) extracted from this fungus induces immune and pulmonary responses typical of allergic asthma in BALB/C mice exposed to this extract by aspiration. Soluble factors from the fungal components (mycelium, conidia, and inducible enzymes) were combined in equal protein amounts to form the crude antigen. SDS-PAGE/western blot analysis identified 4-5 fungal proteins as allergens. In the mycelium extract the IgE-inducing proteins identified as met a I, met a II, met a III, and met a IV have apparent molecular weights of 127.6 kDa, 114.7 kDa, 89.7 kDa, and 52.6 kDa, respectively. However, no IgE inducing proteins were detected in the conidia extract. The possibility of a non-allergenic extract was explored by exposing BALB/C mice to 4 aspirations (ASP) of 10 g of MACA, Conidia extract, bovine serum albumin (BSA) (a weak or non-allergenic control) in 50 l Hank's Balance Salt Solution (HBSS), or HBSS alone over a 4-week period. Serum and bronchoalveolar lavage fluid (BALF) were harvested before, and at 1 and 3 days after the last ASP. Neither Conidia nor BSA exposed mice had increased levels of BALF total protein or lactate dehydrogenase (LDH) or serum total IgE. While Conidia exposed mice had increases in neutrophils, lymphocytes, and eosinophils compared to HBSS and BSA exposed animals, these increases represent low cell counts when compared to MACA exposed mice. These data suggest that the M. anisopliae conidia extract causes mild inflammatory responses but would be classified as a weak or non-allergen. It appears that the conidia extract might be a useful negative control when assessing fungal extracts of unknown allergenicity in mouse models. (Supported by NCSU/EPA Cooperative Training Agreement CT826512010.)(This abstract does not reflect EPA policy.)