A comparison of the allergic responses induced by Penicillium chrysogenum and house dust mite extracts in a mouse model.

UNLABELLED: A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. We compared the ability of the fungal Penicillium chrysogenum (PCE) and house dust mite (HDM) extracts to induce allergic responses in BALB/c mice. The extracts were administered by intratracheal aspiration (IA) at several doses (0, 2.5, 5, 10, 20, 40, and 80 μg) four times over a 4-week period. Three days after the last IA exposure, serum and bronchoalveolar lavage fluid (BALF) were collected. The relative allergenicity of the extracts was evaluated based on the lowest dose able to induce a significant response compared to control (0 μg) and the robustness of the response. PCE induced the most robust response at the lowest dose for most endpoints examined: BALF total, macrophage, neutrophil, and eosinophil cell counts, and antigen-specific IgE. Taken together, our data suggest that PCE may induce a more robust allergic and inflammatory response at lower doses than HDM. PRACTICAL IMPLICATIONS: Our data suggest that Penicillium chrysogenum is a robust allergen and may be a more potent allergen source than house dust mite (HDM) in this mouse model. Two critical factors in the development of human allergic disease, exposure levels and sensitization thresholds, are unknown for most allergens including molds/fungi. Human exposure levels are not within the scope of this article. However, the data presented suggest a threshold dose for the induction of allergic responsiveness to P. chrysogenum. Additionally, P. chrysogenum as well as other molds may play an important role in asthma development in our society.