Mechanisms of airway disease development following inhalation exposure to indoor fungal contaminants Stachybotrys chartarum and Aspergillus versicolor

Author:

Catherine Blackwood, PhD1 , Angela Lemons, MS2 , Rachael Rush3 , Walter McKinney2 , Dori Germolec4 , Donald Beezhold, PhD2 , Brett Green, PhD5 , Tara Croston, PhD6

Author address:

1 National Institute for Occupational Safety and Health, 2 NIOSH, 3 West Virginia University/CDC-NIOSH, 4 NIEHS/NIH, 5 Centers for Disease Control and Prevention, 6 National Institute for Occupational Safe.

Full conference title:

American Academy of Allergy, Asthma and Immunology Annual Meeting 2023

Date: 24 February 2023

Abstract:

RATIONALE: Fungi are found ubiquitously in the environment and chronic repeated exposures have been associated with pulmonary and cognitive effects in humans. Previous studies have shown that two prominent indoor fungal contaminants, Stachybotrys chartarum and Aspergillus versicolor, are associated with allergic airway disease, airway remodeling, and Th2-mediated immunological effects. To understand the mechanisms of disease development, genetically modified murine models are an invaluable tool. METHODS: To examine the immunotoxicological response to each fungal species, a nose-only acoustical generation system was used to deliver dry aerosolized spores to C57BL/6J (WT) and IL-13 and RAG-2 knockout mice, twice weekly for 4 or 13 weeks. Twenty-four-hours after final exposure, the immune response was examined via flow cytometry, antibody quantification, and histology. RESULTS: Wild-type mice had a strong inflammatory immune response to repeated fungal exposure by 13 weeks, which was significantly diminished in knockout mice. The response to S. chartarum resulted in increased T cells and eosinophils, whereas A. versicolor exposure in WT mice was characterized by an increase of B cells in the airways and total serum IgE antibodies. Mice lacking IL-13 or RAG-2 demonstrated a significant reduction of each, indicating that the cytokine IL-13 is necessary for the adaptive immune response to fungal exposure, as are mature B and T cells, as indicated in RAG-2-/- mice. CONCLUSIONS: This study identifies the mechanistic role of IL-13 during fungal exposure. Understanding the interplay of the immune system and indoor fungal contaminants is vital for identifying potential biomarkers and benchmarks for assessment of disease development.

Abstract Number: 583

Conference Year: 2023

Link to conference website: https://aaaai.planion.com/Web.User/SearchSessions?ACCOUNT=AAAAI&CONF=AM2023&USERPID=PUBLIC&ssoOverride=OFF&MOPT=Search_Sessions&standalone=YES

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