A comparative analysis of five fungal species isolated from high-altitude air samples based on their induction of murine lung eosinophilia along with heated Asian sand dust.

Abstract

High-altitude aerosols containing fungi and hyphal debris were collected from the Noto Peninsula, Japan, during Asian sand dust (ASD) events. Five fungal species (Bjerkandera adusta (Bje 07B507), Lecythophora (Lec 13H319), Cladosporium cladosporioides (Cla 16H615), Phialocephala sphaeroides (Phi 15H321), and Coniothyrium fuckelii (Con 15H316) were isolated. Fungi were inactivated using 1% formalin combined with heated-ASD (H-ASD) and introduced into the respiratory tracts of BALB/c mice. Con 15H316 exhibited the most significant exacerbation effect. Con 15H316 + H-ASD increased the number of eosinophils and neutrophils in the bronchoalveolar lavage fluid and along with Con 15H316 and Phi 15H321 + H-ASD enhanced the induction of interleukin (IL) -5, IL-13, and eotaxin compared to other mixed samples. Con 15H316 + H-ASD markedly elevated levels of IL-6, monocyte chemotactic protein-3, regulated upon activation, normal T cell expressed and secreted, and lactate dehydrogenase. These changes led to pathological alterations, including mucosal cell proliferation in the airway epithelium and eosinophil infiltration in the submucosa. The ranking of eosinophil infiltration was: Con 15H316+ H-ASD > Phi 15H321 + H-ASD > Cla 16H615 + H-ASD > Lec 13H319 + H-ASD > Bje 07B507+ H-ASD. These results suggest that fungal debris in ASD particles can exacerbate fungal allergies in human lungs.