Serum immunoglobulin E and immunoglobulin G reactivity to Agaricus bisporus proteins in mushroom cultivation workers

Background and Purpose: Although molds are regarded as the main fungal allergen sources, evidence indicates that spores of Basidiomycota including Agaricus bisporus (A. bisporus) can be also found at high concentrations in the environment and may cause as many respiratory allergies as molds. The aim of the present study was to evaluate specific immunoglobulin E (IgE) and immunoglobulin G (IgG) antibodies against A. bisporus via immunoblotting technique in individuals working at mushroom cultivation centers. Materials and Methods: In this study, ۷۲ workers involved in the cultivation and harvest of button mushrooms were enrolled. For the analysis of serum IgE and IgG, A. bisporus grown in Sabouraud dextrose broth was harvested and ruptured by liquid nitrogen and glass beads. The obtained sample was centrifuged and the supernatant was collected as “crude extract” (CE). CE was separated via Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The separated proteins were transferred to a nitrocellulose filter and the bands responsive to IgE and IgG were identified by anti-human conjugated antibodies. All participants were screened in terms of total IgE level. Results: Among ۷۲ workers, ۱۸ (۲۵%) had a total IgE level higher than ۱۸۸ IU/mL. In SDS-PAGE, the CE of A. bisporus showed ۲۳ different protein bands with a molecular weight range of ۱۳-۸۰ kDa. The sera of ۲۳.۶% and ۵۵.۵% of participants showed positive response, with specific IgE and IgG antibodies against A. bisporus in the blot, respectively. The bands with molecular weights of ۶۲ and ۶۸ kDa were the most reactive protein components of A. bisporus to specific IgE antibodies. Moreover, bands with molecular weights of ۵۷ and ۶۲ kDa showed the highest reactivity to IgG, respectively. Also, ۶۲ and ۶۸ kDa components were the most reactive bands with both specific IgG and IgE antibodies. Conclusion: The obtained findings revealed that A. bisporus has different allergens and antigens, which contribute to its potential as an aeroallergen in hypersensitivity-related reactions of the lungs.

Keywords:

Agaricus bisporus , Immunoblotting , Immunoglobulin E , Immunoglobulin