An association has been observed between indoor mold contamination and lung
allergy and
asthma. This relationship is not fully understood. 1→3-β-Glucan is the major cell wall component of fungi and a good marker of fungi exposure. The objective was to evaluate the adjuvant effect of
zymosan, a crude yeast cell wall preparation of 1→3-β-glucan, during
ovalbumin (OVA) sensitization in an
allergy model. BALB/c mice were sensitized by pharyngeal aspiration with saline, 50 μg of OVA, or OVA with 1, 10, 50, or 75 μg of
zymosan on days 0, 7, and 14. One week after sensitization, each sensitized animal group was challenged with an aspiration dose of 50 μg of OVA once a week for 2 weeks. At 1 day after the last aspiration, bronchoalveolar lavage fluid and blood was collected, and markers of lung
allergy and
inflammation were assessed. An adjuvant effect of
zymosan on OVA
allergy during sensitization was observed as indicated by significant elevations in lung eosinophils, serum OVA-specific
IgE, and lung
IL-5 in the groups sensitized with
zymosan and OVA. Pulmonary treatment with
zymosan also amplified
lung inflammation. Elevations were observed in lung neutrophils, TNF-α, and parameters of
lung injury in the groups primed with both
zymosan and OVA. In nearly all parameters, a non-linear dose-response relationship was observed in the groups primed with OVA and
zymosan. The optimum adjuvant dose of
zymosan was 10 μg. This study demonstrated an adjuvant effect of
zymosan when exposures occurred during the sensitization phase in an OVA-induced
allergy model in BALB/c mice.