A strong association has been observed between indoor mold contamination and the development of lung allergy and asthma. However, the relationship is still not fully understood. 1-->3-beta-Glucan is the major cell wall component of fungi, and has been shown to be a good marker of fungi exposure. The objective of the study was to evaluate the adjuvant effect of 1-->3-beta-glucan exposure during ovalbumin (OVA) sensitization in a mouse allergy model. BALB/c mice were sensitized by pharyngeal aspiration with saline (vehicle control), 50 mu g OVA, or OVA with various doses of zymosan (1, 10, 50, or 75 mu g) at days 0, 7, and 14. One week after sensitization, each sensitized animal group was challenged with aspiration dose of OVA 50 mu g once a week for two weeks. At 24 hrs after the last aspiration, bronchoalveolar lavage (BAL) was done, and the following inflammatory and lung injury markers were measured in recovered BAL fluid: (1) leukocytes infiltration, (2) albumin and lactate dehydrogenase levels, and (3) inflammatory cytokines levels. An additional set of non-lavaged mice from each group was sent for lung pathology evaluation. The results indicated that co-exposure of zymosan and OVA during sensitization induced a synergistic inflammatory/allergic response that was greater than the response of the individual exposures when combined together. The optimum adjuvant dose of zymosan was 10 mu g, inducing a significant eosinophil infiltration in the lungs and blood as analyzed by flow cytometry. This was consistent with the pathological findings of significant increases in perivascular lymphocyte, alveolar macrophage, neutrophil, and eosinophil infiltration when compared to the OVAOVA group. Furthermore, a significant elevation in cytokines (IL-5, IL-13, IL-6, and TNF-alpha) in BAL fluid and increased OVA-specific IgE in blood were observed indicating an allergic inflammation. This study demonstrated an adjuvant effect of 1-->3-beta-glucan (zymosan) when exposed during the sensitization phase in an OVAinduced allergy model in BALB/c mice.
Allergens; Allergic-reactions; Biological-effects; Biomarkers; Bronchial-asthma; Cell-biology; Inhalation-studies; Laboratory-animals; Laboratory-testing; Lung-cells; Lung-disorders; Lung-irritants; Molds; Molecular-biology; Pulmonary-system-disorders; Respiratory-hypersensitivity; Respiratory-irritants; Microorganisms; Animals; Animal-studies; Respiratory-system-disorders
The Toxicologist. Society of Toxicology 50th Annual Meeting and ToxExpo, March 6-10, 2011, Washington, DC