Evaluation of the Suppressive Effects of Ascaris Pseudo-Coelomic Fluid (PCF), Fasciola Excretory/Secretory Antigen (FES) and Hydatid Antigen-B (HAgB) on the Development of Experimental Murine Asthma

Background: There has been a significant increase in the prevalence of allergic diseases over the past 2-3 decades. Currently, more than 155 million people suffer from asthma and the numbers are increasing. Worldwide, helminthic infections and allergic diseases do not overlap despite that both conditions are accompanied by strong T H 2 immune responses. The burden and chronicity of helminthic infections is an important variable that may determine whether helminths act as a risk factor for, or confer protection against allergic diseases. Objective: Evaluation of the possible suppressive effect of three helminthic derived products namely Ascaris pseudo-coelomic fluid (PCF), Fasciola excretory/secretory antigen (FES) and hydatid antigen-B (HAgB) on the development of experimental murine asthma. Materials and Methods: Mice were sensitized with OVA/Alum intra-peritoneally in the absence or presence of the helminthic products on days 1, 14 and 21 and then challenged by inhalation on days 26 and 27 with OVA. One day later, the mice were sacrificed to evaluate suppressive effects of the antigens. Parameters of assessment included the inflammatory responses (histopathology of lung sections and the broncho-alveolar lavage fluid cellularity) and the specific IgE response. Results: Immunization of mice with the three helminthic derived products resulted in reducing the frequency and magnitude of the airway hyper-responsiveness. The reductions were significant in cases of FES antigen and HAgB. No significant changes were detected in the antigen specific IgE serum levels following immunization with three antigens. Conclusion: Products derived from helminths might be potentially useful in immunotherapy of asthma.