Cross tolerance in experimental ashtma model induced by Blomia tropicalis

Abstract

The prevalence and severity of asthma has been increasing worldwide. Asthma is considered a chronic pulmonary inflammatory syndrome and its classical form is associated with deregulated Th2 type immunity. Murine models have been developed to study asthma mechanisms, and ovalbumin (OVA) is the most commonly used antigen. However, the OVA model does not represent the scenario that asthmatic patients are exposed among their lives. Thus, experimental models have been adapted to airborne allergens such as those derived from house dust mite. Blomia tropicalis (Bt) is one of the most common and prevalent mite in Brazil and recently a murine model of allergic asthma with Bt extract was described. Among the possible mechanism of asthma modulation, oral tolerance has a great relevance. Experimental data in immunological tolerance suggests that this phenomenon may have an infectious character and it indicates that tolerance towards an antigen can promote tolerance to another not related antigen a phenomenon known as cross-tolerance. In this project, we intent to use OVA for tolerance induction and Bt for allergen sensitization, emphasizing the role of regulatory T cells in cross-tolerance. This project aims to outline the possible applications of cross-tolerance in the regulation of lung allergic response induced by Bt.