Intranasal application of chitin microparticles down-regulates symptoms of allergic hypersensitivity to Dermatophagoides pteronyssinus and Aspergillus fumigatus in murine models of allergy

Background Previous studies have demonstrated that chitin in the form of microparticles that can be phagocytosed is a potent macrophage stimulator and promotes a Th1 cytokine response and it has been shown that oral administration of chitin microparticles is effective in down-regulating serum IgE and lung eosinophilia in a mouse model of ragweed allergy. To date there have been no studies on the effectivness of directly applying chitin microparticles to the respiratory tract as a treatment for allergic symptoms. Objective To test the effectivness of chitin microparticles when given intranasally as a treatment for the symptoms of respiratory allergy and allergic asthma and to compare its effectivness in two different mouse models of allergy, namely to Dermatophagoides pteronyssinus and Aspergillus fumigatus . Results The intranasal application of microgram doses of chitin microparticles is an effective treatment for reducing serum IgE and peripheral blood eosinophilia, airway hyper-responsiveness and lung inflammation in both allergy models results in elevation in Th1 cytokines IL-12, IFN-gamma and TNF-alpha and reduction in IL-4 production during allergen challenge. Conclusion Chitin microparticle suspensions have Th1 immunostimulatory properties and are effective when administered intranasally in mice. The stimulation of the nasal associated lymphoid tissue with chitin microparticles could offer a novel and natural approach to treating allergic disease in humans.