Background: In recent years, nanoparticle materials have found wide applications in drug transport and release systems. Chitosan is a good carrier for proteins, peptides, and nucleic acids because of its favorable release properties and ability to increase membrane permeability.

Objective: To investigate the effect of chitosan microparticles loaded with the major epitope peptide of mite group 2 allergen Der f 2 from Dermatophagoides farinae (Der f 2-47-67) in alleviating asthma in mice.

Methods: Der f 2-47-67 was entrapped in chitosan to obtain Der f 2-47-67-loaded chitosan microparticles, which were injected intraperitoneally into BALB/c mice prior to an intranasal challenge with a Der f extract allergen. Airway hyperreactivity was measured via
whole-body plethysmography, and bronchoalveolar lavage (BAL) fl uid was collected to calculate total cell and eosinophil counts. Changes in lung histology were assessed after hematoxylin–eosin staining, and serum levels of Der f-specific immunoglobulin (Ig) G2a and IgE were determined by enzyme-linked immunoabsorbent assay.

Results: Mice immunized with Der f 2-47-67-loaded chitosan microparticles displayed decreased airway hyperreactivity, reduced numbers of eosinophils in BAL fl uid, alleviated lung inflammation and mucus production, a reduced serum level of Der f-specifi c IgE and an increased serum level of Der f-specific IgG2a.

Conclusion: Our data showed that Der f 2-47-67-loaded chitosan microparticles inhibited airway allergic inflammation.

Key words: Chitosan. Dermatophagoides farinae. Polypeptide. Microparticles. Allergic airway inflammation.