Efficacies of immunotherapy with polypeptide vaccine from ProDer f 1 in asthmatic mice

Allergic asthma is associated with the major house dust mite group 1 allergens Der p 1 and Der f 1, which belongs to the papin-like protease family and is the most potent of indoor allergens and allergen-specific immunotherapy (SIT), is seen as effective intervention for the entity. The current study was designed to verify the SIT efficacies of the enzymatic hydrolysates (papain and trypsin) in mice with asthma. We initially developed the asthmatic mouse models with ProDer f 1, and respectively applied recombinant ProDer f 1 protein and the two kinds of enzymatic hydrolysates for SIT. The results were verified by measuring the contents of IL-4, IL-10, IL-17 and IFN-γ changed in both bronchoalveolar lavage fluid (BALF) and supernatant of splenocyte culture as well as level changes of specific IgE and IgG2a in the serum. After SIT intervention, the symptoms of allergic inflammation was alleviated significantly in mice treated with ProDer f 1 protein and the two enzymatic hydrolysates via detection of the lung tissue sections, and infiltration of inflammatory cells was also notably depressed as compared with the models, though the epithelial structure in airways remained similar with the PBS group. In addition, we observed lower serum contents of the specific IgE antibody and lower levels of IL-4, IL-17 in BALF and splenic cells in mice undergone SIT, whereas specific IgG2a, IFN-γ and IL-10 in BALF and supernatant of splenocyte culture were higher as compared to the asthma group. The findings suggest the SIT using the above two kinds of hydrolysates may effectively inhibit the allergic inflammation in the airways of mouse models sensitized with ProDer f 1 protein.