Specific immunotherapy with major group 5 allergen derived from Dermatophagoides farinae in murine model of asthma

Dust mite allergen is recognized as contributory cause for allergic asthma, and group 1 (Der f 1) and group 2 (Der f 2) are being extensively studied in the commonly defined allergens. However, few reports are available on the use of Der f 5 as allergen for specific immunotherapy (SIT). In our previous laboratory effort, we successfully developed Der f 5 allergen. In order to verify its immune efficacy, the present work was aimed at investigating the efficacy of SIT with the major group 5 allergen derived from Dermatophagoides farina (Der f 5). Forty specific pathogen-free BALB/c mice were randomized into group of either PBS, ovalbumin (OVA) treatment, asthma model (Der f 5 sensitization) or Der f 5 SIT (n=10 for each group). Our results demonstrated that compared to OVA and asthma models, the pulmonary inflammation was alleviated significantly for SIT group, and the number of total white blood cells, eosinophils, levels of IL-5 and IL-17 in BALF as well as supernatant of cultured splenocytes (SCSS) allergenspecific IgE and IgG1 were greatly decreased in SIT group (all P<0.01), yet BALF IFN-γ levels and SCSS as well as serum IgG2a were significantly increased (P<0.01). Therefore, Der f 5 vaccine developed from Dermatophagoides farina may effectively inhibit airway allergic inflammation, and the findings suggest that it can be a candidate vaccine for treatment of allergic diseases.