Abstract: Objective To investigate the efficacy and mechanism of subcutaneously given recombinant Der p 2 entrapped PLGA nanoparticles （DEPN） on mouse model with allergic airway inflammation. Methods 40 BALB/c mice were randomly divided into 5 groups， group A （normal control） were treated with saline （100 μl） all the time， groups B， C， D and E were sensitized intraperitoneally with crude dust mite extracts （10 μg） and then subcutaneously treated respectively with PBS （100 μl）， 2 mg empty PLGA （EP）， 100 μg rDer p 2， and 2 mg DEPN （loaded with 100 μg rDer p 2） for 3 times， once per day， followed by intranasal challenge of 50 μg rDer p 2. One day post challenge， mice were sac-rificed and bronchoalveolar lavage fluid （BALF） was collected. Number of the total cells and eosinophils was deter-mined， and airway inflammation and mucus secretion were analyzed by haematoxylin and eosin （H&E） staining and pe-riodic acid-Schiff （PAS） staining. Level of cytokines in the supernatant of splenocyte culture was assayed by ELISA. Level of rDer p 2 specific IgG2a and IgE in the sera was determined by ELISA. Results The lung histology showed devel-opment of eosinophil infiltration in the airway of mice in groups B and C. The lung inflammation and mucus secretion in groups D and E were significantly alleviated than that of groups B and C. Number of total cells （63.50±5.12） and eosinophils （15.32±3.04） in BALF decreased in group B. Compared with group B， the number of total cells in groups D（55.3±5.20） × 10⁴ /ml and E （41.00±4.91） ×10⁴ /ml greatly decreased （P＜0.05）， and same with that of eosinophils in groups D （9.56±1.09） ×10⁴ /ml and E （3.22±0.31） ×10⁴ /ml. The rDer p 2 specific IgE and IgG2a antibodies in group B were 1.14±0.105 and 0.14±0.07 respectively. The level of specific IgE was significantly lower （P＜0.01） in groups D （0.93±0.04） and E （0.77±0.09）， and that of IgG2a in groups D （1.02±0.01） and E （1.17±0.46） were significantly higher （P＜0.01） than that in group B. The level of IL-4 and IFN-γ in BALF in group B were （78.90±6.07） pg/ml and （27.30±3.51） pg/ml respectively. IL-4 in groups D and E was （55.6±3.79） pg/ml and （48.6±4.50）pg/ml respectively， significantly lower （P＜0.01） than that of group B; while IFN-γ （68.50±2.87） pg/ml in group E was significantly higher than that of group B （P＜0.01）. IL-4 released from cultured splenocytes in groups D and E was （56.30±4.85） pg/ml and （40.20±4.36） pg/ml respectively， significantly lower than that in group B （81.2±6.84 pg/ml） （P＜0.01）. The released IFN-γ in group E was （70.20±3.85） pg/ml， significantly higher than in group B （34.60±2.25） pg/ml （P＜0.01）. Conclusion DEPN can in-hibit airway allergic inflammation， its mechanism may be relevant to a balance of Th1 and Th2.

Key words: Poly（D, L-lactic-co-glycolic）acid（PLGA）, House dust mite, Allergen, rticle, Allergic airway inflammation, Mouse