1a). p 1 is usually a cysteine protease disrupting epithelial barriers, whereas Der p 2 functionally mimics the LPS-binding compound MD-2 within the TLR4 complex. In this work, we tested the percutaneous sensitizing capacity of recombinant (r) Der p 1 and Der p 2 in BALB/c mice. Mice were sensitized by percutaneous application of low (10 g/application) and high dose (100 g) rDer p 1 or rDer p 2, or with rDer p 1 followed by rDer p 2. Allergen-specific and total IgE antibodies were determined by ELISA. Eczema of BALB/c was classified by the itching score and corresponded to erosions. Infiltrating immune cells were recognized by haematoxylin/eosin and Giemsa staining for eosinophils or mast cells, CD3 staining for T lymphocytes. Percutaneous treatments with rDer p 1, but not rDer p 2-induced specific IgG1. However, cotreatment with rDer p 1 led to increase in anti-Der p 2 IgG titres. Both allergens elicited skin erosions because of scratching, thickening of the epidermis, and eosinophil and T-cell infiltration. Our data show that p53 and MDM2 proteins-interaction-inhibitor racemic recombinant mite allergens in the absence of adjuvant are sufficient for inducing eczema in BALB/c mice. As the enzymatic activity of an allergen might be an important cofactor for specific sensitization via the skin, Der p 1 may act as adjuvant for other allergens too. The offered mouse model is suitable for investigating the mechanisms of allergic eczema. and (12). In a previous study, we reported the generation of mimotopes, which were applied to define the cross-reactive IgE epitopes of group I and II mite allergens (13). For further proof of concept studies, we considered the establishment of a valid mouse model of importance. Owing to their Th2-biased immune response, BALB/c mice may be considered as a model for mimicking allergic diseases. Therefore, we elucidated the potency of recombinant Der p 1 and Der p 2 in the induction of experimental allergic eczema in BALB/c mice. Matsuoka and stored in phosphate-buffered saline (PBS). Enzymatic activity was shown for rDer p 1 (16). BALB/c mice (female, 8 weeks aged) were purchased from your Institute for Laboratory Animal Science and Genetics (University or college of Vienna, Himberg, Austria). All experiments were performed according to European Community rules for animal care with the permission number BMWF-66.009/0145-C/GT/2007 of the Austrian Ministry of Science. Percutaneous sensitization BALB/c mice (= 5/group) were cautiously shaved on the back and the recombinant allergens were applied percutaneously with cotton swabs. Mice were cautiously wet-shaved on the back p53 and MDM2 proteins-interaction-inhibitor racemic using shaving cream. The sensitization was performed 1 day later, using 10 g rDer p 1 or rDer p 2 in 100 l PBS Sele for each mouse (14). After assessment of induced antibody levels (Fig. 1a). As unfavorable controls, na?ve, shaved-only and shaved/PBS-treated (100 l PBS) groups of mice were included in the experiment. The mice were treated three times a week on consecutive days for a period of 8 weeks, that is 24 applications in total (Fig. S1a), according to the protocol published by Matsuoka = 0.008; left panel), while application of rDer p 2 on the skin failed to induce antibodies with the exception of one animal (OD: 1.8 shown in panel a) but not included in panel b). (c) In a second set of experiment (= 8 per group), an additional group of mice was pretreated for 30 min with rDer p 1 (100 g) before applying rDer p 2 (100 g) according to the plan shown in Fig. S1b. The coapplication with the cysteine protease Der p 1 rendered enhanced induction of anti-Der p 2 IgG levels. Blood sampling was performed by tail bleeding before start p53 and MDM2 proteins-interaction-inhibitor racemic of sensitizations and afterwards weekly as indicated in Fig. S1a. In a second set of experiment, BALB/c mice (group size = 8) were shaved as explained previously and sensitized percutaneously every third week, altogether three times, with the elevated concentration (100 g) of rDer p 1 or rDer p 2. In an additional group, mice were pretreated with rDer p 1 (100 g) and 30 min later rDer p 2 (100 g) was applied (Fig. S1b). In this p53 and MDM2 proteins-interaction-inhibitor racemic experiment, blood sampling was performed 1 day before the next immunization (Fig. S1b). Macroscopic evaluation of skin status After each administration of allergen or PBS, mice were observed for 15 min and scratching behaviour within the treatment area was documented and evaluated according to the scratching score (0: no scratching; 1: up to 10.