Induction of atopic eczema/dermatitis syndrome-like skin lesions by repeated topical application of a crude extract of Dermatophagoides pteronyssinus in NC/Nga mice.

Mite antigen has been considered to play important roles in the development of atopic eczema/dermatitis syndrome (AEDS). In the present study, we attempted to induce an AEDS-like skin lesion in mice using Dermatophagoides pteronyssinus crude extract (DPE) as an antigen and performed pathophysiological evaluations. Ears of mice were tape-stripped and DPE was painted 3 times a week. Eczematous skin lesion and ear swelling were apparent in NC/Nga mice treated with DPE after 2 weeks, whereas neither skin lesion nor ear swelling were observed in BALB/c mice even after 30 days. Histological evaluation demonstrated that edema, epidermal hyperplasia and the accumulation of inflammatory cells were apparent in the ears of DPE-treated NC/Nga mice. In contrast to skin lesion and ear swelling, total serum IgE levels were increased in both NC/Nga and BALB/c mice. Treatment with DPE also increased auricular lymph node weight in both NC/Nga mice and BALB/c mice. To further characterize, we analyzed cytokine mRNA expression in ears and lymph nodes of DPE-treated NC/Nga mice. Increased expression of IL-4 and TNF-alpha mRNA was observed in both ears and lymph nodes of NC/Nga mice treated with DPE. Additionally, there was no change in the responsiveness of BALB/c mice to DPE treatment by adaptive transfer of serum from DPE-treated NC/Nga mice to BALB/c mice. Taken together, our results indicate that eczematous skin lesion and ear swelling caused by repeated application of DPE in NC/Nga mice has a Th2-dominant background and that inflammation is involved in this process. The animal model of AEDS established in this report may be used to investigate the pathogenesis of AEDS and evaluate the potential therapeutic agents for AEDS.