Subcutaneous immunotherapy mouse model for atopic dermatitis

 Subcutaneous immunotherapy (SCIT) is a clinically effective treatment in atopic dermatitis. However, there was no mouse model to understand the mechanism of house dust mite immunotherapy in atopic dermatitis. The aim of this study was to establish a mouse model of SCIT mouse model of house dust mite induced atopic dermatitis. Female NC/Nga mice were treated with Dermatophagoides farinae (D.farinae) body extract ointment for 4 weeks to induce atopic dermatitis like skin lesion. Then we separated the mice into 2 groups, control group and immunotherapy (IT) group. Both groups were continuously treated with D.farinae body extract ointment for 4 weeks, however, only immunotherapy (IT) group was treated with 8 injections of D.farinae (100 ug subcutaneouse) twice a week along with D.farinae body extract ointment treatment. Subsequently, clinical severity of skin lesion, histological features, total IgE, IL-4 and IL-10 were measured. We observed that AD-like skin lesions of IT group were milder than control group. In histological examination, epidermis was thinner in IT group than control group. The level of total IgE was decreased in IT group than control group at 3 weeks from the beginning of immunotherapy, while the level of IgG4 was remarkably increased in IT group than control group from the beginning of immunotherapy. Increased level of IL-10 in IT group was observed at 2 weeks from the beginning of immunotherapy than control group. However, there was no significant difference of IL-4 between IT group and control group. In the present study, we have established a house dust mite SCIT mouse model and demonstrated that house dust mite SCIT might improve atopic dermatitis-like skin lesion by decreasing total IgE and increasing the IgG4 and Il-10. Using this model, it will be possible to find novel way to potentiate the effects of allergen immunotherapy.