The efficacy of sublingual immunotherapy with Dermatophagoides farinae vaccine in a murine atopic dermatitis model.

BACKGROUND: Sublingual immunotherapy (SLIT) is a potential treatment for house dust mite-induced atopic dermatitis (AD). However, the mechanisms of action are not clear.

OBJECTIVE: To establish a mouse model of AD in order to study the effect and mechanisms of SLIT.

METHODS: Mice were sensitized and subsequently challenged by repeated cutaneous application of Der f allergen extract. Sensitized mice were SLIT-treated with a Der f vaccine and analyzed for AD symptoms, histopathological and immunological parameters. This experiment was carried in the Laboratory Animal Center, Shanghai University of TCM.

RESULTS: Repeated application of Der f extract caused rapid increase in dermatitis scores. Clinical findings (scratching behaviour, dermatitis and oedema) and histological symptoms (inflammatory cell infiltration) in this model were very similar to those in human AD. Serum total and Der f-specific IgE and IgG levels, and the expression level of T helper (Th)2 cytokine IL-5, IL-13; and Th1 cytokine IL-12 and IFN-γ were elevated compared with the control mice. SLIT treatment of sensitized mice markedly reduced the clinical and histopathological symptoms and decreased both Th1 and Th2 cytokine levels.

CONCLUSIONS AND CLINICAL RELEVANCE: The mouse model induced by Der f allergen extract reflected the typical hallmarks of human AD. In the Der f allergens-sensitized mice, SLIT treatment with Der f vaccine was shown to significantly inhibit AD symptoms through correction of Th2 and Th1 cytokine predominance. Our study suggested that SLIT could be considered as an attractive treatment for patients with extrinsic AD.