Topical application of siRNA targeting cutaneous dendritic cells in allergic skin disease.

RNA interference is a promising method for silencing specific genes and has great potential for therapeutic applications. However, the major hurdle for therapeutic application is the limited stability of double-strand RNA (dsRNA) and the absence of a reliable delivery method to target cells. Skin appears to be a favorable target for small interfering RNA (siRNA) therapy. Dendritic cells (DCs) exist in the skin and mucosae on the front lines of defense; these cells capture antigens and play a crucial role in inducing immunity and tolerance.In our recent work, we have shown a successful treatment using CD86 siRNA targeting cutaneous DCs. A costimulatory molecule, CD86, is induced on DCs in situ after antigen uptake, and CD86-expressing DCs migrate to the regional lymph nodes to present antigens to T cells. Topical application of cream-emulsified CD86 siRNA ameliorated the clinical manifestations in murine contact hypersensitivity (CH) and atopic dermatitis (AD)-like disease. Our method may be advantageous for the treatment of allergic skin diseases.