Engineered immunomodulatory protein tyrosine phosphatase ameliorates inflammatory skin diseases

Atopic dermatitis and psoriasis are the two most common chronic inflammatory skin diseases with unmet needs. There are still no effective and safe topical therapeutics for inflammatory skin diseases and current developing biologics have limitation of administration methods. Here, we identified a novel transdermal delivery peptide (AP) and generated engineered immunomodulatory protein to inhibit dermatitis. AP-conjugated proteins exhibited significant intracellular transduction efficacy in keratinocytes, fibroblasts, and immune cells. Transdermal delivery of AP-dTomato protein showed localization into the dermis and epidermis in both mouse and human skin. Next, we generated AP-conjugated phosphatase domain of TC-PTP protein (AP-rPTP) for regulating cytokine and T cell receptor signaling. AP-rPTP inhibited pSTAT1, pSTAT3, pSTAT5 and pSTAT6 upon cytokine stimulation in mouse splenocytes. AP-rPTP also regulated T cell activation, proliferation and Th1, Th2 differentiation upon CD3/28 stimulation. The transdermal paper-patch of the AP-rPTP protein significantly ameliorated ear thickness, tissue inflammation, and cytokine expression in allergic dermatitis as well as in psoriasis-like mice models. These results collectively demonstrate the feasibility of utilizing AP peptide for biologic drug delivery via paper-patch and suggest AP-rPTP as a novel immune modulatory drug candidate for inflammatory skin diseases.