Differential Features Between Chronic Skin Inflammatory Diseases Revealed in Skin-Humanized Psoriasis and Atopic Dermatitis Mouse Models.

Psoriasis (PS) and atopic dermatitis (AD) are chronic and relapsing inflammatory diseases of the skin affecting a large number of patients worldwide. Psoriasis is characterized by a Th1/Th17 immunological response whereas acute AD lesions exhibit Th2-dominant inflammation. Current single gene and signaling pathways-based models of inflammatory skin diseases are incomplete. Previous work allowed us to model psoriasis in skin-humanized mice through proper combinations of inflammatory cell components and disruption of barrier function. Herein we describe and characterize an animal model for AD using similar bioengineered-based approaches, by intradermal injection of human Th2 lymphocytes in regenerated human skin after partial removal of stratum corneum. In the present work we have extensively compared this model with the previous and an improved version of the PS model, in which Th17/Th1 lymphocytes replace exogenous cytokines. Comparative expression analyses revealed marked differences in specific epidermal proliferation and differentiation markers and immune-related molecules including antimicrobial peptides. Likewise, the composition of the dermal inflammatory infiltrate presented important differences. Availability of accurate and reliable animal models for these diseases will contribute to the understanding of the pathogenesis and provide valuable tools for drug development and testing.Journal of Investigative Dermatology accepted article preview online, 23 September 2015. doi:10.1038/jid.2015.362.