3D skin model to investigate the early epidermal morphological psoriatic features

Epidermal cells, together with different molecules of the immunosystem, promote psoriasis, but several data concerning the early phases of this disease still lack. This study evaluated the early morphological features of psoriasis using an organotypic culture of normal human skin. Cellular proliferation, expressions of Toll-like receptors (TLR) 7 and 9, and keratin 17 were analysed by indirect immunofluorescence in normal human skin biopsies exposed to a cytokine mix strictly reproducing a psoriatic environment. After mix incubation, an early and progressive decrease of cell proliferation was detected. TLR9 was present in the granular layer of mix samples, while TLR7 was expressed throughout the entire epidermal compartment. K17 expression was evident after mix exposure. In conclusion, our results prove that a psoriatic microenvironment is able to induce pivotal morphological changes in our skin model, strongly suggesting that an early epidermal “psoriatic switch” can be reproduced for studying the epidermal homeostasis and innate immune response.