Type 2 cytokine-dependent skin barrier regulation in personalized 2D- and 3D skin models of atopic dermatitis: A pilot study

Keratinocytes from healthy donors stimulated with type 2 cytokines are often used to experimentally study atopic dermatitis (AD) inflammatory responses. Due to potential intrinsic alterations, it seems favorable to use keratinocytes from AD patients. Keratinocytes isolated from hair follicles offer a non-invasive approach to investigate AD-derived keratinocytes. To evaluate whether such AD-derived keratinocytes are suitable to mimic AD inflammatory responses we compared hair follicle-derived keratinocytes from healthy donors and AD patients in a type 2 cytokine environment. Stimulation of AD-derived keratinocytes with IL-4 and IL-13 induced higher expression changes of AD-associated markers as compared to healthy keratinocytes. The combination of IL-4 and IL-13 generally induced highest expression changes, but IL-13 alone also induced significant changes of AD-specific markers. Similar to the 2D cultures, IL-4/IL-13 stimulation of 3D skin models generated with AD-derived keratinocytes modulated the expression of several AD-relevant factors. Whole transcriptome analysis revealed that IL-4 and IL-13 acted similarly on these 3D skin models. Histologically, IL-13 alone and in combination with IL-4 increased epidermal spongiosis, a histological hallmark of AD skin. Taken together, our pilot study suggests that hair follicle-derived keratinocytes from AD patients represent a useful model system to study AD-related inflammation in a personalized in vitro model. Organotypic 3D skin models generated from hair follicle-derived human keratinocytes from two atopic dermatitis patients were left unstimulated or stimulated with Th2 cytokines IL-4, IL-13 and IL-4+IL-13. Two stimulations were done for each donor and each condition.