Studies on the human skin microbiome have taken a flight after the initiation of the human microbiome project. Following descriptive studies on skin microbiota in health and disease, mechanistic studies on the interplay between skin and microbes are on the rise and experimental models are in great demand. We here present a technical advance for the microbial colonization of organotypic skin models ensuring a standardized application area onto the stratum corneum, a homogenous distribution of bacteria, and importantly preventing infection of the basolateral culture medium even during prolonged co-culture up to two weeks. This model allows ample opportunities for studying host-microbe interactions and intervention strategies. Multi-parameter end-point analysis from one single organotypic culture permits the collection of samples for colony forming unit count, bacterial profiling, host gene and protein expression analysis, and microscopic imaging. With this methodology we identified differential host responses to various skin commensals and found striking differences in epidermal responses towards clinical isolates of Staphylococcus aureus from atopic dermatitis patients. The herein presented methodology using glass cylinders is easily transferable to a wide variety of organotypic skin models of different diameters and cellular components and can be used in every cell culture facility considering the various sizes and commercial availability. Our study may therefore kick start the highly needed mechanistic studies into the intricate host-microbe interactions contributing to skin health and disease, providing a platform for intervention studies using pre-, pro- or antibiotics.

ESDR136 - Technical advance: bacterial colonization of 3D organotypic skin models for long-term host-microbe interactions and microbiome intervention studies

50th Annual Meeting of the European Society for Dermatological Research. VIRTUAL MEETING