Atopic dermatitis (AD) is a widespread chronic inflammation of the skin with a diverse and complex pathogenesis. AD is characterized by a dysregulation of barrier molecules such as keratins and filaggrin (FLG) including FLG mutations. In addition, a dysbiosis of the cutaneous microbiota is associated with AD. However, it is still not completely understood whether the dysbiosis of the cutaneous microbiota is a cause or a consequence of the destroyed integrity of the skin barrier in AD. Functional approaches to address this question are rare. Therefore, we aimed to decipher the influence of lesional and non-lesional skin microbiota on the expression of various AD relevant factors like differentiation markers in a 3D skin model. The cutaneous microbiota of healthy volunteers as well as patients with atopic dermatitis were collected using a standardized skin rinsing approach. The microbiota were isolated using two consecutive centrifugation steps and used for stimulation of 3D skin models generated from primary keratinocytes. The expression of various differentiation markers and AD relevant factors were analyzed by real-time PCR. Our results show that the microbiota of lesional AD skin decreases keratin 1 and keratin 10 expression. In contrast, microbiota of non lesional AD skin induced keratin 1 and keratin 10 expression. In addition, AD relevant factors (e.g. transglutaminase-1) were induced in the 3D skin models by the microbiota of lesional AD skin whereas no induction was observed by treatment with microbiota of non-lesional AD skin. Our data indicate that lesional microbiota may have an impact on the skin integrity by downregulating differentiation markers like keratin 1 and increasing AD relevant factors. Our observations highlight the functional difference of non-lesional and lesional AD microbiota. Work is in progress to evaluate the role of the filaggrin mutation status in this scenario.

ESDR397 - Functional impact of the lesional and non-lesional atopic dermatitis microbiota on a 3D skin model

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.