< b > < i > Staphylococcus epidermidis < /i > < /b > Activates Aryl Hydrocarbon Receptor Signaling in Human Keratinocytes: Implications for Cutaneous Defense

We report that the aryl hydrocarbon receptor (AhR) was activated in human primary keratinocytes infected withS. epidermidis, leading to induction of the AhR-responsive gene cytochrome P450 1A1 (CYP1A1). In addition, functional AhR was required forS. epidermidis-mediated induction of IL-1 β expression in keratinocytes. AhR-dependent gene induction of IL-1β and CYP1A1 was mediated by factor(s) #x3c; 2 kDa secreted byS. epidermidis. Blockade of the AhR in a 3D organotypic skin equivalent infected withS. epidermidis attenuated theS. epidermidis-induced CYP1A1 and IL-1 β expression. Moreover,S. epidermidis also induced expression of IL-1 α and of the antimicrobial peptide human β-defensin-3 in an AhR-dependent manner in a 3D skin equivalent. An increased outgrowth ofS. epidermidis on the surface of skin explants treated with a specific AhR inhibitor further indicate a pivotal role of the AhR in mediating an epidermal defense response. Taken together, our data expand the role of the AhR in innate immunity and support a previously unappreciated contribution for the AhR in cutaneous defense.J Innate Immun
Source: Journal of Innate Immunity - Category: Allergy & Immunology Source Type: research