O05 Distinct epidermal cell populations and single-cell gene expression signatures are associated with <i>Staphylococcus aureus</i> in atopic dermatitis

This study investigates the interactions between Staphylococcus aureus and the immune responses in atopic dermatitis (AD) by analyzing the skin microbiome and single-cell gene expression in 4 adult participants. The results reveal distinct epidermal cell populations and gene expression signatures in AD, with SA-high AD (S. aureus abundance > 35%) showing increased T cells, macrophages, and dendritic cells expressing proinflammatory cytokine genes, as well as keratinocytes with skin barrier impairment markers. In contrast, SA-low AD (S. aureus abundance < 10%) has more keratinocytes expressing hair follicle stem cell and skin barrier genes. These findings highlight potential mechanisms of S. aureus-host interactions in AD, offering insights for therapeutic targets.