910 Exploring host-microbiome interactions in optimised 3D skin models

The human microbiome has a fundamental role in skin homeostasis, barrier function and host immune networks. Acute chronic conditions are often associated with imbalances host-microbiome-immune interactions. Despite recent advances research, there limited models for studying these interactions healthy diseased skin, therefore we have developed model to investigate how different profiles alter epidermal homeostasis T-cell responses. Full-thickness were colonized five species:Staphylococcus epidermidis (SE), Staphylococcus capitis (SC), Cutibacterium acnes (CA), Malassezia restricta (MR) globosa (MG), singular or combined (5M) inoculations.The effect of colonization on differentiation formation was observed via the expression K14, K10, E-cadherin Ki67. Increased K14 SE, SC (p=0.0062) 5M. MG significantly reduced K10 (p=0.0180). Expression decreased colonised MR (p=0.0489). significant changes thickness, Ki67 not altered across conditions. Commensal microbes been shown regulate aryl hydrocarbon receptor(AhR). nuclear AhR response SC, CA 5M, suggesting greater activation. Model influenced CD69, cutaneous lymphocyte antigen (CLA) HLA-DR T cells incubating PBMCs conditioned media from inoculated models. SE caused increase CD3+/CLA+ (p=0.0362) 5M CD3+/HLA-DR+ (p=0.0304). RNA-sequencing aims support current analysis elucidate any more targets be explored. Our findings suggest microbial