Abstract
The skin barrier comprises interdependent physical, chemical, immunological, and microbial components, of which the latter is constituted by a community of microbes residing on the skin surface that restricts the expansion of opportunistic pathogens, modulates keratinocyte signaling pathways, and fosters immune tolerance. However, molecular and cellular dynamics of host–microbe interactions remain incompletely characterized, partly due to the limited availability of physiologically relevant and robust preclinical models. We aimed to establish 3D human skin equivalents (HSEs) in co-culture with representative skin commensals to investigate host responses across an in vitro cohort of six biological replicates. Well-characterized HSEs were inoculated with Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. A 48-hour co-culture period enabled microbial expansion, during which S. aureus exhibited the most substantial outgrowth, and strain-dependent variability was observed for S. epidermidis. Assessment of epidermal morphogenesis revealed that S. aureus exerted largest structural impact, whereas C. acnes promoted keratinocyte proliferation. Furthermore, S. aureus elicited a pro-inflammatory response, characterized by elevated secretion of IL-8 and CXCL1. In conclusion, we developed a reproducible experimental framework dissecting host–microbe interactions in HSEs to demonstrate that S. aureus induced substantial alterations in epidermal architecture and inflammatory signaling, underscoring its pathogenic potential in cutaneous environments.
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Data availability
The datasets used and/or analyzed during the current study are available from the corresponding authors on reasonable request.
Abbreviations
- HSE:
-
Human skin equivalent
- IL:
-
Interleukin
- SC:
-
Stratum corneum
- SB:
-
Stratum basale
- SS:
-
Stratum spinosum
- SG:
-
Stratum granulosum
- LEM:
-
Leiden epidermal model
- NHS:
-
Native human skin
- qPCR:
-
Quantitative polymerase chain reaction
- NHEK:
-
Normal human epidermal keratinocytes
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Acknowledgements
The authors are grateful to Anita Ouwens for the contribution on initial exploration on technical feasibility of the co-culture method.
Funding
The project was funded by Health~Holland TKI-Public Private Partnership grant awarded to the consortium of TNO, LUMC, and Beiersdorf, as well as by the consortium partner Beiersdorf.
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Conceptualization: AM, EG, FHJS, AEG. Methodology: AM, FHJS, AEG. Validation: FHJS, AEG. Formal analysis: AM. Investigation: MR, BvL, AS, NP. Resources: MR, BvL, AS, NP. Data curation: MR, BvL, AS, NP. Writing – Original draft: AM, FHJS, AEG. Writing – Reviewing & Editing: all authors. Visualization: AM. Supervision: FHJS, AEG. Project administration: JK, HF, EG, FHJS, AEG. Funding acquisition: JK, HF, FHJS, AEG.
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Health~Holland had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. H.F. and E.G. are employees at Beiersdorf AG, of which author contribution are disclosed according to the CRediT system. The other authors declare no conflicts of interest.
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Mieremet, A., Rietveld, M., van Leijden, B. et al. Advancing human skin models by integrating skin microbes for next-generation research. Sci Rep (2026). https://doi.org/10.1038/s41598-026-44005-6
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DOI: https://doi.org/10.1038/s41598-026-44005-6
