Staphylococcus Aureus Exploits Epidermal Barrier Defects in Atopic Dermatitis to Trigger Cytokine Expression
Overview
Authors
Affiliations
Patients with atopic dermatitis (AD) have an abnormal skin barrier and are frequently colonized by S. aureus. In this study we investigated if S. aureus penetrates the epidermal barrier of subjects with AD and sought to understand the mechanism and functional significance of this entry. S. aureus was observed to be more abundant in the dermis of lesional skin from AD patients. Bacterial entry past the epidermis was observed in cultured human skin equivalents and in mice but was found to be increased in the skin of cathelicidin knockout and ovalbumin-sensitized filaggrin mutant mice. S. aureus penetration through the epidermis was dependent on bacterial viability and protease activity, because killed bacteria and a protease-null mutant strain of S. aureus were unable to penetrate. Entry of S. aureus directly correlated with increased expression of IL-4, IL-13, IL-22, thymic stromal lymphopoietin, and other cytokines associated with AD and with decreased expression of cathelicidin. These data illustrate how abnormalities of the epidermal barrier in AD can alter the balance of S. aureus entry into the dermis and provide an explanation for how such dermal dysbiosis results in increased inflammatory cytokines and exacerbation of disease.
Yokota M, Matsumoto T, Kawamoto A, Dojo K, Toyama S, Moniaga C Exp Dermatol. 2025; 34(3):e70041.
PMID: 40066914 PMC: 11894917. DOI: 10.1111/exd.70041.
The gut-skin axis: a bi-directional, microbiota-driven relationship with therapeutic potential.
Jimenez-Sanchez M, Celiberto L, Yang H, Sham H, Vallance B Gut Microbes. 2025; 17(1):2473524.
PMID: 40050613 PMC: 11901370. DOI: 10.1080/19490976.2025.2473524.
Crosstalk Between the Skin Environment and Microbial Community in Immune-Related Skin Diseases.
Liu K, Deng S, Zhou Y, Xu B, Zhang Y, Li W Clin Rev Allergy Immunol. 2025; 68(1):16.
PMID: 39954089 DOI: 10.1007/s12016-025-09029-2.
Interleukin-4 and Atopic Dermatitis: Why Does it Matter? A Narrative Review.
Torres T, Mendes-Bastos P, Cruz M, Duarte B, Filipe P, Lopes M Dermatol Ther (Heidelb). 2025; 15(3):579-597.
PMID: 39930311 DOI: 10.1007/s13555-025-01352-y.
Skin microbiota: pathogenic roles and implications in atopic dermatitis.
Huang C, Zhuo F, Guo Y, Wang S, Zhang K, Li X Front Cell Infect Microbiol. 2025; 14:1518811.
PMID: 39877655 PMC: 11772334. DOI: 10.3389/fcimb.2024.1518811.