Three-Dimensional (3D) Skin Microbiome and Infection Models

We develop 3D skin microbiome and infection models with an integrated immune system that can be used to study host-pathogen/microbiome interactions.

We use our reconstituted epidermis and full-thickness skin models made from specifically immortalized primary or primary cells as well as models supplemented with immune cells. The developed horny layer (stratum corneum) of the models is colonized with specific skin microbiome or pathogenic microorganisms according to the desired application. 

Skin microbiome models

are reconstructed models whose stratum corneum is colonized with commensal skin microbiome strains such as Staphylococcus ssp, e.g. S. epidermidis, or Micrococcus luteus [1, 2, 3].

Skin infection models

are reconstructed models whose stratum corneum is infected with pathogenic, opportunistic microorganisms such as Staphylococcus aureus, Staphylococcus pyogenes, Escherichia coli, Klebsiella ssp., Pseudomonas aeruginosa, Cutibacterium acnes, Herpes simplex virus 1, Candida albicans or Malassezia furfur, which can cause dermatological infections [4, 5]. 

The skin microbiome consists of different microorganisms and is part of the skin's natural protective mechanism. The main components are commensal microorganisms, which live closely with the host on the skin but do not harm it. 

Commensals can reduce the colonization of pathogenic bacteria on the skin cells. They can also strengthen the immune response to pathogenic bacteria by stimulating the production of interferon and other cytokines as well as phagocytosis [6].

Disruption of the microbiome balance through medication or cosmetics

However, the skin microbiome can also consist of pathogenic, opportunistic microorganisms that trigger diseases. In a healthy host, there is an individual balance between commensal and opportunistic microorganisms. This balance can shift in favor of opportunistic microorganisms due to weakened host defenses, altered hormone production, but also due to the use of drugs, cosmetics or personal care products. According to various studies, such changes in the skin microbiome are involved in the pathophysiology of various dermatoses [7].

Species-specific differences require specific skin models

Although many mouse models are used to study skin physiology and biology, mouse skin differs significantly from human skin in anatomical structure, gene expression, cytokine profile, antimicrobial peptides and the composition of proteins related to the skin barrier and forming the epidermal differentiation complex [8]. As a consequence, these species-specific differences in innate cutaneous defenses influence the interaction between skin and microbiota in different ways. It is therefore obvious that mouse skin is not a suitable model for studying the interaction between skin and the human microbiota and that mouse experiments with organisms of the human skin microbiome can lead to misleading conclusions [9]. 

Human 3D skin models with their fully differentiated epidermal barrier have been established as a valuable tool in dermatological research and are of major importance here [10]. 

With our decades of experience in cell line development, working with (pathogenic) microorganisms and adherence to the highest quality standards, we establish human and animal 3D skin microbiome and infectious models.

The skin models for investigating host reactions of the skin in the presence of microbiome or pathogenic microorganisms can contain immune cells in addition to components of the skin and the microorganisms. 

Unique selling point: species-specific models with high validity

Our 3D skin microbiome and infection models are produced from specifically immortalized primary skin cells from healthy human or animal donors, such as dogs. These cells retain their physiological behavior and are also available indefinitely. 

Our species-specific 3D microbiome and infection models offer a variety of advantages [11]: 

• Independence from donors,
• High reproducibility,
• A fully differentiated epidermis,
• A simple simulation of inflammation or disease by adding cytokines or growth factors or by using targeted genetically modified skin cells that intrinsically increase inflammation and
• Species-specific results and findings