Titel: Staphylococcus aureus and influenza virus: interaction of pathogens can be analysed in an human alveolus-on-a-chip model
Art: Abstractautor
Session: Workshop 01
Virulence Principles in Respiratory Tract Infections (FG MP)

Referent: Stefanie Deinhardt-Emmer (Jena)


Abstract - Text

Question: Postinfluenza models of Staphylococcus aureus pneumonia demonstrate the severe outcome of a coinfection associated with substantial morbidity and mortality, in particular in the immunocompromised host. To date, investigations concerning microbial infections of the lung are usually carried out in animal models. However, lung anatomy and physiology as well as composition of the immune system differ significantly between rodents and humans. To investigate cell interactions between epithelial, endothelial and immune cells after influenza virus/ S. aureus coinfection, we established a human alveolus-model generating a reactive tissue-tissue interface between the vascular endothelium and the airway-facing epithelium. Alterations in the immune system, which are present in immunocompromised host, can be examined as well.

Methods: MOTiF biochips were seeded with human endothelial cells on the vascular site and with epithelial cells and macrophages on the airway site (Figure 1). This organoid was cultured for up to 14 days with a robust and stable air-liquid interphase under dynamic flow conditions. Barrier integrity was proven by transepithelial electrical resistance (TEER) measurements and permeability assays. Expression and localization of cell-type specific markers and functional proteins was proven by immunofluorescence. Viral and bacterial infection was performed through airway up to 8 hours, depending on multiplicity of infection (MOI).

Results: Dynamic conditions for maintaining air-liquid-interface allow a stable barrier with high transepithelial resistance and an intact vascularity. We provide evidence for an increase of barrier integrity after introduction of macrophages proven by TEER measurement and permeability tests. Our data indicate a stable surfactant production of alveolar epithelial cells type II. Subsequent infection has been successfully established and pathogenicity factors can be investigated.

Conclusions: We established a functional, biochip-based human in vitro alveolus model that is suitable for investigation of complex co-infections and immune functions. Separated airway and vascular chambers allow infections with pathogens from the airway site. Thereby inducing an immune response, it is possible to observe migration of immune cells from the vascular site to the infection to study species-specific mechanism of pathogens.