The epithelial cell response to health and disease associated oral biofilm models

Abstract

Background and ObjectiveDifferent bacteria differentially stimulate epithelial cells. Biofilm composition and viability are likely to influence the epithelial response. In vitro model systems are commonly used to investigate periodontitis‐associated bacteria and their interactions with the host; therefore, understanding factors that influence biofilm–cell interactions is essential. The present study aimed to develop in vitro monospecies and multispecies biofilms and investigate the epithelial response to these biofilms.Material and MethodsBacterial biofilms were cultured in vitro and then either live or methanol‐fixed biofilms were co‐cultured with epithelial cells. Changes in epithelial cell viability, gene expression and cytokine content of culture supernatants were evaluated.ResultsBacterial viability was better preserved within mixed‐species biofilm culture than within single‐species biofilm culture. Both mixed‐ and single‐species biofilms stimulated increased expression of mRNA for interleukin 8 (IL8), C‐X‐C motif chemokine ligand 3 (CXCL3), C‐X‐C motif chemokine ligand 1 (CXCL1), interleukin 1 (IL1), interleukin 6 (IL6), colony‐stimulating factor 2 (CSF2) and tumour necrosis factor (TNF), and the response was greatest in response to mixed‐species biofilms. Following co‐culture, cytokines detected in the supernatants included IL‐8, IL‐6, granulocyte colony‐stimulating factor and granulocyte–macrophage colony‐stimulating factor, with the greatest release of cytokines found following co‐culture with methanol‐fixed, mixed‐species biofilms.ConclusionsThese data show that epithelial cells generate a distinct cytokine gene‐ and protein‐expression signature in response to live or fixed, single‐ or multispecies biofilms.

Environmental lead effects on gene expression in oral epithelial cells

“…CXCL1 (Groα) together with IL‐8 are major chemotaxins for neutrophils. This chemokine is upregulated in gingival epithelial cells, and Ramage et al have shown that CXCL1 and CSF2 levels were significantly increased in oral epithelial cell cultures treated with biofilms, particularly associated with a mixed species biofilm containing F. nucleatum and P. gingivalis , as was seen in this study. Regarding a role in periodontitis, both CXCL1 and CXCL2 are expressed in the junctional epithelium potentially contributing to attempts to maintain homeostasis .…”

Fungi at the Scene of the Crime: Innocent Bystanders or Accomplices in Oral Infections?

“…Polymicrobial communities are able to form biofilms upon this vast variety of substrates [5••, 6, 7]. It is now generally well understood that dental plaque biofilms contain many resident species that modulate one another, their environment, and also the host response [8][9][10]. Despite the widely acknowledged presence of yeasts within the oral cavity, their active role and participation in oral diseases is generally perceived to be restricted to mucosal-related diseases.…”

Insights into the Evolution of Host Association through the Isolation and Characterization of a Novel Human Periodontal Pathobiont,Desulfobulbus oralis

“…There is still insufficient data to distinguish the relative roles of oral bacterial lipopolysaccharide (LPS) and surface-associated and secreted proteins in cytokine induction. Various recognized periodontal pathobionts trigger distinct types of inflammatory responses (87)(88)(89), and some (e.g., Porphyromonas gingivalis) can modulate that by interfering with chemokine production (90).…”

“…We used a human immortalized oral keratinocyte cell line (OKF6/TERT-2), which has been previously used as a model to study the interaction of oral bacteria with human epithelial cells (88,91). Cells and filtered medium from the same D. oralis cultures used for proteomic analyses were applied to epithelial cells in culture, and the production of 13 human inflammatory cytokines/chemokines was measured after 48 h using bead-based immunoassays.…”