Oral Epithelial Cell Responses to Multispecies Microbial Biofilms

Peyyala, Rebecca; Kirakodu, Sreenatha; Novak, Karen F.; Ebersole, Jeffrey L.

doi:10.1177/0022034512472508

Cited by 34 publications

(32 citation statements)

References 32 publications

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“…nucleatum while secreted IL-1α levels are reported to be directly related to the amount of F . nucleatum cells present in the biofilms [42, 43]. The observed levels of IL-1α and IL-1β in the present study may be a result of stimulation by F .…”

Section: Resultsmentioning

confidence: 51%

In Vitro Effect of Porphyromonas gingivalis Methionine Gamma Lyase on Biofilm Composition and Oral Inflammatory Response

et al. 2016

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Methanethiol (methyl mercaptan) is an important contributor to oral malodour and periodontal tissue destruction. Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum are key oral microbial species that produce methanethiol via methionine gamma lyase (mgl) activity. The aim of this study was to compare an mgl knockout strain of P. gingivalis with its wild type using a 10-species biofilm co-culture model with oral keratinocytes and its effect on biofilm composition and inflammatory cytokine production. A P. gingivalis mgl knockout strain was constructed using insertion mutagenesis from wild type W50 with gas chromatographic head space analysis confirming lack of methanethiol production. 10-species biofilms consisting of Streptococcus mitis, Streptococcus oralis, Streptococcus intermedius, Fusobacterium nucleatum ssp polymorphum, Fusobacterium nucleatum ssp vincentii, Veillonella dispar, Actinomyces naeslundii, Prevotella intermedia and Aggregatibacter actinomycetemcomitans with either the wild type or mutant P. gingivalis were grown on Thermanox cover slips and used to stimulate oral keratinocytes (OKF6-TERT2), under anaerobic conditions for 4 and 24 hours. Biofilms were analysed by quantitative PCR with SYBR Green for changes in microbial ecology. Keratinocyte culture supernatants were analysed using a multiplex bead immunoassay for cytokines. Significant population differences were observed between mutant and wild type biofilms; V. dispar proportions increased (p<0.001), whilst A. naeslundii (p<0.01) and Streptococcus spp. (p<0.05) decreased in mutant biofilms. Keratinocytes produced less IL-8, IL-6 and IL-1α when stimulated with the mutant biofilms compared to wild type. Lack of mgl in P. gingivalis has been shown to affect microbial ecology in vitro, giving rise to a markedly different biofilm composition, with a more pro-inflammatory cytokine response from the keratinocytes observed. A possible role for methanethiol in biofilm formation and cytokine response with subsequent effects on oral malodor and periodontitis is suggested.

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Section: Resultsmentioning

confidence: 51%

In Vitro Effect of Porphyromonas gingivalis Methionine Gamma Lyase on Biofilm Composition and Oral Inflammatory Response

et al. 2016

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“…Regarding multi-species biofilms, in a comparable 9-species model ( T. denticola not included) IL-1, IL-6 and IL-8 secretion were enhanced by gingival epithelial cells at 4 h, followed by a gradual decrease over 24 h [18], a trend similar to the one observed in the present study. In another in vitro biofilm model consisting of three species, the combination of Streptococcus gordonii , A. naeslundii and F. nucleatum caused a strong up-regulation IL-8 secretion in by oral epithelial cells, whereas the combination of S. gordonii , F. nucleatum and P. gingivalis lowered or even inhibited the production of IL-8 [16]. This could indicate that the presence of P. gingivalis , one of the three “red complex” species, may be involved in the down-play of the chemotactic responses by epithelial cells.…”

Section: Discussionmentioning

confidence: 96%

Interleukin-8 Responses of Multi-Layer Gingival Epithelia to Subgingival Biofilms: Role of the “Red Complex” Species

2013

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Periodontitis is an infectious inflammatory disease that results in the destruction of the tooth-supporting (periodontal) tissues. The Gram-negative anaerobic species Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, (also known as the “red complex” species) are highly associated with subgingival biofilms at periodontitis-affected sites. A major chemokine produced by the gingival epithelium in response to biofilm challenge, is interleukin (IL)-8. The aim of this in vitro study was to investigate the relative effect of the “red complex” species as constituents of subgingival biofilms, on the regulation of IL-8 by gingival epithelia. Multi-layered organotypic human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its 7-species variant, excluding the “red complex”. IL-8 gene expression and secretion analyses were performed by qPCR and ELISA, respectively. After 3 h, both biofilms up-regulated IL-8 gene expression, but the presence of the “red complex” resulted in 3-fold greater response. IL-8 secretion was also up-regulated by both biofilms, with no differences between them. After 24 h, the 10-species biofilm reduced IL-8 secretion to 50% of the control, but this was not affected when the “red complex” was absent. In conclusion, as part of biofilms, “red complex” species differentially regulate IL-8 in gingival epithelia, potentially affecting the chemotactic responses of the tissue.

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“…Future work in this direction might lead to the refinement of antimicrobial strategies in periodontal therapy . To take host parameters into account, co‐culture models have been developed in the past using relatively simple biofilms to trigger monolayers of epithelial cells . A difficulty in these studies is that the host cells (eg, epithelial cells) require an aerobic environment whereas the subgingival biofilms of dysbiotic communities (eg, periodontitis), require an anaerobic environment.…”

Section: Discussionmentioning

confidence: 99%