Effects of Oral Commensal Streptococci on Porphyromonas gingivalis Invasion into Oral Epithelial Cells

The objective of this study was to determine if the interaction between common oral commensal bacteria and oral epithelial cells would provide protective effects against the invasion of periodontopathogen Porphyromonas gingivalis. Oral epithelial OKF6/Tert cells were used in co-cultures with Streptococcus gordonii, Streptococcus oralis, Streptococcus mitis, and Streptococcus intermedius. The viability of OKF6/Tert cells following a bacterial challenge was evaluated by trypan blue exclusion. The adherence of commensal species was determined by CFU counts. P. gingivalis invasion in OKF6/Tert cells was assessed before and after exposure to commensal species according to CFU counts. Viability assays show that only S. gordonii and S. intermedius display low toxicity toward OKF6/Tert cells. Both commensals adhere to OKF6/Tert cells at an average ratio of 1 CFU to 10 cells. P. gingivalis invasion into host cells is significantly reduced by 25% or 60% after exposure to S. gordonii or S. intermedius, respectively. The results suggest that these commensal species bind to host cells and diminish P. gingivalis invasion. This is important in the context of periodontal disease since P. gingivalis primarily acts on the host by invading it. Therefore, efforts to decrease invasion will eventually lead to future therapies harnessing the mechanisms employed by oral commensal bacteria.

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Inhibition of Urokinase-Type Plasminogen Activator Expression by Macelignan in Porphyromonas gingivalis Supernatant-Induced Human Oral Epithelial Cells

HAYATI Journal of Biosciences ◽

10.4308/hjb.17.1.31 ◽

2010 ◽

Vol 17 (1) ◽

pp. 31-37

Author(s):

YANTI

Keyword(s):

Epithelial Cells ◽

Plasminogen Activator ◽

Porphyromonas Gingivalis ◽

Oral Epithelial Cells ◽

Type Plasminogen Activator ◽

Urokinase Type Plasminogen Activator ◽

Oral Epithelial

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Immune Tolerance in the Oral Mucosa

International Journal of Molecular Sciences ◽

10.3390/ijms222212149 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12149

Author(s):

Hector F. Pelaez-Prestel ◽

Jose L. Sanchez-Trincado ◽

Esther M. Lafuente ◽

Pedro A. Reche

Keyword(s):

Epithelial Cells ◽

Oral Mucosa ◽

Immune Cells ◽

Commensal Bacteria ◽

First Line ◽

Innate And Adaptive Immunity ◽

Oral Epithelial Cells ◽

A Site ◽

Oral Epithelial

The oral mucosa is a site of intense immune activity, where a large variety of immune cells meet to provide a first line of defense against pathogenic organisms. Interestingly, the oral mucosa is exposed to a plethora of antigens from food and commensal bacteria that must be tolerated. The mechanisms that enable this tolerance are not yet fully defined. Many works have focused on active immune mechanisms involving dendritic and regulatory T cells. However, epithelial cells also make a major contribution to tolerance by influencing both innate and adaptive immunity. Therefore, the tolerogenic mechanisms concurring in the oral mucosa are intertwined. Here, we review them systematically, paying special attention to the role of oral epithelial cells.

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Analysis of differential expression of tight junction proteins in cultured oral epithelial cells altered by Porphyromonas gingivalis, Porphyromonas gingivalis lipopolysaccharide, and extracellular adenosine triphosphate

International Journal of Oral Science ◽

10.1038/ijos.2017.51 ◽

2018 ◽

Vol 10 (1) ◽

pp. e8-e8 ◽

Cited By ~ 9

Author(s):

Wei Guo ◽

Peng Wang ◽

Zhong-Hao Liu ◽

Ping Ye

Keyword(s):

Epithelial Cells ◽

Tight Junction ◽

Differential Expression ◽

Porphyromonas Gingivalis ◽

Tight Junction Proteins ◽

Extracellular Adenosine ◽

Oral Epithelial Cells ◽

Porphyromonas Gingivalis Lipopolysaccharide ◽

Oral Epithelial ◽

Junction Proteins

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Identification of bistable populations of Porphyromonas gingivalis that differ in epithelial cell invasion

Microbiology ◽

10.1099/mic.0.038075-0 ◽

2010 ◽

Vol 156 (10) ◽

pp. 3052-3064 ◽

Cited By ~ 17

Author(s):

S. Suwannakul ◽

G. P. Stafford ◽

S. A. Whawell ◽

C. W. I. Douglas

Keyword(s):

Epithelial Cells ◽

Porphyromonas Gingivalis ◽

Cell Invasion ◽

Protease Activity ◽

Periodontal Pathogen ◽

Wild Type ◽

Oral Epithelial Cells ◽

Specific Protease ◽

Oral Epithelial ◽

First Time

Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen Porphyromonas gingivalis exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct subtypes within a population of P. gingivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly invasive subtype invades cells at 10–30-fold higher levels than the poorly invasive subtype and remains highly invasive for approximately 12–16 generations. Analysis of the gingipain activity of these subtypes revealed that the highly invasive type had reduced cell-associated arginine-specific protease activity. The role of Arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an Arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition, a population of ΔrgpAB bacteria did not contain a hyperinvasive subtype. Screening of the protease activity of wild-type populations of both strains identified high and low protease subtypes which also showed a corresponding reduction or enhancement, respectively, of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that includes oxidative stress resistance and iron transport genes, and which might be critical to invasion of or survival within epithelial cells.

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