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. 2020 Aug 31:8:785.
doi: 10.3389/fcell.2020.00785. eCollection 2020.

Infection of Human Dental Pulp Stromal Cells by Streptococcus mutans: Shedding Light on Bacteria Pathogenicity and Pulp Inflammation

Elodie Maisonneuve  1 , Julie Chevrier  1 , Marie Dubus  1   2 , Jennifer Varin  1 , Johan Sergheraert  1   2   3 , Sophie C Gangloff  1   4 , Fany Reffuveille  1   4 , Cédric Mauprivez  1   2   3 , Halima Kerdjoudj  1   2
Affiliations

Infection of Human Dental Pulp Stromal Cells by Streptococcus mutans: Shedding Light on Bacteria Pathogenicity and Pulp Inflammation

Elodie Maisonneuve et al. Front Cell Dev Biol. .

Abstract

Cariogenic Streptococcus mutans (S. mutans) is implicated in the dental pulp necrosis but also in cardiovascular tissue infections. Herein, the purpose was to elucidate how human dental pulp derived stromal cells (DPSCs) react toward a direct interaction with S. mutans. DPSCs were challenged with S. mutans. Following 3 h of interaction, DPSCs were able to internalize S. mutans (rate < 1%), and F-actin fibers played a significant role in this process. S. mutans persisted in the DPSCs for 48 h without causing a cytotoxic effect. S. mutans was, however, able to get out of the DPSCs cytoplasm and to proliferate in the extracellular environment. Yet, we noticed several adaptive responses of bacteria to the extracellular environment such as a modification of the kinetic growth, the increase in biofilm formation on type I collagen and polyester fabrics, as well as a tolerance toward amoxicillin. In response to infection, DPSCs adopted a proinflammatory profile by increasing the secretion of IL-8, lL-1β, and TNF-α, strengthening the establishment of the dental pulp inflammation. Overall, these findings showed a direct impact of S. mutans on DPSCs, providing new insights into the potential role of S. mutans in infective diseases.

Keywords: S. mutans; dental pulp derived stromal cells; inflammation; internalization; pathogenicity.

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Figures

FIGURE 1
FIGURE 1
S. mutans internalization. (A) Percentage of viable S. mutans after 3 h of contact with dental pulp stem cells (DPSCs). Tests were performed with or without amoxicillin treatment (Amox-protection assay). S. mutans challenged with Cytochalasin D-treated DPSCs indicates that F-actin fibers are required for S. mutans internalization by DPSCs (Histograms of mean ± SEM, n = 6, Mann & Whitney test). (B) Laser scanning confocal microscopy visualization and orthogonal view of DPSCs infected with S. mutans. Green color corresponds to cytoskeleton labeled with Phalloidin-coupled to Alexa® 488 and magenta color corresponds to S. mutans labeled with DAPI. White arrows indicate bacteria. Scale bar = 10 μm.
FIGURE 2
FIGURE 2
Bacteria persistence. (A) Count of viable intracellular (i-S. mutans) and extracellular (e-S. mutans) bacteria at 3, 24, and 48 h after internalization. Results indicate the absence of intracellular proliferation and the release of S. mutans in the extracellular environment. (B,C) Lactate dehydrogenase cytotoxicity assay and DNA quantification of DPSCs, respectively, indicating the absence of bacteria cytotoxicity after 48 h of culture. (D) Count of viable intracellular and extracellular S. mutans, after 24 h of culture of infected DPSCs in the absence and the presence of cytochalasin D. (Histograms of mean ± SEM, n = 6; Mann & Whitney test; ND = not detected).
FIGURE 3
FIGURE 3
Representative growth curves of the intracellular (i-S. mutans), the extracellular (e-S. mutans) and the bacteria control (S. mutans), indicating a biphasic growth for e-S. mutans (n = 3).
FIGURE 4
FIGURE 4
S. mutans adhesion and biofilm formation. (A,B) Intracellular (i-S. mutans), extracellular (e-S. mutans), and bacteria control (S. mutans) adhesion and biofilm formation on type I collagen coating, respectively. (C) Intracellular (i-S. mutans), extracellular (e-S. mutans) and bacteria control (S. mutans) adhesion on polyester fabrics. (Histograms of mean ± SEM, n = 4; Mann & Whitney test). (D) Scanning electron microscopy visualization of adhered intracellular (i-S. mutans), extracellular (e-S. mutans) and bacteria control (S. mutans) on polyester fabrics. White arrows indicate matrix formation. Lower row indicates a higher magnification of the upper row. Scale bars = 1 μm.
FIGURE 5
FIGURE 5
Proinflammatory response. Released IL-1β (A), IL-8 (B), and TNF-α (C) detected by ELISA (n = 6; Mann & Whitney test).
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References

    1. Abranches J., Zeng L., Bélanger M., Rodrigues P. H., Simpson-Haidaris P. J., Akin D., et al. (2009). Invasion of human coronary artery endothelial cells by Streptococcus mutans OMZ175. Oral Microbiol. Immunol. 24 141–145. 10.1111/j.1399-302X.2008.00487.x - DOI - PMC - PubMed
    1. Andrukhov O., Behm C., Blufstein A., Rausch-Fan X. (2019). Immunomodulatory properties of dental tissue-derived mesenchymal stem cells: implication in disease and tissue regeneration. World J. Stem Cells 11 604–617. 10.4252/wjsc.v11.i9.604 - DOI - PMC - PubMed
    1. Bedoya-Correa C. M., Rincón Rodríguez R. J., Parada-Sanchez M. T. (2019). Genomic and phenotypic diversity of Streptococcus mutans. J. Oral Biosci. 61 22–31. 10.1016/j.job.2018.11.001 - DOI - PubMed
    1. Berlutti F., Catizone A., Ricci G., Frioni A., Natalizi T., Valenti P., et al. (2010). Streptococcus mutans and Streptococcus sobrinus are able to adhere and invade human gingival fibroblast cell line. Int. J. Immunopathol. Pharmacol. 23 1253–1260. 10.1177/039463201002300430 - DOI - PubMed
    1. Bindal P., Ramasamy T. S., Kasim N. H. A., Gnanasegaran N., Chai W. L. (2018). Immune responses of human dental pulp stem cells in lipopolysaccharide-induced microenvironment. Cell Biol. Int. 42 832–840. 10.1002/cbin.10938 - DOI - PubMed

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