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Can Pulp Fibroblasts Kill Cariogenic Bacteria? Role of Complement Activation.
C Jeanneau1, P Rufas1, C Rombouts1
1Aix Marseille Université, CNRS, ISM UMR 7287, Marseille, France.
Journal of Dental Research
|October 15, 2015
Summary
Dental pulp fibroblasts can kill cariogenic bacteria like Streptococcus mutans and Streptococcus sanguinis by activating the complement system and forming the membrane attack complex (MAC). This process is crucial for fighting dental decay.
Area of Science:
- Immunology
- Dental Research
- Microbiology
Background:
- Complement system activation is implicated in dental pulp inflammation and regeneration following carious decay.
- Human pulp fibroblasts synthesize complement components when stimulated by lipoteichoic acid (LTA).
- Complement activation results in membrane attack complex (MAC) formation, known for its antibacterial effects.
Purpose of the Study:
- To investigate if human pulp fibroblasts can kill Streptococcus mutans and Streptococcus sanguinis through complement activation.
- To determine the role of MAC in the interaction between pulp fibroblasts and cariogenic bacteria.
Main Methods:
- Histological staining of carious tooth sections to observe MAC presence.
- In vitro incubation of human pulp fibroblasts with LTA to induce MAC formation.
- Enzymatic assays (MTT assay) and agar well diffusion to assess bacterial sensitivity to LTA-conditioned medium.
- Coculture model of pulp fibroblasts and bacteria with CD59 (MAC inhibitor) to evaluate MAC's role.
Main Results:
- Presence of S. mutans correlated with intense MAC staining in carious teeth.
- LTA-stimulated pulp fibroblasts significantly increased MAC formation on bacteria.
- S. mutans and S. sanguinis were sensitive to MAC produced by pulp fibroblasts.
- Direct contact with pulp fibroblasts induced MAC formation on bacteria, leading to bacterial killing, which was reduced by CD59.
Conclusions:
- Human pulp fibroblasts, stimulated by LTA, produce functional MAC that effectively kills cariogenic bacteria S. mutans and S. sanguinis.
- Pulp fibroblasts play a significant role in the innate immune defense against dental caries by destroying cariogenic bacteria via complement activation.
Keywords:
Streptococcus mutanscarious decaydental pulpinflammationmembrane attack complexmicrobial viabilityMore Related Videos
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