scholarly journals Fusobacterium nucleatum Transports Noninvasive Streptococcus cristatus into Human Epithelial Cells

2006 ◽  
Vol 74 (1) ◽  
pp. 654-662 ◽  
Author(s):  
Andrew M. Edwards ◽  
Tracy J. Grossman ◽  
Joel D. Rudney
Keyword(s):  
Epithelial Cells ◽  
Cell Attachment ◽  
Polyclonal Antibodies ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Host Cells ◽  
Oral Streptococci ◽  
Kb Cells ◽  
Actinomyces Naeslundii ◽  
Adhesive Interactions

ABSTRACT Analysis of human buccal epithelial cells frequently reveals an intracellular polymicrobial consortium of bacteria. Although several oral bacteria have been demonstrated to invade cultured epithelial cells, several others appear unable to internalize. We hypothesized that normally noninvasive bacteria may gain entry into epithelial cells via adhesion to invasive bacteria. Fusobacterium nucleatum is capable of binding to and invading oral epithelial cells. By contrast, Streptococcus cristatus binds weakly to host cells and is not internalized. F. nucleatum and S. cristatus coaggregate strongly via an arginine-sensitive interaction. Coincubation of KB or TERT-2 epithelial cells with equal numbers of F. nucleatum and S. cristatus bacteria led to significantly increased numbers of adherent and internalized streptococci. F. nucleatum also promoted invasion of KB cells by other oral streptococci and Actinomyces naeslundii. Dissection of fusobacterial or streptococcal adhesive interactions by using sugars, amino acids, or antibodies demonstrated that this phenomenon is due to direct attachment of S. cristatus to adherent and invading F. nucleatum. Inhibition of F. nucleatum host cell attachment and invasion with galactose, or fusobacterial-streptococcal coaggregation by the arginine homologue l-canavanine, abrogated the increased S. cristatus adhesion to, and invasion of, host cells. In addition, polyclonal antibodies to F. nucleatum, which inhibited fusobacterial attachment to both KB cells and S. cristatus, significantly decreased invasion by both species. Similar decreases were obtained when epithelial cells were pretreated with cytochalasin D, staurosporine, or cycloheximide. These studies indicate that F. nucleatum may facilitate the colonization of epithelial cells by bacteria unable to adhere or invade directly.

scholarly journals Interactions between Periodontal Bacteria and Human Oral Epithelial Cells: Fusobacterium nucleatum Adheres to and Invades Epithelial Cells

2000 ◽  
Vol 68 (6) ◽  
pp. 3140-3146 ◽  
Author(s):  
Yiping W. Han ◽  
Wenyuan Shi ◽  
George T.-J. Huang ◽  
Susan Kinder Haake ◽  
No-Hee Park ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Periodontal Diseases ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Metabolic Inhibitors ◽  
Kb Cells ◽  
Gingival Epithelial Cells ◽  
Oral Epithelial

ABSTRACT Bacteria are causative agents of periodontal diseases. Interactions between oral bacteria and gingival epithelial cells are essential aspects of periodontal infections. Using an in vitro tissue culture model, a selected group of gram-negative anaerobic bacteria frequently associated with periodontal diseases, includingBacteroides forsythus, Campylobacter curvus,Eikenella corrodens, Fusobacterium nucleatum,Porphyromonas gingivalis, and Prevotella intermedia, were examined for their ability to adhere to and invade primary cultures of human gingival epithelial cells (HGEC). The effects of these bacteria on the production of interleukin-8 (IL-8), a proinflammatory chemokine, were also measured. These studies provided an initial demonstration that F. nucleatum adhered to and invaded HGEC and that this was accompanied by high levels of IL-8 secretion from the epithelial cells. The attachment and invasion characteristics of F. nucleatumwere also tested using KB cells, an oral epithelial cell line. The invasion was verified by transmission electron microscopy and with metabolic inhibitors. Invasion appeared to occur via a “zipping” mechanism and required the involvement of actins, microtubules, signal transduction, protein synthesis, and energy metabolism of the epithelial cell, as well as protein synthesis by F. nucleatum. A spontaneous mutant, lam, of F. nucleatum, isolated as defective in autoagglutination, was unable to attach to or invade HGEC or KB cells, further indicating the requirement of bacterial components in these processes. Sugar inhibition assays indicated that lectin-like interactions were involved in the attachment of F. nucleatum to KB cells. Investigation of these new virulence phenotypes should improve our understanding of the role of F. nucleatum in periodontal infections.

scholarly journals Complementation of the fadA Mutation in Fusobacterium nucleatum Demonstrates that the Surface-Exposed Adhesin Promotes Cellular Invasion and Placental Colonization

2009 ◽  
Vol 77 (7) ◽  
pp. 3075-3079 ◽  
Author(s):  
Akihiko Ikegami ◽  
Peter Chung ◽  
Yiping W. Han
Keyword(s):  
Host Cell ◽  
Cell Attachment ◽  
Adverse Pregnancy Outcome ◽  
Fusobacterium Nucleatum ◽  
Host Cells ◽  
Mouse Placenta ◽  
Host Cell Attachment ◽  
Adverse Pregnancy

ABSTRACT Fusobacterium nucleatum is a gram-negative oral anaerobe implicated in periodontal disease and adverse pregnancy outcome. The organism colonizes the mouse placenta, causing localized infection and inflammation. The mechanism of placental colonization has not been elucidated. Previous studies identified a novel adhesin from F. nucleatum, FadA, as being involved in the attachment and invasion of host cells. The fadA deletion mutant F. nucleatum 12230 US1 was defective in host cell attachment and invasion in vitro, but it also exhibited pleiotropic effects with altered cell morphology and growth rate. In this study, a fadA-complementing clone, F. nucleatum 12230 USF81, was constructed. The expression of FadA on USF81 was confirmed by Western blotting and immunofluorescent labeling. USF81 restored host cell attachment and invasion activities. The ability of F. nucleatum 12230, US1, and USF81 to colonize the mouse placenta was examined. US1 was severely defective in placental colonization compared to the wild type and USF81. Thus, FadA plays an important role in F. nucleatum colonization in vivo. These results also represent the first complementation studies for F. nucleatum. FadA may be a therapeutic target for preventing F. nucleatum colonization of the host.

scholarly journals Porphyromonas gingivalis Fimbriae Bind to Cytokeratin of Epithelial Cells

2002 ◽  
Vol 70 (1) ◽  
pp. 96-101 ◽  
Author(s):  
Hakimuddin T. Sojar ◽  
Ashu Sharma ◽  
Robert J. Genco
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Polyclonal Antibodies ◽  
Cell Extract ◽  
Host Cells ◽  
Amino Terminal ◽  
A Minor ◽  
Sepharose 4B ◽  
Overlay Assay

ABSTRACT The adherence of Porphyromonas gingivalis to host cells is likely a prerequisite step in the pathogenesis of P. gingivalis-induced periodontal disease. P. gingivalis binds to and invades epithelial cells, and fimbriae are shown to be involved in this process. Little is known regarding epithelial receptor(s) involved in binding of P. gingivalis fimbriae. Using an overlay assay with purified P. gingivalis fimbriae as a probe, two major epithelial cell proteins with masses of 50 and 40 kDa were identified by immunoblotting with fimbria-specific antibodies. Iodinated purified fimbriae also bound to the same two epithelial cell proteins. An affinity chromatography technique was utilized to isolate and purify the epithelial components to which P. gingivalis fimbriae bind. Purified fimbriae were coupled to CNBr-activated Sepharose-4B, and the solubilized epithelial cell extract proteins bound to the immobilized fimbriae were isolated from the column. A major 50-kDa component and a minor 40-kDa component were purified and could be digested with trypsin, suggesting that they were proteins. These affinity-eluted 50- and 40-kDa proteins were then subjected to amino-terminal sequencing, and no sequence could be determined, suggesting that these proteins have blocked amino-terminal residues. CNBr digestion of the 50-kDa component resulted in an internal sequence homologous to that of Keratin I molecules. Further evidence that P. gingivalis fimbriae bind to cytokeratin molecule(s) comes from studies showing that multicytokeratin rabbit polyclonal antibodies cross-react with the affinity-purified 50-kDa epithelial cell surface component. Also, binding of purified P. gingivalis fimbriae to epithelial components can be inhibited in an overlay assay by multicytokeratin rabbit polyclonal antibodies. Furthermore, we showed that biotinylated purified fimbriae bind to purified human epidermal keratin in an overlay assay. These studies suggest that the surface-accessible epithelial cytokeratins may act as receptor(s) for P. gingivalis fimbriae. We hypothesize that adherence of P. gingivalis fimbriae to cytokeratin may be important for colonization of oral mucous membranes and possibly also for activation of epithelial cells.

Porphyromonas gingivalis-Epithelial Cell Interactions in Periodontitis

2006 ◽  
Vol 85 (5) ◽  
pp. 392-403 ◽  
Author(s):  
E. Andrian ◽  
D. Grenier ◽  
M. Rouabhia
Keyword(s):  
Epithelial Cells ◽  
Periodontal Disease ◽  
Porphyromonas Gingivalis ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Oral Bacteria ◽  
Host Cells ◽  
Host Responses ◽  
Tissue Destruction ◽  
Adaptive Ability

Emerging data on the consequences of the interactions between invasive oral bacteria and host cells have provided new insights into the pathogenesis of periodontal disease. Indeed, modulation of the mucosal epithelial barrier by pathogenic bacteria appears to be a critical step in the initiation and progression of periodontal disease. Periodontopathogens such as Porphyromonas gingivalis have developed different strategies to perturb the structural and functional integrity of the gingival epithelium. P. gingivalis adheres to, invades, and replicates within human epithelial cells. Adhesion of P. gingivalis to host cells is multimodal and involves the interaction of bacterial cell-surface adhesins with receptors expressed on the surfaces of epithelial cells. Internalization of P. gingivalis within host cells is rapid and requires both bacterial contact-dependent components and host-induced signaling pathways. P. gingivalis also subverts host responses to bacterial challenges by inactivating immune cells and molecules and by activating host processes leading to tissue destruction. The adaptive ability of these pathogens that allows them to survive within host cells and degrade periodontal tissue constituents may contribute to the initiation and progression of periodontitis. In this paper, we review current knowledge on the molecular cross-talk between P. gingivalis and gingival epithelial cells in the development of periodontitis.

scholarly journals Effects of a Chlorhexidine Gluconate-Containing Mouthwash on the Vitality and Antimicrobial Susceptibility of In Vitro Oral Bacterial Ecosystems

2003 ◽  
Vol 69 (8) ◽  
pp. 4770-4776 ◽  
Author(s):  
Andrew J. McBain ◽  
Robert G. Bartolo ◽  
Carl E. Catrenich ◽  
Duane Charbonneau ◽  
Ruth G. Ledder ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Lactobacillus Rhamnosus ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Actinomyces Naeslundii ◽  
Before And After ◽  
Gradient Gel Electrophoresis ◽  
Plate Counts ◽  
Neisseria Subflava

ABSTRACT Oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters. Steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (CHX) gluconate-containing mouthwash (CHXM) diluted to 0.06% (wt/vol) antimicrobial content. The microcosms were characterized by heterotrophic plate counts and PCR-denaturing gradient gel electrophoresis (DGGE). CHXM caused significant decreases in both total anaerobe and total aerobe/facultative anaerobe counts (P < 0.05), together with lesser decreases in gram-negative anaerobes. The degree of streptococcal and actinomycete inhibition varied considerably among individuals. DGGE showed that CHXM exposure caused considerable decreases in microbial diversity, including marked reductions in Prevotella sp. and Selenomonas infelix. Pure-culture studies of 10 oral bacteria (eight genera) showed that Actinomyces naeslundii, Veillonella dispar, Prevotella nigrescens, and the streptococci were highly susceptible to CHX, while Lactobacillus rhamnosus, Fusobacterium nucleatum, and Neisseria subflava were the least susceptible. Determination of the MICs of triclosan, CHX, erythromycin, penicillin V, vancomycin, and metronidazole for microcosm isolates, before and after 5 days of CHXM exposure, showed that CHXM exposure altered the distribution of isolates toward those that were less susceptible to CHX (P < 0.05). Changes in susceptibility distributions for the other test agents were not statistically significant. In conclusion, population changes in plaque microcosms following repeated exposure to CHXM represented an inhibition of the most susceptible flora with a clonal expansion of less susceptible species.

scholarly journals Assessment of Internalization and Viability ofPorphyromonas gingivalis in KB Epithelial Cells by Confocal Microscopy

2001 ◽  
Vol 69 (11) ◽  
pp. 7146-7151 ◽  
Author(s):  
S. Houalet-Jeanne ◽  
P. Pellen-Mussi ◽  
S. Tricot-Doleux ◽  
J. Apiou ◽  
M. Bonnaure-Mallet
Keyword(s):  
Epithelial Cells ◽  
Confocal Microscopy ◽  
Porphyromonas Gingivalis ◽  
Anaerobic Growth ◽  
Host Cells ◽  
Periodontal Pathogens ◽  
Kb Cells ◽  
Internalization Process ◽  
First Time

ABSTRACT Porphyromonas gingivalis (P. gingivalis) is considered to be one of the main periodontal pathogens. The goal of this work was to confirm the ability of P. gingivalis to invade host cells. We detected P. gingivalis inside KB cells by confocal microscopy and analyzed the various aspects of the adherence and internalization process. Lysates of P. gingivalis-infected KB cells were also examined using anaerobic growth techniques. The results showed the viability and ability to replicate, inside the host cells, of the internalized pathogen. The production of vesicles was also tracked for the first time. Confocal microscopy revealed P. gingivalis in a perinuclear position.

scholarly journals Cigarette Smoke Stimulates SARS-CoV-2 Internalization by Activating AhR and Increasing ACE2 Expression in Human Gingival Epithelial Cells

2021 ◽  
Vol 22 (14) ◽  
pp. 7669
Author(s):  
Cassio Luiz Coutinho Almeida-da-Silva ◽  
Harmony Matshik Dakafay ◽  
Kaitlyn Liu ◽  
David M. Ojcius
Keyword(s):  
Epithelial Cells ◽  
Oral Cavity ◽  
Cigarette Smoke ◽  
Large Body ◽  
Receptor Expression ◽  
Host Cells ◽  
Dependent Manner ◽  
Gingival Epithelial Cells ◽  
Human Gingival Epithelial Cells ◽  
Oral Cells

A large body of evidence shows the harmful effects of cigarette smoke to oral and systemic health. More recently, a link between smoking and susceptibility to coronavirus disease 2019 (COVID-19) was proposed. COVID-19 is due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which uses the receptor ACE2 and the protease TMPRSS2 for entry into host cells, thereby infecting cells of the respiratory tract and the oral cavity. Here, we examined the effects of cigarette smoke on the expression of SARS-CoV-2 receptors and infection in human gingival epithelial cells (GECs). We found that cigarette smoke condensates (CSC) upregulated ACE2 and TMPRSS2 expression in GECs, and that CSC activated aryl hydrocarbon receptor (AhR) signaling in the oral cells. ACE2 was known to mediate SARS-CoV-2 internalization, and we demonstrate that CSC treatment potentiated the internalization of SARS-CoV-2 pseudovirus in GECs in an AhR-dependent manner. AhR depletion using small interference RNA decreased SARS-CoV-2 pseudovirus internalization in CSC-treated GECs compared with control GECs. Our study reveals that cigarette smoke upregulates SARS-CoV-2 receptor expression and infection in oral cells. Understanding the mechanisms involved in SARS-CoV-2 infection in cells of the oral cavity may suggest therapeutic interventions for preventing viral infection and transmission.

Fretibacterium fastidiosum gen. nov., sp. nov., isolated from the human oral cavity

2013 ◽  
Vol 63 (Pt_2) ◽  
pp. 458-463 ◽  
Author(s):  
Sonia R. Vartoukian ◽  
Julia Downes ◽  
Richard M. Palmer ◽  
William G. Wade
Keyword(s):  
New Genus ◽  
Novel Species ◽  
Fusobacterium Nucleatum ◽  
Oral Bacteria ◽  
Rrna Gene ◽  
Good Growth ◽  
Content Type ◽  
Cellular Fatty Acids ◽  
Link Type ◽  
Peptone Yeast Extract Glucose

SGP1T, a strain belonging to a lineage of the phylum Synergistetes with no previously cultivated representatives was subjected to a comprehensive range of phenotypic and genotypic tests. For good growth the strain was dependent on co-culture with, or extracts from, selected other oral bacteria. Cells of strain SGP1T were asaccharolytic and major amounts of acetic acid and moderate amounts of propionic acid were produced as end products of metabolism in peptone-yeast extract-glucose broth supplemented with a filtered cell sonicate of Fusobacterium nucleatum subsp. nucleatum ATCC 25586T (25 %, v/v). Hydrogen sulphide was produced and gelatin was weakly hydrolysed. The major cellular fatty acids were C14 : 0, C18 : 0 and C16 : 0. The DNA G+C content of strain SGP1T was 63 mol%. Phylogenetic analysis of the full-length 16S rRNA gene showed that strain SGP1T represented a novel group within the phylum Synergistetes . A novel species in a new genus, Fretibacterium fastidiosum gen. nov., sp. nov., is proposed. The type strain of Fretibacterium fastidiosum is SGP1T ( = DSM 25557T = JCM 16858T).

scholarly journals Host DNA Repair Proteins in Response toPseudomonas aeruginosain Lung Epithelial Cells and in Mice

2010 ◽  
Vol 79 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Min Wu ◽  
Huang Huang ◽  
Weidong Zhang ◽  
Shibichakravarthy Kannan ◽  
Andrew Weaver ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Epithelial Cells ◽  
Critical Role ◽  
Lung Epithelial Cells ◽  
Host Cells ◽  
Myeloperoxidase Activity ◽  
Gram Negative ◽  
Lung Epithelial ◽  
Dna Repair Proteins

ABSTRACTAlthough DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacteriumPseudomonas aeruginosasignificantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection withP. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate thatP. aeruginosainfection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response toP. aeruginosainfection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.

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