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Advances in Experimental Medicine and... 2011Periodontitis is a disease affecting the supporting structures of the teeth. The most severe forms of the disease result in tooth loss and have recently been strongly... (Review)
Review
Periodontitis is a disease affecting the supporting structures of the teeth. The most severe forms of the disease result in tooth loss and have recently been strongly associated with systemic diseases, including cardiovascular and lung diseases and cancer. The disease is caused by biofilms of predominantly anaerobic bacteria. A major pathogen associated with severe, adult forms of the disease is Porphyromonas gingivalis. This organism produces potent cysteine proteases known as gingipains, which have specificity for cleavage after arginine or lysine residues. The lysine-specific gingipain, Kgp, appears to be the major virulence factor of this organism and here we describe its structure and function. We also discuss the inhibitors of the enzyme produced to date and the potential pathways to newer versions of such molecules that will be required to combat periodontitis.
Topics: Adhesins, Bacterial; Bacterial Proteins; Biocatalysis; Cysteine Endopeptidases; Gingipain Cysteine Endopeptidases; Periodontal Diseases; Porphyromonas gingivalis; Protease Inhibitors
PubMed: 21660656
DOI: 10.1007/978-1-4419-8414-2_2 -
Journal of Molecular Biology Dec 2022Porphyromonas gingivalis is a gram-negative oral anaerobic pathogen and is one of the key causative agents of periodontitis. P. gingivalis utilises a range of virulence...
Porphyromonas gingivalis is a gram-negative oral anaerobic pathogen and is one of the key causative agents of periodontitis. P. gingivalis utilises a range of virulence factors, including the cysteine protease RgpB, to drive pathogenesis and these are exported and attached to the cell surface via the type IX secretion system (T9SS). All cargo proteins possess a conserved C-terminal signal domain (CTD) which is recognised by the T9SS, and the outer membrane β-barrel protein PorV (PG0027/LptO) can interact with cargo proteins as they are exported to the bacterial surface. Using a combination of solution nuclear magnetic resonance (NMR) spectroscopy, biochemical analyses, machine-learning-based modelling and molecular dynamics (MD) simulations, we present a structural model of a PorV:RgpB-CTD complex from P. gingivalis. This is the first structural insight into CTD recognition by the T9SS and shows how the conserved motifs in the CTD are the primary sites that mediate binding. In PorV, interactions with extracellular surface loops are important for binding the CTD, and together these appear to cradle and lock RgpB-CTD in place. This work provides insight into cargo recognition by PorV but may also have important implications for understanding other aspects of type-IX dependent secretion.
Topics: Bacterial Proteins; Membrane Proteins; Porphyromonas gingivalis; Virulence Factors; Bacterial Secretion Systems; Molecular Dynamics Simulation; Protein Domains
PubMed: 36404438
DOI: 10.1016/j.jmb.2022.167871 -
Journal of Medical Microbiology Feb 2022Although anaerobic bacteria exist in abundance in cystic fibrosis (CF) airways, their role in disease progression is poorly understood. We hypothesized that the presence...
Although anaerobic bacteria exist in abundance in cystic fibrosis (CF) airways, their role in disease progression is poorly understood. We hypothesized that the presence and relative abundance of the most prevalent, live, anaerobic bacteria in sputum of adults with CF were associated with adverse clinical outcomes. This is the first study to prospectively investigate viable anaerobic bacteria present in the sputum microbiota and their relationship with long-term outcomes in adults with CF. We performed 16S rRNA analysis using a viability quantitative PCR technique on sputum samples obtained from a prospective cohort of 70 adults with CF and collected clinical data over an 8 year follow-up period. We examined the associations of the ten most abundant obligate anaerobic bacteria present in the sputum with annual rate of FEV change. The presence of and were associated with a greater annual rate of FEV change; -52.3 ml yr (95 % CI-87.7;-16.9), -67.9 ml yr (95 % CI-115.6;-20.1), respectively. Similarly, the relative abundance of these live organisms were associated with a greater annual rate of FEV decline of -3.7 ml yr (95 % CI: -6.1 to -1.3, =0.003) and -5.3 ml yr (95 % CI: -8.7 to -1.9, =0.002) for each log increment of abundance, respectively. The presence and relative abundance of certain anaerobes in the sputum of adults with CF are associated with a greater rate of long-term lung function decline. The pathogenicity of anaerobic bacteria in the CF airways should be confirmed with further longitudinal prospective studies with a larger cohort of participants.
Topics: Adult; Cystic Fibrosis; Humans; Lung; Microbiota; Porphyromonas; Prevotella; Prospective Studies; RNA, Ribosomal, 16S; Sputum
PubMed: 35113780
DOI: 10.1099/jmm.0.001481 -
BMJ Open Respiratory Research 2019pulmonary infections are the primary cause of morbi-mortality in patients with cystic fibrosis (CF). In this cohort study, the objective was to identify candidate...
INTRODUCTION
pulmonary infections are the primary cause of morbi-mortality in patients with cystic fibrosis (CF). In this cohort study, the objective was to identify candidate biomarkers of infection within the airway microbiota.
METHODS
A 3-year prospective multicentre study (PYOMUCO study) was conducted in Western France and included patients initially free for at least 1 year. A 16S-targeted metagenomics approach was applied on iterative sputum samples of a first set of patients (n=33). The composition of airway microbiota was compared according to their status at the end of the follow-up (colonised vs non-colonised), and biomarkers associated with were screened. In a second step, the distribution of a candidate biomarker according to the two groups of patients was verified by qPCR on a second set of patients (n=52) coming from the same cohort and its load quantified throughout the follow-up.
RESULTS
(mainly ) was found to be an enriched phylotype in patients uninfected by (p<0.001). This result was confirmed by quantitative PCR. Conversely, in patients who became positive, significantly decreased before acquisition (p=0.014).
DISCUSSION
Further studies on replication cohorts are needed to validate this potential predictive biomarker, which may be relevant for the follow-up in the early years of patients with CF. The identification of infection candidate biomarkers may offer new strategies for CF precision medicine.
Topics: Adolescent; Adult; Biomarkers; Child; Cystic Fibrosis; DNA, Bacterial; Female; Follow-Up Studies; France; Humans; Male; Metagenomics; Microbiota; Porphyromonas; Predictive Value of Tests; Prognosis; Prospective Studies; Pseudomonas Infections; Pseudomonas aeruginosa; RNA, Ribosomal, 16S; Real-Time Polymerase Chain Reaction; Respiratory Mucosa; Sputum; Symbiosis; Young Adult
PubMed: 30956802
DOI: 10.1136/bmjresp-2018-000374 -
Current Protein & Peptide Science Dec 2003Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that is implicated as a major etiologic agent of adult periodontal disease. This bacterium is... (Review)
Review
Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that is implicated as a major etiologic agent of adult periodontal disease. This bacterium is asaccharolytic and possesses strong potency for proteolysis. It produces a novel class of cysteine proteinases, termed gingipains, in the cell-associated and secretory forms. Gingipains consist of arginine-X-specific cysteine proteinases (Arg-gingipains, Rgps) and lysine-X-specific cysteine proteinase (Lys-gingipain, Kgp). Previous studies using various P. gingivalis mutants deficient in Rgp- and/or Kgp-encoding genes have revealed that both enzymes are important for the bacterium both to exhibit its virulence and to survive in periodontal pockets. Mammalian internal proteinase inhibitors such as cystatins, a1-antichymotrypsin, and tissue inhibitor of metalloproteinases (TIMPs) have little or no effects on the proteolytic activities of these enzymes, suggesting the evasion of the bacterium from host defense mechanisms. Recent epidemiological reports have shown a significant relation between periodontal diseases and systemic diseases such as cardiovascular diseases and diabetes. Thus, the development of potent inhibitors specific for gingipains provides new therapeutic approaches to treat periodontal diseases and the related systemic diseases. More recently, we have developed novel synthetic inhibitors specific for Rgp and Kgp, based on the specificity and efficacy of cleavage of histatins by each enzyme. We have also isolated a novel and potent inhibitor of Rgp from the culture supernatant of Streptomyces species strain FA-70, now designated as FA-70C1. Here we summarized the usefulness of these new inhibitors in providing a broader application in studies of this important class of enzymes.
Topics: Adhesins, Bacterial; Animals; Capillary Permeability; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Gingipain Cysteine Endopeptidases; Hemagglutinins; Humans; Porphyromonas gingivalis; Virulence
PubMed: 14683430
DOI: 10.2174/1389203033486992 -
Microbiology and Molecular Biology... Dec 1998Porphyromonas gingivalis, a gram-negative anaerobe, is a major etiological agent in the initiation and progression of severe forms of periodontal disease. An... (Review)
Review
Porphyromonas gingivalis, a gram-negative anaerobe, is a major etiological agent in the initiation and progression of severe forms of periodontal disease. An opportunistic pathogen, P. gingivalis can also exist in commensal harmony with the host, with disease episodes ensuing from a shift in the ecological balance within the complex periodontal microenvironment. Colonization of the subgingival region is facilitated by the ability to adhere to available substrates such as adsorbed salivary molecules, matrix proteins, epithelial cells, and bacteria that are already established as a biofilm on tooth and epithelial surfaces. Binding to all of these substrates may be mediated by various regions of P. gingivalis fimbrillin, the structural subunit of the major fimbriae. P. gingivalis is an asaccharolytic organism, with a requirement for hemin (as a source of iron) and peptides for growth. At least three hemagglutinins and five proteinases are produced to satisfy these requirements. The hemagglutinin and proteinase genes contain extensive regions of highly conserved sequences, with posttranslational processing of proteinase gene products contributing to the formation of multimeric surface protein-adhesin complexes. Many of the virulence properties of P. gingivalis appear to be consequent to its adaptations to obtain hemin and peptides. Thus, hemagglutinins participate in adherence interactions with host cells, while proteinases contribute to inactivation of the effector molecules of the immune response and to tissue destruction. In addition to direct assault on the periodontal tissues, P. gingivalis can modulate eucaryotic cell signal transduction pathways, directing its uptake by gingival epithelial cells. Within this privileged site, P. gingivalis can replicate and impinge upon components of the innate host defense. Although a variety of surface molecules stimulate production of cytokines and other participants in the immune response, P. gingivalis may also undertake a stealth role whereby pivotal immune mediators are selectively inactivated. In keeping with its strict metabolic requirements, regulation of gene expression in P. gingivalis can be controlled at the transcriptional level. Finally, although periodontal disease is localized to the tissues surrounding the tooth, evidence is accumulating that infection with P. gingivalis may predispose to more serious systemic conditions such as cardiovascular disease and to delivery of preterm infants.
Topics: Animals; Bacteroidaceae Infections; Gene Expression Regulation, Bacterial; Humans; Periodontal Diseases; Periodontium; Porphyromonas gingivalis; Virulence
PubMed: 9841671
DOI: 10.1128/MMBR.62.4.1244-1263.1998 -
Journal of Periodontal Research Nov 1999The strategies used by bacterial pathogens to establish and maintain themselves in the host represent one of the fundamental aspects of microbial pathogenesis.... (Review)
Review
The strategies used by bacterial pathogens to establish and maintain themselves in the host represent one of the fundamental aspects of microbial pathogenesis. Characterization of these strategies and the underlying molecular machinery offers new opportunities both to our understanding of how organisms cause disease in susceptible individuals and to the development of novel therapeutic measures designed to undermine or interfere with these determinants of successful survival. With respect to the microbial aetiology of the periodontal diseases, a growing body of evidence suggests that the proteolytic enzymes of Porphyromonas gingivalis represent key survival and, by extrapolation, virulence determinants of this periodontal bacterium. This in turn has led to international efforts to characterize these enzymes at the gene and protein level. Approximately 20 protease genes of P. gingivalis with different names and accession numbers have been deposited in the gene databases and a correspondingly heterogeneous nomenclature system is employed for the products of these genes in the literature. However, it is evident, through comparison of these gene sequences and through gene inactivation studies, that the genetic structure of the proteases of this organism, particularly those with specificity for arginyl and lysyl peptide bonds, is less complicated than originally thought. The major extracellular and surface associated arginine specific protease activity is encoded by 2 genes which we recommend be designated rgpA and rgpB (arg-gingipains A & B). Similarly we recommend that the gene encoding the major lysine specific protease activity is designated kgp (lys-gingipain). These three genes, which account for all the extracellular/surface arginine and lysine protease activity in P. gingivalis, belong to a family of sequence-related proteases and haemagglutinins.
Topics: Amino Acid Sequence; Endopeptidases; Genes, Bacterial; Humans; Isoenzymes; Molecular Biology; Molecular Sequence Data; Mutagenesis; Porphyromonas; Terminology as Topic; Virulence
PubMed: 10697803
DOI: 10.1111/j.1600-0765.1999.tb02282.x -
International Journal of Systematic and... Aug 2015A bacterial strain, designated KUFDS01T, isolated from human saliva was characterized using a polyphasic taxonomic approach that included analysis of physiological and...
A bacterial strain, designated KUFDS01T, isolated from human saliva was characterized using a polyphasic taxonomic approach that included analysis of physiological and biochemical features, cellular fatty acid profiles and phylogenetic position based on 16S rRNA gene sequence analysis. Cells of the strain were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-stain-negative rods. Growth of the strain was inhibited on medium containing 20% bile. The 16S rRNA gene sequence analysis showed that the strain was a member of the genus Porphyromonas. Strain KUFDS01T was closely related to Porphyromonas catoniae JCM 13863T (96.6% sequence similarity). An hsp60 gene sequence analysis indicated that strain KUFDS01T was different from P. catoniae JCM 13863T, with a sequence similarity value of 87.8%. The major cellular fatty acids of strain KUFDS01T were C16 : 0, iso-C15 : 0, anteiso-C15 : 0, C18 : 2ω6, 9c and C18 : 1ω9c. The DNA G+C content of strain KUFDS01T was 57.7 ± 0.66 mol%. On the basis of these data, strain KUFDS01T represents a novel species of the genus Porphyromonas, for which the name Porphyromonas pasteri sp. nov. is proposed. The type strain of P. pasteri is KUFDS01T ( = JCM 30531T = CCUG 66735T).
Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Humans; Molecular Sequence Data; Phylogeny; Porphyromonas; RNA, Ribosomal, 16S; Saliva; Sequence Analysis, DNA
PubMed: 25933621
DOI: 10.1099/ijs.0.000294 -
Journal of Dental Research May 2018Porphyromonas gingivalis is one of the major oral pathogens implicated in the widespread inflammatory disorder periodontitis. Moreover, in recent years, P. gingivalis...
Porphyromonas gingivalis is one of the major oral pathogens implicated in the widespread inflammatory disorder periodontitis. Moreover, in recent years, P. gingivalis has been associated with the autoimmune disease rheumatoid arthritis. The peptidylarginine deiminase enzyme of P. gingivalis (PPAD) is a major virulence factor that catalyzes the citrullination of both bacterial and host proteins, potentially contributing to production of anticitrullinated protein antibodies. Considering that these antibodies are very specific for rheumatoid arthritis, PPAD appears to be a link between P. gingivalis, periodontitis, and the autoimmune disorder rheumatoid arthritis. PPAD was thus far considered unique among prokaryotes, with P. gingivalis being the only bacterium known to produce and secrete it. To challenge this hypothesis, we investigated the possible secretion of PPAD by 11 previously collected Porphyromonas isolates from a dog, 2 sheep, 3 cats, 4 monkeys, and a jaguar with periodontitis. Our analyses uncovered the presence of secreted PPAD homologues in 8 isolates that were identified as Porphyromonas gulae (from a dog, monkeys, and cats) and Porphyromonas loveana (from sheep). In all 3 PPAD-producing Porphyromonas species, the dominant form of the secreted PPAD was associated with outer membrane vesicles, while a minor fraction was soluble. Our results prove for the first time that the citrullinating PPAD exoenzyme is not unique to only 1 prokaryotic species. Instead, we show that PPAD is produced by at least 2 other oral pathogens.
Topics: Animals; Blotting, Western; Cats; Dogs; Electrophoresis, Polyacrylamide Gel; Haplorhini; Panthera; Periodontitis; Phylogeny; Porphyromonas; Porphyromonas gingivalis; Protein-Arginine Deiminases; Sequence Analysis, DNA; Sheep
PubMed: 29298553
DOI: 10.1177/0022034517747575 -
Journal of Oral Biosciences Dec 2020The periodontal pathogen Porphyromonas gingivalis produces gingipains (Kgp, RgpA, and RgpB), cysteine proteases involved in the organism's virulence, and pigmentation....
The periodontal pathogen Porphyromonas gingivalis produces gingipains (Kgp, RgpA, and RgpB), cysteine proteases involved in the organism's virulence, and pigmentation. We previously showed that deletion of the PGN_0297 and PGN_0300 genes reduced the proteolytic activity of gingipains. The role of the PGN_0296 gene, consisting of an operon with the PGN_0297 and PGN_0300 genes, is unclear. Herein, we examined the effect of PGN_0296 gene deletion on the proteolytic activity. Although the proteolytic activity of the gingipains did not decrease in the culture supernatant of a PGN_0296 gene deletion mutant (ΔPGN_0296), the growth was delayed.
Topics: Adhesins, Bacterial; Cysteine Endopeptidases; Gingipain Cysteine Endopeptidases; Hemagglutinins; Porphyromonas gingivalis
PubMed: 33038516
DOI: 10.1016/j.job.2020.09.007