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Pham C, Guo S, Han X, Coleman L, Sze CW, Wang H, Liu J, Li C. A pleiotropic role of sialidase in the pathogenicity of Porphyromonas gingivalis. Infect Immun 2024; 92:e0034423. [PMID: 38376159 PMCID: PMC10929438 DOI: 10.1128/iai.00344-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/01/2024] [Indexed: 02/21/2024] Open
Abstract
As one of the keystone pathogens of periodontitis, the oral bacterium Porphyromonas gingivalis produces an array of virulence factors, including a recently identified sialidase (PG0352). Our previous report involving loss-of-function studies indicated that PG0352 plays an important role in the pathophysiology of P. gingivalis. However, this report had not been corroborated by gain-of-function studies or substantiated in different P. gingivalis strains. To fill these gaps, herein we first confirm the role of PG0352 in cell surface structures (e.g., capsule) and serum resistance using P. gingivalis W83 strain through genetic complementation and then recapitulate these studies using P. gingivalis ATCC33277 strain. We further investigate the role of PG0352 and its counterpart (PGN1608) in ATCC33277 in cell growth, biofilm formation, neutrophil killing, cell invasion, and P. gingivalis-induced inflammation. Our results indicate that PG0352 and PGN1608 are implicated in P. gingivalis cell surface structures, hydrophobicity, biofilm formation, resistance to complement and neutrophil killing, and host immune responses. Possible molecular mechanisms involved are also discussed. In summary, this report underscores the importance of sialidases in the pathophysiology of P. gingivalis and opens an avenue to elucidate their underlying molecular mechanisms.
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Affiliation(s)
- Christopher Pham
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shuaiqi Guo
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Xiao Han
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Laurynn Coleman
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ching Wooen Sze
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Huizhi Wang
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Chunhao Li
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, USA
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Śmiga M, Ślęzak P, Olczak T. Comparative analysis of Porphyromonas gingivalis A7436 and ATCC 33277 strains reveals differences in the expression of heme acquisition systems. Microbiol Spectr 2024; 12:e0286523. [PMID: 38289063 PMCID: PMC10913741 DOI: 10.1128/spectrum.02865-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 12/15/2023] [Indexed: 03/06/2024] Open
Abstract
Porphyromonas gingivalis strains exhibit different phenotypes in vitro, different virulence potential in animal models, and different associations with human diseases, with strains classified as virulent/more virulent (e.g., A7436 and W83) or as less virulent/avirulent (e.g., ATCC 33277). In this study, we comparatively analyzed the A7436 and ATCC 33277 strains to better understand their variability. Global gene expression analysis in response to heme and iron limitation revealed more pronounced differences in the A7436 than in the ATCC 33277 strain; however, in both strains, the largest changes were observed in genes encoding hypothetical proteins, genes whose products participate in energy metabolism, and in genes encoding proteins engaged in transport and binding proteins. Our results confirmed that variability between P. gingivalis strains is due to differences in the arrangement of their genomes. Analysis of gene expression of heme acquisition systems demonstrated that not only the availability of iron and heme in the external environment but also the ability to store iron intracellularly can influence the P. gingivalis phenotype. Therefore, we assume that differences in virulence potential may also be due to differences in the production of systems involved in iron and heme acquisition, mainly the Hmu system. In addition, our study showed that hemoglobin, in a concentration-dependent manner, differentially influences the virulence potential of P. gingivalis strains. We conclude that iron and heme homeostasis may add to the variability observed between P. gingivalis strains. IMPORTANCE Periodontitis belongs to a group of multifactorial diseases, characterized by inflammation and destruction of tooth-supporting tissues. P. gingivalis is one of the most important microbial factors involved in the initiation and progression of periodontitis. To survive in the host, the bacterium must acquire heme as a source of iron and protoporphyrin IX. P. gingivalis strains respond differently to changing iron and heme concentrations, which may be due to differences in the expression of systems involved in iron and heme acquisition. The ability to accumulate iron intracellularly, being different in more and less virulent P. gingivalis strains, may influence their phenotypes, production of virulence factors (including proteins engaged in heme acquisition), and virulence potential of this bacterium.
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Affiliation(s)
- Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Paulina Ślęzak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
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Clark ND, Pham C, Kurniyati K, Sze CW, Coleman L, Fu Q, Zhang S, Malkowski MG, Li C. Functional and structural analyses reveal that a dual domain sialidase protects bacteria from complement killing through desialylation of complement factors. PLoS Pathog 2023; 19:e1011674. [PMID: 37747935 PMCID: PMC10553830 DOI: 10.1371/journal.ppat.1011674] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/05/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023] Open
Abstract
The complement system is the first line of innate immune defense against microbial infections. To survive in humans and cause infections, bacterial pathogens have developed sophisticated mechanisms to subvert the complement-mediated bactericidal activity. There are reports that sialidases, also known as neuraminidases, are implicated in bacterial complement resistance; however, its underlying molecular mechanism remains elusive. Several complement proteins (e.g., C1q, C4, and C5) and regulators (e.g., factor H and C4bp) are modified by various sialoglycans (glycans with terminal sialic acids), which are essential for their functions. This report provides both functional and structural evidence that bacterial sialidases can disarm the complement system via desialylating key complement proteins and regulators. The oral bacterium Porphyromonas gingivalis, a "keystone" pathogen of periodontitis, produces a dual domain sialidase (PG0352). Biochemical analyses reveal that PG0352 can desialylate human serum and complement factors and thus protect bacteria from serum killing. Structural analyses show that PG0352 contains a N-terminal carbohydrate-binding module (CBM) and a C-terminal sialidase domain that exhibits a canonical six-bladed β-propeller sialidase fold with each blade composed of 3-4 antiparallel β-strands. Follow-up functional studies show that PG0352 forms monomers and is active in a broad range of pH. While PG0352 can remove both N-acetylneuraminic acid (Neu5Ac) and N-glycolyl-neuraminic acid (Neu5Gc), it has a higher affinity to Neu5Ac, the most abundant sialic acid in humans. Structural and functional analyses further demonstrate that the CBM binds to carbohydrates and serum glycoproteins. The results shown in this report provide new insights into understanding the role of sialidases in bacterial virulence and open a new avenue to investigate the molecular mechanisms of bacterial complement resistance.
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Affiliation(s)
- Nicholas D. Clark
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York, United States of America
| | - Christopher Pham
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kurni Kurniyati
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ching Wooen Sze
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Laurynn Coleman
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Qin Fu
- Proteomics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America
| | - Sheng Zhang
- Proteomics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America
| | - Michael G. Malkowski
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York, United States of America
| | - Chunhao Li
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
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Uriarte SM, Hajishengallis G. Neutrophils in the periodontium: Interactions with pathogens and roles in tissue homeostasis and inflammation. Immunol Rev 2023; 314:93-110. [PMID: 36271881 PMCID: PMC10049968 DOI: 10.1111/imr.13152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neutrophils are of key importance in periodontal health and disease. In their absence or when they are functionally defective, as occurs in certain congenital disorders, affected individuals develop severe forms of periodontitis in early age. These observations imply that the presence of immune-competent neutrophils is essential to homeostasis. However, the presence of supernumerary or hyper-responsive neutrophils, either because of systemic priming or innate immune training, leads to imbalanced host-microbe interactions in the periodontium that culminate in dysbiosis and inflammatory tissue breakdown. These disease-provoking imbalanced interactions are further exacerbated by periodontal pathogens capable of subverting neutrophil responses to their microbial community's benefit and the host's detriment. This review attempts a synthesis of these findings for an integrated view of the neutrophils' ambivalent role in periodontal disease and, moreover, discusses how some of these concepts underpin the development of novel therapeutic approaches to treat periodontal disease.
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Affiliation(s)
- Silvia M. Uriarte
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
| | - George Hajishengallis
- Department of Basic and Translational Sciences, Laboratory of Innate Immunity and Inflammation, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Shaughnessy J, Chabeda A, Lewis LA, Ram S. Alternative pathway amplification and infections. Immunol Rev 2023; 313:162-180. [PMID: 36336911 DOI: 10.1111/imr.13160] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The alternative pathway (AP) is the phylogenetically oldest arm of the complement system and may have evolved to mark pathogens for elimination by phagocytes. Studies using purified AP proteins or AP-specific serum showed that C3b amplification on bacteria commenced following a lag phase of about 5 min and was highly dependent on the concentration of complement. Most pathogens have evolved several elegant mechanisms to evade complement, including expressing proteases that degrade AP proteins and secreting proteins that block function of C3 convertases. In an example of convergent evolution, many microbes recruit the AP inhibitor factor H (FH) using molecular mechanisms that mimic FH interactions with host cells. In most instances, the AP serves to amplify C3b deposited on microbes by the classical pathway (CP). The role of properdin on microbes appears to be restricted to stabilization of C3 convertases; scant evidence exists for its role as an initiator of the AP on pathogens in the context of serum. Therapeutic complement inhibition carries with it an increased risk of infection. Antibody (Ab)-dependent AP activation may be critical for complement activation by vaccine-elicited Ab when the CP is blocked, and its molecular mechanism is discussed.
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Affiliation(s)
- Jutamas Shaughnessy
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Aleyo Chabeda
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Lisa A Lewis
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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Porphyromonas gingivalis resistance and virulence: An integrated functional network analysis. Gene 2022; 839:146734. [PMID: 35835406 DOI: 10.1016/j.gene.2022.146734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/23/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND The gram-negative bacteria Porphyromonas gingivalis (PG) is the most prevalent cause of periodontal diseases and multidrug-resistant (MDR) infections. Periodontitis and MDR infections are severe due to PG's ability to efflux antimicrobial and virulence factors. This gives rise to colonisation, biofilm development, evasion, and modulation of the host defence system. Despite extensive studies on the MDR efflux pump in other pathogens, little is known about the efflux pump and its association with the virulence factor in PG. Prolonged infection of PG leads to complete loss of teeth and other systemic diseases. This necessitates the development of new therapeutic interventions to prevent and control MDR. OBJECTIVE The study aims to identify the most indispensable proteins that regulate both resistance and virulence in PG, which could therefore be used as a target to fight against the MDR threat to antibiotics. METHODS We have adopted a hierarchical network-based approach to construct a protein interaction network. Firstly, individual networks of four major efflux pump proteins and two virulence regulatory proteins were constructed, followed by integrating them into one. The relationship between proteins was investigated using a combination of centrality scores, k-core network decomposition, and functional annotation, to computationally identify the indispensable proteins. RESULTS Our study identified four topologically significant genes, PG_0538, PG_0539, PG_0285, and PG_1797, as potential pharmacological targets. PG_0539 and PG_1797 were identified to have significant associations between the efflux pump and virulence genes. This type of underpinning research may help in narrowing the drug spectrum used for treating periodontal diseases, and may also be exploited to look into antibiotic resistance and pathogenicity in bacteria other than PG.
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Moradali MF, Ghods S, Bähre H, Lamont RJ, Scott DA, Seifert R. Atypical cyclic di-AMP signaling is essential for Porphyromonas gingivalis growth and regulation of cell envelope homeostasis and virulence. NPJ Biofilms Microbiomes 2022; 8:53. [PMID: 35794154 PMCID: PMC9259658 DOI: 10.1038/s41522-022-00316-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/13/2022] [Indexed: 02/04/2023] Open
Abstract
Microbial pathogens employ signaling systems through cyclic (di-) nucleotide monophosphates serving as second messengers to increase fitness during pathogenesis. However, signaling schemes via second messengers in Porphyromonas gingivalis, a key Gram-negative anaerobic oral pathogen, remain unknown. Here, we report that among various ubiquitous second messengers, P. gingivalis strains predominantly synthesize bis-(3',5')-cyclic di-adenosine monophosphate (c-di-AMP), which is essential for their growth and survival. Our findings demonstrate an unusual regulation of c-di-AMP synthesis in P. gingivalis. P. gingivalis c-di-AMP phosphodiesterase (PDE) gene (pdepg) positively regulates c-di-AMP synthesis and impedes a decrease in c-di-AMP concentration despite encoding conserved amino acid motifs for phosphodiesterase activity. Instead, the predicted regulator gene cdaR, unrelated to the c-di-AMP PDE genes, serves as a potent negative regulator of c-di-AMP synthesis in this anaerobe. Further, our findings reveal that pdepg and cdaR are required to regulate the incorporation of ATP into c-di-AMP upon pyruvate utilization, leading to enhanced biofilm formation. We show that shifts in c-di-AMP signaling change the integrity and homeostasis of cell envelope, importantly, the structure and immunoreactivity of the lipopolysaccharide layer. Additionally, microbe-microbe interactions and the virulence potential of P. gingivalis were modulated by c-di-AMP. These studies provide the first glimpse into the scheme of second messenger signaling in P. gingivalis and perhaps other Bacteroidetes. Further, our findings indicate that c-di-AMP signaling promotes the fitness of the residents of the oral cavity and the development of a pathogenic community.
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Affiliation(s)
- M Fata Moradali
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA.
| | - Shirin Ghods
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - Heike Bähre
- Research Core Unit Metabolomics, Hannover Medical School, Hanover, Germany
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - David A Scott
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - Roland Seifert
- Research Core Unit Metabolomics, Hannover Medical School, Hanover, Germany
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Kim HM, Ranjit DK, Walker AR, Getachew H, Progulske-Fox A, Davey ME. A Novel Regulation of K-antigen Capsule Synthesis in Porphyromonas gingivalis Is Driven by the Response Regulator PG0720-Directed Antisense RNA. FRONTIERS IN ORAL HEALTH 2022; 2:701659. [PMID: 35048039 PMCID: PMC8757827 DOI: 10.3389/froh.2021.701659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
The periodontal pathogen Porphyromonas gingivalis strain W83 displays at least three different surface glycans, specifically two types of lipopolysaccharides (O-LPS and A-LPS) and K-antigen capsule. Despite the importance of K-antigen capsule to the virulence of P. gingivalis, little is known as to how expression of genes involved in the synthesis of this surface glycan is regulated. The genes required for K-antigen capsule synthesis are located in a locus that encodes a number of transcripts, including an operon (PG0104 to PG0121, generating ~19.4-kb transcript) which contains a non-coding 77-bp inverted repeat (77 bpIR) region near the 5'-end. Previously, we identified a 550-nucleotide antisense RNA molecule (designated asSuGR for antisense Surface Glycan Regulator) encoded within the 77-bpIR element that influences the synthesis of surface glycans. In this study, we demonstrate that the DNA-binding response regulator PG0720 can bind the promoter region of asSuGR and activate expression of asSuGR, indicating that PG0720 may indirectly influence transcript levels of the K-antigen capsule operon expressed from the sense strand. The data show that deletion of the PG0720 gene confers a defect in the presentation of surface polysaccharides compared with the parent strain and quantitative RT-PCR (qPCR) analysis determined that the overall expression of genes involved in K-antigen capsule synthesis were down-regulated in the PG0720 mutant. Furthermore, the defects of the PG0720 deletion mutant were restored by complementation. Importantly, the PG0720 deletion mutant showed reduced virulence. Altogether, our data show that the response regulator PG0720 regulates expression of asSuGR, a trans-acting antisense RNA molecule involved in modulating the production of surface polysaccharides in P. gingivalis strain W83. The data provide further evidence that surface glycans are key virulence determinants and significantly advances our understanding of the molecular mechanisms controlling the synthesis of P. gingivalis K-antigen capsule, a key virulence determinant.
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Affiliation(s)
- Hey-Min Kim
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Dev K Ranjit
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Alejandro R Walker
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Heran Getachew
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Ann Progulske-Fox
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Mary E Davey
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
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Hajishengallis G, Hasturk H, Lambris JD. C3-targeted therapy in periodontal disease: moving closer to the clinic. Trends Immunol 2021; 42:856-864. [PMID: 34483038 PMCID: PMC8487962 DOI: 10.1016/j.it.2021.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/03/2021] [Accepted: 08/06/2021] [Indexed: 02/07/2023]
Abstract
Complement plays a key role in immunosurveillance and homeostasis. When dysregulated or overactivated, complement can become a pathological effector, as seen in several inflammatory disorders, including periodontal disease. Recently, clinical correlative studies and preclinical mechanistic investigations have collectively demonstrated that complement is hyperactivated during periodontitis and that targeting its central component (C3) provides therapeutic benefit in nonhuman primates (NHPs). The preclinical efficacy of a C3-targeted drug candidate combined with excellent safety and pharmacokinetic profiles supported its use in a recent Phase IIa clinical study in which C3 inhibition resolved gingival inflammation in patients with periodontal disease. We posit that C3-targeted intervention might represent a novel and transformative host-modulation therapy meriting further investigation in Phase III clinical trials for the treatment of periodontitis.
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Affiliation(s)
- George Hajishengallis
- University of Pennsylvania, Penn Dental Medicine, Department of Basic and Translational Sciences, Philadelphia, PA, USA.
| | - Hatice Hasturk
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA, USA.
| | - John D Lambris
- University of Pennsylvania, Perelman School of Medicine, Department of Pathology and Laboratory Medicine, Philadelphia, USA.
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Olsen I. Possible effects of Porphyromonas gingivalis on the blood-brain barrier in Alzheimer's disease. Expert Rev Anti Infect Ther 2021; 19:1367-1371. [PMID: 33938372 DOI: 10.1080/14787210.2021.1925540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway,
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Rao A, D'Souza C, Subramanyam K, Rai P, Thomas B, Gopalakrishnan M, Karunasagar I, Kumar BK. Molecular analysis shows the presence of periodontal bacterial DNA in atherosclerotic plaques from patients with coronary artery disease. Indian Heart J 2021; 73:218-220. [PMID: 33865522 PMCID: PMC8065351 DOI: 10.1016/j.ihj.2021.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/10/2020] [Accepted: 01/08/2021] [Indexed: 11/27/2022] Open
Abstract
Links between periodontitis and atherosclerosis can be predicted based on inflammatory mechanisms initiated by bacteria associated with periodontal lesions, which then influence the initiation or propagation of the atherosclerotic lesion. This study aimed to detect the presence of three periodontal pathogens, in atheromatous plaques of patients with coronary artery disease. Subgingival and atherosclerotic plaque samples were obtained from 80 patients scheduled for CABG or angioplasty. A nested PCR was done for the detection of the pathogens in the plaque samples. Porphyromonas gingivalis, Tanarella forsythia, and Treponema denticola were detected in 10%, 12.5%, and 1.3% of the atherosclerotic plaque samples respectively. It was also observed that patients whose atherosclerotic plaques tested positive for one or more of the pathogens had chronic periodontitis.
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Affiliation(s)
- Amita Rao
- Nitte (Deemed to be University), AB Shetty Memorial Institute of Dental Sciences (ABSMIDS), Department of Periodontics, Deralakatte, Mangaluru, 575018, India.
| | - Caroline D'Souza
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research (NUCSER), Division of Infectious Diseases, Deralakatte, Mangaluru, 575018, India
| | - K Subramanyam
- Nitte (Deemed to be University), KS Hegde Medical Academy (KSHEMA), Department of Cardiology, Deralakatte, Mangaluru, 575018, India
| | - Praveen Rai
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research (NUCSER), Division of Infectious Diseases, Deralakatte, Mangaluru, 575018, India
| | - Biju Thomas
- Nitte (Deemed to be University), AB Shetty Memorial Institute of Dental Sciences (ABSMIDS), Department of Periodontics, Deralakatte, Mangaluru, 575018, India
| | - Mundayat Gopalakrishnan
- Nitte (Deemed to be University), KS Hegde Medical Academy (KSHEMA), Department of Cardiothoracic Surgery, Deralakatte, Mangaluru, 575018, India
| | - Indrani Karunasagar
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research (NUCSER), Division of Infectious Diseases, Deralakatte, Mangaluru, 575018, India
| | - Ballamoole Krishna Kumar
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research (NUCSER), Division of Infectious Diseases, Deralakatte, Mangaluru, 575018, India.
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12
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Guo Y, Wang Y, Wang Y, Jin Y, Wang C. Heme Competition Triggers an Increase in the Pathogenic Potential of Porphyromonas gingivalis in Porphyromonas gingivalis-Candida albicans Mixed Biofilm. Front Microbiol 2020; 11:596459. [PMID: 33343538 PMCID: PMC7738433 DOI: 10.3389/fmicb.2020.596459] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022] Open
Abstract
As one of the main pathogens of periodontitis, Porphyromonas gingivalis often forms mixed biofilms with other bacteria or fungi under the gingiva, such as Candida albicans. Heme is an important iron source for P. gingivalis and C. albicans that supports their growth in the host. From the perspective of heme competition, this study aims to clarify that the competition for heme enhances the pathogenic potential of P. gingivalis during the interaction between P. gingivalis and C. albicans. Porphyromonas gingivalis single-species biofilm and P. gingivalis-C. albicans dual-species biofilm were established in a low- and high-heme environment. The results showed that the vitality of P. gingivalis was increased in the dual-species biofilm under the condition of low heme, and the same trend was observed under a laser confocal microscope. Furthermore, the morphological changes in P. gingivalis were observed by electron microscope, and the resistance of P. gingivalis in dual-species biofilm was stronger against the killing effect of healthy human serum and antibiotics. The ability of P. gingivalis to agglutinate erythrocyte was also enhanced in dual-species biofilm. These changes disappeared when heme was sufficient, which confirmed that heme competition was the cause of thepathogenicy change in P. gingivalis. Gene level analysis showed that P. gingivalis was in a superior position in the competition relationship by increasing the expression of heme utilization-related genes, such as HmuY, HmuR, HusA, and Tlr. In addition, the expression of genes encoding gingipains (Kgp, RgpA/B) was also significantly increased. They not only participate in the process of utilizing heme, but also are important components of the virulence factors of P. gingivalis. In conclusion, our results indicated that the pathogenic potential of P. gingivalis was enhanced by C. albicans through heme competition, which ultimately promoted the occurrence and development of periodontitis and, therefore, C. albicans subgingival colonization should be considered as a factor in assessing the risk of periodontitis.
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Affiliation(s)
- Yanyang Guo
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yu Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yijin Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yabing Jin
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Chen Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
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13
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Chugh P, Dutt R, Sharma A, Bhagat N, Dhar MS. A critical appraisal of the effects of probiotics on oral health. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.103985] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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14
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Zeng F, Liu Y, Huang W, Qing H, Kadowaki T, Kashiwazaki H, Ni J, Wu Z. Receptor for advanced glycation end products up-regulation in cerebral endothelial cells mediates cerebrovascular-related amyloid β accumulation after Porphyromonas gingivalis infection. J Neurochem 2020; 158:724-736. [PMID: 32441775 PMCID: PMC8451939 DOI: 10.1111/jnc.15096] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 12/16/2022]
Abstract
Cerebrovascular‐related amyloidogenesis is found in over 80% of Alzheimer's disease (AD) cases, and amyloid β (Aβ) generation is increased in the peripheral macrophages during infection of Porphyromonas gingivalis (P. gingivalis), a causal bacterium for periodontitis. In this study, we focused on receptor for advanced glycation end products (RAGE), the key molecule involves in Aβ influx after P. gingivalis infection to test our hypothesis that Aβ transportation from periphery into the brain, known as “Aβ influx,” is enhanced by P. gingivalis infection. Using cultured hCMEC/D3 cell line, in comparison to uninfected cells, directly infection with P. gingivalis (multiplicity of infection, MOI = 5) significantly increased a time‐dependent RAGE expression resulting in a dramatic increase in Aβ influx in the hCMEC/D3 cells; the P. gingivalis‐up‐regulated RAGE expression was significantly decreased by NF‐κB and Cathepsin B (CatB)‐specific inhibitors, and the P.gingivalis‐increased IκBα degradation was significantly decreased by CatB‐specific inhibitor. Furthermore, the P. gingivalis‐increased Aβ influx was significantly reduced by RAGE‐specific inhibitor. Using 15‐month‐old mice (C57BL/6JJmsSlc, female), in comparison to non‐infection mice, systemic P. gingivalis infection for three consecutive weeks (1 × 108 CFU/mouse, every 3 days, intraperitoneally) significantly increased the RAGE expression in the CD31‐positive endothelial cells and the Aβ loads around the CD31‐positive cells in the mice's brains. The RAGE expression in the CD31‐positive cells was positively correlated with the Aβ loads. These observations demonstrate that the up‐regulated RAGE expression in cerebral endothelial cells mediates the Aβ influx after P. gingivalis infection, and CatB plays a critical role in regulating the NF‐κB/RAGE expression.
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Affiliation(s)
- Fan Zeng
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan
| | - Yicong Liu
- The Affiliated Stomatology Hospital, School of Medical, Zhejiang University, Zhejiang, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, School of Stomatology, Zhejiang University, Zhejiang, China
| | - Wanyi Huang
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Tomoko Kadowaki
- Division of Frontier Life Science, Department of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Haruhiko Kashiwazaki
- Section of Geriatric Dentistry and Perioperative Medicine in Dentistry, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Junjun Ni
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan.,Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Zhou Wu
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan.,Faculty of Dental Science, OBT Research Center, Kyushu University, Fukuoka, Japan
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15
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Zeng F, Liu Y, Huang W, Qing H, Kadowaki T, Kashiwazaki H, Ni J, Wu Z. Receptor for advanced glycation end products up-regulation in cerebral endothelial cells mediates cerebrovascular-related amyloid β accumulation after Porphyromonas gingivalis infection. J Neurochem 2020. [PMID: 32441775 DOI: 10.1111/jnc.15073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cerebrovascular-related amyloidogenesis is found in over 80% of Alzheimer's disease (AD) cases, and amyloid β (Aβ) generation is increased in the peripheral macrophages during infection of Porphyromonas gingivalis (P. gingivalis), a causal bacterium for periodontitis. In this study, we focused on receptor for advanced glycation end products (RAGE), the key molecule involves in Aβ influx after P. gingivalis infection to test our hypothesis that Aβ transportation from periphery into the brain, known as "Aβ influx," is enhanced by P. gingivalis infection. Using cultured hCMEC/D3 cell line, in comparison to uninfected cells, directly infection with P. gingivalis (multiplicity of infection, MOI = 5) significantly increased a time-dependent RAGE expression resulting in a dramatic increase in Aβ influx in the hCMEC/D3 cells; the P. gingivalis-up-regulated RAGE expression was significantly decreased by NF-κB and Cathepsin B (CatB)-specific inhibitors, and the P.gingivalis-increased IκBα degradation was significantly decreased by CatB-specific inhibitor. Furthermore, the P. gingivalis-increased Aβ influx was significantly reduced by RAGE-specific inhibitor. Using 15-month-old mice (C57BL/6JJmsSlc, female), in comparison to non-infection mice, systemic P. gingivalis infection for three consecutive weeks (1 × 108 CFU/mouse, every 3 days, intraperitoneally) significantly increased the RAGE expression in the CD31-positive endothelial cells and the Aβ loads around the CD31-positive cells in the mice's brains. The RAGE expression in the CD31-positive cells was positively correlated with the Aβ loads. These observations demonstrate that the up-regulated RAGE expression in cerebral endothelial cells mediates the Aβ influx after P. gingivalis infection, and CatB plays a critical role in regulating the NF-κB/RAGE expression. Cover Image for this issue: https://doi.org/10.1111/jnc.15073.
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Affiliation(s)
- Fan Zeng
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan
| | - Yicong Liu
- The Affiliated Stomatology Hospital, School of Medical, Zhejiang University, Zhejiang, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, School of Stomatology, Zhejiang University, Zhejiang, China
| | - Wanyi Huang
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Tomoko Kadowaki
- Division of Frontier Life Science, Department of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Haruhiko Kashiwazaki
- Section of Geriatric Dentistry and Perioperative Medicine in Dentistry, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Junjun Ni
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan.,Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Zhou Wu
- Department of Aging Science and Pharmacology, Kyushu University, Fukuoka, Japan.,Faculty of Dental Science, OBT Research Center, Kyushu University, Fukuoka, Japan
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16
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OmpA-Like Proteins of Porphyromonas gingivalis Mediate Resistance to the Antimicrobial Peptide LL-37. J Pathog 2018; 2018:2068435. [PMID: 30687554 PMCID: PMC6327258 DOI: 10.1155/2018/2068435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/30/2018] [Accepted: 12/09/2018] [Indexed: 11/29/2022] Open
Abstract
Subgingival bacteria are continually exposed to gingival crevicular fluids that are derived from serum, which contain various bactericidal agents. The periodontopathic bacterium Porphyromonas gingivalis has been demonstrated to possess a variety of abilities to resist bactericidal agents, due to which it is able to propagate in the subgingival environment. We previously demonstrated that the major surface glycoproteins of P. gingivalis—Pgm6 and Pgm7, also called outer membrane protein A-like proteins (OmpALPs)—mediate resistance to the bactericidal activity of human serum, but their precise role remains unknown. In this study, we investigated the sensitivity of the wild-type and Pgm6/Pgm7-deficient P. gingivalis strains toward major antimicrobial peptides in the oral cavity, human β-defensins (hBDs) 1-3, and human cathelicidin LL-37. hBDs showed a considerably weak bactericidal activity against both bacterial strains. LL-37 also showed a weak activity against the wild-type strain; however, it showed a significant activity against the Pgm6/Pgm7-deficient strain. In the Pgm6/Pgm7-deficient strain, LL-37 remarkably accumulated on the bacterial cell surface, which may result in the destruction of the outer membrane. Additionally, the bactericidal activity of hBDs against the Pgm6/Pgm7-deficient strain was found to be synergistically promoted in the presence of LL-37. Our results suggest that OmpALPs specifically protect P. gingivalis from the bactericidal activity of LL-37; thus, P. gingivalis may adeptly survive in LL-37-producing subgingival environments.
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17
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Phosphatidylinositol 3-Kinase/Akt signal pathway resists the apoptosis and inflammation in human extravillous trophoblasts induced by Porphyromonas gingivalis. Mol Immunol 2018; 104:100-107. [DOI: 10.1016/j.molimm.2018.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 09/28/2018] [Accepted: 10/01/2018] [Indexed: 12/14/2022]
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18
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OmpA-like proteins of Porphyromonas gingivalis contribute to serum resistance and prevent Toll-like receptor 4-mediated host cell activation. PLoS One 2018; 13:e0202791. [PMID: 30153274 PMCID: PMC6112661 DOI: 10.1371/journal.pone.0202791] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/09/2018] [Indexed: 12/03/2022] Open
Abstract
Porphyromonas gingivalis possesses various abilities to evade and disrupt host immune responses, by which it acts as an important periodontal pathogen. P. gingivalis produces outer membrane protein A (OmpA)-like proteins (OmpALPs), Pgm6 and Pgm7, as major O-linked glycoproteins, but their pathological roles in P. gingivalis infection are largely unknown. Here, we report that OmpALP-deficient strains of P. gingivalis show an enhanced stimulatory activity in coculture with host cells. Such an altered ability of the OmpALP-deficient strains was found to be due to their impaired survival in coculture and the release of LPS from dead bacterial cells to stimulate Toll-like receptor 4 (TLR4). Further analyses revealed that the OmpALP-deficient strains were inviable in serum-containing media although they grew normally in the bacterial medium. The wild-type strain was able to grow in 90% normal human serum, while the OmpALP-deficient strains did not survive even at 5%. The OmpALP-deficient strains did not survive in heat-inactivated serum, but they gained the ability to survive and grow in proteinase K-treated serum. Of note, the sensitivity of the OmpALP-deficient strains to the bactericidal activity of human β-defensin 3 was increased as compared with the WT. Thus, this study suggests that OmpALPs Pgm6 and Pgm7 are important for serum resistance of P. gingivalis. These proteins prevent bacterial cell destruction by serum and innate immune recognition by TLR4; this way, P. gingivalis may adeptly colonize serum-containing gingival crevicular fluids and subgingival environments.
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19
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Olsen I, Singhrao SK. Importance of heterogeneity in Porhyromonas gingivalis lipopolysaccharide lipid A in tissue specific inflammatory signalling. J Oral Microbiol 2018; 10:1440128. [PMID: 29503705 PMCID: PMC5827638 DOI: 10.1080/20002297.2018.1440128] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/09/2018] [Indexed: 02/08/2023] Open
Abstract
Lipopolysaccharide (LPS) of Porphyromonas gingivalis exists in at least two known forms, O-LPS and A-LPS. A-LPS shows heterogeneity in which two isoforms designated LPS1,435/1,449 and LPS1,690 appear responsible for tissue-specific immune signalling pathways activation and increased virulence. The modification of lipid A to tetra-acylated1,435/1,449 and/or penta-acylated1,690 fatty acids indicates poor growth conditions and bioavailability of hemin. Hemin protects P. gingivalis from serum resistance and the lipid A serves as a site for its binding. The LPS1,435/1,449 and LPS1,690 isoforms can produce opposite effects on the human Toll-like receptors (TLR) TLR2 and TLR4 activation. This enables P. gingivalis to select the conditions for its entry, survival, and that of its co-habiting species in the host, orchestrating its virulence to control innate immune pathway activation and biofilm dysbiosis. This review describes a number of effects that LPS1,435/1,449 and LPS1,690 can exert on the host tissues such as deregulation of the innate immune system, subversion of host cell autophagy, regulation of outer membrane vesicle production, and adverse effects on pregnancy outcome. The ability to change its LPS1,435/1,449 and/or LPS1,690 composition may enable P. gingivalis to paralyze local pro-inflammatory cytokine production, thereby gaining access to its primary location in periodontal tissue.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Sim K. Singhrao
- Dementia and Neurodegenerative Diseases Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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20
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Shoji M, Sato K, Yukitake H, Kamaguchi A, Sasaki Y, Naito M, Nakayama K. Identification of genes encoding glycosyltransferases involved in lipopolysaccharide synthesis inPorphyromonas gingivalis. Mol Oral Microbiol 2017; 33:68-80. [DOI: 10.1111/omi.12200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2017] [Indexed: 12/16/2022]
Affiliation(s)
- M. Shoji
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - K. Sato
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - H. Yukitake
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - A. Kamaguchi
- Department of Oral Microbiology; School of Dentistry; Health Sciences University of Hokkaido; Hokkaido Japan
| | - Y. Sasaki
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - M. Naito
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - K. Nakayama
- Department of Microbiology and Oral Infection; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
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21
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Rangarajan M, Aduse‐Opoku J, Paramonov N, Hashim A, Curtis M. Hemin binding by Porphyromonas gingivalis strains is dependent on the presence of A-LPS. Mol Oral Microbiol 2017; 32:365-374. [PMID: 28107612 PMCID: PMC5600137 DOI: 10.1111/omi.12178] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 11/29/2022]
Abstract
Porphyromonas gingivalis is a Gram-negative black pigmenting anaerobe that is unable to synthesize heme [Fe(II)-protoporphyrin IX] or hemin [Fe(III)-protoporphyrin IX-Cl], which are important growth/virulence factors, and must therefore derive them from the host. Porphyromonas gingivalis expresses several proteinaceous hemin-binding sites, which are important in the binding/transport of heme/hemin from the host. It also synthesizes several virulence factors, namely cysteine-proteases Arg- and Lys-gingipains and two lipopolysaccharides (LPS), O-LPS and A-LPS. The gingipains are required for the production of the black pigment, μ-oxo-bisheme {[Fe(III)PPIX]2 O}, which is derived from hemoglobin and deposited on the bacterial cell-surface leading to the characteristic black colonies when grown on blood agar. In this study we investigated the role of LPS in the deposition of μ-oxo-bisheme on the cell-surface. A P. gingivalis mutant defective in the biosynthesis of Arg-gingipains, namely rgpA/rgpB, produces brown colonies on blood agar and mutants defective in Lys-gingipain (kgp) and LPS biosynthesis namely porR, waaL, wzy, and pg0129 (α-1, 3-mannosyltransferase) produce non-pigmented colonies. However, only those mutants lacking A-LPS showed reduced hemin-binding when cells in suspension were incubated with hemin. Using native, de-O-phosphorylated and de-lipidated LPS from P. gingivalis W50 and porR strains, we demonstrated that hemin-binding to O-polysaccharide (PS) and to the lipid A moiety of LPS was reduced compared with hemin-binding to A-PS. We conclude that A-LPS in the outer-membrane of P. gingivalis serves as a scaffold/anchor for the retention of μ-oxo-bisheme on the cell surface and pigmentation is dependent on the presence of A-LPS.
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Affiliation(s)
- M. Rangarajan
- Institute of DentistryBarts and The London School of Medicine & DentistryQueen Mary University of LondonLondonUK
| | - J. Aduse‐Opoku
- Institute of DentistryBarts and The London School of Medicine & DentistryQueen Mary University of LondonLondonUK
| | - N.A. Paramonov
- Institute of DentistryBarts and The London School of Medicine & DentistryQueen Mary University of LondonLondonUK
| | - A. Hashim
- Institute of DentistryBarts and The London School of Medicine & DentistryQueen Mary University of LondonLondonUK
- College of DentistryKing Faisal UniversityAl‐AhsaSaudi Arabia
| | - M.A. Curtis
- Institute of DentistryBarts and The London School of Medicine & DentistryQueen Mary University of LondonLondonUK
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22
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Veith PD, Glew MD, Gorasia DG, Reynolds EC. Type IX secretion: the generation of bacterial cell surface coatings involved in virulence, gliding motility and the degradation of complex biopolymers. Mol Microbiol 2017; 106:35-53. [DOI: 10.1111/mmi.13752] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Paul D. Veith
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Michelle D. Glew
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Dhana G. Gorasia
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Eric C. Reynolds
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
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23
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Olsen I, Lambris JD, Hajishengallis G. Porphyromonas gingivalis disturbs host-commensal homeostasis by changing complement function. J Oral Microbiol 2017; 9:1340085. [PMID: 28748042 PMCID: PMC5508361 DOI: 10.1080/20002297.2017.1340085] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/06/2017] [Indexed: 02/07/2023] Open
Abstract
Porphyromonas gingivalis is a Gram-negative anaerobic rod that has been proposed as an orchestrator of complement-dependent dysbiotic inflammation. This notion was suggested from its capacities to manipulate the complement–Toll-like receptor crosstalk in ways that promote dysbiosis and periodontal disease in animal models. Specifically, while at low colonization levels, P. gingivalis interferes with innate immunity and leads to changes in the counts and composition of the oral commensal microbiota. The resulting dysbiotic microbial community causes disruption of host–microbial homeostasis, leading to inflammatory bone loss. These findings suggested that P. gingivalis can be considered as a keystone pathogen. The concept of keystone pathogens is one where their effects have community-wide significance and are disproportionate of their abundance. The present review summarizes the relevant literature and discusses whether the results from the animal models can be extrapolated to man.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - George Hajishengallis
- Department of Microbiology, School of Dental Medicine; University of Pennsylvania, PA, USA
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24
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Moriguchi K, Hasegawa Y, Higuchi N, Murakami Y, Yoshimura F, Nakata K, Honda M. Energy dispersive spectroscopy-scanning transmission electron microscope observations of free radical production in human polymorphonuclear leukocytes phagocytosing non-opsonized Tannerella forsythia. Microsc Res Tech 2017; 80:555-562. [PMID: 28439996 DOI: 10.1002/jemt.22819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/07/2016] [Accepted: 11/28/2016] [Indexed: 11/08/2022]
Abstract
We investigated the association between human polymorphonuclear leukocytes (PMNs) and non-opsonized Tannerella forsythia ATCC 43037 displaying a serum-resistant surface layer (S-layer). When PMNs were mixed with T. forsythia in suspension, the cells phagocytosed T. forsythia cells. Nitro blue tetrazolium (NBT) reduction, indicative of O2- production, was observed by light microscopy; cerium (Ce) perhydroxide deposition, indicative of H2 O2 production, was observed by electron microscopy. We examined the relationship between high-molecular-weight proteins of the S-layer and Ce reaction (for T. forsythia phagocytosis) using electron microscopic immunolabeling. Immunogold particles were localized within the PMNs and on cell surfaces, labelling at the same Ce-reacted sites where the S-layer was present. We then used energy dispersive spectroscopy (EDS)-scanning transmission electron microscope (STEM) to perform Ce and nitrogen (N) (for S-layer immunocytochemistry) elemental analysis on the phagocytosed cells. That is, the elemental mapping and analysis of N by EDS appeared to reflect the presence of the same moieties detected by the 3,3'-diaminobenzidine-tetrahydrochloride (DAB) reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies, instead of immunogold labeling. We focused on the use of EDS-STEM to visualize the presence of N resulting from the DAB reaction. In a parallel set of experiments, we used EDS-STEM to perform Ce and gold (Au; from immunogold labeling of the S-layer) elemental analysis on the same phagocytosing cells.
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Affiliation(s)
- Keiichi Moriguchi
- Department of Oral Anatomy, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Yoshiaki Hasegawa
- Department of Microbiology, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Naoya Higuchi
- Department of Endodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Yukitaka Murakami
- Department of Oral Microbiology, Division of Oral Infections and Health Science, Asahi University School of Dentistry, 1851 Hozumi Mizuho, Gifu, 501-0296, Japan
| | - Fuminobu Yoshimura
- Department of Microbiology, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Kazuhiko Nakata
- Department of Endodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Masaki Honda
- Department of Oral Anatomy, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, 464-8650, Japan
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25
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Evidence for a LOS and a capsular polysaccharide in Capnocytophaga canimorsus. Sci Rep 2016; 6:38914. [PMID: 27974829 PMCID: PMC5156936 DOI: 10.1038/srep38914] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022] Open
Abstract
Capnocytophaga canimorsus is a dog’s and cat’s oral commensal which can cause fatal human infections upon bites or scratches. Infections mainly start with flu-like symptoms but can rapidly evolve in fatal septicaemia with a mortality as high as 40%. Here we present the discovery of a polysaccharide capsule (CPS) at the surface of C. canimorsus 5 (Cc5), a strain isolated from a fulminant septicaemia. We provide genetic and chemical data showing that this capsule is related to the lipooligosaccharide (LOS) and probably composed of the same polysaccharide units. A CPS was also found in nine out of nine other strains of C. canimorsus. In addition, the genomes of three of these strains, sequenced previously, contain genes similar to those encoding CPS biosynthesis in Cc5. Thus, the presence of a CPS is likely to be a common property of C. canimorsus. The CPS and not the LOS confers protection against the bactericidal effect of human serum and phagocytosis by macrophages. An antiserum raised against the capsule increased the killing of C. canimorsus by human serum thus showing that anti-capsule antibodies have a protective role. These findings provide a new major element in the understanding of the pathogenesis of C. canimorsus.
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Farsi D, Tanner A. In vitro Resistance Testing of Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia to Triclosan. J Contemp Dent Pract 2016; 17:282-5. [PMID: 27340161 DOI: 10.5005/jp-journals-10024-1842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM To determine the sensitivity of Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia to triclosan, and determine if these bacteria develop resistance to triclosan upon prolonged exposure. MATERIALS AND METHODS Susceptibility to triclosan was tested against three periodontal pathogens P. gingivalis, P. intermedia, and T. forsythia. Escherichia coli strains sensitive and resistant to triclosan were used as biological controls to confirm the efficacy of triclosan in the assays. Agar plates were prepared locally with vitamin K and hemin-supplemented medium. RESULTS Porphyromonas gingivalis and P. intermedia did not grow on plates containing ≥ 2 μg/ml triclosan, while T. forsythia did not grow on ≥ 1.66 μg/ml. Colonies of P. intermedia resistant to triclosan developed after prolonged incubation at 2 μg/ml, but this resistance disappeared during subculture in the absence of triclosan. CONCLUSION No significant resistance to triclosan was detected for these species. CLINICAL SIGNIFICANCE Dental products containing triclosan can be beneficial in controlling periodontal disease.
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Affiliation(s)
- Deema Farsi
- Assistant Professor, Department of Pediatric Dentistry, King Abdulaziz University Jeddah, Kingdom of Saudi Arabia, e-mail:
| | - Anne Tanner
- Department of Microbiology, The Forsyth Institute, Cambridge Massachusetts, USA
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27
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Shoji M, Nakayama K. Glycobiology of the oral pathogen Porphyromonas gingivalis and related species. Microb Pathog 2015; 94:35-41. [PMID: 26456570 DOI: 10.1016/j.micpath.2015.09.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 10/22/2022]
Abstract
Until recently, glycoproteins had only been described in eukaryotes. However, advances in detection methods and genome analyses have allowed the discovery of N-linked or O-linked glycoproteins, similar to those found in eukaryotes, in some bacterial species. These prokaryotic glycoproteins play roles in adhesion, solubility, formation of protein complexes, protection from protein degradation, and changes in antigenicity. Periodontal pathogen Porphyromonas gingivalis secretes virulence proteins via the type IX secretion system, some of which localize on the cell surface by binding to lipopolysaccharide (LPS). These virulence proteins have a conserved C-terminal domain (CTD) region, which is used as a secretion signal. However, it is still uncertain how the secreted proteins on the cell surface bind to LPS. In this review, we discuss the synthesis of P. gingivalis O polysaccharide, which plays a role in anchoring the CTD protein on the cell surface, and recent discoveries of glycoproteins in P. gingivalis as well as other species in the phylum Bacteroidetes.
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Affiliation(s)
- Mikio Shoji
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Koji Nakayama
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan.
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Gorasia DG, Veith PD, Chen D, Seers CA, Mitchell HA, Chen YY, Glew MD, Dashper SG, Reynolds EC. Porphyromonas gingivalis Type IX Secretion Substrates Are Cleaved and Modified by a Sortase-Like Mechanism. PLoS Pathog 2015; 11:e1005152. [PMID: 26340749 PMCID: PMC4560394 DOI: 10.1371/journal.ppat.1005152] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/14/2015] [Indexed: 12/11/2022] Open
Abstract
The type IX secretion system (T9SS) of Porphyromonas gingivalis secretes proteins possessing a conserved C-terminal domain (CTD) to the cell surface. The C-terminal signal is essential for these proteins to translocate across the outer membrane via the T9SS. On the surface the CTD of these proteins is cleaved prior to extensive glycosylation. It is believed that the modification on these CTD proteins is anionic lipopolysaccharide (A-LPS), which enables the attachment of CTD proteins to the cell surface. However, the exact site of modification and the mechanism of attachment of CTD proteins to the cell surface are unknown. In this study we characterized two wbaP (PG1964) mutants that did not synthesise A-LPS and accumulated CTD proteins in the clarified culture fluid (CCF). The CTDs of the CTD proteins in the CCF were cleaved suggesting normal secretion, however, the CTD proteins were not glycosylated. Mass spectrometric analysis of CTD proteins purified from the CCF of the wbaP mutants revealed the presence of various peptide/amino acid modifications from the growth medium at the C-terminus of the mature CTD proteins. This suggested that modification occurs at the C-terminus of T9SS substrates in the wild type P. gingivalis. This was confirmed by analysis of CTD proteins from wild type, where a 648 Da linker was identified to be attached at the C-terminus of mature CTD proteins. Importantly, treatment with proteinase K released the 648 Da linker from the CTD proteins demonstrating a peptide bond between the C-terminus and the modification. Together, this is suggestive of a mechanism similar to sortase A for the cleavage and modification/attachment of CTD proteins in P. gingivalis. PG0026 has been recognized as the CTD signal peptidase and is now proposed to be the sortase-like protein in P. gingivalis. To our knowledge, this is the first biochemical evidence suggesting a sortase-like mechanism in Gram-negative bacteria.
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Affiliation(s)
- Dhana G. Gorasia
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Paul D. Veith
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Dina Chen
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Christine A. Seers
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Helen A. Mitchell
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Yu-Yen Chen
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Michelle D. Glew
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Stuart G. Dashper
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
| | - Eric C. Reynolds
- Oral Health Cooperative Research Centre, Melbourne Dental School, and The Bio21 Institute, The University of Melbourne, Victoria, Australia
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Porphyromonas gingivalis Periodontal Infection and Its Putative Links with Alzheimer's Disease. Mediators Inflamm 2015; 2015:137357. [PMID: 26063967 PMCID: PMC4430664 DOI: 10.1155/2015/137357] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/01/2015] [Indexed: 12/18/2022] Open
Abstract
Periodontal disease (PD) and Alzheimer's disease (AD) are inflammatory conditions affecting the global adult population. In the pathogenesis of PD, subgingival complex bacterial biofilm induces inflammation that leads to connective tissue degradation and alveolar bone resorption around the teeth. In health, junctional epithelium seals the gingiva to the tooth enamel, thus preventing bacteria from entering the gingivae. Chronic PD involves major pathogens (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) which have an immune armoury that can circumvent host's immune surveillance to create and maintain an inflammatory mediator rich and toxic environment to grow and survive. The neurodegenerative condition, AD, is characterised by poor memory and specific hallmark proteins; periodontal pathogens are increasingly being linked with this dementing condition. It is therefore becoming important to understand associations of periodontitis with relevance to late-onset AD. The aim of this review is to discuss the relevance of finding the keystone periodontal pathogen P. gingivalis in AD brains and its plausible contribution to the aetiological hypothesis of this dementing condition.
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Ibrahim MI, Abdelhafeez MA, Ellaithy MI, Salama AH, Amin AS, Eldakrory H, Elhadad NI. Can Porphyromonas gingivalis be a novel aetiology for recurrent miscarriage? EUR J CONTRACEP REPR 2015; 20:119-27. [PMID: 25328050 DOI: 10.3109/13625187.2014.962651] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To study the association between Porphyromonas gingivalis (P. gingivalis) infection and recurrent miscarriage. METHODS This case control study included women with early pregnancy failure admitted for surgical evacuation of retained products of conception. Cases (group 1) included 50 women with unexplained recurrent early miscarriage whereas the control group (group 2) consisted of 50 women with no such history. The evacuated products of conception, subgingival plaques, cervicovaginal secretions and saliva of all participants were examined to detect P. gingivalis deoxyribonucleic acid (DNA) using a polymerase chain reaction. RESULTS The prevalence of P. gingivalis DNA in the chorionic villous tissue samples of group 1 was significantly higher than in group 2 (8 [16%] vs. 1 [2%], respectively; p = 0.036, odds ratio [OR]: 9.3, 95% confidence interval [CI]: 1.1-76.9). The prevalence of P. gingivalis DNA was significantly higher in cervicovaginal secretions of group 1 than in group 2 (9 [18%] vs. 1 [2%], respectively; p = 0.02, OR: 10.8, 95% CI: 1.3-88.5). On the contrary, P. gingivalis DNA could not be detected in subgingival plaques and saliva samples of either group. CONCLUSION The current study found an association between P. gingivalis infection of the female genital tract and the occurrence of recurrent miscarriage.
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Affiliation(s)
- Moustafa I Ibrahim
- * Obstetrics & Gynaecology Department, Ain-Shams Faculty of Medicine , Cairo , Egypt
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Hussain M, Stover CM, Dupont A. P. gingivalis in Periodontal Disease and Atherosclerosis - Scenes of Action for Antimicrobial Peptides and Complement. Front Immunol 2015; 6:45. [PMID: 25713575 PMCID: PMC4322733 DOI: 10.3389/fimmu.2015.00045] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 01/24/2015] [Indexed: 12/17/2022] Open
Abstract
According to the NHS, it is estimated that over 50% of the adult population are, to some extent, affected by gum disease and approximately 15% of UK population have been diagnosed with severe periodontitis. Periodontitis, a chronic polymicrobial disease of the gums, causes inflammation in its milder form, whereas in its severe form affects the surrounding tissues and can result in tooth loss. During periodontitis, plaque accumulates and sits between the junctional epithelium and the tooth itself, resulting in inflammation and the formation of a periodontal pocket. An interface is formed directly between the subgingival bacteria and the junctional epithelial cells. Bacterial pathogens commonly associated with periodontal disease are, among others, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, together known as the "red complex." This review will mostly concentrate on the role of P. gingivalis, a Gram-negative anaerobic bacterium and one of the major and most studied contributors of this disease. Because periodontal disease is associated with the development of atherosclerosis, it is important to understand the local immune response to P. gingivalis. Innate immune players, in particular, complement and antimicrobial peptides and their effects with regard to P. gingivalis during periodontitis and in the development of atherosclerosis will be presented.
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Affiliation(s)
- Mehak Hussain
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Cordula M. Stover
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Aline Dupont
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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Deletion of a 77-base-pair inverted repeat element alters the synthesis of surface polysaccharides in Porphyromonas gingivalis. J Bacteriol 2015; 197:1208-20. [PMID: 25622614 DOI: 10.1128/jb.02589-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Bacterial cell surface glycans, such as capsular polysaccharides and lipopolysaccharides (LPS), influence host recognition and are considered key virulence determinants. The periodontal pathogen Porphyromonas gingivalis is known to display at least three different types of surface glycans: O-LPS, A-LPS, and K-antigen capsule. We have shown that PG0121 (in strain W83) encodes a DNABII histone-like protein and that this gene is transcriptionally linked to the K-antigen capsule synthesis genes, generating a large ∼19.4-kb transcript (PG0104-PG0121). Furthermore, production of capsule is deficient in a PG0121 mutant strain. In this study, we report on the identification of an antisense RNA (asRNA) molecule located within a 77-bp inverted repeat (77bpIR) element located near the 5' end of the locus. We show that overexpression of this asRNA decreases the amount of capsule produced, indicating that this asRNA can impact capsule synthesis in trans. We also demonstrate that deletion of the 77bpIR element and thereby synthesis of the large 19.4-kb transcript also diminishes, but does not eliminate, capsule synthesis. Surprisingly, LPS structures were also altered by deletion of the 77bpIR element, and reactivity to monoclonal antibodies specific to both O-LPS and A-LPS was eliminated. Additionally, reduced reactivity to these antibodies was also observed in a PG0106 mutant, indicating that this putative glycosyltransferase, which is required for capsule synthesis, is also involved in LPS synthesis in strain W83. We discuss our finding in the context of how DNABII proteins, an antisense RNA molecule, and the 77bpIR element may modulate expression of surface polysaccharides in P. gingivalis. IMPORTANCE The periodontal pathogen Porphyromonas gingivalis displays at least three different types of cell surface glycans: O-LPS, A-LPS, and K-antigen capsule. We have shown using Northern analysis that the K-antigen capsule locus encodes a large transcript (∼19.4 kb), encompassing a 77-bp inverted repeat (77bpIR) element near the 5' end. Here, we report on the identification of an antisense RNA (asRNA) encoded within the 77bpIR. We show that overexpression of this asRNA or deletion of the element decreases the amount of capsule. LPS structures were also altered by deletion of the 77bpIR, and reactivity to monoclonal antibodies to both O-LPS and A-LPS was eliminated. Our data indicate that the 77bpIR element is involved in modulating both LPS and capsule synthesis in P. gingivalis.
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Huynh AHS, Veith PD, McGregor NR, Adams GG, Chen D, Reynolds EC, Ngo LH, Darby IB. Gingival crevicular fluid proteomes in health, gingivitis and chronic periodontitis. J Periodontal Res 2014; 50:637-49. [PMID: 25439677 DOI: 10.1111/jre.12244] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2014] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The aim of this study was to compare the proteome composition of gingival crevicular fluid obtained from healthy periodontium, gingivitis and chronic periodontitis affected sites. BACKGROUND Owing to its site-specific nature, gingival crevicular fluid is ideal for studying biological processes that occur during periodontal health and disease progression. However, few studies have been conducted into the gingival crevicular fluid proteome due to the small volumes obtained. METHODS Fifteen males were chosen for each of three different groups, healthy periodontium, gingivitis and chronic periodontitis. They were categorized based on clinical measurements including probing depth, bleeding on probing, plaque index, radiographic bone level, modified gingival index and smoking status. Gingival crevicular fluid was collected from each patient, pooled into healthy, gingivitis and chronic periodontitis groups and their proteome analyzed by gel electrophoresis and liquid chromatography electrospray ionization ion trap tandem mass spectrometry. RESULTS One hundred and twenty-one proteins in total were identified, and two-thirds of these were identified in all three conditions. Forty-two proteins were considered to have changed in abundance. Of note, cystatin B and cystatin S decreased in abundance from health to gingivitis and further in chronic periodontitis. Complement proteins demonstrated an increase from health to gingivitis followed by a decrease in chronic periodontitis. Immunoglobulins, keratin proteins, fibronectin, lactotransferrin precursor, 14-3-3 protein zeta/delta, neutrophil defensin 3 and alpha-actinin exhibited fluctuations in levels. CONCLUSION The gingival crevicular fluid proteome in each clinical condition was different and its analysis may assist us in understanding periodontal pathogenesis.
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Affiliation(s)
- A H S Huynh
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - P D Veith
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - N R McGregor
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - G G Adams
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - D Chen
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - E C Reynolds
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - L H Ngo
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
| | - I B Darby
- Melbourne Dental School, Oral Health Cooperative Research Centre, Bio21 Institute, The University of Melbourne, Melbourne, Vic., Australia
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Berends ETM, Kuipers A, Ravesloot MM, Urbanus RT, Rooijakkers SHM. Bacteria under stress by complement and coagulation. FEMS Microbiol Rev 2014; 38:1146-71. [PMID: 25065463 DOI: 10.1111/1574-6976.12080] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 06/23/2014] [Accepted: 07/14/2014] [Indexed: 02/03/2023] Open
Abstract
The complement and coagulation systems are two related protein cascades in plasma that serve important roles in host defense and hemostasis, respectively. Complement activation on bacteria supports cellular immune responses and leads to direct killing of bacteria via assembly of the Membrane Attack Complex (MAC). Recent studies have indicated that the coagulation system also contributes to mammalian innate defense since coagulation factors can entrap bacteria inside clots and generate small antibacterial peptides. In this review, we will provide detailed insights into the molecular interplay between these protein cascades and bacteria. We take a closer look at how these pathways are activated on bacterial surfaces and discuss the mechanisms by which they directly cause stress to bacterial cells. The poorly understood mechanism for bacterial killing by the MAC will be reevaluated in light of recent structural insights. Finally, we highlight the strategies used by pathogenic bacteria to modulate these protein networks. Overall, these insights will contribute to a better understanding of the host defense roles of complement and coagulation against bacteria.
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Affiliation(s)
- Evelien T M Berends
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Characterization of wheat germ agglutinin lectin-reactive glycosylated OmpA-like proteins derived from Porphyromonas gingivalis. Infect Immun 2014; 82:4563-71. [PMID: 25135681 DOI: 10.1128/iai.02069-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Glycosylation is one of the common posttranslational modifications in eukaryotes. Recently, glycosylated proteins have also been identified in prokaryotes. A few glycosylated proteins, including gingipains, have been identified in Porphyromonas gingivalis, a major pathogen associated with chronic periodontitis. However, no other glycosylated proteins have been found. The present study identified glycoproteins in P. gingivalis cell lysates by lectin blotting. Whole-cell lysates reacted with concanavalin A (ConA), Lens culinaris agglutinin (LCA), Phaseolus vulgaris erythroagglutinin (PHA-E4), and wheat germ agglutinin (WGA), suggesting the presence of mannose-, N-acetylgalactosamine-, or N-acetylglucosamine (GlcNAc)-modified proteins. Next, glycoproteins were isolated by ConA-, LCA-, PHA-E4-, or WGA-conjugated lectin affinity chromatography although specific proteins were enriched only by the WGA column. Mass spectrometry analysis showed that an OmpA-like, heterotrimeric complex formed by Pgm6 and Pgm7 (Pgm6/7) was the major glycoprotein isolated from P. gingivalis. Deglycosylation experiments and Western blotting with a specific antibody indicated that Pgm6/7 was modified with O-GlcNAc. When whole-cell lysates from P. gingivalis mutant strains with deletions of Pgm6 and Pgm7 were applied to a WGA column, homotrimeric Pgm7, but not Pgm6, was isolated. Heterotrimeric Pgm6/7 had the strongest affinity for fibronectin of all the extracellular proteins tested, whereas homotrimeric Pgm7 showed reduced binding activity. These findings suggest that the heterotrimeric structure is important for the biological activity of glycosylated WGA-binding OmpA-like proteins in P. gingivalis.
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Shoji M, Sato K, Yukitake H, Naito M, Nakayama K. Involvement of the Wbp pathway in the biosynthesis of Porphyromonas gingivalis lipopolysaccharide with anionic polysaccharide. Sci Rep 2014; 4:5056. [PMID: 24852504 PMCID: PMC4031482 DOI: 10.1038/srep05056] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/06/2014] [Indexed: 11/15/2022] Open
Abstract
The periodontal pathogen Porphyromonas gingivalis has two different lipopolysaccharide (LPS) molecules, O-LPS and A-LPS. We have recently shown that P. gingivalis strain HG66 lacks A-LPS. Here, we found that introduction of a wild-type wbpB gene into strain HG66 restored formation of A-LPS. Sequencing of the wbpB gene from strain HG66 revealed the presence of a nonsense mutation in the gene. The wbpB gene product is a member of the Wbp pathway, which plays a role in the synthesis of UDP-ManNAc(3NAc)A in Pseudomonas aeruginosa; UDP-ManNAc(3NAc)A is sequentially synthesized by the WbpA, WbpB, WbpE, WbpD and WbpI proteins. We then determined the effect of the PGN_0002 gene, a wbpD homolog, on the biosynthesis of A-LPS. A PGN_0002-deficient mutant demonstrated an A-LPS biosynthesis deficiency. Taken together with previous studies, the present results suggest that the final product synthesized by the Wbp pathway is one of the sugar substrates necessary for the biosynthesis of A-LPS.
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Affiliation(s)
- Mikio Shoji
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Keiko Sato
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Hideharu Yukitake
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Mariko Naito
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
| | - Koji Nakayama
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
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Hajishengallis G, Lamont RJ. Breaking bad: manipulation of the host response by Porphyromonas gingivalis. Eur J Immunol 2014; 44:328-38. [PMID: 24338806 DOI: 10.1002/eji.201344202] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/02/2013] [Accepted: 12/09/2013] [Indexed: 02/06/2023]
Abstract
Recent metagenomic and mechanistic studies are consistent with a new model of periodontal pathogenesis. This model proposes that periodontal disease is initiated by a synergistic and dysbiotic microbial community rather than by a select few bacteria traditionally known as "periopathogens." Low-abundance bacteria with community-wide effects that are critical for the development of dysbiosis are now known as keystone pathogens, the best-documented example of which is Porphyromonas gingivalis. Here, we review established mechanisms by which P. gingivalis interferes with host immunity and enables the emergence of dysbiotic communities. We integrate the role of P. gingivalis with that of other bacteria acting upstream and downstream in pathogenesis. Accessory pathogens act upstream to facilitate P. gingivalis colonization and co-ordinate metabolic activities, whereas commensals-turned pathobionts act downstream and contribute to destructive inflammation. The recent concepts of keystone pathogens, along with polymicrobial synergy and dysbiosis, have profound implications for the development of therapeutic options for periodontal disease.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Barth K, Remick DG, Genco CA. Disruption of immune regulation by microbial pathogens and resulting chronic inflammation. J Cell Physiol 2013; 228:1413-22. [PMID: 23255141 DOI: 10.1002/jcp.24299] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 11/27/2012] [Indexed: 12/23/2022]
Abstract
Activation of the immune response is a tightly regulated, coordinated effort that functions to control and eradicate exogenous microorganisms, while also responding to endogenous ligands. Determining the proper balance of inflammation is essential, as chronic inflammation leads to a wide array of host pathologies. Bacterial pathogens can instigate chronic inflammation via an extensive repertoire of evolved evasion strategies that perturb immune regulation. In this review, we discuss two model pathogens, Mycobacterium tuberculosis and Porphyromonas gingivalis, which efficiently escape various aspects of the immune system within professional and non-professional immune cell types to establish chronic inflammation.
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Affiliation(s)
- Kenneth Barth
- Department of Medicine Section of Infectious Disease, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Hajishengallis G, Abe T, Maekawa T, Hajishengallis E, Lambris JD. Role of complement in host-microbe homeostasis of the periodontium. Semin Immunol 2013; 25:65-72. [PMID: 23684627 DOI: 10.1016/j.smim.2013.04.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 04/13/2013] [Indexed: 02/08/2023]
Abstract
Complement plays a key role in immunity and inflammation through direct effects on immune cells or via crosstalk and regulation of other host signaling pathways. Deregulation of these finely balanced complement activities can link infection to inflammatory tissue damage. Periodontitis is a polymicrobial community-induced chronic inflammatory disease that can destroy the tooth-supporting tissues. In this review, we summarize and discuss evidence that complement is involved in the dysbiotic transformation of the periodontal microbiota and in the inflammatory process that leads to the destruction of periodontal bone. Recent insights into the mechanisms of complement involvement in periodontitis have additionally provided likely targets for therapeutic intervention against this oral disease.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Shoji M, Yukitake H, Sato K, Shibata Y, Naito M, Aduse-Opoku J, Abiko Y, Curtis MA, Nakayama K. Identification of an O-antigen chain length regulator, WzzP, in Porphyromonas gingivalis. Microbiologyopen 2013; 2:383-401. [PMID: 23509024 PMCID: PMC3684754 DOI: 10.1002/mbo3.84] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/11/2013] [Accepted: 02/19/2013] [Indexed: 01/22/2023] Open
Abstract
The periodontal pathogen Porphyromonas gingivalis has two different lipopolysaccharides (LPSs) designated O-LPS and A-LPS, which are a conventional O-antigen polysaccharide and an anionic polysaccharide that are both linked to lipid A-cores, respectively. However, the precise mechanisms of LPS biosynthesis remain to be determined. In this study, we isolated a pigment-less mutant by transposon mutagenesis and identified that the transposon was inserted into the coding sequence PGN_2005, which encodes a hypothetical protein of P. gingivalis ATCC 33277. We found that (i) LPSs purified from the PGN_2005 mutant were shorter than those of the wild type; (ii) the PGN_2005 protein was located in the inner membrane fraction; and (iii) the PGN_2005 gene conferred Wzz activity upon an Escherichia coli wzz mutant. These results indicate that the PGN_2005 protein, which was designated WzzP, is a functional homolog of the Wzz protein in P. gingivalis. Comparison of amino acid sequences among WzzP and conventional Wzz proteins indicated that WzzP had an additional fragment at the C-terminal region. In addition, we determined that the PGN_1896 and PGN_1233 proteins and the PGN_1033 protein appear to be WbaP homolog proteins and a Wzx homolog protein involved in LPS biosynthesis, respectively.
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Affiliation(s)
- Mikio Shoji
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan
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The surface layer of Tannerella forsythia contributes to serum resistance and oral bacterial coaggregation. Infect Immun 2013; 81:1198-206. [PMID: 23357386 DOI: 10.1128/iai.00983-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Tannerella forsythia is an anaerobic, Gram-negative bacterium involved in the so-called "red complex," which is associated with severe and chronic periodontitis. The surface layer (S-layer) of T. forsythia is composed of cell surface glycoproteins, such as TfsA and TfsB, and is known to play a role in adhesion/invasion and suppression of proinflammatory cytokine expression. Here we investigated the association of this S-layer with serum resistance and coaggregation with other oral bacteria. The growth of the S-layer-deficient mutant in a bacterial medium containing more than 20% non-heat-inactivated calf serum (CS) or more than 40% non-heat-inactivated human serum was significantly suppressed relative to that of the wild type (WT). Next, we used confocal microscopy to perform quantitative analysis on the effect of serum. The survival ratio of the mutant exposed to 100% non-heat-inactivated CS (76% survival) was significantly lower than that of the WT (97% survival). Furthermore, significant C3b deposition was observed in the mutant but not in the WT. In a coaggregation assay, the mutant showed reduced coaggregation with Streptococcus sanguinis, Streptococcus salivarius, and Porphyromonas gingivalis but strong coaggregation with Fusobacterium nucleatum. These results indicated that the S-layer of T. forsythia plays multiple roles in virulence and may be associated with periodontitis.
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Pseudomonas aeruginosa possesses two putative type I signal peptidases, LepB and PA1303, each with distinct roles in physiology and virulence. J Bacteriol 2012; 194:4521-36. [PMID: 22730125 DOI: 10.1128/jb.06678-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Type I signal peptidases (SPases) cleave signal peptides from proteins during translocation across biological membranes and hence play a vital role in cellular physiology. SPase activity is also of fundamental importance to the pathogenesis of infection for many bacteria, including Pseudomonas aeruginosa, which utilizes a variety of secreted virulence factors, such as proteases and toxins. P. aeruginosa possesses two noncontiguous SPase homologues, LepB (PA0768) and PA1303, which share 43% amino acid identity. Reverse transcription (RT)-PCR showed that both proteases were expressed, while a FRET-based assay using a peptide based on the signal sequence cleavage region of the secreted LasB elastase showed that recombinant LepB and PA1303 enzymes were both active. LepB is positioned within a genetic locus that resembles the locus containing the extensively characterized SPase of E. coli and is of similar size and topology. It was also shown to be essential for viability and to have high sequence identity with SPases from other pseudomonads (≥ 78%). In contrast, PA1303, which is small for a Gram-negative SPase (20 kDa), was found to be dispensable. Mutation of PA1303 resulted in an altered protein secretion profile and increased N-butanoyl homoserine lactone production and influenced several quorum-sensing-controlled phenotypic traits, including swarming motility and the production of rhamnolipid and elastinolytic activity. The data indicate different cellular roles for these P. aeruginosa SPase paralogues; the role of PA1303 is integrated with the quorum-sensing cascade and includes the suppression of virulence factor secretion and virulence-associated phenotypes, while LepB is the primary SPase.
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Bostanci N, Belibasakis GN. Porphyromonas gingivalis: an invasive and evasive opportunistic oral pathogen. FEMS Microbiol Lett 2012; 333:1-9. [PMID: 22530835 DOI: 10.1111/j.1574-6968.2012.02579.x] [Citation(s) in RCA: 365] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/18/2012] [Accepted: 04/20/2012] [Indexed: 12/22/2022] Open
Abstract
Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis, an inflammatory disease that destroys the tissues supporting the tooth, eventually leading to tooth loss. Porphyromonas gingivalis has can locally invade periodontal tissues and evade the host defence mechanisms. In doing so, it utilizes a panel of virulence factors that cause deregulation of the innate immune and inflammatory responses. The present review discusses the invasive and evasive strategies of P. gingivalis and the role of its major virulence factors in these, namely lipopolysaccharide, capsule, gingipains and fimbriae. Moreover, the role of P. gingivalis as a 'keystone' biofilm species in orchestrating a host response, is highlighted.
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Affiliation(s)
- Nagihan Bostanci
- Oral Translational Research, Institute of Oral Biology, Center of Dental Medicine, Faculty of Medicine, University of Zürich, Zürich, Switzerland
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Li C, Kurniyati, Hu B, Bian J, Sun J, Zhang W, Liu J, Pan Y, Li C. Abrogation of neuraminidase reduces biofilm formation, capsule biosynthesis, and virulence of Porphyromonas gingivalis. Infect Immun 2012; 80:3-13. [PMID: 22025518 PMCID: PMC3255687 DOI: 10.1128/iai.05773-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/18/2011] [Indexed: 01/27/2023] Open
Abstract
The oral bacterium Porphyromonas gingivalis is a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide. P. gingivalis exhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence of P. gingivalis remain elusive. In this report, we found that P. gingivalis encodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed that PG0352 is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPg is an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that the PG0352 deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type, in vitro studies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement. In vivo studies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPg is an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity of P. gingivalis, and it can potentially serve as a new target for developing therapeutic agents against P. gingivalis infection.
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Affiliation(s)
- Chen Li
- Department of Oral Biology, The State University of New York at Buffalo, New York, USA
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Kurniyati
- Department of Oral Biology, The State University of New York at Buffalo, New York, USA
| | - Bo Hu
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Texas, USA
| | - Jiang Bian
- Department of Oral Biology, The State University of New York at Buffalo, New York, USA
| | - Jianlan Sun
- Department of Pathology and Anatomical Sciences
| | - Weiyan Zhang
- Department of Pharmaceutical Sciences, The State University of New York at Buffalo, New York, USA
| | - Jun Liu
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Texas, USA
| | - Yaping Pan
- Department of Periodontics, School of Stomatology, China Medical University, Shenyang, Liaoning, China
| | - Chunhao Li
- Department of Oral Biology, The State University of New York at Buffalo, New York, USA
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Pathogenic microbes and community service through manipulation of innate immunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 946:69-85. [PMID: 21948363 DOI: 10.1007/978-1-4614-0106-3_5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The periodontal pathogen Porphyromonas gingivalis undermines major components of innate immunity, such as complement, Toll-like receptors (TLR), and their crosstalk pathways. At least in principle, these subversive activities could promote the adaptive fitness of the entire periodontal biofilm community. In this regard, the virulence factors responsible for complement and TLR exploitation (gingipain enzymes, atypical lipopolysaccharide molecules, and fimbriae) are released as components of readily diffusible membrane vesicles, which can thus become available to other biofilm organisms. This review summarizes important immune subversive tactics of P. gingivalis which might enable it to exert a supportive impact on the oral microbial community.
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Shoji M, Sato K, Yukitake H, Kondo Y, Narita Y, Kadowaki T, Naito M, Nakayama K. Por secretion system-dependent secretion and glycosylation of Porphyromonas gingivalis hemin-binding protein 35. PLoS One 2011; 6:e21372. [PMID: 21731719 PMCID: PMC3120885 DOI: 10.1371/journal.pone.0021372] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/26/2011] [Indexed: 01/22/2023] Open
Abstract
The anaerobic Gram-negative bacterium Porphyromonas gingivalis is a major pathogen in severe forms of periodontal disease and refractory periapical perodontitis. We have recently found that P. gingivalis has a novel secretion system named the Por secretion system (PorSS), which is responsible for secretion of major extracellular proteinases, Arg-gingipains (Rgps) and Lys-gingipain. These proteinases contain conserved C-terminal domains (CTDs) in their C-termini. Hemin-binding protein 35 (HBP35), which is one of the outer membrane proteins of P. gingivalis and contributes to its haem utilization, also contains a CTD, suggesting that HBP35 is translocated to the cell surface via the PorSS. In this study, immunoblot analysis of P. gingivalis mutants deficient in the PorSS or in the biosynthesis of anionic polysaccharide-lipopolysaccharide (A-LPS) revealed that HBP35 is translocated to the cell surface via the PorSS and is glycosylated with A-LPS. From deletion analysis with a GFP-CTD[HBP35] green fluorescent protein fusion, the C-terminal 22 amino acid residues of CTD[HBP35] were found to be required for cell surface translocation and glycosylation. The GFP-CTD fusion study also revealed that the CTDs of CPG70, peptidylarginine deiminase, P27 and RgpB play roles in PorSS-dependent translocation and glycosylation. However, CTD-region peptides were not found in samples of glycosylated HBP35 protein by peptide map fingerprinting analysis, and antibodies against CTD-regions peptides did not react with glycosylated HBP35 protein. These results suggest both that the CTD region functions as a recognition signal for the PorSS and that glycosylation of CTD proteins occurs after removal of the CTD region. Rabbits were used for making antisera against bacterial proteins in this study.
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Affiliation(s)
- Mikio Shoji
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Keiko Sato
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hideharu Yukitake
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yoshio Kondo
- Department of Pediatric Dentistry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yuka Narita
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Tomoko Kadowaki
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Mariko Naito
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Koji Nakayama
- Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Global COE Program at Nagasaki University, Nagasaki, Japan
- * E-mail:
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Riewe SD, Mans JJ, Hirano T, Katz J, Shiverick KT, Brown TA, Lamont RJ. Human trophoblast responses to Porphyromonas gingivalis infection. Mol Oral Microbiol 2010; 25:252-9. [PMID: 20618699 DOI: 10.1111/j.2041-1014.2010.00573.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Porphyromonas gingivalis is a periodontal pathogen that is also associated with preterm low-birthweight delivery. We investigated the transcriptional responses of human extravillous trophoblasts (HTR-8) to infection with P. gingivalis. Over 2000 genes were differentially regulated in HTR-8 cells by P. gingivalis. In ontology analyses of regulated genes, overpopulated biological pathways included mitogen-activated protein (MAP) kinase signaling and cytokine production. Immunoblots confirmed overexpression of the MAP kinase pathway components MEK3, p38 and Max. Furthermore, P. gingivalis infection induced phosphorylation and activation of MEK3 and p38. Increased production of interleukin (IL)-1beta and IL-8 by HTR-8 cells was demonstrated phenotypically by enzyme-linked immunosorbent assay of HTR-8 cell lysates and culture supernatants. Hence, infection of trophoblasts by P. gingivalis can impact signal transduction pathways and modulate cytokine expression, outcomes that could disrupt the maintenance of pregnancy.
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Affiliation(s)
- S D Riewe
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL 32610-0424, USA
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HU protein affects transcription of surface polysaccharide synthesis genes in Porphyromonas gingivalis. J Bacteriol 2010; 192:6217-29. [PMID: 20889748 DOI: 10.1128/jb.00106-10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
K-antigen capsule synthesis is an important virulence determinant of the oral anaerobe Porphyromonas gingivalis. We previously reported that the locus required for synthesis of this surface polysaccharide in strain W83 (TIGR identification PG0106 to PG0120) is transcribed as a large (∼16.7-kb) polycistronic message. Through sequence analysis, we have now identified a 77-bp inverted repeat located upstream (206 bp) of the start codon of PG0106 that is capable of forming a large hairpin structure. Further sequence analysis just upstream and downstream of the capsule synthesis genes revealed the presence of two genes oriented in the same direction as the operon that are predicted to encode DNA binding proteins: PG0104, which is highly similar (57%) to DNA topoisomerase III, and PG0121, which has high similarity (72%) to DNA binding protein HU (β-subunit). In this report, we show that these two genes, as well as the 77-bp inverted repeat region, are cotranscribed with the capsule synthesis genes, resulting in a large transcript that is ∼19.4 kb (based on annotation). We also show that a PG0121 recombinant protein is a nonspecific DNA binding protein with strong affinity to the hairpin structure, in vitro, and that transcript levels of the capsule synthesis genes are downregulated in a PG0121 deletion mutant. Furthermore, we show that this decrease in transcript levels corresponds to a decrease in the amount of polysaccharide produced. Interestingly, expression analysis of another polysaccharide synthesis locus (PG1136 to PG1143) encoding genes involved in synthesis of a surface-associated phosphorylated branched mannan (APS) indicated that this locus is also downregulated in the PG0121 mutant. Altogether our data indicate that HU protein modulates expression of surface polysaccharides in P. gingivalis strain W83.
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Abstract
The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host's innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections.
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Affiliation(s)
- Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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