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Yoshida K, Yoshida K, Mouri Y, Takai A, Seyama M, Mekata M, Mizusawa N, Miyoshi K, Kudo Y, Ozaki K. Porphyromonas gingivalis infection alters microRNA composition in extracellular vesicles. J Oral Biosci 2024; 66:365-372. [PMID: 38579987 DOI: 10.1016/j.job.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
OBJECTIVES Periodontitis, commonly associated with Porphyromonas gingivalis (Pg), involves intricate alterations of oral intercellular interactions, in which extracellular vesicles (EVs) play a pivotal role. The understanding of the miRNA profiles in the EVs derived from Pg-infected cells (Pg-EVs) remains incomplete despite acknowledging their importance in intercellular communication during periodontitis. Therefore, our objective was to identify and characterize the miRNAs enriched in Pg-EVs. METHODS Microarray analysis was conducted to examine the miRNA profiles in the EVs derived from Pg-infected THP-1 cells. We compared the identified miRNAs with those upregulated in the EVs after stimulation with LPS. Additionally, we explored how inhibiting TLR signaling during Pg infection affects the transcription of specific miRNAs. We investigated the unique sequence motifs specific to the miRNAs concentrated in Pg-EVs. RESULTS The levels of eleven miRNAs, including miR-155, were increased in Pg-EVs compared with those elevated after LPS stimulation. The Pg-induced miR-155 upregulation via TLR2 but not TLR4 signaling suggests the influence of TLR signaling on the miRNA composition of EVs. Furthermore, the miRNAs upregulated in Pg-EVs contained AGAGGG and GRGGSGC sequence motifs. CONCLUSIONS Our findings demonstrate that Pg-induced alterations in EV-containing miRNA composition occur in a TLR4-independent manner. Notably, the concentrated miRNAs in Pg-EVs harbor specific motifs with a high G + C content within their sequences. The upregulation of specific miRNAs in EVs under infectious conditions suggests the influence of both innate immune receptor signals and miRNA sequence characteristics.
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Affiliation(s)
- Kayo Yoshida
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Kaya Yoshida
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Yasuhiro Mouri
- Department of Oral Bioscience, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Ayu Takai
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Mariko Seyama
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Mana Mekata
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Noriko Mizusawa
- Department of Oral Bioscience, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Keiko Miyoshi
- Department of Oral Bioscience, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Yasusei Kudo
- Department of Oral Bioscience, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
| | - Kazumi Ozaki
- Department of Oral Healthcare Promotion, Tokushima University Graduate School of Biomedical Sciences, 3-18-15, Kuramoto, Tokushima, 770-8504, Japan.
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Pandi K, Angabo S, Makkawi H, Benyamini H, Elgavish S, Nussbaum G. P. gingivalis-Induced TLR2 Interactome Analysis Reveals Association with PARP9. J Dent Res 2024; 103:329-338. [PMID: 38344758 DOI: 10.1177/00220345231222181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
Porphyromonas gingivalis is a Gram-negative anaerobic bacterium strongly associated with periodontal disease. Toll-like receptor 2 (TLR2) is indispensable for the host response to P. gingivalis, but P. gingivalis escapes from immune clearance via TLR2-dependent activation of phosphoinositide-3-kinase (PI3K). To probe the TLR2-dependent escape pathway of P. gingivalis, we analyzed the TLR2 interactome induced following P. gingivalis infection or activation by a synthetic lipopeptide TLR2/1 agonist on human macrophages overexpressing TLR2. Interacting proteins were stabilized by cross-linking and then immunoprecipitated and analyzed by mass spectrometry. In total, 792 proteins were recovered and network analysis enabled mapping of the TLR2 interactome at baseline and in response to infection. The P. gingivalis infection-induced TLR2 interactome included the poly (ADP-ribose) polymerase family member mono-ADP-ribosyltransferase protein 9 (PARP9) and additional members of the PARP9 complex (DTX3L and NMI). PARP9 and its complex members are highly upregulated in macrophages exposed to P. gingivalis or to the synthetic TLR2/1 ligand Pam3Cys-Ser-(Lys)4 (PAM). Consistent with its known role in virally induced interferon production, PARP9 knockdown blocked type I interferon (IFN-I) production in response to P. gingivalis and reduced inflammatory cytokine production. We found that P. gingivalis drives signal transducer and activation of transcription (STAT) 1 (S727) phosphorylation through TLR2-PARP9, explaining PARP9's role in the induction of IFN-I downstream of TLR2. Furthermore, PARP9 knockdown reduced PI3K activation by P. gingivalis, leading to improved macrophage bactericidal activity. In summary, PARP9 is a novel TLR2 interacting partner that enables IFN-I induction and P. gingivalis immune escape in macrophages downstream of TLR2 sensing.
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Affiliation(s)
- K Pandi
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - S Angabo
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - H Makkawi
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - H Benyamini
- Info-CORE, Bioinformatics Unit of the I-CORE, Hebrew University of Jerusalem, Jerusalem, Israel
| | - S Elgavish
- Info-CORE, Bioinformatics Unit of the I-CORE, Hebrew University of Jerusalem, Jerusalem, Israel
| | - G Nussbaum
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
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Hajishengallis G. Illuminating the oral microbiome and its host interactions: animal models of disease. FEMS Microbiol Rev 2023; 47:fuad018. [PMID: 37113021 PMCID: PMC10198557 DOI: 10.1093/femsre/fuad018] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 04/29/2023] Open
Abstract
Periodontitis and caries are driven by complex interactions between the oral microbiome and host factors, i.e. inflammation and dietary sugars, respectively. Animal models have been instrumental in our mechanistic understanding of these oral diseases, although no single model can faithfully reproduce all aspects of a given human disease. This review discusses evidence that the utility of an animal model lies in its capacity to address a specific hypothesis and, therefore, different aspects of a disease can be investigated using distinct and complementary models. As in vitro systems cannot replicate the complexity of in vivo host-microbe interactions and human research is typically correlative, model organisms-their limitations notwithstanding-remain essential in proving causality, identifying therapeutic targets, and evaluating the safety and efficacy of novel treatments. To achieve broader and deeper insights into oral disease pathogenesis, animal model-derived findings can be synthesized with data from in vitro and clinical research. In the absence of better mechanistic alternatives, dismissal of animal models on fidelity issues would impede further progress to understand and treat oral disease.
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Affiliation(s)
- George Hajishengallis
- Department of Basic and Translational Sciences, Laboratory of Innate Immunity and Inflammation, School of Dental Medicine, University of Pennsylvania, 240 S. 40th Street, Philadelphia, PA 19104-6030, USA
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4
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Pandi K, Angabo S, Gnanasekaran J, Makkawi H, Eli-Berchoer L, Glaser F, Nussbaum G. Porphyromonas gingivalis induction of TLR2 association with Vinculin enables PI3K activation and immune evasion. PLoS Pathog 2023; 19:e1011284. [PMID: 37023213 PMCID: PMC10112799 DOI: 10.1371/journal.ppat.1011284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 04/18/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Abstract
Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that thrives in the inflamed environment of the gingival crevice, and is strongly associated with periodontal disease. The host response to P. gingivalis requires TLR2, however P. gingivalis benefits from TLR2-driven signaling via activation of PI3K. We studied TLR2 protein-protein interactions induced in response to P. gingivalis, and identified an interaction between TLR2 and the cytoskeletal protein vinculin (VCL), confirmed using a split-ubiquitin system. Computational modeling predicted critical TLR2 residues governing the physical association with VCL, and mutagenesis of interface residues W684 and F719, abrogated the TLR2-VCL interaction. In macrophages, VCL knock-down led to increased cytokine production, and enhanced PI3K signaling in response to P. gingivalis infection, effects that correlated with increased intracellular bacterial survival. Mechanistically, VCL suppressed TLR2 activation of PI3K by associating with its substrate PIP2. P. gingivalis induction of TLR2-VCL led to PIP2 release from VCL, enabling PI3K activation via TLR2. These results highlight the complexity of TLR signaling, and the importance of discovering protein-protein interactions that contribute to the outcome of infection.
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Affiliation(s)
- Karthikeyan Pandi
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Sarah Angabo
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Jeba Gnanasekaran
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Hasnaa Makkawi
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Luba Eli-Berchoer
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Fabian Glaser
- Bioinformatics Knowledge Unit, The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Gabriel Nussbaum
- Institute of Biomedical and Oral Research, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
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5
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Chen WA, Dou Y, Fletcher HM, Boskovic DS. Local and Systemic Effects of Porphyromonas gingivalis Infection. Microorganisms 2023; 11:470. [PMID: 36838435 PMCID: PMC9963840 DOI: 10.3390/microorganisms11020470] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023] Open
Abstract
Porphyromonas gingivalis, a gram-negative anaerobe, is a leading etiological agent in periodontitis. This infectious pathogen can induce a dysbiotic, proinflammatory state within the oral cavity by disrupting commensal interactions between the host and oral microbiota. It is advantageous for P. gingivalis to avoid complete host immunosuppression, as inflammation-induced tissue damage provides essential nutrients necessary for robust bacterial proliferation. In this context, P. gingivalis can gain access to the systemic circulation, where it can promote a prothrombotic state. P. gingivalis expresses a number of virulence factors, which aid this pathogen toward infection of a variety of host cells, evasion of detection by the host immune system, subversion of the host immune responses, and activation of several humoral and cellular hemostatic factors.
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Affiliation(s)
- William A Chen
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Yuetan Dou
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Danilo S Boskovic
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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6
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Ciaston I, Dobosz E, Potempa J, Koziel J. The subversion of toll-like receptor signaling by bacterial and viral proteases during the development of infectious diseases. Mol Aspects Med 2022; 88:101143. [PMID: 36152458 PMCID: PMC9924004 DOI: 10.1016/j.mam.2022.101143] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 02/05/2023]
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that respond to pathogen-associated molecular patterns (PAMPs). The recognition of specific microbial ligands by TLRs triggers an innate immune response and also promotes adaptive immunity, which is necessary for the efficient elimination of invading pathogens. Successful pathogens have therefore evolved strategies to subvert and/or manipulate TLR signaling. Both the impairment and uncontrolled activation of TLR signaling can harm the host, causing tissue destruction and allowing pathogens to proliferate, thus favoring disease progression. In this context, microbial proteases are key virulence factors that modify components of the TLR signaling pathway. In this review, we discuss the role of bacterial and viral proteases in the manipulation of TLR signaling, highlighting the importance of these enzymes during the development of infectious diseases.
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Affiliation(s)
- Izabela Ciaston
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Ewelina Dobosz
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Potempa
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Oral Health and Systemic Disease, University of Louisville School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Joanna Koziel
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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7
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Yoshimoto T, Kittaka M, Doan AAP, Urata R, Prideaux M, Rojas RE, Harding CV, Henry Boom W, Bonewald LF, Greenfield EM, Ueki Y. Osteocytes directly regulate osteolysis via MYD88 signaling in bacterial bone infection. Nat Commun 2022; 13:6648. [PMID: 36333322 PMCID: PMC9636212 DOI: 10.1038/s41467-022-34352-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
The impact of bone cell activation on bacterially-induced osteolysis remains elusive. Here, we show that matrix-embedded osteocytes stimulated with bacterial pathogen-associated molecular patterns (PAMPs) directly drive bone resorption through an MYD88-regulated signaling pathway. Mice lacking MYD88, primarily in osteocytes, protect against osteolysis caused by calvarial injections of bacterial PAMPs and resist alveolar bone resorption induced by oral Porphyromonas gingivalis (Pg) infection. In contrast, mice with targeted MYD88 restoration in osteocytes exhibit osteolysis with inflammatory cell infiltration. In vitro, bacterial PAMPs induce significantly higher expression of the cytokine RANKL in osteocytes than osteoblasts. Mechanistically, activation of the osteocyte MYD88 pathway up-regulates RANKL by increasing binding of the transcription factors CREB and STAT3 to Rankl enhancers and by suppressing K48-ubiquitination of CREB/CREB binding protein and STAT3. Systemic administration of an MYD88 inhibitor prevents jawbone loss in Pg-driven periodontitis. These findings reveal that osteocytes directly regulate inflammatory osteolysis in bone infection, suggesting that MYD88 and downstream RANKL regulators in osteocytes are therapeutic targets for osteolysis in periodontitis and osteomyelitis.
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Affiliation(s)
- Tetsuya Yoshimoto
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Mizuho Kittaka
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Andrew Anh Phuong Doan
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Rina Urata
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Matthew Prideaux
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | | | - Clifford V Harding
- Department of Pathology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
| | - W Henry Boom
- Department of Pathology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
- Department of Molecular Biology and Microbiology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
| | - Lynda F Bonewald
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Edward M Greenfield
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Yasuyoshi Ueki
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA.
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA.
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8
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Wielento A, Bereta GP, Łagosz-Ćwik KB, Eick S, Lamont RJ, Grabiec AM, Potempa J. TLR2 Activation by Porphyromonas gingivalis Requires Both PPAD Activity and Fimbriae. Front Immunol 2022; 13:823685. [PMID: 35432342 PMCID: PMC9010743 DOI: 10.3389/fimmu.2022.823685] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/02/2022] [Indexed: 02/05/2023] Open
Abstract
Porphyromonas gingivalis, a keystone oral pathogen implicated in development and progression of periodontitis, may also contribute to the pathogenicity of diseases such as arthritis, atherosclerosis, and Alzheimer's. P. gingivalis is a master manipulator of host immune responses due to production of a large variety of virulence factors. Among these, P. gingivalis peptidilarginine deiminase (PPAD), an enzyme unique to P. gingivalis, converts C-terminal Arg residues in bacterium- and host-derived proteins and peptides into citrulline. PPAD contributes to stimulation of proinflammatory responses in host cells and is essential for activation of the prostaglandin E2 (PGE2) synthesis pathway in gingival fibroblasts. Since P. gingivalis is recognized mainly by Toll-like receptor-2 (TLR2), we investigated the effects of PPAD activity on TLR2-dependent host cell responses to P. gingivalis, as well as to outer membrane vesicles (OMVs) and fimbriae produced by this organism. Using reporter cell lines, we found that PPAD activity was required for TLR2 activation by P. gingivalis cells and OMVs. We also found that fimbriae, an established TLR2 ligand, from wild-type ATCC 33277 (but not from its isogenic PPAD mutant) enhanced the proinflammatory responses of host cells. Furthermore, only fimbriae from wild-type ATCC 33277, but not from the PPAD-deficient strains, induced cytokine production and stimulated expression of genes within the PGE2 synthesis pathway in human gingival fibroblasts via activation of the NF-ĸB and MAP kinase-dependent signaling pathways. Analysis of ten clinical isolates revealed that type I FimA is preferable for TLR2 signaling enhancement. In conclusion, the data strongly suggest that both PPAD activity and fimbriae are important for TLR2-dependent cell responses to P. gingivalis infection.
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Affiliation(s)
- Aleksandra Wielento
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Grzegorz P. Bereta
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Katarzyna B. Łagosz-Ćwik
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Sigrun Eick
- Department of Periodontology, Laboratory of Oral Microbiology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Richard J. Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States
| | - Aleksander M. Grabiec
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland,*Correspondence: Aleksander M. Grabiec, ; Jan Potempa,
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland,Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States,*Correspondence: Aleksander M. Grabiec, ; Jan Potempa,
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Francisco S, Billod JM, Merino J, Punzón C, Gallego A, Arranz A, Martin-Santamaria S, Fresno M. Induction of TLR4/TLR2 Interaction and Heterodimer Formation by Low Endotoxic Atypical LPS. Front Immunol 2022; 12:748303. [PMID: 35140704 PMCID: PMC8818788 DOI: 10.3389/fimmu.2021.748303] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/27/2021] [Indexed: 12/01/2022] Open
Abstract
The Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) complex is considered the major receptor of the innate immune system to recognize lipopolysaccharides (LPSs). However, some atypical LPSs with different lipid A and core saccharide moiety structures and compositions than the well-studied enterobacterial LPSs can induce a TLR2-dependent response in innate immune cells. Ochrobactrum intermedium, an opportunistic pathogen, presents an atypical LPS. In this study, we found that O. intermedium LPS exhibits a weak inflammatory activity compared to Escherichia coli LPS and, more importantly, is a specific TLR4/TLR2 agonist, able to signal through both receptors. Molecular docking analysis of O. intermedium LPS predicts a favorable formation of a TLR2/TLR4/MD-2 heterodimer complex, which was experimentally confirmed by fluorescence resonance energy transfer (FRET) in cells. Interestingly, the core saccharide plays an important role in this interaction. This study reveals for the first time TLR4/TLR2 heterodimerization that is induced by atypical LPS and may help to escape from recognition by the innate immune system.
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Affiliation(s)
- Sara Francisco
- Diomune S. L., Parque Científico de Madrid, Madrid, Spain
- Department of Molecular Biology, Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad Autónoma de Madrid, Madrid, Spain
| | - Jean-Marc Billod
- Department of Structural Biology, Centro de Investigaciones Biologicas “Margarita Salas”, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain
| | - Javier Merino
- Diomune S. L., Parque Científico de Madrid, Madrid, Spain
- Department of Molecular Biology, Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad Autónoma de Madrid, Madrid, Spain
| | - Carmen Punzón
- Diomune S. L., Parque Científico de Madrid, Madrid, Spain
| | - Alicia Gallego
- Department of Molecular Biology, Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad Autónoma de Madrid, Madrid, Spain
| | - Alicia Arranz
- Department of Molecular Biology, Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad Autónoma de Madrid, Madrid, Spain
| | - Sonsoles Martin-Santamaria
- Department of Structural Biology, Centro de Investigaciones Biologicas “Margarita Salas”, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain
| | - Manuel Fresno
- Diomune S. L., Parque Científico de Madrid, Madrid, Spain
- Department of Molecular Biology, Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad Autónoma de Madrid, Madrid, Spain
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Snyder LM, Doherty CM, Mercer HL, Denkers EY. Induction of IL-12p40 and type 1 immunity by Toxoplasma gondii in the absence of the TLR-MyD88 signaling cascade. PLoS Pathog 2021; 17:e1009970. [PMID: 34597344 PMCID: PMC8513874 DOI: 10.1371/journal.ppat.1009970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/13/2021] [Accepted: 09/25/2021] [Indexed: 12/18/2022] Open
Abstract
Toxoplasma gondii is an orally acquired pathogen that induces strong IFN-γ based immunity conferring protection but that can also be the cause of immunopathology. The response in mice is driven in part by well-characterized MyD88-dependent signaling pathways. Here we focus on induction of less well understood immune responses that do not involve this Toll-like receptor (TLR)/IL-1 family receptor adaptor molecule, in particular as they occur in the intestinal mucosa. Using eYFP-IL-12p40 reporter mice on an MyD88-/- background, we identified dendritic cells, macrophages, and neutrophils as cellular sources of MyD88-independent IL-12 after peroral T. gondii infection. Infection-induced IL-12 was lower in the absence of MyD88, but was still clearly above noninfected levels. Overall, this carried through to the IFN-γ response, which while generally decreased was still remarkably robust in the absence of MyD88. In the latter mice, IL-12 was strictly required to induce type I immunity. Type 1 and type 3 innate lymphoid cells (ILC), CD4+ T cells, and CD8+ T cells each contributed to the IFN-γ pool. We report that ILC3 were expanded in infected MyD88-/- mice relative to their MyD88+/+ counterparts, suggesting a compensatory response triggered by loss of MyD88. Furthermore, bacterial flagellin and Toxoplasma specific CD4+ T cell populations in the lamina propria expanded in response to infection in both WT and KO mice. Finally, we show that My88-independent IL-12 and T cell mediated IFN-γ production require the presence of the intestinal microbiota. Our results identify MyD88-independent intestinal immune pathways induced by T. gondii including myeloid cell derived IL-12 production, downstream type I immunity and IFN-γ production by ILC1, ILC3, and T lymphocytes. Collectively, our data reveal an underlying network of immune responses that do not involve signaling through MyD88. Toxoplasma gondii is an apicomplexan parasite estimated to infect 30–50% of humans worldwide. The parasite normally establishes latency in brain and muscle tissue marked by persistent asymptomatic infection. T. gondii masterfully strikes a balance between eliciting strong, anti-parasite immunity while also persisting in the host. Although the murine host recognizes Toxoplasma profilin via MyD88 and Toll-like receptors 11/12, humans lack these receptors and MyD88 deficient patients retain resistance to T. gondii infection. Given these observations, it is important to identify MyD88 independent pathways of immunity. Using an oral infection mouse model, we identified cellular sources of IL-12 and IFN-γ, two cytokines that are essential for host resistance to this microbial pathogen. We determined how these responses are impacted by the presence and absence of MyD88 and the intestinal microbiota. Our data demonstrate that T. gondii triggers MyD88-independent innate and adaptive immunity in the intestinal mucosa that requires the presence of intestinal microbes. These pathways may be conserved among species and understanding how they work in rodents will likely help determine how humans recognize and respond to T. gondii infection.
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Affiliation(s)
- Lindsay M Snyder
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Claire M Doherty
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Heather L Mercer
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Eric Y Denkers
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
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11
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Illouz T, Biragyn A, Iulita MF, Flores-Aguilar L, Dierssen M, De Toma I, Antonarakis SE, Yu E, Herault Y, Potier MC, Botté A, Roper R, Sredni B, London J, Mobley W, Strydom A, Okun E. Immune Dysregulation and the Increased Risk of Complications and Mortality Following Respiratory Tract Infections in Adults With Down Syndrome. Front Immunol 2021; 12:621440. [PMID: 34248930 PMCID: PMC8267813 DOI: 10.3389/fimmu.2021.621440] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 06/02/2021] [Indexed: 12/12/2022] Open
Abstract
The risk of severe outcomes following respiratory tract infections is significantly increased in individuals over 60 years, especially in those with chronic medical conditions, i.e., hypertension, diabetes, cardiovascular disease, dementia, chronic respiratory disease, and cancer. Down Syndrome (DS), the most prevalent intellectual disability, is caused by trisomy-21 in ~1:750 live births worldwide. Over the past few decades, a substantial body of evidence has accumulated, pointing at the occurrence of alterations, impairments, and subsequently dysfunction of the various components of the immune system in individuals with DS. This associates with increased vulnerability to respiratory tract infections in this population, such as the influenza virus, respiratory syncytial virus, SARS-CoV-2 (COVID-19), and bacterial pneumonias. To emphasize this link, here we comprehensively review the immunobiology of DS and its contribution to higher susceptibility to severe illness and mortality from respiratory tract infections.
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Affiliation(s)
- Tomer Illouz
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
- The Paul Feder Laboratory on Alzheimer’s Disease Research, Bar-Ilan University, Ramat Gan, Israel
| | - Arya Biragyn
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institute of Health, Baltimore, MD, United States
| | - Maria Florencia Iulita
- Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
- Biomedical Research Institute Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Lisi Flores-Aguilar
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Mara Dierssen
- Center for Genomic Regulation, The Barcelona Institute for Science and Technology, Barcelona, Spain
- University Pompeu Fabra, Barcelona, Spain
- Biomedical Research Networking Center for Rare Diseases (CIBERER), Barcelona, Spain
| | - Ilario De Toma
- Center for Genomic Regulation, The Barcelona Institute for Science and Technology, Barcelona, Spain
- University Pompeu Fabra, Barcelona, Spain
- Biomedical Research Networking Center for Rare Diseases (CIBERER), Barcelona, Spain
| | - Stylianos E. Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
- Medigenome, Swiss Institute of Genomic Medicine, Geneva, Switzerland
- iGE3 Institute of Genetics and Genomics of Geneva, Geneva, Switzerland
| | - Eugene Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
- Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY, United States
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique Biologie Moléculaire et Cellulaire, IGBMC - UMR 7104 - Inserm U1258, Illkirch, France
| | - Marie-Claude Potier
- Paris Brain Institute (ICM), CNRS UMR7225, INSERM U1127, Sorbonne Université, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Alexandra Botté
- Paris Brain Institute (ICM), CNRS UMR7225, INSERM U1127, Sorbonne Université, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Randall Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Benjamin Sredni
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | | | - William Mobley
- Department of Neurosciences, University of California, San Diego, San Diego, CA, United States
| | - Andre Strydom
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry Psychology and Neuroscience, King’s College London, London, United Kingdom
- South London and Maudsley NHS Foundation Trust, London, United Kingdom
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
- The Paul Feder Laboratory on Alzheimer’s Disease Research, Bar-Ilan University, Ramat Gan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
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12
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He B, Nie Q, Wang F, Han Y, Yang B, Sun M, Fan X, Ye Z, Liu P, Wen J. Role of pyroptosis in atherosclerosis and its therapeutic implications. J Cell Physiol 2021; 236:7159-7175. [PMID: 33755211 DOI: 10.1002/jcp.30366] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/20/2021] [Accepted: 03/08/2021] [Indexed: 12/11/2022]
Abstract
Atherosclerosis is a significant cardiovascular burden and a leading cause of death worldwide, recognized as a chronic sterile inflammatory disease. Pyroptosis is a novel proinflammatory regulated cell death, characterized by cell swelling, plasma membrane bubbling, and robust release of proinflammatory cytokines (such as interleukin IL-1β and IL-18). Mounting studies have addressed the crucial contribution of pyroptosis to atherosclerosis and clarified the candidate therapeutic agents targeting pyroptosis for atherosclerosis. Herein, we review the initial characterization of pyroptosis, the detailed mechanisms of pyroptosis, current evidence about pyroptosis and atherosclerosis, and potential therapeutic strategies that target pyroptosis in the development of atherosclerosis.
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Affiliation(s)
- Bin He
- Department of Cardiovascular Surgery, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China
| | - Qiangqiang Nie
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Feng Wang
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Yongxin Han
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Bo Yang
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Mingsheng Sun
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Xueqiang Fan
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Zhidong Ye
- Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Peng Liu
- Department of Cardiovascular Surgery, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China.,Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Jianyan Wen
- Department of Cardiovascular Surgery, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China.,Department of Cardiovascular Surgery, China-Japan Friendship Hospital, Beijing, China
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13
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Jiang Q, Zhao Y, Shui Y, Zhou X, Cheng L, Ren B, Chen Z, Li M. Interactions Between Neutrophils and Periodontal Pathogens in Late-Onset Periodontitis. Front Cell Infect Microbiol 2021; 11:627328. [PMID: 33777839 PMCID: PMC7994856 DOI: 10.3389/fcimb.2021.627328] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/03/2021] [Indexed: 02/05/2023] Open
Abstract
Late-onset periodontitis is associated with a series of inflammatory reactions induced by periodontal pathogens, such as Porphyromonas gingivalis, a keystone pathogen involved in periodontitis. Neutrophils are the most abundant leukocytes in the periodontal pocket/gingival crevice and inflamed periodontal tissues. They form a “wall” between the dental plaque and the junctional epithelium, preventing microbial invasion. The balance between neutrophils and the microbial community is essential to periodontal homeostasis. Excessive activation of neutrophils in response to periodontal pathogens can induce tissue damage and lead to periodontitis persistence. Therefore, illuminating the interactions between neutrophils and periodontal pathogens is critical for progress in the field of periodontitis. The present review aimed to summarize the interactions between neutrophils and periodontal pathogens in late-onset periodontitis, including neutrophil recruitment, neutrophil mechanisms to clear the pathogens, and pathogen strategies to evade neutrophil-mediated elimination of bacteria. The recruitment is a multi-step process, including tethering and rolling, adhesion, crawling, and transmigration. Neutrophils clear the pathogens mainly by phagocytosis, respiratory burst responses, degranulation, and neutrophil extracellular trap (NET) formation. The mechanisms that pathogens activate to evade neutrophil-mediated killing include impairing neutrophil recruitment, preventing phagocytosis, uncoupling killing from inflammation, and resistance to ROS, degranulation products, and NETs.
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Affiliation(s)
- Qingsong Jiang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Yuxi Zhao
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Yusen Shui
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Biao Ren
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
| | - Zhu Chen
- Department of Conservative Dentistry and Endodontics, Guiyang Hospital of Stomatology, Guiyang, China
| | - Mingyun Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China
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14
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Hajishengallis G, Lamont RJ. Polymicrobial communities in periodontal disease: Their quasi-organismal nature and dialogue with the host. Periodontol 2000 2021; 86:210-230. [PMID: 33690950 DOI: 10.1111/prd.12371] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/05/2020] [Accepted: 03/28/2020] [Indexed: 12/11/2022]
Abstract
In health, indigenous polymicrobial communities at mucosal surfaces maintain an ecological balance via both inter-microbial and host-microbial interactions that promote their own and the host's fitness, while preventing invasion by exogenous pathogens. However, genetic and acquired destabilizing factors (including immune deficiencies, immunoregulatory defects, smoking, diet, obesity, diabetes and other systemic diseases, and aging) may disrupt this homeostatic balance, leading to selective outgrowth of species with the potential for destructive inflammation. This process, known as dysbiosis, underlies the development of periodontitis in susceptible hosts. The pathogenic process is not linear but involves a positive-feedback loop between dysbiosis and the host inflammatory response. The dysbiotic community is essentially a quasi-organismal entity, where constituent organisms communicate via sophisticated physical and chemical signals and display functional specialization (eg, accessory pathogens, keystone pathogens, pathobionts), which enables polymicrobial synergy and dictates the community's pathogenic potential or nososymbiocity. In this review, we discuss early and recent studies in support of the polymicrobial synergy and dysbiosis model of periodontal disease pathogenesis. According to this concept, disease is not caused by individual "causative pathogens" but rather by reciprocally reinforced interactions between physically and metabolically integrated polymicrobial communities and a dysregulated host inflammatory response.
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Affiliation(s)
- George Hajishengallis
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, USA
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, USA
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15
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Meka SRK, Younis T, Reich E, Elayyan J, Kumar A, Merquiol E, Blum G, Kalmus S, Maatuf YH, Batshon G, Nussbaum G, Houri-Haddad Y, Dvir-Ginzberg M. TNFα expression by Porphyromonas gingivalis-stimulated macrophages relies on Sirt1 cleavage. J Periodontal Res 2021; 56:535-546. [PMID: 33559894 DOI: 10.1111/jre.12853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/15/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Periodontitis is one the most common chronic inflammatory conditions, resulting in destruction of tooth-supporting tissues and leading to tooth loss. Porphyromonas gingivalis activates host macrophages to secrete pro-inflammatory cytokines and elicit tissue damage, in part by inducing NF-kappa-B transactivation. Since NFκB transactivation is negatively regulated by the Nicotinamide adenine dinucleotide (NAD)-dependent deacetylase enzyme Sirt1, we sought to assess if RAW264.7 macrophages exposed to P. gingivalis demonstrate impaired Sirt1 activity, to ultimately induce a pro-inflammatory response. METHODS RAW264.7 macrophages were incubated with heat- killed P. gingivalis for 2, 4, 8, and 24 h. Stimulated RAW264.7 were assessed for TNFα expression via PCR, ELISA, and ChIP analysis. Following the activation of RAW264.7 macrophages, immunoblot analysis was executed to detect modifications in Sirt1 and the NFκB subunit RelA that is essential for NFκB transcriptional activity. RESULTS TNFα expression was elevated 4 h after exposure to P. gingivalis. ChIP confirmed that RelA was enriched in the mouse TNFα promoter 4 h following stimulation, which correlated with the increased TNFα mRNA levels. Preceding TNFα expression, we detected Phosphoserine 536 and acetylated lysine 310 of RelA after 2 hours exposure with P. gingivalis. Moreover, reduced Sirt1 activity was associated with its cleavage in RAW264.7 protein extracts, after 2 hours of P. gingivalis exposure. Blocking TLR2/4 signaling prevented Sirt1 cleavage, loss of deacetylase activity, and TNFα secretion, while co-administering CA074Me (a cathepsin B inhibitor) with P. gingivalis reduced RelA promoter enrichment, resulting in impaired TNFα expression. CONCLUSIONS Together, the results suggest that P. gingivalis induces TNFα expression, at least in part, by enhancing cleavage of Sirt1 via a TLR-dependent signaling circuit.
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Affiliation(s)
- Sai R K Meka
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Tahsin Younis
- Department of Prosthodontics, Faculty of Dental Medicine, Jerusalem, Israel
| | - Eli Reich
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Jinan Elayyan
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Ashok Kumar
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Emmanuelle Merquiol
- School of Pharmacy- Institute for Drug Research, Faculty of Medicine, The Hebrew University- Jerusalem, Jerusalem, Israel
| | - Galia Blum
- School of Pharmacy- Institute for Drug Research, Faculty of Medicine, The Hebrew University- Jerusalem, Jerusalem, Israel
| | - Shira Kalmus
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Yonathan H Maatuf
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - George Batshon
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Gabriel Nussbaum
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
| | - Yael Houri-Haddad
- Department of Prosthodontics, Faculty of Dental Medicine, Jerusalem, Israel
| | - Mona Dvir-Ginzberg
- Faculty of Dental Medicine, Institute of Dental Sciences, Jerusalem, Israel
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16
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Miralda I, Uriarte SM. Periodontal Pathogens' strategies disarm neutrophils to promote dysregulated inflammation. Mol Oral Microbiol 2020; 36:103-120. [PMID: 33128827 PMCID: PMC8048607 DOI: 10.1111/omi.12321] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/16/2020] [Accepted: 10/28/2020] [Indexed: 12/26/2022]
Abstract
Periodontitis is an irreversible, chronic inflammatory disease where inflammophilic pathogenic microbial communities accumulate in the gingival crevice. Neutrophils are a major component of the innate host response against bacterial challenge, and under homeostatic conditions, their microbicidal functions typically protect the host against periodontitis. However, a number of periodontal pathogens developed survival strategies to evade neutrophil microbicidal functions while promoting inflammation, which provides a source of nutrients for bacterial growth. Research on periodontal pathogens has largely focused on a few established species: Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis. However, advances in culture-independent techniques have facilitated the identification of new bacterial species in periodontal lesions, such as the two Gram-positive anaerobes, Filifactor alocis and Peptoanaerobacter stomatis, whose characterization of pathogenic potential has not been fully described. Additionally, there is not a full understanding of the pathogenic mechanisms used against neutrophils by organisms that are abundant in periodontal lesions. This presents a substantial barrier to the development of new approaches to prevent or ameliorate the disease. In this review, we first summarize the neutrophil functions affected by the established periodontal pathogens listed above, denoting unknown areas that still merit a closer look. Then, we review the literature on neutrophil functions and the emerging periodontal pathogens, F. alocis and P. stomatis, comparing the effects of the emerging microbes to that of established pathogens, and speculate on the contribution of these putative pathogens to the progression of periodontal disease.
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Affiliation(s)
- Irina Miralda
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
| | - Silvia M Uriarte
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
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17
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Cai X, Li Z, Zhao Y, Katz J, Michalek SM, Feng X, Li Y, Zhang P. Enhanced dual function of osteoclast precursors following calvarial Porphyromonas gingivalis infection. J Periodontal Res 2020; 55:410-425. [PMID: 31944305 PMCID: PMC7250733 DOI: 10.1111/jre.12725] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/23/2019] [Accepted: 11/25/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND OBJECTIVE Excessive osteoclast activity is a major characteristic of pathogenic bone loss in inflammatory bone diseases including periodontitis. However, beyond the knowledge that osteoclasts are differentiated from the monocyte/macrophage lineage and share common ancestry with macrophages and DC, the nature and function of osteoclast precursors are not completely understood. Furthermore, little is known about how osteoclast precursors respond to bacterial infection in vivo. We have previously demonstrated in vitro that the periodontal pathogen Porphyromonas gingivalis (Pg) plays a biphasic role on the receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclast differentiation. In this study, we investigated the in vivo effect of Pg infection on the regulation of osteoclast precursors, using a mouse calvarial infection model. METHODS AND RESULTS C57BL/6 wild-type and the myeloid differentiation factor 88 knockout (MyD88-/- ) mice were infected with Pg by calvarial injection. Local and systemic bone loss, and the number and function of CD11b+ c-fms+ cells from bone marrow and spleen were analyzed. Our results show that Pg infection induces localized inflammatory infiltration and osteoclastogenesis, as well as increased number and osteoclastogenic potential of CD11b+ c-fms+ osteoclast precursors in the bone marrow and periphery. We also show that CD11b+ c-fms+ RANK+ and CD11b+ c-fms+ RANK- are precursors with similar osteoclastogenic and pro-inflammatory potentials. In addition, CD11b+ c-fms+ cells exhibit an antigen-specific T-cell immune-suppressive activity, which are increased with Pg infection. Moreover, we demonstrate that MyD88 is involved in the regulation of osteoclast precursors upon Pg infection. CONCLUSIONS In this study, we demonstrate an enhanced dual function of osteoclast precursors following calvarial Pg infection. Based on our findings, we propose the following model: Pg infection increases a pool of precursor cells that can be shunted toward osteoclast formation at the infection/inflammation sites, while at the same time dampening host immune responses, which is beneficial for the persistence of infection and maintenance of the characteristic chronic nature of periodontitis. Understanding the nature, function, and regulation of osteoclast precursors will be helpful for identifying therapeutic interventions to aid in the control and prevention of inflammatory bone loss diseases including periodontitis.
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Affiliation(s)
- Xia Cai
- Department of Pediatric DentistrySchool of DentistryUniversity of Alabama at BirminghamBirminghamALUSA
- Department of PeriodonticsThe Affiliated Stomatological HospitalSchool of MedicineZhejiang UniversityHangzhouChina
| | - Zhaofei Li
- Department of Pediatric DentistrySchool of DentistryUniversity of Alabama at BirminghamBirminghamALUSA
- Department of EndodonticsSchool of StomatologyWuhan UniversityWuhanChina
| | - Yanfang Zhao
- Department of Pediatric DentistrySchool of DentistryUniversity of Alabama at BirminghamBirminghamALUSA
| | - Jenny Katz
- Department of Pediatric DentistrySchool of DentistryUniversity of Alabama at BirminghamBirminghamALUSA
| | - Suzanne M. Michalek
- Department of MicrobiologyUniversity of Alabama at BirminghamBirminghamALUSA
| | - Xu Feng
- Department of Molecular & Cellular PathologySchool of MedicineUniversity of Alabama at BirminghamBirminghamALUSA
| | - Yuhong Li
- Department of EndodonticsSchool of StomatologyWuhan UniversityWuhanChina
| | - Ping Zhang
- Department of Pediatric DentistrySchool of DentistryUniversity of Alabama at BirminghamBirminghamALUSA
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18
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Hajishengallis G. New developments in neutrophil biology and periodontitis. Periodontol 2000 2019; 82:78-92. [DOI: 10.1111/prd.12313] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- George Hajishengallis
- Department of Microbiology Penn Dental Medicine University of Pennsylvania Philadelphia Pennsylvania, USA
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The Distinct Immune-Stimulatory Capacities of Porphyromonas gingivalis Strains 381 and ATCC 33277 Are Determined by the fimB Allele and Gingipain Activity. Infect Immun 2019; 87:IAI.00319-19. [PMID: 31570556 DOI: 10.1128/iai.00319-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/19/2019] [Indexed: 11/20/2022] Open
Abstract
The Porphyromonas gingivalis strain ATCC 33277 (33277) and 381 genomes are nearly identical. However, strain 33277 displays a significantly diminished capacity to stimulate host cell Toll-like receptor 2 (TLR2)-dependent signaling and interleukin-1β (IL-1β) production relative to 381, suggesting that there are strain-specific differences in one or more bacterial immune-modulatory factors. Genomic sequencing identified a single nucleotide polymorphism in the 33277 fimB allele (A→T), creating a premature stop codon in the 33277 fimB open reading frame relative to the 381 fimB allele. Gene exchange experiments established that the 33277 fimB allele reduces the immune-stimulatory capacity of this strain. Transcriptome comparisons revealed that multiple genes related to carboxy-terminal domain (CTD) family proteins, including the gingipains, were upregulated in 33277 relative to 381. A gingipain substrate degradation assay demonstrated that cell surface gingipain activity is higher in 33277, and an isogenic mutant strain deficient for the gingipains exhibited an increased ability to induce TLR2 signaling and IL-1β production. Furthermore, 33277 and 381 mutant strains lacking CTD cell surface proteins were more immune-stimulatory than the parental wild-type strains, consistent with an immune-suppressive role for the gingipains. Our data show that the combination of an intact fimB allele and limited cell surface gingipain activity in P. gingivalis 381 renders this strain more immune-stimulatory. Conversely, a defective fimB allele and high-level cell surface gingipain activity reduce the capacity of P. gingivalis 33277 to stimulate host cell innate immune responses. In summary, genomic and transcriptomic comparisons identified key virulence characteristics that confer divergent host cell innate immune responses to these highly related P. gingivalis strains.
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Jia L, Han N, Du J, Guo L, Luo Z, Liu Y. Pathogenesis of Important Virulence Factors of Porphyromonas gingivalis via Toll-Like Receptors. Front Cell Infect Microbiol 2019; 9:262. [PMID: 31380305 PMCID: PMC6657652 DOI: 10.3389/fcimb.2019.00262] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/04/2019] [Indexed: 12/18/2022] Open
Abstract
Periodontitis is a common intraoral infection and is inextricably linked to systemic diseases. Recently, the regulation between host immunologic response and periodontal pathogens has become a hotspot to explain the mechanism of periodontitis and related systemic diseases. Since Porphyromonas gingivalis (P. gingivalis) was proved as critical periodontal pathogen above all, researches focusing on the mechanism of its virulence factors have received extensive attention. Studies have shown that in the development of periodontitis, in addition to the direct release of virulent factors by periodontal pathogens to destroy periodontal tissues, over-low or over-high intrinsic immune and inflammatory response mediated by Toll-like receptors (TLRs) can lead to more lasting destruction of periodontal tissues. It is very necessary to sort out how various cytopathic factors of P. gingivalis mediate inflammation and immune responses between the host through TLRs so as to help precisely prevent, diagnose, and treat periodontitis in clinic. This review summarizes the role of three most widely studied pathogenic factors produced by P. gingivalis (lipopolysaccharide, gingipains, pili) and their interactions with TLRs at the cellular and molecular level in the progress of periodontitis.
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Affiliation(s)
- Lu Jia
- Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing, China
| | - Nannan Han
- Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing, China
| | - Juan Du
- Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing, China
| | - Lijia Guo
- Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China
| | - Zhenhua Luo
- Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing, China
| | - Yi Liu
- Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing, China
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Polak D, Zigron A, Eli-Berchoer L, Shapira L, Nussbaum G. Myd88 plays a major role in the keratinocyte response to infection with Porphyromonas gingivalis. J Periodontal Res 2019; 54:396-404. [PMID: 30793777 DOI: 10.1111/jre.12641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 12/11/2018] [Accepted: 01/13/2019] [Indexed: 11/28/2022]
Abstract
AIM To explore the role of keratinocyte myeloid differentiation primary response 88 (MyD88) expression in the adhesion of Porphyromonas gingivalis to the cells and its subsequent invasion and intracellular survival. MATERIALS AND METHODS Primary mouse keratinocytes from wild-type (WT) or Myd88-/- mice were infected with P gingivalis alone or co-infected with Fusobacterium nucleatum. Bacterial adhesion and invasion were measured using fluorescent microscopy and flow cytometry, and intracellular survival in keratinocytes was quantified by an antibiotic protection assay. Keratinocyte expression of antimicrobial peptides was measured by real-time PCR. RESULTS In the absence of MyD88, P gingivalis adherence, invasion, and intracellular survival were enhanced compared with WT keratinocytes. The presence of F nucleatum during infection increased the adhesion of P gingivalis to WT keratinocytes but reduced the adhesion to Myd88-/- keratinocytes. Fusobacterium nucleatum improved mildly the invasion and survival of P gingivalis in both cell types. Baseline expression of beta-defensin 2, 3, 4 and RegIII-γ was elevated in Myd88-/- keratinocytes compared to WT cells; however, following infection beta-defensin expression was strongly induced in WT cells but decreased dramatically in the MyD88 deficient cells. CONCLUSION In the absence of MyD88 expression, P gingivalis adhesion to keratinocytes is improved, and invasion and intracellular survival are increased. Furthermore, keratinocyte infection by P gingivalis induces antimicrobial peptide expression in a MyD88-dependent manner. Thus, MyD88 plays a key role in the interaction between P gingivalis and keratinocytes.
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Affiliation(s)
- David Polak
- Department of Periodontology, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
| | - Asaf Zigron
- Department of Periodontology, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel.,Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
| | - Luba Eli-Berchoer
- Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
| | - Lior Shapira
- Department of Periodontology, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
| | - Gabriel Nussbaum
- Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
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22
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Jiang L, Chen XQ, Gao MJ, Lee W, Zhou J, Zhao YF, Wang GD. The Pros1/Tyro3 axis protects against periodontitis by modulating STAT/SOCS signalling. J Cell Mol Med 2019; 23:2769-2781. [PMID: 30729671 PMCID: PMC6433735 DOI: 10.1111/jcmm.14183] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 11/21/2018] [Accepted: 01/10/2019] [Indexed: 12/17/2022] Open
Abstract
Periodontitis, an oral inflammatory disease caused by periodontal pathogen infection, is the most prevalent chronic inflammatory disease and a major burden on healthcare. The TAM receptor tyrosine kinases (Tyro3, Axl and Mertk) and their ligands (Gas6 and Pros1) play a pivotal role in the resolution of inflammation and have been associated with chronic inflammatory and autoimmune diseases. In this study, we evaluated the effects of exogenous Pros1 in in vitro and in vivo models of periodontitis. We detected higher Pros1 but lower Tyro3 levels in inflamed gingival specimens of periodontitis patients compared with healthy controls. Moreover, Pros1 was mostly localized in the gingival epithelium of all specimens. In cultured human gingival epithelial cells (hGECs), Porphyromonas gingivalis LPS (p.g-LPS) stimulation down-regulated Pros1 and Tyro3. Exogenous Pros1 inhibited p.g-LPS-induced production of TNF-α, IL-6, IL-1β, MMP9/2 and RANKL in a Tyro3-dependent manner as revealed by PCR, Western blot analysis, ELISA and gelatin zymography. Pros1 also restored Tyro3 expression down-regulated by p.g-LPS in hGECs. In rats treated with ligature and p.g-LPS, administration of Pros1 attenuated periodontitis-associated gingival inflammation and alveolar bone loss. Our mechanistic studies implicated SOCS1/3 and STAT1/3 as mediators of the in vitro and in vivo anti-inflammatory effects of Pros1. Collectively, the findings from this work supported Pros1 as a novel anti-inflammatory therapy for periodontitis.
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Affiliation(s)
- Lei Jiang
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Xiao Qing Chen
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Ming Jing Gao
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Wai Lee
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Jie Zhou
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Yun Fu Zhao
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
| | - Guo Dong Wang
- Department of Stomatology, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China
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Abstract
The dynamic and polymicrobial oral microbiome is a direct precursor of diseases such as dental caries and periodontitis, two of the most prevalent microbially induced disorders worldwide. Distinct microenvironments at oral barriers harbour unique microbial communities, which are regulated through sophisticated signalling systems and by host and environmental factors. The collective function of microbial communities is a major driver of homeostasis or dysbiosis and ultimately health or disease. Despite different aetiologies, periodontitis and caries are each driven by a feedforward loop between the microbiota and host factors (inflammation and dietary sugars, respectively) that favours the emergence and persistence of dysbiosis. In this Review, we discuss current knowledge and emerging mechanisms governing oral polymicrobial synergy and dysbiosis that have both enhanced our understanding of pathogenic mechanisms and aided the design of innovative therapeutic approaches for oral diseases.
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Affiliation(s)
- Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Hyun Koo
- Department of Orthodontics and Divisions of Pediatric Dentistry and Community Oral Health, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - George Hajishengallis
- Department of Microbiology, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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24
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Wallet SM, Puri V, Gibson FC. Linkage of Infection to Adverse Systemic Complications: Periodontal Disease, Toll-Like Receptors, and Other Pattern Recognition Systems. Vaccines (Basel) 2018; 6:E21. [PMID: 29621153 PMCID: PMC6027258 DOI: 10.3390/vaccines6020021] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/25/2018] [Accepted: 03/30/2018] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptors (TLRs) are a group of pattern recognition receptors (PRRs) that provide innate immune sensing of conserved pathogen-associated molecular patterns (PAMPs) to engage early immune recognition of bacteria, viruses, and protozoa. Furthermore, TLRs provide a conduit for initiation of non-infectious inflammation following the sensing of danger-associated molecular patterns (DAMPs) generated as a consequence of cellular injury. Due to their essential role as DAMP and PAMP sensors, TLR signaling also contributes importantly to several systemic diseases including cardiovascular disease, diabetes, and others. The overlapping participation of TLRs in the control of infection, and pathogenesis of systemic diseases, has served as a starting point for research delving into the poorly defined area of infection leading to increased risk of various systemic diseases. Although conflicting studies exist, cardiovascular disease, diabetes, cancer, rheumatoid arthritis, and obesity/metabolic dysfunction have been associated with differing degrees of strength to infectious diseases. Here we will discuss elements of these connections focusing on the contributions of TLR signaling as a consequence of bacterial exposure in the context of the oral infections leading to periodontal disease, and associations with metabolic diseases including atherosclerosis and type 2 diabetes.
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Affiliation(s)
- Shannon M Wallet
- Department of Oral Biology, College of Dental Medicine, University of Florida, Gainesville, FL 32610, USA.
| | - Vishwajeet Puri
- Department of Biomedical Sciences and Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Frank C Gibson
- Department of Oral Biology, College of Dental Medicine, University of Florida, Gainesville, FL 32610, USA.
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25
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Makkawi H, Hoch S, Burns E, Hosur K, Hajishengallis G, Kirschning CJ, Nussbaum G. Porphyromonas gingivalis Stimulates TLR2-PI3K Signaling to Escape Immune Clearance and Induce Bone Resorption Independently of MyD88. Front Cell Infect Microbiol 2017; 7:359. [PMID: 28848717 PMCID: PMC5550410 DOI: 10.3389/fcimb.2017.00359] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/25/2017] [Indexed: 01/18/2023] Open
Abstract
Porphyromonas gingivalis is a gram-negative anaerobic periodontal pathogen that persists in dysbiotic mixed-species biofilms alongside a dense inflammatory infiltrate of neutrophils and other leukocytes in the subgingival areas of the periodontium. Toll-like receptor 2 (TLR2) mediates the inflammatory response to P. gingivalis and TLR2-deficient mice resist alveolar bone resorption following oral challenge with this organism. Although, MyD88 is an adaptor protein considered necessary for TLR2-induced inflammation, we now report for the first time that oral challenge with P. gingivalis leads to alveolar bone resorption in the absence of MyD88. Indeed, in contrast to prototypical TLR2 agonists, such as the lipopeptide Pam3CSK4 that activates TLR2 in a strictly MyD88-dependent manner, P. gingivalis strikingly induced TLR2 signaling in neutrophils and macrophages regardless of the presence or absence of MyD88. Moreover, genetic or antibody-mediated inactivation of TLR2 completely reduced cytokine production in P. gingivalis-stimulated neutrophils or macrophages, suggesting that TLR2 plays a non-redundant role in the host response to P. gingivalis. In the absence of MyD88, inflammatory TLR2 signaling in P. gingivalis-stimulated neutrophils or macrophages depended upon PI3K. Intriguingly, TLR2-PI3K signaling was also critical to P. gingivalis evasion of killing by macrophages, since their ability to phagocytose this pathogen was reduced in a TLR2 and PI3K-dependent manner. Moreover, within those cells that did phagocytose bacteria, TLR2-PI3K signaling blocked phago-lysosomal maturation, thereby revealing a novel mechanism whereby P. gingivalis can enhance its intracellular survival. Therefore, P. gingivalis uncouples inflammation from bactericidal activity by substituting TLR2-PI3K in place of TLR2-MyD88 signaling. These findings further support the role of P. gingivalis as a keystone pathogen, which manipulates the host inflammatory response in a way that promotes bone loss but not bacterial clearance. Modulation of these host response factors may lead to novel therapeutic approaches to improve outcomes in disease conditions associated with P. gingivalis.
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Affiliation(s)
- Hasnaa Makkawi
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental MedicineJerusalem, Israel
| | - Shifra Hoch
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental MedicineJerusalem, Israel
| | - Elia Burns
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental MedicineJerusalem, Israel
| | - Kavita Hosur
- Department of Microbiology, School of Dental Medicine, University of PennsylvaniaPhiladelphia, PA, United States
| | - George Hajishengallis
- Department of Microbiology, School of Dental Medicine, University of PennsylvaniaPhiladelphia, PA, United States
| | | | - Gabriel Nussbaum
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental MedicineJerusalem, Israel
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26
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Hajishengallis G, Lambris JD. More than complementing Tolls: complement-Toll-like receptor synergy and crosstalk in innate immunity and inflammation. Immunol Rev 2017; 274:233-244. [PMID: 27782328 DOI: 10.1111/imr.12467] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Complement and Toll-like receptors (TLRs) play key roles in the host immune response and are swiftly activated by infection or other types of immunological stress. This review focuses on the capacity of complement and TLRs to engage in signaling crosstalk, ostensibly to coordinate immune and inflammatory responses through synergistic or antagonistic (regulatory) interactions. However, overactivation or dysregulation of either system may lead-often synergistically-to exaggerated inflammation and host tissue injury. Intriguingly, moreover, certain pathogens can manipulate complement-TLR crosstalk pathways in ways that undermine host immunity and favor their persistence. In the setting of polymicrobial inflammatory disease, subversion of complement-TLR crosstalk by keystone pathogens can promote dysbiosis. Knowledge of the molecular mechanisms underlying complement-TLR crosstalk pathways can, therefore, be used productively for tailored therapeutic approaches, such as, to enhance host immunity, mitigate destructive inflammation, or counteract microbial subversion of the host response.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
| | - John D Lambris
- Perelman School of Medicine, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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27
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Tzach-Nahman R, Mizraji G, Shapira L, Nussbaum G, Wilensky A. Oral infection with Porphyromonas gingivalis
induces peri-implantitis in a murine model: Evaluation of bone loss and the local inflammatory response. J Clin Periodontol 2017; 44:739-748. [DOI: 10.1111/jcpe.12735] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Rinat Tzach-Nahman
- Department of Periodontology; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
- The Institute of Dental Sciences; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Gabriel Mizraji
- Department of Periodontology; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
- The Institute of Dental Sciences; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Lior Shapira
- Department of Periodontology; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Gabriel Nussbaum
- The Institute of Dental Sciences; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Asaf Wilensky
- Department of Periodontology; Faculty of Dental Medicine; The Hebrew University-Hadassah Medical Center; Jerusalem Israel
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28
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Suzuki JI, Sato H, Kaneko M, Yoshida A, Aoyama N, Akimoto S, Wakayama K, Kumagai H, Ikeda Y, Akazawa H, Izumi Y, Isobe M, Komuro I. Periodontitis and myocardial hypertrophy. Hypertens Res 2016; 40:324-328. [DOI: 10.1038/hr.2016.146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/15/2016] [Accepted: 10/03/2016] [Indexed: 02/07/2023]
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29
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Papadopoulos G, Shaik-Dasthagirisaheb YB, Huang N, Viglianti GA, Henderson AJ, Kantarci A, Gibson FC. Immunologic environment influences macrophage response to Porphyromonas gingivalis. Mol Oral Microbiol 2016; 32:250-261. [PMID: 27346827 DOI: 10.1111/omi.12168] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2016] [Indexed: 02/03/2023]
Abstract
Macrophages adapt both phenotypically and functionally to the cytokine balance in host tissue microenvironments. Recent studies established that macrophages contribute an important yet poorly understood role in the development of infection-elicited oral bone loss. We hypothesized that macrophage adaptation to inflammatory signals encountered before pathogen interaction would significantly influence the subsequent immune response of these cells to the keystone oral pathobiont Porphyromonas gingivalis. Employing classically activated (M1) and alternatively activated (M2) murine bone-marrow-derived macrophage (BMDMø), we observed that immunologic activation of macrophages before P. gingivalis challenge dictated phenotype-specific changes in the expression of inflammation-associated molecules important to sensing and tuning host response to bacterial infection including Toll-like receptors 2 and 4, CD14, CD18 and CD11b (together comprising CR3), major histocompatibility complex class II, CD80, and CD86. M2 cells responded to P. gingivalis with higher expression of tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, regulated on activation normal T cell expressed and secreted, and KC than M1 cells. M1 BMDMø expressed higher levels of interleukin-10 to P. gingivalis than M2 BMDMø. Functionally, we observed that M2 BMDMø bound P. gingivalis more robustly than M1 BMDMø. These data describe an important contribution of macrophage skewing in the subsequent development of the cellular immune response to P. gingivalis.
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Affiliation(s)
- G Papadopoulos
- Section of infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Y B Shaik-Dasthagirisaheb
- Section of infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - N Huang
- Section of infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - G A Viglianti
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA
| | - A J Henderson
- Section of infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - A Kantarci
- Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA, USA
| | - F C Gibson
- Section of infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
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30
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Olsen I, Hajishengallis G. Major neutrophil functions subverted by Porphyromonas gingivalis. J Oral Microbiol 2016; 8:30936. [PMID: 26993626 PMCID: PMC4799392 DOI: 10.3402/jom.v8.30936] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 01/21/2016] [Accepted: 02/22/2016] [Indexed: 01/11/2023] Open
Abstract
Polymorphonuclear leukocytes (neutrophils) constitute an integrated component of the innate host defense in the gingival sulcus/periodontal pocket. However, the keystone periodontal pathogen Porphyromonas gingivalis has in the course of evolution developed a number of capacities to subvert this defense to its own advantage. The present review describes the major mechanisms that P. gingivalis uses to subvert neutrophil homeostasis, such as impaired recruitment and chemotaxis, resistance to granule-derived antimicrobial agents and to the oxidative burst, inhibition of phagocytic killing while promoting a nutritionally favorable inflammatory response, and delay of neutrophil apoptosis. Studies in animal models have shown that at least some of these mechanisms promote the dysbiotic transformation of the periodontal polymicrobial community, thereby leading to inflammation and bone loss. It is apparent that neutrophil–P. gingivalis interactions and subversion of innate immunity are key contributing factors to the pathogenesis of periodontal disease.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Microbiology, Faculty of Dentistry, University of Oslo, Oslo, Norway;
| | - George Hajishengallis
- Department of Microbiology, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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31
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Immune and regulatory functions of neutrophils in inflammatory bone loss. Semin Immunol 2016; 28:146-58. [PMID: 26936034 DOI: 10.1016/j.smim.2016.02.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/06/2016] [Accepted: 02/14/2016] [Indexed: 02/06/2023]
Abstract
Although historically viewed as merely anti-microbial effectors in acute infection or injury, neutrophils are now appreciated to be functionally versatile with critical roles also in chronic inflammation. Periodontitis, a chronic inflammatory disease that destroys the tooth-supporting gums and bone, is particularly affected by alterations in neutrophil numbers or function, as revealed by observations in monogenic disorders and relevant mouse models. Besides being a significant debilitating disease and health burden in its own right, periodontitis is thus an attractive model to dissect uncharted neutrophil-associated (patho)physiological pathways. Here, we summarize recent evidence that neutrophils can contribute to inflammatory bone loss not only through the typical bystander injury dogma but intriguingly also through their absence from the affected tissue, where they normally perform important immunomodulatory functions. Moreover, we discuss recent advances in the interactions of neutrophils with the vascular endothelium and - upon extravasation - with bacteria, and how the dysregulation of these interactions leads to inflammatory tissue damage. Overall, neutrophils have both protective and destructive roles in periodontitis, as they are involved in both the maintenance of periodontal tissue homeostasis and the induction of inflammatory bone loss. This highlights the importance of developing approaches that promote or sustain a fine balance between homeostatic immunity and inflammatory pathology.
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32
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Neutrophil Functions in Periodontal Homeostasis. J Immunol Res 2016; 2016:1396106. [PMID: 27019855 PMCID: PMC4785262 DOI: 10.1155/2016/1396106] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/07/2016] [Indexed: 12/13/2022] Open
Abstract
Oral tissues are constantly exposed to damage from the mechanical effort of eating and to microorganisms, mostly bacteria. In healthy gingiva tissue remodeling and a balance between bacteria and innate immune cells are maintained. However, excess of bacteria biofilm (plaque) creates an inflammation state that recruits more immune cells, mainly neutrophils to the gingiva. Neutrophils create a barrier for bacteria to reach inside tissues. When neutrophils are insufficient, bacteria thrive causing more inflammation that has been associated with systemic effects on other conditions such as atherosclerosis, diabetes, and cancer. But paradoxically when neutrophils persist, they can also promote a chronic inflammatory state that leads to periodontitis, a condition that leads to damage of the bone-supporting tissues. In periodontitis, bone loss is a serious complication. How a neutrophil balance is needed for maintaining healthy oral tissues is the focus of this review. We present recent evidence on how alterations in neutrophil number and function can lead to inflammatory bone loss, and how some oral bacteria signal neutrophils to block their antimicrobial functions and promote an inflammatory state. Also, based on this new information, novel therapeutic approaches are discussed.
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33
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Steinmetz O, Hoch S, Avniel-Polak S, Gavish K, Eli-Berchoer L, Wilensky A, Nussbaum G. CX3CR1hi Monocyte/Macrophages Support Bacterial Survival and Experimental Infection-Driven Bone Resorption. J Infect Dis 2015; 213:1505-15. [PMID: 26704610 DOI: 10.1093/infdis/jiv763] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 12/17/2015] [Indexed: 12/13/2022] Open
Abstract
Porphyromonas gingivalis,an anaerobic bacterium strongly linked to infection-driven inflammatory bone erosion, thrives within a highly inflamed milieu and disseminates to distant sites, such as atherosclerotic plaque. We examined the role of monocyte/macrophages in determining the outcome of infection with P. gingivalis. Surprisingly, transient monocyte/macrophage depletion led to greatly improved clearance of P. gingivalis. The chemokine receptors CCR2 and CX3CR1 play a major role in monocyte recruitment and differentiation to Ly6C(hi) vs CX3CR1(hi) subsets, respectively. To determine the contribution of particular monocyte/macrophage subsets to bacterial survival, we challenged chemokine receptor knockout mice and found that P. gingivalis clearance is significantly improved in the absence of CX3CR1. CX3CR1(hi) monocyte/macrophages promote P. gingivalis survival by downregulating neutrophil phagocytosis. Furthermore, CX3CR1 knockout mice resist bone resorption in the oral cavity following challenge with P. gingivalis Our findings provide an explanation for bacterial coexistence alongside an activate neutrophil infiltrate.
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Affiliation(s)
- Orit Steinmetz
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Shifra Hoch
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Shani Avniel-Polak
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Keren Gavish
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Luba Eli-Berchoer
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Asaf Wilensky
- Department of Periodontology, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
| | - Gabriel Nussbaum
- Institute of Dental Sciences, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel
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34
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Taguchi H, Aono Y, Kawato T, Asano M, Shimizu N, Saigusa T. Intragingival injection of Porphyromonas gingivalis-derived lipopolysaccharide induces a transient increase in gingival tumour necrosis factor-α, but not interleukin-6, in anaesthetised rats. Int J Oral Sci 2015; 7:155-60. [PMID: 26047579 PMCID: PMC4582562 DOI: 10.1038/ijos.2015.9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2015] [Indexed: 11/09/2022] Open
Abstract
This study used in vivo microdialysis to examine the effects of intragingival application of lipopolysaccharide (LPS) derived from Porphyromonas gingivalis (Pg-LPS) on gingival tumour necrosis factor (TNF)-α and interleukin (IL)-6 levels in rats. A microdialysis probe with an injection needle attached to the surface of the dialysis membrane was implanted into the gingiva of the upper incisor. For comparison, the effects of LPS derived from Escherichia coli (Ec-LPS) on IL-6 and TNF-α levels were also analysed. Pg-LPS (1 μg/1 μL) or Ec-LPS (1 or 6 μg/1 μL) was applied by microsyringe, with gingival dialysates collected every hour. Enzyme-linked immunosorbent assay (ELISA) revealed that gingival dialysates contained approximately 389 pg·mL−1 of IL-6 basally; basal TNF-α levels were lower than the detection limit of the ELISA. Pg-LPS failed to alter IL-6 levels but markedly increased TNF-α levels, which remained elevated for 2 h after treatment. Neither IL-6 nor TNF-α were affected by Ec-LPS. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that the gingiva expresses Toll-like receptor (TLR) 2 and TLR4 mRNA. Immunohistochemical examination showed that TLR2 and TLR4 are expressed by gingival epithelial cells. The present study provides in vivo evidence that locally applied Pg-LPS, but not Ec-LPS, into the gingiva transiently increases gingival TNF-α without affecting IL-6. The present results suggest that TLR2 but not TLR4 expressed on gingival epithelial cells may mediate the Pg-LPS-induced increase in gingival TNF-α in rats.
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Affiliation(s)
- Hiroko Taguchi
- Department of Orthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Yuri Aono
- Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.,Department of Pharmacology, Nihon University School of Dentistry, Tokyo, Japan
| | - Takayuki Kawato
- Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan
| | - Masatake Asano
- Department of Pathology, Nihon University School of Dentistry, Tokyo, Japan
| | - Noriyoshi Shimizu
- Department of Orthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Tadashi Saigusa
- Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Chiba, Japan
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Huang N, Shaik-Dasthagirisaheb YB, LaValley MP, Gibson FC. Liver X receptors contribute to periodontal pathogen-elicited inflammation and oral bone loss. Mol Oral Microbiol 2015; 30:438-50. [PMID: 25946408 DOI: 10.1111/omi.12103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2015] [Indexed: 12/29/2022]
Abstract
Periodontal diseases are chronic oral inflammatory diseases that are polymicrobial in nature. The presence of specific bacteria in subgingival plaque such as Porphyromonas gingivalis is associated with microbial dysbiosis and the modulation of host immune response. Bacterially elicited innate immune activation and inflammation are key elements implicated in the destruction of soft and hard tissues supporting the teeth. Liver X receptors (LXRs) are nuclear hormone receptors with important function in lipid homeostasis, inflammation, and host response to infection; however, their contribution to chronic inflammatory diseases such as periodontal disease is not understood. The aim of this study was to define the contribution of LXRs in the development of immune response to P. gingivalis and to assess the roles that LXRs play in infection-elicited oral bone loss. Employing macrophages, we observed that P. gingivalis challenge led to reduced LXRα and LXRβ gene expression compared with that observed with unchallenged wild-type cells. Myeloid differentiation primary response gene 88 (MyD88)-independent, Toll/interleukin-1 receptor-domain-containing adapter-inducing interferon-β (TRIF)-dependent signaling affected P. gingivalis-mediated reduction in LXRα expression, whereas neither pathway influenced the P. gingivalis effect on LXRβ expression. Employing LXR agonist and mice deficient in LXRs, we observed functional effects of LXRs in the development of a P. gingivalis-elicited cytokine response at the level of the macrophage, and participation of LXRs in P. gingivalis-elicited oral bone loss. These findings identify novel importance for LXRs in the pathogenesis of P. gingivalis infection-elicited inflammation and oral bone loss.
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Affiliation(s)
- N Huang
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Y B Shaik-Dasthagirisaheb
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - M P LaValley
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - F C Gibson
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
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CD36/SR-B2-TLR2 Dependent Pathways Enhance Porphyromonas gingivalis Mediated Atherosclerosis in the Ldlr KO Mouse Model. PLoS One 2015; 10:e0125126. [PMID: 25938460 PMCID: PMC4418723 DOI: 10.1371/journal.pone.0125126] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/25/2015] [Indexed: 12/11/2022] Open
Abstract
There is strong epidemiological association between periodontal disease and cardiovascular disease but underlying mechanisms remain ill-defined. Because the human periodontal disease pathogen, Porphyromonas gingivalis (Pg), interacts with innate immune receptors Toll-like Receptor (TLR) 2 and CD36/scavenger receptor-B2 (SR-B2), we studied how CD36/SR-B2 and TLR pathways promote Pg-mediated atherosclerosis. Western diet fed low density lipoprotein receptor knockout (Ldlr°) mice infected orally with Pg had a significant increase in lesion burden compared with uninfected controls. This increase was entirely CD36/SR-B2-dependent, as there was no significant change in lesion burden between infected and uninfected Ldlr° mice. Western diet feeding promoted enhanced CD36/SR-B2-dependent IL1β generation and foam cell formation as a result of Pg lipopolysaccharide (PgLPS) exposure. CD36/SR-B2 and TLR2 were necessary for inflammasome activation and optimal IL1ß generation, but also resulted in LPS induced lethality (pyroptosis). Modified forms of LDL inhibited Pg-mediated IL1ß generation in a CD36/SR-B2-dependent manner and prevented pyroptosis, but promoted foam cell formation. Our data show that Pg infection in the oral cavity can lead to significant TLR2-CD36/SR-B2 dependent IL1ß release. In the vessel wall, macrophages encountering systemic release of IL1ß, PgLPS and modified LDL have increased lipid uptake, foam cell formation, and release of IL1ß, but because pyroptosis is inhibited, this enables macrophage survival and promotes increased plaque development. These studies may explain increased lesion burden as a result of periodontal disease, and suggest strategies for development of therapeutics.
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Hajishengallis G, Chavakis T, Hajishengallis E, Lambris JD. Neutrophil homeostasis and inflammation: novel paradigms from studying periodontitis. J Leukoc Biol 2014; 98:539-48. [PMID: 25548253 DOI: 10.1189/jlb.3vmr1014-468r] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 11/28/2014] [Indexed: 12/30/2022] Open
Abstract
Once viewed as simply antibacterial effector cells packed with antimicrobials, neutrophils are now increasingly appreciated for their regulatory roles in immunity and inflammation. The homeostatic regulation of neutrophils is thus crucial for optimal operation of the immune system. An attractive model to understand mechanistically the role of neutrophils is periodontitis, an oral inflammatory disease that is particularly sensitive to neutrophil alterations in numbers or function. The recruitment and proper activation of neutrophils are largely dependent on leukocyte integrins and complement. This review discusses how these processes are affected by host genetic or microbial factors leading to the development of periodontitis. For instance, both hypo- and hyper-recruitment of neutrophils as a result of deficiencies in the expression of β2 integrins or their negative regulators, respectively, causes unwarranted IL-17-dependent inflammatory bone loss. Moreover, microbial hijacking of C5aR (CD88) signaling in neutrophils impairs their antimicrobial function while promoting destructive inflammatory responses. These studies not only support the concept that neutrophil homeostasis is key to periodontal health but also reveal promising, new therapeutic targets as discussed in the review.
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Affiliation(s)
- George Hajishengallis
- Departments of *Microbiology and Preventive and Restorative Sciences, Division of Pediatric Dentistry, Penn Dental Medicine, and Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Technische Universität Dresden, Faculty of Medicine, Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - Triantafyllos Chavakis
- Departments of *Microbiology and Preventive and Restorative Sciences, Division of Pediatric Dentistry, Penn Dental Medicine, and Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Technische Universität Dresden, Faculty of Medicine, Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - Evlambia Hajishengallis
- Departments of *Microbiology and Preventive and Restorative Sciences, Division of Pediatric Dentistry, Penn Dental Medicine, and Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Technische Universität Dresden, Faculty of Medicine, Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - John D Lambris
- Departments of *Microbiology and Preventive and Restorative Sciences, Division of Pediatric Dentistry, Penn Dental Medicine, and Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Technische Universität Dresden, Faculty of Medicine, Department of Clinical Pathobiochemistry and Institute for Clinical Chemistry and Laboratory Medicine, Dresden, Germany
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McClure R, Massari P. TLR-Dependent Human Mucosal Epithelial Cell Responses to Microbial Pathogens. Front Immunol 2014; 5:386. [PMID: 25161655 PMCID: PMC4129373 DOI: 10.3389/fimmu.2014.00386] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 07/29/2014] [Indexed: 12/17/2022] Open
Abstract
Toll-like receptor (TLR) signaling represents one of the best studied pathways to implement defense mechanisms against invading microbes in human being as well as in animals. TLRs respond to specific microbial ligands and to danger signals produced by the host during infection, and initiate downstream cascades that activate both innate and adaptive immunity. TLRs are expressed by professional immune cells and by the large majority of non-hematopoietic cells, including epithelial cells. In epithelial tissues, TLR functions are particularly important because these sites are constantly exposed to microorganisms, due to their location at the host interface with the environment. While at these sites specific defense mechanisms and inflammatory responses are initiated via TLR signaling against pathogens, suppression or lack of TLR activation is also observed in response to the commensal microbiota. The mechanisms by which TLR signaling is regulated in mucosal epithelial cells include differential expression and levels of TLRs (and their signaling partners), their cellular localization and positioning within the tissue in a fashion that favors responses to pathogens while dampening responses to commensals and maintaining tissue homeostasis in physiologic conditions. In this review, the expression and activation of TLRs in mucosal epithelial cells of several sites of the human body are examined. Specifically, the oral cavity, the ear canal and eye, the airways, the gut, and the reproductive tract are discussed, along with how site-specific host defense mechanisms are implemented via TLR signaling.
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Affiliation(s)
- Ryan McClure
- Department of Microbiology, Boston University School of Medicine , Boston, MA , USA
| | - Paola Massari
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine , Boston, MA , USA
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Pathogenic bacterial species associated with endodontic infection evade innate immune control by disabling neutrophils. Infect Immun 2014; 82:4068-79. [PMID: 25024367 DOI: 10.1128/iai.02256-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Endodontic infections, in which oral bacteria access the tooth pulp chamber, are common and do not resolve once established. To investigate the effects of these infections on the innate immune response, we established a mouse subcutaneous chamber model, where a mixture of four oral pathogens commonly associated with these infections (endodontic pathogens [EP]), i.e., Fusobacterium nucleatum, Streptococcus intermedius, Parvimonas micra, and Prevotella intermedia, was inoculated into subcutaneously implanted titanium chambers. Cells that infiltrated the chamber after these infections were primarily neutrophils; however, these neutrophils were unable to control the infection. Infection with a nonpathogenic oral bacterial species, Streptococcus mitis, resulted in well-controlled infection, with bacterial numbers reduced by 4 to 5 log units after 7 days. Propidium iodide (PI) staining of the chamber neutrophils identified three distinct populations: neutrophils from EP-infected chambers were intermediate in PI staining, while cells in chambers from mice infected with S. mitis were PI positive (apoptotic) or negative (live). Strikingly, neutrophils from EP-infected chambers were severely impaired in their ability to phagocytose and to generate reactive oxygen species in vitro after removal from the chamber compared to cells from S. mitis-infected chambers. The mechanism of neutrophil impairment was necrotic cell death as determined by morphological analyses. P. intermedia alone could induce a similar neutrophil phenotype. We conclude that the endodontic pathogens, particularly P. intermedia, can efficiently disable and kill infiltrating neutrophils, allowing these infections to become established. These results can help explain the persistence of endodontic infections and demonstrate a new virulence mechanism associated with P. intermedia.
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Maekawa T, Krauss JL, Abe T, Jotwani R, Triantafilou M, Triantafilou K, Hashim A, Hoch S, Curtis MA, Nussbaum G, Lambris JD, Hajishengallis G. Porphyromonas gingivalis manipulates complement and TLR signaling to uncouple bacterial clearance from inflammation and promote dysbiosis. Cell Host Microbe 2014; 15:768-78. [PMID: 24922578 PMCID: PMC4071223 DOI: 10.1016/j.chom.2014.05.012] [Citation(s) in RCA: 290] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 02/28/2014] [Accepted: 04/21/2014] [Indexed: 02/06/2023]
Abstract
Certain low-abundance bacterial species, such as the periodontitis-associated oral bacterium Porphyromonas gingivalis, can subvert host immunity to remodel a normally symbiotic microbiota into a dysbiotic, disease-provoking state. However, such pathogens also exploit inflammation to thrive in dysbiotic conditions. How these bacteria evade immunity while maintaining inflammation is unclear. As previously reported, P. gingivalis remodels the oral microbiota into a dysbiotic state by exploiting complement. Now we show that in neutrophils P. gingivalis disarms a host-protective TLR2-MyD88 pathway via proteasomal degradation of MyD88, whereas it activates an alternate TLR2-Mal-PI3K pathway. This alternate TLR2-Mal-PI3K pathway blocks phagocytosis, provides "bystander" protection to otherwise susceptible bacteria, and promotes dysbiotic inflammation in vivo. This mechanism to disengage bacterial clearance from inflammation required an intimate crosstalk between TLR2 and the complement receptor C5aR and can contribute to the persistence of microbial communities that drive dysbiotic diseases.
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Affiliation(s)
- Tomoki Maekawa
- University of Pennsylvania, School of Dental Medicine, Department of Microbiology, Philadelphia, PA 19104, USA
| | - Jennifer L Krauss
- University of Louisville, Center for Oral Health and Systemic Disease, Louisville, KY 40292, USA
| | - Toshiharu Abe
- University of Pennsylvania, School of Dental Medicine, Department of Microbiology, Philadelphia, PA 19104, USA
| | - Ravi Jotwani
- University of Louisville, Center for Oral Health and Systemic Disease, Louisville, KY 40292, USA
| | - Martha Triantafilou
- Cardiff University School of Medicine, Institute of Infection and Immunity, Cardiff CF14 4XN, UK
| | - Kathy Triantafilou
- Cardiff University School of Medicine, Institute of Infection and Immunity, Cardiff CF14 4XN, UK
| | - Ahmed Hashim
- Queen Mary University of London, Centre for Immunology and Infectious Disease, Blizard Institute, Barts and The London School of Medicine and Dentistry, London E1 2AT, UK
| | - Shifra Hoch
- Hebrew University, Hadassah Dental School, Jerusalem 12272, Israel
| | - Michael A Curtis
- Queen Mary University of London, Centre for Immunology and Infectious Disease, Blizard Institute, Barts and The London School of Medicine and Dentistry, London E1 2AT, UK
| | - Gabriel Nussbaum
- Hebrew University, Hadassah Dental School, Jerusalem 12272, Israel
| | - John D Lambris
- University of Pennsylvania, Perelman School of Medicine, Department of Pathology and Laboratory Medicine, Philadelphia, PA 19104, USA
| | - George Hajishengallis
- University of Pennsylvania, School of Dental Medicine, Department of Microbiology, Philadelphia, PA 19104, USA.
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Multiple roles of Myd88 in the immune response to the plague F1-V vaccine and in protection against an aerosol challenge of Yersinia pestis CO92 in mice. J Immunol Res 2014; 2014:341820. [PMID: 24995344 PMCID: PMC4065692 DOI: 10.1155/2014/341820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 04/23/2014] [Accepted: 05/03/2014] [Indexed: 01/08/2023] Open
Abstract
The current candidate vaccine against Yersinia pestis infection consists of two subunit proteins: the capsule protein or F1 protein and the low calcium response V protein or V-antigen. Little is known of the recognition of the vaccine by the host's innate immune system and how it affects the acquired immune response to the vaccine. Thus, we vaccinated Toll-like receptor (Tlr) 2, 4, and 2/4-double deficient, as well as signal adaptor protein Myd88-deficient mice. We found that Tlr4 and Myd88 appeared to be required for an optimal immune response to the F1-V vaccine but not Tlr2 when compared to wild-type mice. However, there was a difference between the requirement for Tlr4 and MyD88 in vaccinated animals. When F1-V vaccinated Tlr4 mutant (lipopolysaccharide tolerant) and Myd88-deficient mice were challenged by aerosol with Y. pestis CO92, all but one Tlr4 mutant mice survived the challenge, but no vaccinated Myd88-deficient mice survived the challenge. Spleens from these latter nonsurviving mice showed that Y. pestis was not cleared from the infected mice. Our results suggest that MyD88 appears to be important for both an optimal immune response to F1-V and in protection against a lethal challenge of Y. pestis CO92 in F1-V vaccinated mice.
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Ghaderi H, Kiany F, Razmkhah M, Dadras S, Chenari N, Hosseini A, Younesi V, Ghaderi A. mRNA expression of pattern recognition receptors and their signaling mediators in healthy and diseased gingival tissues. J Indian Soc Periodontol 2014; 18:150-4. [PMID: 24872620 PMCID: PMC4033878 DOI: 10.4103/0972-124x.131309] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 10/07/2013] [Indexed: 01/19/2023] Open
Abstract
Background: Gingivitis and periodontitis are initiated by inflammation caused by microorganisms. Pathogen-associated molecular patterns (PAMPs) from these microorganisms are recognized through various toll-like receptors (TLRs) and NOD-like receptors (NLRs). In this study, we have chosen five TLRs and two NLRs as representatives taking part in the recognition and inflammation process, along with a few of their signaling mediators including CD14, MYD88, and TRIF to compare their mRNA expression levels between healthy and diseased gingival tissues. This will provide deeper insight into the mechanisms underlying gingivitis and periodontitis. Understanding the mechanisms involved in the onset and progression of the periodontal diseases could greatly help in establishing effective ways for prevention and treatment of these diseases besides decreasing the risk factor for relevant systemic disorders. Materials and Methods: Gingival tissue samples for mRNA extraction and cDNA synthesis were taken from patients with gingivitis and periodontitis and from healthy control subjects. Messenger RNA expression of all genes was assessed using real-time polymerase chain reaction (PCR). Results: Among the genes studied in different groups, only MYD88 mRNA expression was significantly higher in the periodontitis group compared to that of the controls. The expression level of this molecule was also significantly higher in patients with severe periodontitis compared to other patients and also compared to healthy individuals. In different tissues, positive significant correlations were observed between the mRNA expression levels of some genes. Conclusions: Elevated mRNA levels of MYD88 in periodontitis might have a key role in the pathogenesis of this disease. Therefore, MYD88 may be a useful target for the therapy of this disease.
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Affiliation(s)
- Hamid Ghaderi
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran ; Department of Periodontology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farin Kiany
- Department of Periodontology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahboobeh Razmkhah
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Somayeh Dadras
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Noushafarin Chenari
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ahmad Hosseini
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Vahid Younesi
- Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abbas Ghaderi
- Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran ; Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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Kwa MQ, Nguyen T, Huynh J, Ramnath D, De Nardo D, Lam PY, Reynolds EC, Hamilton JA, Sweet MJ, Scholz GM. Interferon regulatory factor 6 differentially regulates Toll-like receptor 2-dependent chemokine gene expression in epithelial cells. J Biol Chem 2014; 289:19758-68. [PMID: 24872416 DOI: 10.1074/jbc.m114.584540] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Epidermal and mucosal epithelial cells are integral to host defense. They not only act as a physical barrier but also utilize pattern recognition receptors, such as the Toll-like receptors (TLRs), to detect and respond to pathogens. Members of the interferon regulatory factor (IRF) family of transcription factors are key components of TLR signaling as they impart specificity to downstream responses. Although IRF6 is a critical regulator of epithelial cell proliferation and differentiation, its role in TLR signaling has not previously been addressed. We show here that IRF6 is activated by IRAK1 as well as by MyD88 but not by TRIF or TBK1. Co-immunoprecipitation experiments further demonstrated that IRF6 can interact with IRAK1. Gene silencing in epithelial cells along with gene promoter reporter assays showed that IRAK1 mediates TLR2-inducible CCL5 gene expression at least in part by promoting IRF6 activation. Conversely, IRAK1 regulated CXCL8 gene expression independently of IRF6, thus identifying a molecular mechanism by which TLR2 signaling differentially regulates the expression of specific chemokines in epithelial cells. Bioinformatics analysis and mutagenesis-based experiments identified Ser-413 and Ser-424 as key regulatory sites in IRF6. Phosphomimetic mutation of these residues resulted in greatly enhanced IRF6 dimerization and trans-activator function. Collectively, our findings suggest that, in addition to its importance for epithelial barrier function, IRF6 also contributes to host defense by providing specificity to the regulation of inflammatory chemokine expression by TLR2 in epithelial cells.
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Affiliation(s)
- Mei Qi Kwa
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Thao Nguyen
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Jennifer Huynh
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Divya Ramnath
- the Institute for Molecular Bioscience, and Australian Infectious Disease Research Centre, The University of Queensland, Queensland 4072, Australia
| | - Dominic De Nardo
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Pui Yeng Lam
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Eric C Reynolds
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and
| | - John A Hamilton
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
| | - Matthew J Sweet
- the Institute for Molecular Bioscience, and Australian Infectious Disease Research Centre, The University of Queensland, Queensland 4072, Australia
| | - Glen M Scholz
- From the Oral Health Cooperative Research Centre, Melbourne Dental School, and Bio21 Institute, and Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3010, Australia, and
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Shaik-Dasthagirisaheb YB, Huang N, Weinberg EO, Shen SS, Genco CA, Gibson FC. Aging and contribution of MyD88 and TRIF to expression of TLR pathway-associated genes following stimulation with Porphyromonas gingivalis. J Periodontal Res 2014; 50:89-102. [PMID: 24862405 DOI: 10.1111/jre.12185] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND OBJECTIVE Periodontal disease is a highly complex chronic inflammatory disease of the oral cavity. Multiple factors influence periodontal disease, including socio-economic status, genetics and age; however, inflammation elicited by the presence of specific bacteria in the subgingival space is thought to drive the majority of soft- and hard-tissue destruction. Porphyromonas gingivalis is closely associated with periodontal disease. Toll-like receptors (TLRs) and their intracellular signaling pathways play roles in the host response to P. gingivalis. The focus of the current study was to use microarray analysis to define the contributions of the TLR adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/interleukin-1 receptor domain-containing adaptor inducing interferon-beta (TRIF), and aging, on the expression of TLR pathway-associated mRNAs in response to P. gingivalis. MATERIAL AND METHODS Bone marrow-derived macrophages (BMØ) from wild-type (Wt), MyD88 knockout (MyD88-KO) and Trif(Lps2) [i.e. containing a point mutation in the lipopolysaccharide 2 (Lps2) gene rendering the Toll/interleukin (IL)-1 receptor domain-containing adaptor inducing interferon-beta (TRIF) protein nonfunctional] mice, at 2-and 12-mo of age, were cultured with P. gingivalis. Expression of genes in BMØ cultured with P. gingivalis was determined in comparison with expression of genes in BMØ cultured in medium only. RESULTS Using, as criteria, a twofold increase or decrease in mRNA expression, differential expression of 32 genes was observed when Wt BMØ from 2-mo-old mice were cultured with P. gingivalis compared with the medium-only control. When compared with 2-mo-old Wt mice, 21 and 12 genes were differentially expressed (p < 0.05) as a result of the mutations in MyD88 or TRIF, respectively. The expression of five genes was significantly (p < 0.05) reduced in Wt BMØ from 12-mo-old mice compared with those from 2-mo-old mice following culture with P. gingivalis. Age also influenced the expression of genes in MyD88-KO and Trif(Lps2) mice challenged with P. gingivalis. CONCLUSIONS Our results indicate that P. gingivalis induces differential expression of TLR pathway-associated genes, and both MyD88 and TRIF play roles in the expression of these genes. Age also played a role in the expression of TLR-associated genes following stimulation of BMØ with P. gingivalis.
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Affiliation(s)
- Y B Shaik-Dasthagirisaheb
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, MA, USA
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Huang N, Gibson FC. Immuno-pathogenesis of Periodontal Disease: Current and Emerging Paradigms. ACTA ACUST UNITED AC 2014; 1:124-132. [PMID: 24839590 DOI: 10.1007/s40496-014-0017-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Periodontal disease (PD) is a highly complex disease involving many factors; however, two principal facets central to initiation and progression of the majority of PD are the composition of the microbes in the sub-gingival plaque, and the host immune response to these organisms. Numerous studies point to the complexity of PD, and to the fact that despite innate and adaptive immune activation, and resultant inflammation, our immune response fails to cure disease. Stunning new findings have begun to clarify several complexities of the host-pathogen interaction of PD pointing to key roles for microbial dysboisis and immune imbalance in the pathogenesis of disease. Furthermore, these investigations have identified novel translational opportunities to intercede in PD treatment. In this review we will highlight a select few recent findings in innate and adaptive immunity, and host pathogen interactions of PD at a micro-environmental level that may have profound impact on PD progression.
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Affiliation(s)
- Nasi Huang
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, 02118
| | - Frank C Gibson
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, 02118
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Zoccal KF, Bitencourt CDS, Paula-Silva FWG, Sorgi CA, de Castro Figueiredo Bordon K, Arantes EC, Faccioli LH. TLR2, TLR4 and CD14 recognize venom-associated molecular patterns from Tityus serrulatus to induce macrophage-derived inflammatory mediators. PLoS One 2014; 9:e88174. [PMID: 24516606 PMCID: PMC3917877 DOI: 10.1371/journal.pone.0088174] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 01/06/2014] [Indexed: 12/12/2022] Open
Abstract
Scorpion sting-induced human envenomation provokes an intense inflammatory reaction. However, the mechanisms behind the recognition of scorpion venom and the induction of mediator release in mammalian cells are unknown. We demonstrated that TLR2, TLR4 and CD14 receptors sense Tityus serrulatus venom (TsV) and its major component, toxin 1 (Ts1), to mediate cytokine and lipid mediator production. Additionally, we demonstrated that TsV induces TLR2- and TLR4/MyD88-dependent NF-κB activation and TLR4-dependent and TLR2/MyD88-independent c-Jun activation. Similar to TsV, Ts1 induces MyD88-dependent NF-κB phosphorylation via TLR2 and TLR4 receptors, while c-Jun activation is dependent on neither TLR2 nor TLR4/MyD88. Therefore, we propose the term venom-associated molecular pattern (VAMP) to refer to molecules that are introduced into the host by stings and are recognized by PRRs, resulting in inflammation.
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Affiliation(s)
- Karina Furlani Zoccal
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Claudia da Silva Bitencourt
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Francisco Wanderley Garcia Paula-Silva
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carlos Artério Sorgi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Karla de Castro Figueiredo Bordon
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Eliane Candiani Arantes
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Lúcia Helena Faccioli
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail:
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Kobayashi N, Suzuki JI, Ogawa M, Aoyama N, Komuro I, Izumi Y, Isobe M. Porphyromonas gingivalis promotes neointimal formation after arterial injury through toll-like receptor 2 signaling. Heart Vessels 2013; 29:542-9. [PMID: 24002697 DOI: 10.1007/s00380-013-0405-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 08/16/2013] [Indexed: 02/06/2023]
Abstract
We previously demonstrated that Porphyromonas gingivalis infection induces neointimal hyperplasia with an increase in monocyte chemoattractant protein (MCP)-1 after arterial injury in wild-type mice. Toll-like receptor (TLR) 2 is a key receptor for the virulence factors of P. gingivalis. The aim of this study was to assess whether TLR2 plays a role in periodontopathic bacteria-induced neointimal formation after an arterial injury. Wild-type and TLR2-deficient mice were used in this study. The femoral arteries were injured, and P. gingivalis or vehicle was injected subcutaneously once per week. Fourteen days after arterial injury, the murine femoral arteries were obtained for histopathologic and immunohistochemical analyses. The immunoglobulin-G levels of the P. gingivalis-infected groups were significantly increased in comparison with the level in the corresponding noninfected groups in both wild-type and TLR2-deficient mice. TLR2 deficiency negated the P. gingivalis-induced neointimal formation in comparison with the wild-type mice, and reduced the number of positive monocyte chemoattractant protein-1 cells in the neointimal area. These findings demonstrate that P. gingivalis infection can promote neointimal formation after an arterial injury through TLR2 signaling.
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Affiliation(s)
- Naho Kobayashi
- Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Shaik-Dasthagirisaheb YB, Huang N, Gibson FC. Inflammatory response to Porphyromonas gingivalis partially requires interferon regulatory factor (IRF) 3. Innate Immun 2013; 20:312-9. [PMID: 23803413 DOI: 10.1177/1753425913492180] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Innate immune activation with expression of pro-inflammatory molecules such as TNF-α is a hallmark of the chronic inflammation associated with periodontal disease (PD). Porphyromonas gingivalis, a bacterium associated with PD, engages TLRs and activates MyD88-dependent and TIR-domain-containing adapter-inducing IFN-β (TRIF)-dependent signaling pathways. IFN regulatory factor (IRF) 3 is activated in a TRIF-dependent manner and participates in production of cytokines such as TNF-α; however, little is known regarding IRF3 and the host response to PD pathogens. We speculated that IRF3 participates in the host inflammatory response to P. gingivalis. Our results show that bone marrow macrophages (MØ) from WT mice respond to P. gingivalis with activation and nuclear translocation of IRF3. Compared with WT, MØ from IRF3(-/-), TRIF(-/-), and TLR4(-/-) mice responded with reduced levels of TNF-α on P. gingivalis challenge. In addition, full expression of IL-6 and RANTES by MØ to P. gingivalis was dependent on IRF3. Lastly, employing MØ from IRF3(-/-) and IRF7(-/-) mice we observed a significant role for IRF3 and a modest role for IRF7 in the P. gingivalis-elicited TNF-α response. These studies identify a role for IRF3 in the inflammatory response by MØ to the periodontal pathogen P. gingivalis.
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Herath TDK, Darveau RP, Seneviratne CJ, Wang CY, Wang Y, Jin L. Tetra- and penta-acylated lipid A structures of Porphyromonas gingivalis LPS differentially activate TLR4-mediated NF-κB signal transduction cascade and immuno-inflammatory response in human gingival fibroblasts. PLoS One 2013; 8:e58496. [PMID: 23554896 PMCID: PMC3595299 DOI: 10.1371/journal.pone.0058496] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/05/2013] [Indexed: 12/21/2022] Open
Abstract
Background Porphyromonas gingivalis is a major pathogen of periodontal disease that affects a majority of adults worldwide. Increasing evidence shows that periodontal disease is linked to various systemic diseases like diabetes and cardiovascular disease, by contributing to increased systemic levels of inflammation. Lipopolysaccharides (LPS), as a key virulent attribute of P. gingivalis, possesses significant amount of lipid A heterogeneity containing tetra- (LPS1435/1449) and penta-acylated (LPS1690) structures. Hitherto, the exact molecular mechanism of P. gingivalis LPS involved in periodontal pathogenesis remains unclear, due to limited understanding of the specific receptors and signaling pathways involved in LPS-host cell interactions. Methodology/Principal Findings This study systematically investigated the effects of P. gingivalis LPS1435/1449 and LPS1690 on the expression of TLR2 and TLR4 signal transduction and the activation of pro-inflammatory cytokines IL-6 and IL-8 in human gingival fibroblasts (HGFs). We found that LPS1435/1449 and LPS1690 differentially modulated TLR2 and TLR4 expression. NF-κB pathway was significantly activated by LPS1690 but not by LPS1435/1449. In addition, LPS1690 induced significant expression of NF-κB and p38 MPAK pathways-related genes, such as NFKBIA, NFKB1, IKBKB, MAP2K4 and MAPK8. Notably, the pro-inflammatory genes including GM-CSF, CXCL10, G-CSF, IL-6, IL-8 and CCL2 were significantly upregulated by LPS1690 while down-regulated by LPS1435/1449. Blocking assays confirmed that TLR4-mediated NF-κB signaling was vital in LPS1690-induced expression of IL-6 and IL-8 in HGFs. Conclusions/Significance The present study suggests that the tetra- and penta-acylated lipid A structures of P. gingivalis LPS differentially activate TLR4-mediated NF-κB signaling pathway, and significantly modulate the expression of IL-6 and IL-8 in HGFs. The ability to alter the lipid A structure of LPS could be one of the strategies carried-out by P. gingivalis to evade innate host defense in gingival tissues, thereby contributing to periodontal pathogenesis.
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Affiliation(s)
- Thanuja D. K. Herath
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Richard P. Darveau
- School of Dentistry, University of Washington, Seattle, Washington, United States of America
| | - Chaminda J. Seneviratne
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Cun-Yu Wang
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Yu Wang
- Department of Pharmacology & Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lijian Jin
- Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- * E-mail:
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Shaik-Dasthagirisaheb YB, Huang N, Baer MT, Gibson FC. Role of MyD88-dependent and MyD88-independent signaling in Porphyromonas gingivalis-elicited macrophage foam cell formation. Mol Oral Microbiol 2013; 28:28-39. [PMID: 23194377 PMCID: PMC3543481 DOI: 10.1111/omi.12003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2012] [Indexed: 12/13/2022]
Abstract
Clinical studies and experimental modeling identify a potential link between periodontal disease and periodontal pathogens such as Porphyromonas gingivalis and atherosclerosis and formation of macrophage foam cells. Toll-like receptors and molecules governing their intracellular signaling pathways such as MyD88 play roles in atherosclerosis, as well as host response to P. gingivalis. The aim of this study was to define roles of MyD88 and TRIF during macrophage foam cell formation in response to P. gingivalis. In the presence of human low-density lipoprotein (LDL) mouse bone-marrow-derived macrophages (BMφ) cultured with P. gingivalis responded with significant reduction in tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The BMφ stained strongly with oil red O, regardless of whether bacterial challenge occurred concurrent with or before LDL treatment. Heat-killed P. gingivalis stimulated foam cell formation in a similar way to live bacteria. The BMφ from MyD88-knockout and Lps2 mice revealed a significant role for MyD88, and a minor role for TRIF in P. gingivalis-elicited foam cell formation. Porphyromonas gingivalis-elicited TNF-α and IL-6 were affected by MyD88 ablation and to a lesser extent by TRIF status. These data indicate that LDL affects the TNF-α and IL-6 response of macrophages to P. gingivalis challenge and that MyD88 and TRIF play important roles in P. gingivalis-elicited foam cell formation.
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Affiliation(s)
| | - Nasi Huang
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, MA 02118
| | | | - Frank C. Gibson
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, MA 02118
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