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P. Gingivalis Infection (p + gingivali_infection)
Selected AbstractsThe effect of immunization on the response to P. gingivalis infection in mice is adjuvant-dependentJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2005Yael Houri-Haddad Abstract Aim: Studies on vaccines against the periodontal pathogen Porphyromonas gingivalis have produced conflicting results, but no consideration has been given to the role of different adjuvants in these vaccines. We have previously shown that an intra-chamber challenge with heat-killed P. gingivalis was modified by immunization with different adjuvants. This study tested the hypothesis that different adjuvants in P. gingivalis vaccines would differentially modify the host response to a live P. gingivalis infection. Results: Using P. gingivalis -infected subcutaneous chambers in mice, we show that vaccination with P. gingivalis in alum attenuated the pro-inflammatory cytokine levels at the site of infection, while the vaccine containing incomplete Freund's adjuvant did the opposite. Although both vaccines induced a similar humoral IgG response, P. gingivalis -induced abscesses were significantly smaller in the alum-adjuvant group. Conclusions: The results suggest that the immune response and the resultant protection to a P. gingivalis infection, in P. gingivalis -vaccinated mice, are adjuvant-dependent. [source] Enhanced monocyte migration and pro-inflammatory cytokine production by Porphyromonas gingivalis infectionJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2010A. Pollreisz Pollreisz A, Huang Y, Roth GA, Cheng B, Kebschull M, Papapanou PN, Schmidt AM, Lalla E. Enhanced monocyte migration and pro-inflammatory cytokine production by Porphyromonas gingivalis infection. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2009.01225.x. © 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard Background and Objective:,Porphyromonas gingivalis, a major periodontal pathogen, has been reported to be involved in atherogenesis. In order to further understand this pathogen's link with systemic inflammation and vascular disease, we investigated its influence on murine monocytes and macrophages from three different sources. Material and Methods:, Concanavalin A-elicited peritoneal macrophages, peripheral blood monocyte-derived macrophages and WEHI 274.1 monocytes were infected with either P. gingivalis 381 or its non-invasive fimbriae-deficient mutant, DPG3. Results:, Infection with P. gingivalis 381 markedly induced monocyte migration and significantly enhanced production of the pro-inflammatory cytokines, tumor necrosis factor-, and interleukin-6. Consistent with a role for this pathogen's major fimbriae and/or its invasive capacity, infection with DPG3 had a minimal effect on both monocyte attraction and pro-inflammatory cytokine production. Conclusion:, Since monocyte recruitment and activation are important steps in the development of vascular inflammation and atherosclerosis, these results suggest that P. gingivalis infection may be involved in these processes. [source] Oral immunization with Porphyromonas gingivalis outer membrane protein and CpG oligodeoxynucleotides elicits T helper 1 and 2 cytokines for enhanced protective immunityMOLECULAR ORAL MICROBIOLOGY, Issue 3 2010C. Liu Summary The aim of this study was to evaluate the efficacy of an oral vaccine containing the 40-kDa outer membrane protein of Porphyromonas gingivalis (40K-OMP) and synthetic oligodeoxynucleotides containing unmethylated CpG dinucleotides (CpG ODN) to control oral infection by P. gingivalis. Oral immunization with 40K-OMP plus CpG ODN induced significant 40K-OMP-specific serum immunoglobulin G (IgG), IgA, and saliva IgA antibody responses. The 40K-OMP-specific CD4+ T cells induced by oral 40K-OMP plus CpG ODN produced both T helper type 1 (Th1; interferon-,) and Th2 (interleukin-4) cytokines. Furthermore, increased frequencies of CD11c+ B220+ dendritic cells (DCs) and CD11c+ CD11b+ DCs with upregulated expression of CD80, CD86, CD40, and major histocompatibility complex class II molecules were noted in spleen, Peyer's patches, and cervical lymph nodes. Immunized mice were then infected orally with P. gingivalis to determine whether the immune responses induced by oral 40K-OMP plus CpG ODN were capable of suppressing the bone resorption caused by P. gingivalis infection. Mice given 40K-OMP plus CpG ODN showed significantly reduced bone loss associated with oral infection by P. gingivalis. Oral administration of 40K-OMP together with CpG ODN induces Th1-type and Th2-type cells, which provide help for protective immunity against P. gingivalis infection. This may be an important tool for the prevention of chronic periodontitis. [source] Signaling pathways in osteoblast proinflammatory responses to infection by Porphyromonas gingivalisMOLECULAR ORAL MICROBIOLOGY, Issue 2 2008T. Ohno Introduction:, We recently investigated global gene expression in ST2 mouse stromal cells infected by the periodontal pathogen Porphyromonas gingivalis using microarray technology, and found that the bacterium induces a wide range of proinflammatory gene expression. Here, we reported the signaling pathways involved in those proinflammatory responses. Methods:, ST2 cells and primary calvarial osteoblasts from C3H/HeN, C57BL/6, and MyD88-deficient (MyD88,/,) mice were infected with P. gingivalis ATCC33277 and its gingipain-deficient mutant KDP136. Expression of the chemokines CCL5 and CXCL10, and matrix metalloproteinase-9 (MMP9) were quantified by real-time polymerase chain reaction, while phosphorylation of protein kinases and degradation of an inhibitor of nuclear factor-,B, I,B-,, were detected by Western blotting, and activation of transcriptional factors was determined by a luciferase reporter assay. The effects of inhibitors of transcriptional factors and protein kinases were also investigated. Results:, Infection by P. gingivalis elicited gene expression of CCL5, CXCL10, and MMP9 in both ST2 cells and osteoblasts. Western blot and reporter assay results revealed activation of nuclear factor-,B (NF-,B) and activator protein-1 transcription factors. The NF-,B inhibitor suppressed the expression of CCL5 and MMP9, but not that of CXCL10, whereas P. gingivalis infection induced significant CCL5 expression in MyD88,/, osteoblasts. In addition, activation of protease-activated receptors by trypsin elicited significant induction of CXCL10. Conclusion:, Our results suggest that various proinflammatory responses in P. gingivalis -infected stromal/osteoblast cells are NF-,B-dependent, but not always dependent on the Toll-like receptor/MyD88 pathway, while some responses are related to the activation of protease-activated receptors. Thus, P. gingivalis does not fully utilize well-established pathogen recognition molecules such as Toll-like receptors. [source] Omega-3 fatty acid regulates inflammatory cytokine/mediator messenger RNA expression in Porphyromonas gingivalis -induced experimental periodontal diseaseMOLECULAR ORAL MICROBIOLOGY, Issue 4 2007L. Kesavalu Introduction:,Porphyromonas gingivalis is strongly implicated in the etiology of adult periodontitis by inducing inflammatory cytokines, resulting in gingival and periodontal tissue inflammation and alveolar bone resorption. This study tested the hypothesis that supplementing the diet with omega-3 fatty acid (,-3 FA; i.e. fish oil) would exert anti-inflammatory effects in the gingival tissues of P. gingivalis -infected rats. Methods:, Rats were fed either fish oil or corn oil diets ad libitum for 22 weeks and infected with P. gingivalis strain 381 or strain A7A1-28. After sacrifice, rat gingival tissues were excised and the RNA was isolated and analyzed for proinflammatory mediators [interleukin-1, (IL-1,), tumor necrosis factor-, (TNF-,), IL-6], T helper type 1 and type 2 cytokines [interferon-, (IFN-,), IL-4, IL-10), antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD)], and genes critical for eicosanoid mediator production [cyclo-oxygenase-2 (COX-2), 5-lipoxygenase (5-LO)] by reverse transcription-polymerase chain reaction using rat-specific primers. Results:, Rats on the ,-3 FA diet exhibited decreased proinflammatory cytokine gene expression (IL-1,, TNF-,) and enhanced IFN-,, CAT and SOD messenger RNA expression compared to rats fed a corn oil diet, supporting a diet-induced modulation of host inflammatory reactions. Analyses of alveolar bone resorption in the rats related to gene expression profiles demonstrated significant positive correlations with IL-1,, IL-6 and COX-2 and negative correlations with CAT and SOD. Conclusion:, These findings suggest that diets enriched for ,-3 FA modulate the local gingival inflammatory milieu of the host following oral P. gingivalis infection, which impacts on alveolar bone resorption in rats. [source] Identification and characterization of B-cell epitopes of a 53-kDa outer membrane protein from Porphyromonas gingivalisMOLECULAR ORAL MICROBIOLOGY, Issue 2 2001K. Oyaizu We have previously reported that Porphyromonas gingivalis FDC 381 possesses a 53-kDa protein antigen (Ag53) on its outer membrane that evokes a strong humoral immune response in many patients with periodontal disease and that the humoral immune responses to Ag53 differ greatly among patients. To understand how the individual humoral immune system against Ag53 was determined, the regions of Ag53 recognized by specific antibody (B-cell epitopes) and dominant subclasses of serum immunoglobulin G (IgG) against major B-cell epitopes were examined by enzyme-linked immunosorbent assay. This study used sera from six patients with periodontitis, which all reacted strongly with sonic extracts of P. gingivalis 381 and with purified Ag53, and sera from six periodontally healthy children, which did not react with either sonic extracts of P. gingivalis 381 or Ag53. The epitopes were identified using synthetic 5-residue overlapping decapeptides covering the entire Ag53. Thirteen of 89 synthetic decapeptides showed a strong reaction with sera from the periodontal patients, but no reaction with those from the healthy children. Four peptides of 13 exerted different immune responses among patients. Furthermore, restriction analyses of the highly antigenic regions revealed that three sequences, RAAIRAS, YYLQ and MSPARR, were identified as major B-cell epitopes. Additionally, these epitopes were recognized mainly by the IgG2 isotype. These data suggest that the difference of B-cell epitopes might influence individual differences in antibody titer against Ag53 and also that the epitopes recognized commonly by multiple antibodies are quite valuable for peptide vaccine development against P. gingivalis infection. [source] Relationship between periodontal infections and systemic diseaseCLINICAL MICROBIOLOGY AND INFECTION, Issue 2007G. J. Seymour Abstract Oral conditions such as gingivitis and chronic periodontitis are found worldwide and are among the most prevalent microbial diseases of mankind. The cause of these common inflammatory conditions is the complex microbiota found as dental plaque, a complex microbial biofilm. Despite 3000 years of history demonstrating the influence of oral status on general health, it is only in recent decades that the association between periodontal diseases and systemic conditions such as coronary heart disease and stroke, and a higher risk of preterm low birth-weight babies, has been realised. Similarly, recognition of the threats posed by periodontal diseases to individuals with chronic diseases such as diabetes, respiratory diseases and osteoporosis is relatively recent. Despite these epidemiological associations, the mechanisms for the various relationships remain unknown. Nevertheless, a number of hypotheses have been postulated, including common susceptibility, systemic inflammation with increased circulating cytokines and mediators, direct infection and cross-reactivity or molecular mimicry between bacterial antigens and self-antigens. With respect to the latter, cross-reactive antibodies and T-cells between self heat-shock proteins (HSPs) and Porphyromonas gingivalis GroEL have been demonstrated in the peripheral blood of patients with atherosclerosis as well as in the atherosclerotic plaques themselves. In addition, P. gingivalis infection has been shown to enhance the development and progression of atherosclerosis in apoE-deficient mice. From these data, it is clear that oral infection may represent a significant risk-factor for systemic diseases, and hence the control of oral disease is essential in the prevention and management of these systemic conditions. [source] | ||||||||||