RESUMEN
Porphyromonas gingivalis (Pg) and its gingipain proteases contribute to Alzheimer's disease (AD) pathogenesis through yet unclear mechanisms. Cellular secretion of small extracellular vesicles or exosomes (EXO) increases with aging as part of the senescence-associated secretory phenotype (SASP). We have shown that EXO isolated from Pg-infected dendritic cells contain gingipains and other Pg antigens and transmit senescence to bystander gingival cells, inducing alveolar bone loss in mice in vivo. Here, EXO were isolated from the gingiva of mice and humans with/without periodontitis (PD) to determine their ability to penetrate the blood-brain barrier (BBB) in vitro and in vivo. PD was induced by Pg oral gavage for 6 weeks in C57B6 mice. EXO isolated from the gingiva or brain of donor Pg-infected (PD EXO) or control animals (Con EXO) were characterized by NTA, Western blot, and TEM. Gingival PD EXO or Con EXO were labeled and injected into the gingiva of uninfected WT mouse model. EXO biodistribution in brains was tracked by an in vivo imaging system (IVIS) and confocal microscopy. The effect of human PD EXO on BBB integrity and permeability was examined using TEER and FITC dextran assays in a human in vitro 3D model of the BBB. Pg antigens (RGP and Mfa-1) were detected in EXO derived from gingival and brain tissues of donor Pg-infected mice. Orally injected PD EXO from donor mice penetrated the brains of recipient uninfected mice and colocalized with hippocampal microglial cells. IL-1ß and IL-6 were expressed in human PD EXO and not in Con EXO. Human PD EXO promoted BBB permeability and penetrated the BBB in vitro. This is the first demonstration that microbial-induced EXO in the oral cavity can disseminate, cross the BBB, and may contribute to AD pathogenesis.
Asunto(s)
Barrera Hematoencefálica , Vesículas Extracelulares , Encía , Periodontitis , Porphyromonas gingivalis , Barrera Hematoencefálica/metabolismo , Animales , Humanos , Ratones , Vesículas Extracelulares/metabolismo , Porphyromonas gingivalis/metabolismo , Porphyromonas gingivalis/patogenicidad , Periodontitis/microbiología , Periodontitis/metabolismo , Periodontitis/patología , Encía/metabolismo , Encía/microbiología , Ratones Endogámicos C57BL , Masculino , Exosomas/metabolismo , Femenino , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/metabolismoRESUMEN
Exosomes (exos) contain molecular cargo of therapeutic and diagnostic value for cancers and other inflammatory diseases, but their therapeutic potential for periodontitis (PD) remains unclear. Dendritic cells (DCs) are the directors of immune response and have been extensively used in immune therapy. We previously reported in a mouse model of PD that custom murine DC-derived exo subtypes could reprogram the immune response toward a bone-sparing or bone-loss phenotype, depending on immune profile. Further advancement of this technology requires the testing of human DC-based exos with human target cells. Our main objective in this study is to test the hypothesis that human monocyte-derived dendritic cell (MoDC)-derived exos constitute a well-tolerated and effective immune therapeutic approach to modulate human target DC and T cell immune responses in vitro. MoDC subtypes were generated with TGFb/IL-10 (regulatory (reg) MoDCs, CD86lowHLA-DRlowPDL1high), E. coli LPS (stimulatory (stim) MoDCs, CD86highHLA-DRhighPDL1low) and buffer (immature (i) MoDCs, CD86lowHLA-DRmedPDL1low). Exosomes were isolated from different MoDC subtypes and characterized. Once released from the secreting cell into the surrounding environment, exosomes protect their prepackaged molecular cargo and deliver it to bystander cells. This modulates the functions of these cells, depending on the cargo content. RegMoDCexos were internalized by recipient MoDCs and induced upregulation of PDL1 and downregulation of costimulatory molecules CD86, HLADR, and CD80, while stimMoDCexos had the opposite influence. RegMoDCexos induced CD25+Foxp3+ Tregs, which expressed CTLA4 and PD1 but not IL-17A. In contrast, T cells treated with stimMoDCexos induced IL-17A+ Th17 T cells, which were negative for immunoregulatory CTLA4 and PD1. T cells and DCs treated with iMoDCexos were immune 'neutral', equivalent to controls. In conclusion, human DC exos present an effective delivery system to modulate human DC and T cell immune responses in vitro. Thus, MoDC exos may present a viable immunotherapeutic agent for modulating immune response in the gingival tissue to inhibit bone loss in periodontal disease.
Asunto(s)
Exosomas , Humanos , Ratones , Animales , Antígeno CTLA-4 , Escherichia coli , Células Dendríticas , Antígenos HLA-DR , Inmunidad , Diferenciación Celular , MonocitosRESUMEN
Extensive research in humans and animal models has begun to unravel the complex mechanisms that drive the immunopathogenesis of periodontitis. Neutrophils mount an early and rapid response to the subgingival oral microbiome, producing destructive enzymes to kill microbes. Chemokines and cytokines are released that attract macrophages, dendritic cells, and T cells to the site. Dendritic cells, the focus of this review, are professional antigen-presenting cells on the front line of immune surveillance. Dendritic cells consist of multiple subsets that reside in the epithelium, connective tissues, and major organs. Our work in humans and mice established that myeloid dendritic cells are mobilized in periodontitis. This occurs in lymphoid and nonlymphoid oral tissues, in the bloodstream, and in response to Porphyromonas gingivalis. Moreover, the dendritic cells mature in situ in gingival lamina propria, forming immune conjugates with cluster of differentiation (CD) 4+ T cells, called oral lymphoid foci. At such foci, the decisions are made as to whether to promote bone destructive T helper 17 or bone-sparing regulatory T cell responses. Interestingly, dendritic cells lack potent enzymes and reactive oxygen species needed to kill and degrade endocytosed microbes. The keystone pathogen P. gingivalis exploits this vulnerability by invading dendritic cells in the tissues and peripheral blood using its distinct fimbrial adhesins. This promotes pathogen dissemination and inflammatory disease at distant sites, such as atherosclerotic plaques. Interestingly, our recent studies indicate that such P. gingivalis-infected dendritic cells release nanosized extracellular vesicles called exosomes, in higher numbers than uninfected dendritic cells do. Secreted exosomes and inflammasome-related cytokines are a key feature of the senescence-associated secretory phenotype. Exosomes communicate in paracrine with neighboring stromal cells and immune cells to promote and amplify cellular senescence. We have shown that dendritic cell-derived exosomes can be custom tailored to target and reprogram specific immune cells responsible for inflammatory bone loss in mice. The long-term goal of these immunotherapeutic approaches, ongoing in our laboratory and others, is to promote human health and longevity.
Asunto(s)
Pérdida de Hueso Alveolar , Periodontitis , Animales , Citocinas , Células Dendríticas , Susceptibilidad a Enfermedades , Humanos , Inmunoterapia , Ratones , Porphyromonas gingivalisRESUMEN
BACKGROUND: The effect of non-surgical periodontal treatment on oral and systemic inflammatory mediators in subjects with periodontitis and hyperglycemia remains largely unknown. Therefore, the aim of this clinical study was to compare the short-term effect of non-surgical periodontal treatment on serum, saliva and GCF inflammatory markers levels in GP subjects with or without hyperglycemia. METHODS: Sixty subjects divided into four groups of equal size were selected to participate: type 2 diabetics with generalized periodontitis (T2DM + GP), pre-diabetics with GP (PD + GP), normoglycemic subjects with GP (NG + GP), and healthy controls. GCF, serum, and saliva samples were obtained at baseline and 30 days after scaling and root planning (SRP) and the levels of interleukin-1ß (IL-1 ß), IL-8, IL-6, IL-2, IL-5, IL-4, IL-10, Interferon gamma (IFN-γ), Granulocyte macrophage colony-stimulating factor (GM-CSF) and Tumor necrosis factor-alpha (TNF-α) were determined by ultrasensitive multiplex assay. Clinical periodontal measurements were recorded. RESULTS: SRP yielded significant improvement of all periodontal parameters for all GP groups (p < 0.01). A significant reduction in GCF levels of several cytokines were observed; however, only IL-1B and IFN-γ were consistently reduced post-treatment across all GP groups. Salivary levels of IL-1ß were significantly reduced in all GP groups following treatment. No significant differences were observed for serum levels after SRP. CONCLUSIONS: Periodontal treatment reduced local inflammatory markers, specifically IL-1B and IFN-γ, irrespective of the diabetes status. Periodontal treatment had no significant effect on serum levels of the inflammatory markers evaluated in this study.
Asunto(s)
Citocinas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Líquido del Surco Gingival/metabolismo , Hiperglucemia/metabolismo , Periodontitis/metabolismo , Administración Oral , Adulto , Anciano , Biomarcadores/metabolismo , Glucemia/análisis , Femenino , Líquido del Surco Gingival/química , Humanos , Inflamación , Mediadores de Inflamación , Masculino , Persona de Mediana Edad , Saliva/química , Factores de TiempoRESUMEN
Dendritic cells are an important link between innate and adaptive immune response. The role of dendritic cells in bone homeostasis, however, is not understood. Osteoporosis medications that inhibit osteoclasts have been associated with osteonecrosis, a condition limited to the jawbone, thus called medication-related osteonecrosis of the jaw. We propose that disruption of the local immune response renders the oral microenvironment conducive to osteonecrosis. We tested whether zoledronate (Zol) treatment impaired dendritic cell (DC) functions and increased bacterial load in alveolar bone in vivo and whether DC inhibition alone predisposed the animals to osteonecrosis. We also analyzed the role of Zol in impairment of differentiation and function of migratory and tissue-resident DCs, promoting disruption of T-cell activation in vitro. Results demonstrated a Zol induced impairment in DC functions and an increased bacterial load in the oral cavity. DC-deficient mice were predisposed to osteonecrosis following dental extraction. Zol treatment of DCs in vitro caused an impairment in immune functions including differentiation, maturation, migration, antigen presentation, and T-cell activation. We conclude that the mechanism of Zol-induced osteonecrosis of the jaw involves disruption of DC immune functions required to clear bacterial infection and activate T cell effector response.
Asunto(s)
Conservadores de la Densidad Ósea/farmacología , Huesos/efectos de los fármacos , Células Dendríticas/metabolismo , Homeostasis/inmunología , Enfermedades Maxilomandibulares/inmunología , Osteonecrosis/tratamiento farmacológico , Ácido Zoledrónico/farmacología , Animales , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Células Dendríticas/inmunología , Homeostasis/efectos de los fármacos , Imidazoles/farmacología , Enfermedades Maxilomandibulares/tratamiento farmacológico , Osteoclastos/efectos de los fármacos , Osteoclastos/inmunología , Osteonecrosis/inmunología , Extracción Dental/métodos , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Periodontitis (PD) is a common dysbiotic inflammatory disease that leads to local bone deterioration and tooth loss. PD patients experience low-grade bacteremias with oral microbes implicated in the risk of heart disease, cancer, and kidney failure. Although Th17 effectors are vital to fighting infection, functional imbalance of Th17 effectors and regulatory T cells (Tregs) promote inflammatory diseases. In this study, we investigated, in a small pilot randomized clinical trial, whether expansion of inflammatory blood myeloid dendritic cells (DCs) and conversion of Tregs to Th17 cells could be modulated with antibiotics (AB) as part of initial therapy in PD patients. PD patients were randomly assigned to either 7 d of peroral metronidazole/amoxicillin AB treatment or no AB, along with standard care debridement and chlorhexidine mouthwash. 16s ribosomal RNA analysis of keystone pathogen Porphyromonas gingivalis and its consortium members Fusobacterium nucleatum and Streptococcus gordonii confirmed the presence of all three species in the reservoirs (subgingival pockets and blood DCs) of PD patients before treatment. Of the three species, P. gingivalis was reduced in both reservoirs 4-6 wk after therapy. Further, the frequency of CD1C+CCR6+ myeloid DCs and IL-1R1 expression on IL-17A+FOXP3+CD4+ T cells in PD patients were reduced to healthy control levels. The latter led to decreased IL-1ß-stimulated Treg plasticity in PD patients and improvement in clinical measures of PD. Overall, we identified an important, albeit short-term, beneficial role of AB therapy in reducing inflammatory DCs and Treg-Th17 plasticity in humans with PD.
Asunto(s)
Amoxicilina/administración & dosificación , Bacterias , Infecciones Bacterianas , Células Dendríticas , Metronidazol/administración & dosificación , Periodontitis , Linfocitos T Reguladores , Células Th17 , Bacterias/inmunología , Bacterias/metabolismo , Infecciones Bacterianas/sangre , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/inmunología , Infecciones Bacterianas/patología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Dendríticas/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodontitis/sangre , Periodontitis/tratamiento farmacológico , Periodontitis/inmunología , Periodontitis/patología , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/parasitología , Linfocitos T Reguladores/patología , Células Th17/inmunología , Células Th17/metabolismo , Células Th17/patologíaRESUMEN
Traditional antimicrobial therapies for periodontitis (PD) have long focused on non-selective and direct approaches. Professional cleaning of the subgingival biofilm by instrumentation of dental root surfaces, known as scaling and root planning (SRP), is the mainstay of periodontal therapy and is indisputably effective. Non-physical approaches used as adjuncts to SRP, such as chemical and biological agents, will be the focus of this review. In this regard, traditional agents such as oral antiseptics and antibiotics, delivered either locally or systemically, were briefly reviewed as a backdrop. While generally effective in winning the "battle" against PD in the short term, by reducing its signs and symptoms, patients receiving such therapies are more susceptible to recurrence of PD. Moreover, the long-term consequences of such therapies are still in question. In particular, concern about chronic use of systemic antibiotics and their influence on the oral and gut microbiota is warranted, considering antibiotic resistance plasmids, and potential transfer between oral and non-oral microbes. In the interest of winning the "battle and the war", new more selective and targeted antimicrobials and biologics for PD are being studied. These are principally indirect, blocking pathways involved in bacterial colonization, nutrient acquisition, inflammation or cellular invasion without directly killing the pathogens. This review will focus on current and prospective antimicrobial therapies for PD, emphasizing therapies that act indirectly on the microbiota, with clearly defined cellular and molecular targets.
Asunto(s)
Antibacterianos/uso terapéutico , Periodontitis/tratamiento farmacológico , Periodontitis/microbiología , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Terapia Combinada , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Vías de Administración de Medicamentos , Humanos , Periodontitis/metabolismo , Resultado del TratamientoRESUMEN
Enterococcus faecalis, long implicated in serious systemic infections and failure of root canal treatment, is a persistent inhabitant of oral periapical lesions. Dendritic cells (DCs) and other innate immune cells patrol the oral mucosa for infecting microbes. Dendritic cells are efficient at capturing microbes when immature, whereupon they can transform into potent antigen-presenting cells upon full maturation. Autophagy, a sophisticated intracellular process first described for elimination of damaged organelles, regulates DC maturation and other important immune functions of DCs. The present study examined how E. faecalis influences the differentiation of murine bone marrow-derived stem cells (BMSCs) into functional DCs in the presence of the cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). Although the viability and differentiation of DCs were not affected by E. faecalis, expression of the autophagy-related proteins ATG7, Beclin1, and LC3bI/II were significantly suppressed in an mTOR-dependent manner. Ultrastructurally, E. faecalis was identified in single-membrane vacuoles, some of which were in the process of binary fission. Bacterium-containing autophagosomes were absent within the cytoplasm. Accessory molecules (major histocompatibility complex class II [MHC-II], CD80, and CD86) and anti-inflammatory cytokine (transforming growth factor ß1 [TGF-ß1]) were suppressed in E. faecalis-induced DCs, while IL-1ß, tumor necrosis factor alpha (TNF-α), and IL-12 levels were upregulated. When pulsed with ovalbumin (OVA), the E. faecalis-induced DCs showed reduction in CD4+ OVA-specific OT-II T cell proliferation. It is concluded that E. faecalis promotes the differentiation of bone marrow stem cells into CD11c-positive DCs with aberrant immune functions while retaining the capability of proinflammatory cytokine induction.
Asunto(s)
Diferenciación Celular/inmunología , Células Dendríticas/inmunología , Enterococcus faecalis/inmunología , Infecciones por Bacterias Grampositivas/inmunología , Células Madre Hematopoyéticas/inmunología , Animales , RatonesRESUMEN
Mucosal health and disease is mediated by a complex interplay between the microbiota ("spark") and the inflammatory response ("flame"). Pathobionts, a specific class of microbes, exemplified by the oral microbe Porphyromonas gingivalis, live mostly "under the radar" in their human hosts, in a cooperative relationship with the indigenous microbiota. Dendritic cells (DCs), mucosal immune sentinels, often remain undisturbed by such microbes and do not alert adaptive immunity to danger. At a certain tipping point of inflammation, an "awakening" of pathobionts occurs, wherein their active growth and virulence are stimulated, leading to a dysbiosis. Pathobiont becomes pathogen, and commensal becomes accessory pathogen. The local inflammatory outcome is the Th17-mediated degenerative bone disease, periodontitis (PD). In systemic circulation of PD subjects, inflammatory DCs expand, carrying an oral microbiome and promoting Treg and Th17 responses. At distant peripheral sites, comorbid diseases including atherosclerosis, Alzheimer's disease, macular degeneration, chronic kidney disease, and others are reportedly induced. This review will review the immunobiology of DCs, examine the complex interplay of microbes and DCs in the pathogenesis of PD and its comorbid inflammatory diseases, and discuss the role of apoptosis and autophagy in this regard. Overall, the pathophysiological mechanisms of DC-mediated chronic inflammation and tissue destruction will be summarized.
Asunto(s)
Células Dendríticas/patología , Inflamación/patología , Microbiota , Enfermedades de la Boca/microbiología , Mucosa Bucal/microbiología , Mucosa Bucal/patología , Animales , Autofagia , HumanosRESUMEN
OBJECTIVES: Vitamin D deficiency/insufficiency is a worldwide public health issue that has been linked to numerous inflammatory disorders, including periodontitis. There is increasing support for a role for adequate vitamin D levels in overall health. Populations with darker skin color have a higher prevalence of vitamin D deficiency/insufficiency and periodontitis. The purpose of this small pilot study was to investigate the influence of 12 weeks of 25(OH)D vitamin D supplementation (VDS) on mediators of systemic inflammation in dark-skinned, periodontitis patients. MATERIALS AND METHODS: A total of 23 patients with moderate to severe periodontitis were randomly assigned to the vitamin D group or placebo group and received intensive single visit scaling and root planning to elicit a systemic inflammatory response. RESULTS: Vitamin D supplementation increased serum 25(OH)D levels approximately 2-fold over baseline levels; moreover, VDS group had reduced peripheral blood CD3 and CD3+CD8+ cytotoxic T lymphocyte (CTLs) counts and reduced pro-inflammatory salivary cytokines. In contrast, VDS group had higher levels of the autophagy-related proteins and other proteins crucial for anti-microbial autophagy in whole blood PBMCs. CONCLUSION: In conclusion, VDS has multiple benefits for reducing systemic inflammation and promoting induction of autophagy-related proteins related to anti-microbial functions.
Asunto(s)
Mediadores de Inflamación/sangre , Inflamación/etiología , Periodontitis , Deficiencia de Vitamina D , Vitamina D/administración & dosificación , Suplementos Dietéticos , Humanos , Inflamación/sangre , Proyectos Piloto , Vitamina D/uso terapéutico , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/complicaciones , Deficiencia de Vitamina D/inmunología , Vitaminas/uso terapéuticoRESUMEN
OBJECTIVE: To compare the myeloid and plasmacytoid DC counts and maturation status among subjects with/without generalized periodontitis (GP) and type 2 diabetes mellitus (T2DM). METHODS: The frequency and maturation status of myeloid and plasmacytoid blood DCs were analyzed by flow cytometry in four groups of 15 subjects: healthy controls, T2DM with generalized CP (T2DM + GP), prediabetes with GP (PD + GP), and normoglycemics with GP (NG + GP). RT-PCR was used to determine levels of Porphyromonas gingivalis in the oral biofilms and within panDCs. The role of exogenous glucose effects on differentiation and apoptosis of healthy human MoDCs was explored in vitro. RESULTS: Relative to controls and to NG + GP, T2DM + GP showed significantly lower CD1c + and CD303 + DC counts, while CD141 + DCs were lower in T2DM + GP relative to controls. Blood DC maturation required for mobilization and immune responsiveness was not observed. A statistically significant trend was observed for P. gingivalis levels in the biofilms of groups as follows: controls Asunto(s)
Células Dendríticas/inmunología
, Diabetes Mellitus Tipo 2
, Periodontitis
, Estado Prediabético
, Adulto
, Anciano
, Brasil
, Humanos
, Persona de Mediana Edad
, Porphyromonas gingivalis
RESUMEN
Visceral adipose tissue (VAT) inflammation and metabolic dysregulation are key components of obesity-induced metabolic disease. Upregulated arginase, a ureahydrolase enzyme with two isoforms (A1-cytosolic and A2-mitochondrial), is implicated in pathologies associated with obesity and diabetes. This study examined A2 involvement in obesity-associated metabolic and vascular disorders. WT and globally deleted A2(-/-) or A1(+/-) mice were fed either a high fat/high sucrose (HFHS) diet or normal diet (ND) for 16 weeks. Increases in body and VAT weight of HFHS-fed WT mice were abrogated in A2-/-, but not A1+/-, mice. Additionally, A2-/- HFHS-fed mice exhibited higher energy expenditure, lower blood glucose, and insulin levels compared to WT HFHS mice. VAT and adipocytes from WT HFHS fed mice showed greater A2 expression and adipocyte size and reduced expression of PGC-1α, PPAR-γ, and adiponectin. A2 deletion blunted these effects, increased levels of active AMPK-α, and upregulated genes involved in fatty acid metabolism. A2 deletion prevented HFHS-induced VAT collagen deposition and inflammation, which are involved in adipocyte metabolic dysfunction. Endothelium-dependent vasorelaxation, impaired by HFHS diet, was significantly preserved in A2-/- mice, but more prominently maintained in A1+/- mice. In summary, A2 is critically involved in HFHS-induced VAT inflammation and metabolic dysfunction.
Asunto(s)
Tejido Adiposo/metabolismo , Arginasa/metabolismo , Dieta Alta en Grasa/efectos adversos , Metabolismo Energético , Ácidos Grasos/metabolismo , Obesidad/etiología , Obesidad/metabolismo , Adipocitos/metabolismo , Adipocitos/patología , Tejido Adiposo/patología , Animales , Arginasa/genética , Biomarcadores , Modelos Animales de Enfermedad , Fibrosis , Eliminación de Gen , Hipertrofia , Ratones , Obesidad/patología , Oxidación-Reducción , Estrés Oxidativo , Consumo de Oxígeno , Sacarosa/metabolismoRESUMEN
BACKGROUND: Lip repositioning is a conservative surgical technique used to treat excess gingival display. An array of modifications has been introduced to the technique over time and as studies show the technique and its modifications to be successful, there is little standardized information for clinicians to make informed decisions when choosing this technique for the treatment of patients with excessive gingival display (EGD). OBJECTIVES: To review the current literature on the topic of lip repositioning for the treatment of excessive EGD, exploring outcome, and result longevity. METHODS: A structured systematic search was carried out using the Ovid database and Web of Science to identify published studies on lip repositioning technique. Search was restricted to studies in the English language, describing a surgical intervention. Case reports were included as the number of published studies was limited. RESULTS: The electronic search identified 93 articles, hand search identified 1 article, and reference search identified 1 article. After excluding duplicates and screening articles, a total of 22 articles met the inclusion criteria. An estimated mean improvement of 3.4 mm (95% confidence interval, 3.0-3.8 mm) was found possible with lip repositioning. Data analysis was performed using only 4 studies, amounting to a total of 33 patients. Potential risk of bias was identified in some of the studies included. CONCLUSIONS: Despite the limited available studies on lip repositioning, an estimated mean improvement of 3.4 mm was found to be possible with surgical lip repositioning, suggesting that the technique could be used successfully to treat EGD. However, more studies are necessary to properly evaluate the treatment approach and stability of the technique. CLINICAL SIGNIFICANCE: Recently, the demand for esthetics has significantly increased, driven by increased patient awareness and the search for an ideal smile. Creating the perfect smile is an intricate process that requires a multidisciplinary approach, with careful consideration of the lips and the gingival outline. Excess gingival display results in an unaesthetic smile, lip repositioning offers a comparatively simple solution for this problem. While the quality literature on this topic is limited statistical analysis of collected studies show that an estimated mean improvement of 3.4 mm can be achieved with surgical lip repositioning.
Asunto(s)
Estética Dental , Labio , Encía , Gingivectomía , Humanos , Labio/cirugía , SonrisaRESUMEN
Signaling via pattern recognition receptors (PRRs) expressed on professional antigen presenting cells, such as dendritic cells (DCs), is crucial to the fate of engulfed microbes. Among the many PRRs expressed by DCs are Toll-like receptors (TLRs) and C-type lectins such as DC-SIGN. DC-SIGN is targeted by several major human pathogens for immune-evasion, although its role in intracellular routing of pathogens to autophagosomes is poorly understood. Here we examined the role of DC-SIGN and TLRs in evasion of autophagy and survival of Porphyromonas gingivalis in human monocyte-derived DCs (MoDCs). We employed a panel of P. gingivalis isogenic fimbriae deficient strains with defined defects in Mfa-1 fimbriae, a DC-SIGN ligand, and FimA fimbriae, a TLR2 agonist. Our results show that DC-SIGN dependent uptake of Mfa1+P. gingivalis strains by MoDCs resulted in lower intracellular killing and higher intracellular content of P. gingivalis. Moreover, Mfa1+P. gingivalis was mostly contained within single membrane vesicles, where it survived intracellularly. Survival was decreased by activation of TLR2 and/or autophagy. Mfa1+P. gingivalis strain did not induce significant levels of Rab5, LC3-II, and LAMP1. In contrast, P. gingivalis uptake through a DC-SIGN independent manner was associated with early endosomal routing through Rab5, increased LC3-II and LAMP-1, as well as the formation of double membrane intracellular phagophores, a characteristic feature of autophagy. These results suggest that selective engagement of DC-SIGN by Mfa-1+P. gingivalis promotes evasion of antibacterial autophagy and lysosome fusion, resulting in intracellular persistence in myeloid DCs; however TLR2 activation can overcome autophagy evasion and pathogen persistence in DCs.
Asunto(s)
Autofagia/inmunología , Moléculas de Adhesión Celular/metabolismo , Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Células Mieloides/metabolismo , Porphyromonas gingivalis/metabolismo , Receptores de Superficie Celular/metabolismo , Receptor Toll-Like 2/metabolismo , Dendritas/ultraestructura , Células Dendríticas/inmunología , Células Dendríticas/ultraestructura , Fimbrias Bacterianas , Humanos , Espacio Intracelular/inmunología , Espacio Intracelular/metabolismo , Monocitos/inmunología , Monocitos/ultraestructura , Células Mieloides/inmunología , Receptor Toll-Like 2/inmunologíaRESUMEN
Dendritic cells are potent antigen-capture and antigen-presenting cells that play a key role in the initiation and regulation of the adaptive immune response. This process of immune homeostasis, as maintained by dendritic cells, is susceptible to dysregulation by certain pathogens during chronic infections. Such dysregulation may lead to disease perpetuation with potentially severe systemic consequences. Here we discuss in detail how intracellular pathogens exploit dendritic cells and escape degradation by altering or evading autophagy. This novel mechanism explains, in part, the chronic, persistent nature observed in several immuno-inflammatory diseases, including periodontal disease. We also propose a hypothetical model of the plausible role of autophagy in the context of periodontal disease. Promotion of autophagy may open new therapeutic strategies in the search of a 'cure' for periodontal disease in humans.
Asunto(s)
Inmunidad Adaptativa , Autofagia , Células Dendríticas/inmunología , Periodontitis/inmunología , Periodontitis/microbiología , Células Dendríticas/patología , Interacciones Huésped-Patógeno , Humanos , Membrana Mucosa/inmunología , Periodontitis/patología , FagocitosisRESUMEN
Several intracellular pathogens, including a key etiological agent of chronic periodontitis, Porphyromonas gingivalis, infect blood myeloid dendritic cells (mDCs). This infection results in pathogen dissemination to distant inflammatory sites (i.e., pathogen trafficking). The alteration in chemokine-chemokine receptor expression that contributes to this pathogen trafficking function, particularly toward sites of neovascularization in humans, is unclear. To investigate this, we utilized human monocyte-derived DCs (MoDCs) and primary endothelial cells in vitro, combined with ex vivo-isolated blood mDCs and serum from chronic periodontitis subjects and healthy controls. Our results, using conditional fimbria mutants of P. gingivalis, show that P. gingivalis infection of MoDCs induces an angiogenic migratory profile. This profile is enhanced by expression of DC-SIGN on MoDCs and minor mfa-1 fimbriae on P. gingivalis and is evidenced by robust upregulation of CXCR4, but not secondary lymphoid organ (SLO)-homing CCR7. This disruption of SLO-homing capacity in response to respective chemokines closely matches surface expression of CXCR4 and CCR7 and is consistent with directed MoDC migration through an endothelial monolayer. Ex vivo-isolated mDCs from the blood of chronic periodontitis subjects, but not healthy controls, expressed a similar migratory profile; moreover, sera from chronic periodontitis subjects expressed elevated levels of CXCL12. Overall, we conclude that P. gingivalis actively "commandeers" DCs by reprogramming the chemokine receptor profile, thus disrupting SLO homing, while driving migration toward inflammatory vascular sites.
Asunto(s)
Infecciones por Bacteroidaceae/metabolismo , Movimiento Celular/fisiología , Periodontitis Crónica/metabolismo , Células Dendríticas/microbiología , Células Mieloides/microbiología , Porphyromonas gingivalis/fisiología , Receptores de Quimiocina/metabolismo , Infecciones por Bacteroidaceae/inmunología , Infecciones por Bacteroidaceae/microbiología , Estudios de Casos y Controles , Moléculas de Adhesión Celular/metabolismo , Quimiocina CXCL12/metabolismo , Quimiotaxis/fisiología , Periodontitis Crónica/inmunología , Periodontitis Crónica/microbiología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Endoteliales/metabolismo , Fimbrias Bacterianas/genética , Fimbrias Bacterianas/fisiología , Humanos , Lectinas Tipo C/metabolismo , Lipopolisacáridos/farmacología , Células Mieloides/efectos de los fármacos , Células Mieloides/inmunología , Células Mieloides/metabolismo , Neovascularización Patológica/microbiología , Fenotipo , Receptores CCR7/metabolismo , Receptores CXCR4/metabolismo , Receptores de Superficie Celular/metabolismo , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
The low-grade oral infection chronic periodontitis (CP) has been implicated in coronary artery disease risk, but the mechanisms are unclear. In this study, a pathophysiological role for blood dendritic cells (DCs) in systemic dissemination of oral mucosal pathogens to atherosclerotic plaques was investigated in humans. The frequency and microbiome of CD19(-)BDCA-1(+)DC-SIGN(+) blood myeloid DCs (mDCs) were analyzed in CP subjects with or without existing acute coronary syndrome and in healthy controls. FACS analysis revealed a significant increase in blood mDCs in the following order: healthy controls < CP < acute coronary syndrome/CP. Analysis of the blood mDC microbiome by 16S rDNA sequencing showed Porphyromonas gingivalis and other species, including (cultivable) Burkholderia cepacia. The mDC carriage rate with P. gingivalis correlated with oral carriage rate and with serologic exposure to P. gingivalis in CP subjects. Intervention (local debridement) to elicit a bacteremia increased the mDC carriage rate and frequency in vivo. In vitro studies established that P. gingivalis enhanced by 28% the differentiation of monocytes into immature mDCs; moreover, mDCs secreted high levels of matrix metalloproteinase-9 and upregulated C1q, heat shock protein 60, heat shock protein 70, CCR2, and CXCL16 transcripts in response to P. gingivalis in a fimbriae-dependent manner. Moreover, the survival of the anaerobe P. gingivalis under aerobic conditions was enhanced when within mDCs. Immunofluorescence analysis of oral mucosa and atherosclerotic plaques demonstrate infiltration with mDCs, colocalized with P. gingivalis. Our results suggest a role for blood mDCs in harboring and disseminating pathogens from oral mucosa to atherosclerosis plaques, which may provide key signals for mDC differentiation and atherogenic conversion.
Asunto(s)
Diferenciación Celular/inmunología , Células Dendríticas/inmunología , Células Dendríticas/microbiología , Placa Aterosclerótica/inmunología , Placa Aterosclerótica/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Infecciones por Bacteroidaceae/sangre , Infecciones por Bacteroidaceae/inmunología , Infecciones por Bacteroidaceae/microbiología , Infecciones por Burkholderia/sangre , Infecciones por Burkholderia/inmunología , Infecciones por Burkholderia/microbiología , Portador Sano/sangre , Portador Sano/inmunología , Portador Sano/microbiología , Enfermedad Crónica , Células Dendríticas/patología , Femenino , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Monocitos/microbiología , Monocitos/patología , Mucosa Bucal/inmunología , Mucosa Bucal/microbiología , Mucosa Bucal/patología , Células Mieloides/inmunología , Células Mieloides/microbiología , Células Mieloides/patología , Periodontitis , Placa Aterosclerótica/sangre , Porphyromonas gingivalisRESUMEN
AIM: Test whether human periodontal ligament fibroblasts (PDLFs) retain homeostatic responses to a physiological compressive force during chronic periodontitis. MATERIAL AND METHODS: Six cell lines were established from periodontally healthy individuals (H-PDLFs) and another six were cultured from patients diagnosed with chronic periodontitis (D-PDLFs). Compressive force at 150 psi was applied to H-and D-PDLFs for 3 h on 2 consecutive days. After compression, comparisons between H-and D-PDLFs were performed by gene expression analysis of IL-6, proteases and 84 inflammation-related targets using real-time PCR. RESULTS: Compression of H-PDLFs resulted in a significant increase only in MMP-1 mRNA. In contrast, the same compressive force on D-PDLFs produced significant increases in the expression of MMPs-1,-7,-9 and -16. Moreover, compression of H-PDLFs resulted in down-regulation of IL-6, while IL-6 was significantly up-regulated in compressed D-PDLFs. Compression of H-PDLFs slightly up-regulated 3 and significantly down-regulated 15 inflammation-related genes, while the same treatment strongly up-regulated 21 inflammation-related genes in D-PDLFs. CONCLUSION: These results suggest a fundamental difference in the inflammatory response of healthy versus diseased PDLFs under physiological compression. Maintenance of these characteristics in vitro suggests that these cells may be at least partly responsible for the persistence of inflammation and localized susceptibility in chronic periodontitis.
Asunto(s)
Periodontitis Crónica/patología , Fibroblastos/fisiología , Ligamento Periodontal/citología , Técnicas de Cultivo de Célula , Línea Celular , Células Cultivadas , Quimiocinas/análisis , Homeostasis/fisiología , Humanos , Presión Hidrostática , Mediadores de Inflamación/análisis , Interleucina-6/análisis , Interleucinas/análisis , Metaloproteinasa 1 de la Matriz/análisis , Metaloproteinasa 16 de la Matriz/análisis , Metaloproteinasa 7 de la Matriz/análisis , Metaloproteinasa 9 de la Matriz/análisis , Metaloproteinasas de la Matriz/análisis , Ligamento Periodontal/fisiología , Factores de Tiempo , Inhibidor Tisular de Metaloproteinasa-1/análisis , Inhibidor Tisular de Metaloproteinasa-2/análisisRESUMEN
The active form of vitamin D is the hormonally active 1,25(OH)2D3 (Vit D) vitamin, which plays an important role in bone biology and host immunity. The vitamin D receptor (VDR) is a nuclear ligand-dependent transcription factor expressed by many cells. Ligation of VDR by VitD regulates a wide plethora of genes and physiologic functions through the formation of the complex Vit D-VDR signaling cascade. The influence of Vit D-VDR signaling in host immune response to microbial infection has been of interest to many researchers. This is particularly important in oral health and diseases, as oral mucosa is exposed to a complex microbiota, with certain species capable of causing disruption to immune homeostasis. In this review, we focus on the immune modulatory roles of Vit D in the bone degenerative oral disease, periodontitis.
RESUMEN
As the aging population grows, chronic age-related bone degenerative diseases become more prevalent and severe. One such disease, periodontitis (PD), rises to 70.1% prevalence in Americans 65 years and older. PD has been linked to increased risk of other age-related diseases with more serious mortality and morbidity profiles such as Alzheimer's disease and cardiovascular disease, but the cellular and biological mechanisms remain unclear. Recent in vitro studies from our group indicate that murine dendritic cells (DCs) and T cells are vulnerable to immune senescence. This occurs through a distinct process involving invasion of DCs by dysbiotic pathogen Porphyromonas gingivalis (Pg) activating the senescence associated secretory phenotype (SASP). Exosomes of the Pg-induced SASP transmit senescence to normal bystander DC and T cells, ablating antigen presentation. The biological significance of these findings in vivo and the mechanisms involved were examined in the present study using young (4-5mo) or old (22-24mo) mice subjected to ligature-induced PD, with or without dysbiotic oral pathogen and injection of Pg-induced DC exosomes. Senescence profiling of gingiva and draining lymph nodes (LN) corroborates role of advanced age and PD in elevation of senescence biomarkers beta galactosidase (SA-ß-Gal), p16 INK4A p21Waf1/Clip1, IL6, TNFα, and IL1ß, with attendant increase in alveolar bone loss, reversed by senolytic agent rapamycin. Immunophenotyping of gingiva and LN revealed that myeloid CD11c+ DCs and T cells are particularly vulnerable to senescence in vivo under these conditions. Moreover, Pg-induced DC exosomes were the most potent inducers of alveolar bone loss and immune senescence, and capable of overcoming senescence resistance of LN T cells in young mice. We conclude that immune senescence, compounded by advanced age, and accelerated by oral dysbiosis and its induced SASP exosomes, plays a pivotal role in the pathophysiology of experimental periodontitis.