牙龈卟啉单胞菌与阿尔茨海默病的相关性研究进展

牙龈卟啉单胞菌（Porphyromonas gingivalis,P.gingivalis）是一种革兰氏阴性厌氧菌,是牙周病的主要致病菌。由于P.gingivalis具有激活宿主炎症、调节免疫反应的能力,其与全身性疾病,特别是阿尔茨海默病（Alzheimer's disease,AD）的相互关系已成为研究热点。AD是一种常见的引起老年人群痴呆的神经退行性病变,以多种炎症介质参与的炎症反应为关键病理机制。本文就二者可能的相互关联机制作一综述。     

牙龈卟啉单胞菌对脐静脉血管内皮细胞产生sICAM-1的影响

目的：观察牙龈卟啉单胞菌（Porphyromonas gingivalis,P.gingivalis)对人类脐静脉血管内皮细胞（human umbilical vein endothelial cells,HUVECs)产生可溶性细胞间粘附分子－1（soluble intercellular adhesion molecule-1,sICAM-1)的影响。方法：应用厌氧袋法培养P.gingivalis，并用其感染HUVECs，采和酶联免疫吸附实验（enzyme-linked immunosorbent assay,ELISA)测定培养上清中sICAM-1的含量，结果：HUVECs基础表达少量的sICAM-1;P.gingivalis剂量依赖性增强HUVECs产生sICAM-1蛋白的水平；紫外线、超声波和65℃的热处理都不能抑制P.gingivalis的作用；sICAM-1蛋白水平在P.gingivalis刺激后的4h未见改变，增高的作用从刺激后的8h开始，在12h,16h和20h继续增加。结论：活的和灭活的P.gingivalis都剂量依赖性和时间依赖性地增强HUVECs产生sICAM-1,P.gingivalis可能同样诱导牙龈血管内皮细胞表达sICAM-1，升高的sICAM-1可能参与调节牙周病炎症反应和免疫反应过程。     

牙龈卟啉单胞菌及其牙龈蛋白酶K对青少年牙龈健康的影响

目的：分析牙龈卟啉单胞菌（P. gingivalis）及牙龈蛋白酶K（Kgp）对青少年牙龈健康的影响。方法???收集12~17岁青少年牙龈正常组（50例）、牙龈炎症指数Ⅰ级组（25例）和牙龈炎症指数Ⅱ级组（32例）的3组龈沟液标本,应用16S?rDNA?PCR技术检测各样本中的P. gingivalis及Kgp。3组P. gingivalis和Kgp阳性检出率的比较采用χ2检验;P. gingivalis和Kgp的相对含量与牙龈炎症指数之间的关系采用Spearman相关分析。结果???P. gingivalis在牙龈炎症指数Ⅰ级组的检出率大于牙龈正常组,牙龈炎症指数Ⅱ级组的检出率大于牙龈炎症指数Ⅰ级组和牙龈正常组,牙龈炎症指数Ⅰ级组、Ⅱ级组与牙龈正常组间有明显差异（P<0.01）,牙龈炎症指数Ⅰ级组与Ⅱ级组间差异具有统计学意义（P<0.05）。Kgp在牙龈炎症指数Ⅰ级组的检出率大于牙龈正常组,牙龈炎症指数Ⅱ级组的检出率大于牙龈炎症指数Ⅰ级组和牙龈正常组,牙龈炎症指数Ⅰ级组与牙龈正常组间差异具有统计学意义（P<0.05）,牙龈炎症指数Ⅱ级组与牙龈正常组间有明显差异（P<0.01）。P. gingivalis和Kgp的检出率随着牙龈炎症指数的增加而升高。结论???P. gingivalis和Kgp与青少年牙龈健康密切相关。     

牙龈卟啉单胞菌感染宿主细胞后对其凋亡调控研究进展

牙龈卟啉单胞菌（Porphyromonas gingivalis）是证据充分的重要的牙周致病菌之一,参与牙周炎的发生、发展及牙周组织的破坏过程。以往研究表明,牙周感染与全身健康及系统疾病均有着密切关系。P. gingivalis感染多种宿主细胞后,通过干扰相关信号传导及蛋白表达,对宿主细胞凋亡进行调控。现就P. gingivalis感染宿主细胞后对其凋亡调控研究进展做一综述。     

高脂血症抑制载脂蛋白E基因敲除小鼠对牙龈卟啉单胞菌炎症反应的影响

目的:研究高脂血症在ApoE基因敲除(ApoE-/-)小鼠对牙龈卟啉单胞菌(P. gingivalis)炎症反应过程中的影响及其机制。方法:利用ApoE-/-小鼠建立长时间高脂血症模型,腹腔注射活P. gingivalis以建立腹膜炎症模型,倍比稀释法分析腹腔内清除细菌能力,ELISA法检测血液中白细胞介素6(IL-6)和单核细胞趋化因子1(MCP-1)的分泌,实时定量PCR检测腹腔细胞IL-6和MCP-1的转录水平,采用SPSS13.0软件包进行统计学分析。结果:高脂血症显著降低了腹腔清除P. gingivalis的能力,ApoE-/-小鼠腹腔细胞中IL-6和MCP-1转录水平下降,释放入血液中的IL-6和MCP-1水平下降。结论:高脂血症导致宿主对P. gingivalis炎症反应不足,清除细菌能力下降,加速了牙周病的发展进程。     

牙龈卟啉单胞菌与免疫细胞调亡

牙周病是口腔的常见病和多发病.大量研究证实,牙周病是由口腔微生物所引起,微生物与宿主之间的相互作用同时会影响牙周病的发展与严重程度.近年来,口腔疾病与细胞调亡的关系的研究日益受到普遍重视,牙周病与免疫细胞调亡的关系已成为研究热点.本文就成人牙周炎主要致病菌--牙龈卟啉单胞菌与免疫细胞调亡的关系作一综迷,意在探讨其在牙周病病因中的作用.     

牙龈卟啉单胞菌与免疫细胞凋亡

牙周病是口腔的常见病和多发病。大量研究证实，牙周病是由口腔微生物所引起，微生物与宿主之间的相互作用同时会影响牙周病的发展与严重程度。近年来，口腔疾病与细胞凋亡的关系的研究日益受到普遍重视，牙周病与免疫细胞凋亡的关系已成为研究热点。本文就成人牙周炎主要致病菌——牙龈卟啉单胞菌与免疫细胞凋亡的关系作一综述，意在探讨其在牙周病病因中的作用。     

牙龈卟啉单胞菌对牙龈上皮细胞焦点黏附成分paxillin和FAK的作用

目的:研究牙龈卟啉单胞菌(P.gingivalis)对牙周组织的破坏机制,探讨菌毛的致病作用.方法:应用Western blot法检测P.gingivalis ATCC 33277及其fimA缺陷突变株对Hela细胞及永生化人牙龈上皮细胞 (immortalized human gingival epithelial cells, IHGE细胞) 的焦点黏附成分——焦点黏附蛋白paxillin和焦点黏附激酶 (focal adhesion kinase,FAK) 蛋白表达的影响.结果:P.gingivalis ATCC 33277野生株和fimA缺陷突变株能够使HeLa细胞和IHGE细胞的paxillin和FAK发生降解,fimA缺陷突变株对paxillin和FAK的降解能力较野生株显著减弱.在IHGE细胞中,paxillin和FAK的降解呈时间依赖性和MOI依赖性.结论:菌毛介导的P.gingivalis的黏附和侵入可能对焦点黏附成分的降解起促进作用,IHGE细胞较Hela细胞更适用于牙周致病菌的研究.     

牙龈卟啉单胞菌上调钙结合蛋白1促进牙龈上皮细胞增殖

目的 探究钙结合蛋白1在牙龈卟啉单胞菌(P.gingivalis)影响牙龈上皮细胞增殖和凋亡中的作用.方法 P.gingivalis感染CA9-22细胞,在感染24 h后,采用实时荧光定量聚合酶链反应、免疫印迹法和免疫荧光法检测钙结合蛋白1(CALB1)的表达.通过RNA干扰法抑制CALB1表达,BrdU分析检测细胞增...     

灌饲牙龈卟啉单胞菌对小鼠肠道炎症影响的研究

目的　研究灌饲牙龈卟啉单胞菌（Porphyromonas gingivalis，P. gingivalis）对C57bl/6小鼠结肠炎症的诱导作用。方法　将P. gingivalis ATCC33277液体增菌后备用。将15只C57bl/6小鼠适应1周后随机均分为3组，高浓度组灌饲1 × 109 CFU P. gingivalis，低浓度组灌饲1 × 108 CFU P. gingivalis，而对照组则灌饲等量无菌BHI培养液。每只小鼠每天灌饲1次，3周后处死小鼠，采集结肠及脾脏组织，行HE染色观察组织学变化，并采用实时荧光定量PCR（qRT-PCR）检测结肠组织中CD3抗原（CD3 antigen，epsilon polypeptide，CD3）、受体型蛋白酪氨酸磷酸酶C（protein tyrosine phosphatase，receptor type C，B220）、黏附G蛋白偶联受体E1（adhesion G protein-coupled receptor E1，F4/80）、转化生长因子-β（transforming growth factor-β，TGF-β）及干扰素-γ（interferon-gamma，IFN-γ）的表达水平。结果　HE染色显示高浓度组小鼠结肠黏膜下结缔组织中淋巴滤泡增多，且高浓度组小鼠脾指数出现增高的趋势，但差异无统计学意义（P > 0.05）。qRT-PCR结果显示，与对照组及低浓度组相比，高浓度组小鼠的结肠组织中B220及TGF-β的表达水平显著增高（P < 0.05），其余指标表达水平差异无统计学意义（P > 0.05）。结论　P. gingivalis可诱导结肠炎症，从而增加牙周病患者对消化系统疾病的易感性，且其可能与牙周病病情的严重程度相关。     

Porphyromonas gingivalis-epithelial cell interactions in periodontitis

Emerging data on the consequences of the interactions between invasive oral bacteria and host cells have provided new insights into the pathogenesis of periodontal disease. Indeed, modulation of the mucosal epithelial barrier by pathogenic bacteria appears to be a critical step in the initiation and progression of periodontal disease. Periodontopathogens such as Porphyromonas gingivalis have developed different strategies to perturb the structural and functional integrity of the gingival epithelium. P. gingivalis adheres to, invades, and replicates within human epithelial cells. Adhesion of P. gingivalis to host cells is multimodal and involves the interaction of bacterial cell-surface adhesins with receptors expressed on the surfaces of epithelial cells. Internalization of P. gingivalis within host cells is rapid and requires both bacterial contact-dependent components and host-induced signaling pathways. P. gingivalis also subverts host responses to bacterial challenges by inactivating immune cells and molecules and by activating host processes leading to tissue destruction. The adaptive ability of these pathogens that allows them to survive within host cells and degrade periodontal tissue constituents may contribute to the initiation and progression of periodontitis. In this paper, we review current knowledge on the molecular cross-talk between P. gingivalis and gingival epithelial cells in the development of periodontitis.     

The immune modulation of B-cell responses by Porphyromonas ginginvalis and interleukin-10

BACKGROUND: Polyclonal B-cell activation induced by periodontopathic bacteria has been cited as being important for elevated numbers of B cells, but the role of bacteria in the pathogenesis of periodontal disease remains unknown. In this study, we used an in vitro model to investigate the activation of immune cells by the periodontopathic bacterium Porphyromonas gingivalis in healthy subjects. METHODS: Peripheral blood mononuclear cells (PBMC) or purified subsets of lymphocytes were stimulated with sonicated extracts of P. gingivalis for 24 hours. Cells were harvested and monitored for expression of CD69 by flow cytometry. Cytokine production (IL-10, IL-12, and IL-15) in P. gingivalis-stimulated PBMC cultures was measured by ELISA. To identify IL-10 producer cells, a cell depletion experiment was used and confirmed by the ability of the purified cell population to produce IL-10. To evaluate the effect of P. gingivalis and IL-10, the proliferative response of purified B cells was assessed by [3H] thymidine uptake. RESULTS: PBMC cultured with P. gingivalis led to a large number of activated B and natural killer (NK) cells as monitored by CD69 expression. When positively sorted cells were used, the bacterium itself could directly activate only B cells but not NK cells, alphabeta, and gammadelta T cells. Measurement of B-cell regulatory cytokine production in P. gingivalis-stimulated PBMC cultures revealed a large amount of IL-10 but no detectable IL-12 or IL-15; the major producing cells were monocytes, not B cells or alphabeta T cells. When IL-10 was added to B cells in the presence of bacteria, significantly increased B-cell proliferative responses were observed. CONCLUSIONS: These results suggest that P. gingivalis, both directly and indirectly via macrophage IL-10, may play an important role in polyclonal B-cell activation associated with periodontal disease.     

Immune evasion strategies of Porphyromonas gingivalis

Porphyromonas gingivalis is strongly correlated with chronic periodontitis. Its chronic persistence in the periodontium depends on its ability to evade host immunity without inhibiting the overall inflammatory response, which is actually beneficial for this and other periodontal bacteria. Indeed, the inflammatory exudate (gingival crevicular fluid) is a source of essential nutrients, such as peptides and hemin-derived iron. In this review, I discuss how P. gingivalis can promote its adaptive fitness through instigation of subversive crosstalk signaling. These interactions involve Toll-like receptor-2, complement receptor 3, C5a anaphylatoxin receptor, and CXC-chemokine receptor 4. Their exploitation by P. gingivalis allows the pathogen to escape elimination, obtain nutrients, and collaterally inflict periodontal tissue injury.     

DNA probe analysis in smoker and non smoker rapidly progressive periodontitis patients--a pilot study.

Smoking is one of the most significant risk factors in the development and further advancement of inflammatory periodontal disease. The bacteria A. actinomycetemcomitans, P. gingivalis and P. intermedius as indicated as the potential pathogens associated with periodontal disease. Since the bacteria mentioned as well as smoking are factors associated with periodontitis it is of importance to elucidate the interrelationship between these factors. The purpose of this study was to investigate the prevalence of A. actinomycetemcomitans, P. gingivalis and P. intermedius in subgingival plaque samples obtained form healthy and diseased sites of patients with rapidly progressive periodontitis who were smokers and non smokers along with other clinical parameters.     

Periodontal bone level and gingival proteinase activity in gnotobiotic rats immunized with Bacteroides gingivalis

Bacteroides gingivalis is associated with various forms of periodontal disease. To assess the role of the immune response in modulating B. gingivalis-associated periodontal disease, the effect of immunization of B. gingivalis-induced periodontal bone loss was evaluated in gnotobiotic rats. Male Sprague-Dawley rats immunized with various doses of whole cells or sham-immunized with incomplete Freund's adjuvant were monoinfected with B. gingivalis in carboxymethylcellulose by gavage. Two additional groups served as either sham-immunized or untreated germ-free controls. Forty-two days after infection, all rats were killed, periodontal bone level was assessed morphometrically and radiographically, and gingival proteinase (mammalian collagenase and acid cathepsin) activity was assessed biochemically. B. gingivalis was present in oral samples from all monoinfected rats, and no contaminating bacteria were detected in any oral or fecal sample. Animals immunized with B. gingivalis cells had elevated serum and saliva antibodies to whole cells and partially purified fimbriae from B. gingivalis. Infected sham-immunized rats had significantly more periodontal bone loss than noninfected controls, whereas the periodontal bone level in infected rats immunized with 10(10) B. gingivalis cells was similar to that of the noninfected controls. The activities of gingival collagenase and cathepsin B and L were high in sham-immunized infected rats and low in all other animal groups. In conclusion, it is possible to reduce B. gingivalis-induced periodontal tissue loss in gnotobiotic rats by immunization.     

牙周炎与抗心磷脂抗体相关性研究进展

抗心磷脂抗体（anti-cardiolipin antibody，ACA）是与血栓形成、血小板减少有关的自身免疫抗体，受细菌感染因素影响。牙周炎是一种慢性感染性疾病，通过菌斑微生物引发宿主免疫反应产生炎症介质导致牙周组织破坏。目前研究发现，牙周炎患者的牙周致病菌可通过“分子模拟”机制导致血清ACA水平升高，牙周基础治疗可使血清ACA水平降低，ACA可通过调控炎性因子介导牙周炎症。文章就牙周炎与ACA相关性及其机制的研究进展做一综述。     

The role of cytokines in a Porphyromonas gingivalis-induced murine abscess model

INTRODUCTION: Porphyromonas gingivalis is an important periodontopathic bacterium that is strongly associated with periodontal disease and is part of human dental plaque. Periodontal disease results from the interaction of the host with bacterial products, and T-cell-derived cytokines remain critical in the immunoregulation of periodontal disease. METHODS: The aim of this study was to examine the role of T helper type 1 [interleukin-12p40 (IL-12p40), interferon-gamma, tumour necrosis factor (TNF)] and type 2 (IL-4, IL-10) cytokines in the immune response to a subcutaneous challenge with P. gingivalis using a well-established murine abscess model, in genetically modified cytokine-specific knockout mice. RESULTS: IL-12p40(-/-) mice exhibited more advanced tissue destruction and a reduced inflammatory cell infiltrate after subcutaneous P. gingivalis challenge. Deficiency of IL-4 or IL-10 did not result in increased susceptibility to P. gingivalis-mediated tissue destruction. Furthermore, TNF deficiency appeared to reduce local tissue destruction. Interestingly, serum-specific antibodies suggested a strong T helper type 2 response. CONCLUSION: The results of our study indicate an important role for IL-12 in a primary P. gingivalis subcutaneous challenge.     

Deficiency of iNOS contributes to Porphyromonas gingivalis-induced tissue damage

Periodontitis is a chronic inflammatory disease that results in extensive soft and hard tissue destruction of the periodontium. Porphyromonas gingivalis possesses an array of virulence factors and has been shown to induce expression of inducible nitric oxide synthase (iNOS) in inflammatory cells. The aim of this study was to investigate the effect of eliminating iNOS in a murine model of P. gingivalis infection. This was achieved by utilizing a P. gingivalis-induced skin abscess model, and an alveolar bone loss model employing an oral infection of P. gingivalis in iNOS knockout mice. The results indicated that iNOS knockout mice exhibit more extensive soft tissue damage and alveolar bone loss in response to P. gingivalis infection compared to wild-type mice. The local immune response to P. gingivalis in iNOS knockout mice was characterized by increased numbers of polymorphonuclear monocytes, while the systemic immune response was characterized by high levels of interleukin-12. The iNOS is required for an appropriate response to P. gingivalis infection.