Virulence factors of periodontopathogens

牙周病原菌的毒力因子

• 批准号: 8089434
• 负责人: Janina P Lewis
• 金额: $ 27.45万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-03 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8089434
• 关键词: Anaerobic Bacteria; Bacteria; Cardiovascular Diseases; Carrier Proteins; Cell Fraction; Chromosomes; Cytoplasm; Data; Diabetes Mellitus; Environment; Gene Expression; Generations; Genome; Genomics; Gram-Negative Anaerobic Bacteria; Growth; Health; Hemeproteins; Hemin; Homologous Gene; Iron; Knowledge; Light; Location; Low Birth Weight Infant; Mediating; Membrane; Nutrient; Operon; Organism; Oxidative Stress; Periodontal Diseases; Peroxides; Play; Porphyromonas gingivalis; Positioning Attribute; Proteins; Regulation; Research Personnel; Role; Source; Structure; Testing; Transcript; Virulence; Virulence Factors; antimicrobial drug; defined contribution; design; genetic regulatory protein; haptoglobin-hemoglobin complex; mutant; periodontopathogen; programs; promoter; protein expression; response; stem; uptake

DESCRIPTION (provided by applicant): Gram negative anaerobic bacteria are the major etiological agents of periodontal diseases. In addition, they have been shown to be associated with other health complications such as cardiovascular diseases, diabetes, and preterm low birth weight babies. Both P. gingivalis and Prev. intermedia lack the capacity to synthesize hemin and must acquire the nutrient from the environment. Despite the importance of hemin acquisition in the periodontopathogens, major gaps in knowledge exist regarding the mechanisms of uptake and regulation of the nutrient. Several loci encoding hemin transport proteins have been identified on the genome of P. gingivalis W83; however, the contribution of these loci to hemin uptake in this organism remains unknown. Also, the role of the proteins encoded by the loci is not well defined. We have identified an operon, hmuYRSTUV, required for growth of P. gingivalis with hemoglobin-haptoglobin complexes as a hemin source. A homolog of the operon is also present on the genome of other Gram-negative anaerobic bacteria including Prev. intermedia 17. Our preliminary data indicate that the hmu operon is iron regulated. Although the ferric uptake regulator, Fur, was demonstrated to regulate the expression of hemin uptake loci in variety of bacteria, our preliminary studies show the peroxide responsive regulator, OxyR, plays a role in regulation of expression of the hmu locus. Thus, first we will characterize the OxyR-mediated mechanism of regulation. Second, we will further define the role of the hmu locus in hemin uptake in P. gingivalis. We will start our characterization from comparison of the role of the hmu locus with the other two hemin uptake loci, iht and tlr, present on the genome of P. gingivalis W83 in hemin uptake in this organism. Next, we will test the hypothesis that the hmu operon is an important hemin acquisition mechanism in both periodontopathogens and encodes proteins necessary to extract the hemin molecule from host hemoproteins and transport the hemin across both membranes (into the cytoplasm). Thus we will determine the cellular location of the hmu - encoded proteins, examine the ability of the proteins to interact with each other and with other proteins, and define the contribution of proteins encoded by the locus to hemin uptake in P. gingivalis W83. Lastly, to broaden our understanding of the role of hemin in virulence of P. gingivalis, we will examine the role of hemin and hemoproteins on gene expression in this bacterium.

描述（由申请人提供）：革兰氏阴性厌氧菌是牙周病的主要病原菌。此外，它们已被证明与其他健康并发症有关，例如心血管疾病、糖尿病和早产低出生体重儿。 P. gingivalis 和 Prev。中间体缺乏合成血红素的能力，必须从环境中获取营养。尽管氯化血红素的获取对于牙周病原菌很重要，但关于营养物质的吸收和调节机制的知识仍存在重大差距。已在牙龈卟啉单胞菌 W83 的基因组上鉴定出几个编码血红素转运蛋白的基因座；然而，这些基因座对该生物体吸收血红素的贡献仍然未知。此外，基因座编码的蛋白质的作用尚不明确。我们已经确定了操纵子 hmuYRSTUV，它是牙龈卟啉单胞菌以血红蛋白-触珠蛋白复合物作为氯化血红素来源生长所需的。操纵子的同源物也存在于其他革兰氏阴性厌氧细菌的基因组中，包括 Prev。中间体 17. 我们的初步数据表明 hmu 操纵子受铁调控。虽然铁吸收调节剂 Fur 被证明可以调节多种细菌中血红素吸收位点的表达，但我们的初步研究表明过氧化物响应调节剂 OxyR 在 hmu 位点的表达调节中发挥作用。因此，首先我们将描述 OxyR 介导的调节机制。其次，我们将进一步确定 hmu 基因座在牙龈卟啉单胞菌吸收氯化血红素中的作用。我们将从比较 hmu 基因座与其他两个氯高铁血红素摄取基因座 iht 和 tlr 的作用开始我们的表征，这两个基因座存在于 P. gingivalis W83 基因组中，在该生物体的血红素摄取中。接下来，我们将测试以下假设：hmu 操纵子是两种牙周病原菌中重要的血红素获取机制，并编码从宿主血红素蛋白中提取血红素分子并将血红素跨膜运输（进入细胞质）所必需的蛋白质。因此，我们将确定 hmu 编码蛋白质的细胞位置，检查蛋白质之间以及与其他蛋白质相互作用的能力，并确定该基因座编码的蛋白质对牙龈卟啉单胞菌 W83 中氯化血红素摄取的贡献。最后，为了加深我们对血红素在牙龈卟啉单胞菌毒力中作用的理解，我们将研究血红素和血红素蛋白对该细菌基因表达的作用。

项目成果

Interaction of Prevotella intermedia strain 17 leucine-rich repeat domain protein AdpF with eukaryotic cells promotes bacterial internalization.

中间普雷沃氏菌菌株 17 富含亮氨酸的重复结构域蛋白 AdpF 与真核细胞的相互作用促进细菌内化。

• DOI: 10.1128/iai.01361-13
• 发表时间: 2014
• 期刊: Infection and immunity
• 影响因子: 3.1
• 作者: Sengupta,Dipanwita;Kang,Dae-Joong;Anaya-Bergman,Cecilia;Wyant,Tiana;Ghosh,ArnabK;Miyazaki,Hiroshi;Lewis,JaninaP
• 通讯作者: Lewis,JaninaP