Genetic basis for divergent virulence of P. gingivalis strains 33277 and 381

摘要 牙龈卟啉单胞菌是一种革兰氏阴性细菌，具有独特的鉴别特征 在口腔微生物群落中。它能够间接促进牙周病的结果，通过 群落生态失调机制此外，细菌还发挥许多直接的免疫调节作用， 对宿主先天免疫应答机制的影响，以抑制宿主解决这两种免疫应答机制的能力。 细胞外和细胞内感染。因此，牙龈卟啉单胞菌保持存活、感染宿主的能力， 细胞，全身分散，并加剧或逃避选择的宿主炎症反应。一些 细菌因子，包括菌毛、脂质A磷酸酶、牙龈菌蛋白酶、多糖荚膜和粘附素 与牙龈卟啉单胞菌相关的致病性表型有很大关系。 然而，目前还不清楚这些因素是如何相互协调，或与其他未定性 免疫调节因子赋予与特定菌株相关的疾病相关表型。在这 应用我们提出了一种创新的方法来确定一个新的毒性属性牙龈卟啉单胞菌， 比较两个高度相关的菌株33277和381的基因组，它们显示出显著不同， 炎症体激活和Toll样受体2应答，两种关键的先天免疫应答途径。我们 使用实验室和公开可用的序列信息进行的初步比较表明， 牙龈卟啉单胞菌33277和381之间的基因组差异数量惊人地有限（少于150 多态性）。在目标1中，我们将系统地评估基因组序列数据和RNA表达数据 来自33277和381菌株，它们已经测试了它们激活宿主细胞炎性体的能力， TLR2，以获得编码表现出特征的产物的高优先级候选基因序列 预测赋予菌株特异性炎症效应，如已证实作用的细菌因子 免疫调节在目标2中，我们将优先创建携带靶向缺失的突变株 33277和381背景的候选人。将评估突变菌株的能力， 激活巨噬细胞炎性小体或TLR2信号传导，以鉴定 确定菌株33277和381的不同免疫原性特征。利用功能基因组学 阐明牙龈卟啉单胞菌的特异性免疫原性基础，为进一步研究其免疫原性奠定基础 在确定菌株类型、疾病关联和潜在治疗干预之间的相关性方面， 严重影响人类健康的炎症性疾病。

Abstract Porphyromonas ginigvalis is a Gram negative bacterium that displays unique distinguishing characteristics among the oral microbial community. It is capable of indirectly promoting a periodontal disease outcome via a community dysbiosis mechanism. In addition, the bacterium exerts a number of direct immunomodulatory effects on the host innate immune response machinery to dampen the ability of the host to resolve both extracellular and intracellular infections. Consequently, P. gingivalis maintains the ability to survive, infect host cells, disperse systemically, and either exacerbate or evade select host inflammatory responses. A number of bacterial factors including fimbriae, lipid A phosphatases, gingipains, polysaccharide capsule, and adhesins have been strongly implicated in contributing to the pathogenic phenotype associated with P. gingivalis. However, it is unclear how these factors are coordinated with each other, or with additional uncharacterized immunomodulatory factors to confer disease-related phenotypes associated with particular strains. In this application we propose an innovative approach to identify a novel virulence attribute of P. gingivalis by comparing the genomes of two highly related strains, 33277 and 381, which display significantly different inflammasome activation and Toll-like receptor 2 responses, two key innate immune response pathways. Our preliminary comparisons, using laboratory and publicly available sequence information indicate that the number of genomic differences between P. gingivalis 33277 and 381 is surprisingly limited (less than 150 polymorphisms). In Aim 1 we will systematically evaluate genomic sequence data and RNA expression data from 33277 and 381 strains that have been tested for their abilities to activate host cell inflammasome and TLR2, in order to obtain high priority candidate gene sequences encoding products that exhibit features predicted to confer the strain-specific inflammatory effects, such as bacterial factors having demonstrated roles in immunomodulation. In Aim 2 we will create mutant strains bearing targeted deletions in high priority candidates in both the 33277 and 381 backgrounds. The mutant strains will be assessed for their abilities to activate the macrophage inflammasome or TLR2 signaling in order to identify the genetic factor(s) that determine the distinct immunogenic characteristics strains 33277 and 381. The use of functional genomics to elucidate the basis P. gingivalis' strain-specific immunogenicity will lay the foundation for further studies aimed at determining correlations between strain type, disease associations, and potential therapeutic interventions in inflammatory disorders that significantly impact human health.