P. gingivalis genes essential for tobacco smoke survival

项目总结/摘要 牙周炎是一种高度流行的疾病， 包括血管和肺部疾病、糖尿病和早产。最新流行病学 有证据表明，吸烟占大多数破坏性牙周病病例， 发达国家。吸烟增加了感染率，增加了一种关键牙周病原体的数量， 牙龈卟啉菌。然而，这种现象背后的机制需要阐明。在 在为期两年的NIGMS资助机制的推动下，第一轮奖励产生了8万个殖民地 牙龈卟啉单胞菌菌株ATCC 33277的转座子测序文库，并利用该资源： (i)成功鉴定了256个对烟草诱导的胁迫生存至关重要的基因; (ii)描绘烟草生存、上皮定植通常所需的“核心压力基因组” 及皮下脓肿形成;及 (iii)验证了牙龈卟啉单胞菌在香烟烟雾中生存所必需的几个基因- 通过产生单基因缺失突变体在体外诱导应激， 在烟熏培养基中与亲本牙龈卟啉单胞菌菌株的竞争测定中的绝对适合度; (iv)我们还建立了一种新的烟草加重牙周炎小鼠模型。 我们现在计划通过以下三个具体目标在这些成功的基础上再接再厉： 目的1：通过在单个基因中产生突变体，进一步阐明牙龈卟啉单胞菌CSE相关的存活策略 这两个都是CSE必需的（TnSeq数据）;和烟草调控的（RNAseq和qPCR）;但不妥协， 它们在口腔上皮细胞上定殖的能力（TIGK模型）或免疫抗性（鼠脓肿模型）。 目的2：使用鼠烟雾暴露测定小鼠CSE必需基因的体内相关性 在牙龈卟啉单胞菌诱导的牙周炎的慢性Baker模型中的室模型。 目标3：通过确认生物学功能，确定目标1和2中收集的数据的广泛适用性 和CSE必需基因在多种牙龈卟啉单胞菌菌株中的分布。 长期的进展可能包括：（a）更好地了解牙龈卟啉单胞菌如何在环境中生长， （B）控制牙龈卟啉单胞菌的必需基因的未来治疗靶向 吸烟者感染（CSE-必要性数据）和一般感染（多种疾病相关疾病，核心压力 （c）基于对吸烟引起的吸烟相关疾病的机制性认识的吸烟者替代治疗方案 及/或牙周病恶化;及（四）建立烟草必需基因资料库- 增强的病原体，这将有助于识别烟草存活的常见细菌策略 因此，吸烟暴露扩大了研究口腔以外的意义。

PROJECT SUMMARY/ABSTRACT Periodontitis is a highly prevalent disease associated with several debilitating systemic conditions, including vascular and lung diseases, diabetes mellitus, and pre-term birth. The most recent epidemiological evidence suggests that tobacco smoking accounts for the majority of destructive periodontal disease cases in developed nations. Smoking enhances infection rates and enriches numbers of a key periodontal pathogen, Porphyromonas gingivalis. However, the mechanisms underlying this phenomenon are in need of elucidation. In the first iteration of award, facilitated by a two year NIGMS-funding mechanism, we generated an 80,000 colony transposon sequencing library for P. gingivalis strains ATCC 33277 and exploited this resource to: (i) Successfully identify 256 genes that are putatively essential for surviving tobacco-induced stress; (ii) Delineate a “core stress genome” commonly required for tobacco-survival, epithelial colonization and subcutaneous abscess formation; and (iii) Validated several genes as conditionally essential for P. gingivalis to survival of cigarette smoke- induced stress in vitro by generating single gene deletion mutants that exhibit either reduced absolute fitness in competition assays with the parental P. gingivalis strain in smoked medium; (iv) We have also generated a novel murine model of tobacco-exacerbated periodontitis. We now plan to build on these successes via three specific aims, as follow: Aim 1: Further elucidate P. gingival CSE-related survival strategies by generating mutants in single genes that are both CSE-essential (TnSeq data) ;and tobacco-regulated (RNAseq and qPCR); yet not compromised in their ability to colonize oral epithelial cells (TIGK model) or immune resistance (murine abscess model). Aim 2: Determine in vivo relevance of putatively CSE-essential genes using a murine smoke-exposure chamber model in a chronic Baker model of P. gingivalis-induced periodontitis. Aim 3: Establish the broad applicability of data gathered in Aims 1 and 2 by confirming biological function and distribution of CSE essential genes in multiple P. gingivalis strains. Long term advances are likely to include (a) A better understanding of how P. gingivalis thrives in a tobacco-toxin rich environment; (b) Future therapeutic targeting of essential genes to control P. gingivalis infection in smokers (CSE-essentiality data) and in general (multiple disease-relevant conditions, core stress genome data); (c) Alternate treatment regimens for smokers based on mechanistic insight into smoke-induced and/or exacerbated periodontal diseases;and (d) The establishment of an essential gene database for tobacco- enhanced pathogens that will facilitate the identification of common bacterial strategies for surviving tobacco smoke exposure, thus, broadening the significance of the research beyond the oral cavity.