Determinants of H. influenzae Virulence in Otitis Media

中耳炎中流感嗜血杆菌毒力的决定因素

• 批准号: 7850050
• 负责人: Lauren O Bakaletz
• 金额: $ 23.22万
• 依托单位: RESEARCH INST NATIONWIDE CHILDREN'S HOSP
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7850050
• 关键词: Acute; Adjuvant; Amino Acids; Animal Model; Animals; Antigens; Biological; Biological Assay; Biophotonics; Childhood; Chinchilla (genus); Chronic; Clinical; Complex; Data; Development; Diagnosis; Disease; Eustachian Tube; Evaluation; Facilities and Administrative Costs; Focus Groups; Funding; Gene Expression Profile; Gene Expression Profiling; Genes; Genome; Goals; Haemophilus influenza virulence; Haemophilus influenzae; Image; Immune response; Immunization; Immunobiology; In Situ; In Vitro; Incidence; Infection; Invaded; Investigation; Laboratories; Lead; Life; Mediating; Methodology; Methods; Microarray Analysis; Modeling; Molecular; Molecular Profiling; Monitor; Morbidity - disease rate; Mutagenesis; Nasopharynx; Nontypable Haemophilus influenza; Office Visits; Otitis Media; Otitis Media with Effusion; Outcome Measure; Pathogenesis; Phase; Positioning Attribute; Prevention; Process; Relative (related person); Research Personnel; Resources; Role; Route; Series; Staging; System; Time; Tympanic cavity; Upper respiratory tract; Vaccines; Virulence; Virus; adenylate; antimicrobial; base; cost; design; dosage; ear infection; experience; human disease; improved; in vivo; interest; middle ear; mortality; mutant; novel; parent grant; pathogen; plasmid DNA; pre-clinical; prevent; promoter; protective efficacy; research study; response; socioeconomics; superinfection; therapeutic target; vaccine candidate; vaccine development

DESCRIPTION (provided by applicant): Middle ear infection or otitis media (OM) is a highly prevalent pediatric disease worldwide. There were nearly twenty-five million physician's office visits made for OM in 1990, and available evidence suggests that the incidence is increasing. While only very rarely associated with mortality, the morbidity associated with OM is significant. The socioeconomic impact of OM is also great. Direct and indirect costs of diagnosing and managing OM exceed $5 billion annually in the U.S. alone. Clearly, there is a tremendous need to develop more effective and accepted approaches to the management and preferably, the prevention of OM. Vaccine development holds the greatest promise and would be the most cost-effective method to accomplish this goal. However, progress in terms of vaccine development for nontypeable Haemophilus influenzae (NTHI), the Gram-negative pathogen that both predominates in chronic otitis media with effusion or OME, as well as being a significant etiologic agent of acute OM, continues to be hampered by our incomplete understanding of the pathogenesis and immunobiology ofOM, a polymicrobial disease caused by one or more of the three predominant bacterial pathogens, whose ability to invade the tympanum is facilitated by virtually any upper respiratory tract (URT) virus. During the past 4 years, we have: sequenced and will soon complete the annotation of the genome of an OM isolate of nontypeable Haemophilus influenzae (NTHI); developed and used DNA plasmid based microarrays to conduct strain comparison studies for two clinical OM isolates; developed a promoter trap system in NTHI with which we have monitored gene expression in vivo, during experimental OM; and have developed a signature tag mutagenesis system in NTHI that provided us with a complementary system to identify genes that are essential for colonization and induction of OM. Not only are all these tremendous resources available to us to capitalize upon as we extend our studies of the pathogenesis of NTHI-induced OM, but they have also already resulted in the identification of multiple potential new virulence determinants for NTHI. We propose experiments for the next funding period designed to continue to enhance our understanding of both NTHI pathogenesis in OM at the molecular level as well as further our investigation of a focused group of novel virulence determinants. We will first rigorously assess the feasibility of using lux-expressing NTHI strain 86-028NP to provide a non-invasive, whole animal imaging system to be applied to, and significantly advance, our studies of both pathogenesis and vaccine-mediated prevention of OM. Secondly, we will use a chinchilla super infection model to assess the protective efficacy of one well-developed candidate antigen and one novel and highly promising, but less developed candidate, for ability to prevent ascending OM after intranasal immunization. We will also continue to identify and characterize putative virulence determinants and assess their potential as vaccine or therapeutic targets via a variety of methodologies, including gene expression profiling by microarray analysis. Overall, our studies will lead to an improved understanding of OM caused by NTHI and lead to new strategies to prevent OM.

描述（由申请人提供）：中耳感染或中耳炎 (OM) 是世界范围内高度流行的儿科疾病。 1990 年，有近 2500 万人次因 OM 就诊，现有证据表明该病的发病率正在增加。虽然与死亡率相关的情况很少，但与 OM 相关的发病率却很高。 OM 的社会经济影响也很大。仅在美国，每年诊断和管理 OM 的直接和间接成本就超过 50 亿美元。显然，非常需要开发更有效和可接受的方法来管理，最好是预防 OM。疫苗开发前景广阔，也是实现这一目标最具成本效益的方法。然而，不可分型流感嗜血杆菌 (NTHI) 的疫苗开发进展仍然受到阻碍，NTHI 是一种革兰氏阴性病原体，在慢性渗出性中耳炎或 OME 中占主导地位，也是急性 OM 的重要病原体。我们对 OM 的发病机制和免疫生物学的了解不完全，OM 是一种由三种主要细菌病原体中的一种或多种引起的多种微生物疾病，其能够侵入几乎任何上呼吸道 (URT) 病毒都会促进鼓室感染。 在过去 4 年里，我们已经： 对不可分型流感嗜血杆菌 (NTHI) 的 OM 分离株进行了测序，并将很快完成基因组注释；开发并使用基于 DNA 质粒的微阵列对两种临床 OM 分离株进行菌株比较研究；在 NTHI 中开发了启动子捕获系统，我们在实验 OM 期间用该系统监测体内基因表达；并在 NTHI 中开发了一个特征标签诱变系统，为我们提供了一个补充系统来识别 OM 定植和诱导所必需的基因。当我们扩展对 NTHI 诱导的 OM 发病机制的研究时，我们不仅可以利用所有这些巨大的资源，而且还已经鉴定了 NTHI 的多个潜在的新毒力决定因素。 我们建议在下一个资助期进行实验，旨在继续增强我们对 OM 的 NTHI 发病机制在分子水平上的理解，并进一步研究一组新的毒力决定因素。我们将首先严格评估使用表达 lux 的 NTHI 菌株 86-028NP 提供非侵入性全动物成像系统的可行性，该系统可应用于并显着推进我们对 OM 发病机制和疫苗介导预防的研究。其次，我们将使用龙猫超级感染模型来评估一种成熟的候选抗原和一种新颖且高度有前途但尚未开发的候选抗原的保护功效，以预防鼻内免疫后上行性 OM 的能力。我们还将继续识别和表征假定的毒力决定因素，并通过各种方法评估其作为疫苗或治疗靶点的潜力，包括通过微阵列分析进行基因表达谱分析。 总体而言，我们的研究将提高对 NTHI 引起的 OM 的了解，并制定预防 OM 的新策略。