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）是全球范围内高度流行的儿科疾病。1990年有近2500万人因OM就诊，现有证据表明发病率正在上升。虽然与死亡率相关的情况非常罕见，但与OM相关的发病率很高。OM的社会经济影响也很大。仅在美国，诊断和管理OM的直接和间接成本每年就超过50亿美元。显然，非常需要开发更有效和更可接受的方法来管理，最好是预防OM。疫苗的开发是最有希望的，也是实现这一目标的最具成本效益的方法。然而，由于我们对OM的发病机制和免疫生物学的不完全理解，无法分型的流感嗜血杆菌（NTHI）疫苗开发的进展继续受到阻碍，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，OM是由三种主要细菌病原体中的一种或多种引起的多微生物疾病，几乎任何上呼吸道（URT）病毒都能促进其侵入鼓膜的能力。 在过去的4年中，我们已经：测序，并将很快完成注释的一个OM分离的不可分型流感嗜血杆菌（NTHI）的基因组;开发和使用DNA质粒为基础的微阵列进行菌株比较研究的两个临床OM分离株;开发了一个启动子陷阱系统在NTHI，我们已经监测基因表达在体内，在实验OM;并在NTHI中开发了一个签名标签诱变系统，为我们提供了一个互补系统来鉴定对OM定殖和诱导至关重要的基因。不仅是所有这些巨大的资源可供我们利用，因为我们扩大我们的研究NTHI诱导OM的发病机制，但他们也已经导致在NTHI的多个潜在的新的毒力决定因素的鉴定。 我们提出了下一个资助期的实验，旨在继续提高我们对OM中NTHI发病机制在分子水平上的理解，以及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- 028 NP来提供非侵入性的整个动物成像系统的可行性，该系统将被应用于并显著推进我们对OM的发病机制和疫苗介导的预防的研究。其次，我们将使用灰鼠超级感染模型来评估一种成熟的候选抗原和一种新的和非常有前途的，但欠发达的候选抗原的保护效力，以防止鼻内免疫后OM上升的能力。我们还将继续鉴定和表征推定的毒力决定因素，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。 总的来说，我们的研究将导致对NTHI引起的OM的更好的理解，并导致预防OM的新策略。