Understanding the Emergence of Highly Pathogenic Avian Influenza Viruses

了解高致病性禽流感病毒的出现

• 批准号: 8946530
• 负责人: Heinrich Feldmann
• 金额: $ 25.14万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8946530
• 关键词: Agriculture; Animals; Attenuated; Avian Influenza; Avian Influenza A Virus; Basic Amino Acids; Biological Assay; Birds; Blood Circulation; Capital; Cercopithecus pygerythrus; Chickens; Chiroptera; Collaborations; Communities; Congo; Data; Development; Diagnostic; Disease Outbreaks; Domestic Fowls; Dose; Ecology; Environment; Food Safety; Funding; Future; Genetic Transcription; Genomics; Goals; Guatemala; Health; Hemagglutinin; Human; Immune response; Incidence; Influenza A Virus, H5N1 Subtype; Influenza A virus; International; Intervention; Intravenous; Laboratories; Life; Mammals; Modeling; Monitor; National Institute of Allergy and Infectious Disease; Nucleotides; Pathogenicity; Pattern; Phenotype; Poly U; Population; Porcine Influenza A Virus; Prevalence; Principal Investigator; Productivity; Proteins; Public Health; Publications; Publishing; Research; Research Infrastructure; Respiratory System; Respiratory tract structure; Risk; Risk Assessment; Science; Sequence Analysis; Serum; Shoulder; Site; Stretching; Surveillance Program; Technology; Testing; United States National Institutes of Health; Upper respiratory tract; Vaccines; Viral; Virus; Virus Replication; Work; base; deep sequencing; field survey; food security; human subject; immunogenicity; indexing; influenza outbreak; influenza virus vaccine; influenzavirus; neutralizing antibody; novel; pandemic disease; pandemic influenza; positional cloning; protective efficacy; surveillance study; transmission process; vaccine candidate; wild bird

(A) Experimental Laboratory Component: Using reverse genetics, low pathogenic avian influenza (LPAI) viruses (H5N1 and H6N1) with the minimal multibasic cleavage site (MBCS) motif will be generated and the intravenous pathogenicity index (IVPI) and 50% bird infectious dose (BID50) will be determined in chicken and compared to LPAI H5N1 and H6N1. Next, these viruses will be serially passaged (10x) in chicken to see whether the minimal MBCS will evolve into a MBCS and the highly pathogenic avian influenza (HPAI) phenotype. Deep sequencing (RML Research Technologies Section, Genomics Unit) will be used to analyze the cleavage site motif of viruses from chicken in each passage. Note - This part of the project is still on hold due to the effects of the H5 moratorium and subsequent restrictions by NIAID, NIH. No work has been done on this project in fiscal year 2013/14. Instead we have evaluated in collaboration with Dr. Subbarao's group the replication of wildtype (wt) and cold-adapted (ca) viruses of avian influenza (AI) virus subtypes H5N1, H6N1, H7N3, and H9N2 in the respiratory tract of African green monkeys (AGMs). All of the wt viruses replicated efficiently, while replication of the ca vaccine viruses was restricted to the upper respiratory tract. Interestingly, the patterns and sites of virus replication differed among the different subtypes. We also evaluated the immunogenicity and protective efficacy of H5N1, H6N1, H7N3, and H9N2 ca vaccines. Protection from wt virus challenge correlated well with the level of serum neutralizing antibodies. Immune responses were slightly better when vaccine was delivered by both intranasal and intratracheal delivery than when it was delivered intranasally by sprayer. We conclude that live attenuated pandemic influenza virus vaccines replicate similarly in AGMs and human subjects and that AGMs may be a useful model to evaluate the replication of ca vaccine candidates. (B) Field Survey Component: Historically, the natural reservoir for all influenza A viruses were considered wild birds. However, the recent identification of a novel H17 influenza A virus in yellow-shouldered bats in Guatemala has put the focus on novel reservoirs besides wild birds. Certain influenza A viruses in particular are a direct threat to both animal and public health. In particular, Highly Pathogenic Avian influenza A viruses (HPAI H5 and H7 subtypes) and a wide variety of swine influenza viruses (H1, H2 and H3) are notorious for crossing the species barrier from animals to humans. Public health, animal health, agricultural productivity and food security in the Republic of Congo (RC) and the wider Congo basin region are directly threatened by outbreaks of influenza A viruses. In addition, the potential zoonotic transmission of influenza viruses to the human population could spark outbreaks and the emergence of a new pandemic. To date little or no information has been published on the prevalence, incidence and identity of animal influenza viruses, in particular avian influenza viruses, in RC and there are currently no surveillance programs for avian influenza viruses in place. Therefore, there is a real need to develop baseline information with reference to the circulation of avian influenza viruses. During the fiscal year 2012/13, the laboratory infrastructure has been established at the Laboratoire National de Sant Publique in Brazzaville (RC capital) and diagnostic/surveillance assays have been developed and implemented. Surveillance studies have continued over the 2013/14 funding period and results are currently analyzed and prepared for publications. This project will be continued by Dr. Vincent Munster, Viral Ecology Unit, LV, NIAID, NIH. Dr. Feldmann will no longer serve as the principal investigator for this project.

(A)实验室组成： 使用反向遗传学，将产生具有最小多碱基切割位点（MBCS）基序的低致病性禽流感（LPAI）病毒（H5 N1和H6 N1），并将在鸡中测定静脉内致病性指数（IVPI）和50%禽感染剂量（BID 50），并与LPAI H5 N1和H6 N1进行比较。接下来，这些病毒将在鸡中连续传代（10倍），以观察最小MBCS是否会演变为MBCS和高致病性禽流感（HPAI）表型。将使用深度测序（RML Research Technologies Section，Genomics Unit）分析每次传代鸡病毒的切割位点基序。注-由于H5暂停的影响和NIAID，NIH随后的限制，该项目的这一部分仍处于搁置状态。在2013/14财政年度，该项目没有开展任何工作。 相反，我们与Subbarao博士的小组合作，评估了禽流感（AI）病毒亚型H5 N1、H6 N1、H7 N3和H9 N2的野生型（wt）和冷适应型（ca）病毒在非洲绿色猴（AGM）呼吸道中的复制。所有野生型病毒都能有效复制，而ca疫苗病毒的复制仅限于上呼吸道。有趣的是，病毒复制的模式和位点在不同亚型之间存在差异。我们还评估了H5 N1、H6 N1、H7 N3和H9 N2 ca疫苗的免疫原性和保护效力。野生型病毒攻击的保护与血清中和抗体水平密切相关。当疫苗通过鼻内和鼻腔内递送时，免疫应答略好于通过喷雾器鼻内递送时。我们的结论是，减毒流感病毒活疫苗复制类似AGM和人类受试者，AGM可能是一个有用的模型，以评估复制的CA疫苗候选人。 (B)实地调查部分： 从历史上看，所有甲型流感病毒的天然宿主都被认为是野生鸟类。然而，最近在危地马拉的黄肩蝙蝠中发现了一种新型H17甲型流感病毒，这使得人们把注意力集中在野生鸟类以外的新型宿主上。特别是某些甲型流感病毒对动物和公共卫生都是直接威胁。特别是，高致病性禽流感A病毒（HPAI H5和H7亚型）和各种猪流感病毒（H1，H2和H3）因跨越动物到人类的物种屏障而臭名昭著。刚果共和国（RC）和更广泛的刚果盆地地区的公共卫生、动物健康、农业生产力和粮食安全受到甲型流感病毒爆发的直接威胁。此外，流感病毒向人群的潜在人畜共患传播可能引发暴发和新的大流行的出现。 迄今为止，关于动物流感病毒（特别是禽流感病毒）在克罗地亚共和国的流行率、发病率和身份的信息很少或没有发表，目前没有针对禽流感病毒的监测计划。因此，真实的需要制定关于禽流感病毒传播的基线信息。 在2012/13财政年度期间，在布拉柴维尔（克罗地亚共和国首都）的国立公共卫生学院建立了实验室基础设施，并开发和实施了诊断/监测分析。在2013/14资助期内继续进行了监测研究，目前正在分析结果并准备发表。 该项目将由美国国立卫生研究院病毒生态学部门的Vincent Munster博士继续进行。Feldmann博士将不再担任该项目的主要研究者。