Virus Vaccine Neurotoxicity Test Development

病毒疫苗神经毒性测试开发

• 批准号: 6839038
• 负责人: K. M CARBONE
• 金额: --
• 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/6839038
• 关键词: Orthomyxoviridae; autism; biomarker; developmental neurobiology; disease /disorder model; drug adverse effect; drug screening /evaluation; gene mutation; genetic library; genetic mapping; genetic strain; laboratory mouse; laboratory rat; measles virus; model design /development; mumps virus; nervous system infection; neurotoxicology; newborn animals; smallpox vaccine; technology /technique development; vaccine evaluation; vaccinia virus; viral vaccines

Some wild type viruses, such as mumps virus, measles virus, influenza virus, HIV, West Nile Virus, smallpox virus, and parainfluenza virus have a significant potential for infecting and damaging the nervous system (i.e., neurotoxicity). Live, attenuated vaccines derived from these and other related viruses must be sufficiently attenuated to reduce the risk of neurotoxic adverse events (AE). In order to identify safer vaccines, pre-clinical neurotoxicity tests need to be developed to screen experimental vaccine candidates prior to use in humans as well as to determine manufacturing consistency (i.e., when new vaccine master seed stocks are derived). Because neurotoxicity is a disease syndrome dependent upon the host's genetic and developmental state (i.e., vaccines for pediatric use), we include in our research efforts studies of the effects of viruses on the developing nervous system. Since we lack sufficient information about the pathophysiological responses to viruses that infect the nervous system, we have developed an animal model of wild type virus-induced developmental damage that serves as the first virus-associated model for autism, and have used this information to develop neurotoxicity test paradigms, including mumps, measles, influenza, and vaccinia-based smallpox vaccines. Using the basic discoveries from these and other studies, we develop research-based specific neurotoxicity tests for these and other virus vaccines initially with animal models (with behavioral, anatomical, neurochemical, and molecular biological endpoints) to evaluate risk for neurotoxicity or relative attenuation for the nervous system. Once the animal disease model is developed, our goal is to develop cell culture or molecular biological assays to test for virus vaccine neurotoxicity. Following development of the research-based neurotoxicity test, we seek international regulatory laboratory collaborations to evaluate the potential regulatory use of the test paradigms. Smallpox Vaccine Safety: Development and Validation of Pre-Clinical Toxoclogy Tests for Vaccinia-based Smallpox Vaccine through Molecular Mechanism of Vaccine Neurotoxology. Smallpox virus is a Category A bioterrorism/biowarfare agent. The licensed vaccinia virus-based vaccine (Dryvax) is effective, but produces significant and serious adverse events (AE) (Lane, 1969; Vega, 1969; Adams, 1973; Terzin, 1974; Edis, 1975; Gurvich, 1975; Kurata, 1977); one of the most deadly AEs is central nervous system (CNS) disease, with children being at greater risk than adults. Fortunately, new, and, it is hoped, safer smallpox vaccines are in development. As a standard regulatory consideration, pre-clinical neurotoxicity assays are used as in an attempt to predict the risk of damage to the human CNS (neurotoxicity) from live virus vaccines; no such validated neurotoxicity assay is available for vaccinia-based smallpox vaccines. To avoid the expense and validation problems inherent in primate testing, we have developed a prototype smallpox vaccine neurotoxicity assay using rodents. Preliminary data indicate this assay can discriminate differences in vaccinia virus strain-specific neurotoxicity among smallpox vaccines (Dryvax, Lister), and laboratory strains (WR, MVA), with WR>Lister>Dryvax>MVA in order of decreasing neuro-toxicity. Here we propose to 1) complete development and validation of the in vivo mouse neurotoxicity assay as a standardized regulatory safety test to expedite the licensing of safer smallpox vaccines, and 2) use this assay as a disease model to study the molecular pathogenesis of vaccinia-based smallpox vaccine neurotoxicity by identifying critical virus-neural cell gene/gene-product interactions. These studies will improve smallpox vaccine safety tests, e.g., small animal, in vitro and molecular biological-based neurotoxicity assays, and can promote new vaccine development, and e.g., rational attenuation of smallpox vaccines via targeted mutations. PROGRESS. We have developed and tested a neonatal mouse model for assessing the relative toxicity of vaccinia virus strains. We have also made progress towards achieving the second objective of the project by identifying the viral and host gene interactions in adult and infant using human brain tissue-derived cDNA libraries. We are currently assessing the functional role of these interactions. Vaccine Safety: Pathogenesis of virus vaccine neurotoxicity. a) Molecular Markers of Neurotoxicity: We have identified mutations in the mumps virus genome associated with increased and decreased risk of neurotoxicity. b) Animal Models of CNS Diseases: 1) Autism. Viruses are known etiologic agents of autism (e.g., intrautarine infection with rubella virus). Therefore, concerns are raised by the public regarding a possible relationship between childhood vaccines and autism. Because no valid animal models existed to study the pathogenesis of the neuroanatomical and behavioral signs of autism, we have developed a rat model of autism using neonatal infection with neurotropic viruse, Borna disease virus. We have characterized autistic-like changes in neuroanatomy, neurochemistry, neurological disease and behavior in these rats. In addition, we have identified regional and developmental changes in neurotransmitters, including serotonin and norepinephrine. We have now identified host genetic background features that affect neurotoxic outcomes.We have identified genomic changes in the G and L proteins associated with changes in neurotoxicity outcomes. 2) We have established a model to study the pathogenesis of wild type measles virus in the developing mouse brain 3) We have established a model to study the pathogenesis of wild type influenza virus in the developing rat brain. Vaccine Safety: Neurotoxicity safety test development, validation and evaluation. Human brain continues to develop during the first few years of postnatal life. Since the developing brain is uniquely sensitive to damage following virus infection, administration of neurovirulent vaccines to infants can place the child's nervous system at increased risk for vaccine related injury. There is a need to develop a test to assess the vaccine's human neurotoxicity potential, in order to develop the safest vaccines possible, and to perform appropriate risk assessment/risk management, particularly for new vaccines. 1. A newborn rat mumps virus neurotoxicity test was developed we are proceeding with international validation studies with international regulatory laboratories such as NIBSC in England, Health Canada and are in preliminary stages with health authorities in Brazil. We have also discovered virus genomic changes associated with neurotoxicity alterations, as well as molecular markers of host neuronal damage following infection. 2. Although rare, CNS events associated with wild type influenza virus can occur. In this project we are developing an assay to evaluate the relative neurotoxicity of influenza viruses (wild type and vaccine) using a newborn rat model. Our data show that we can differentiate between wild type influenza virus and vaccine strains in our neurotoxicity test. 3. We have developed a newborn mouse model for differentiating the toxicity of vaccinia virus strains. We can differentiate between vaccinia strains of greater or lesser neurotoxicity, suggesting this test will have utility as a pre-clinical toxicity test for new smallpox vaccines. 4. We have developed a mouse model for measles virus neurotoxicity testing using newborn mice. This project incorporates FY2002 projects 1Z01BK002007-07 and 1Z01BK002008-07.

一些野生型病毒，如腮腺炎病毒、麻疹病毒、流感病毒、艾滋病毒、西尼罗河病毒、天花病毒和副流感病毒，具有感染和损害神经系统的重大潜力（即神经毒性）。来自这些病毒和其他相关病毒的减毒活疫苗必须经过充分减毒，以降低神经毒性不良事件（AE）的风险。为了确定更安全的疫苗，需要开展临床前神经毒性试验，以便在用于人类之前筛选实验性候选疫苗，并确定生产一致性（即，当衍生出新的疫苗主种子库存时）。由于神经毒性是一种依赖于宿主遗传和发育状态的疾病综合征（即儿童使用的疫苗），我们的研究工作包括病毒对发育中的神经系统的影响的研究。由于我们缺乏对感染神经系统的病毒的病理生理反应的足够信息，我们开发了野生型病毒诱导的发育损伤的动物模型，作为自闭症的第一个病毒相关模型，并利用这些信息开发了神经毒性测试范例，包括腮腺炎、麻疹、流感和基于牛痘的天花疫苗。利用这些和其他研究的基本发现，我们开发了基于研究的特定神经毒性测试，最初使用动物模型（具有行为，解剖，神经化学和分子生物学终点）来评估神经毒性风险或神经系统的相对衰减。一旦动物疾病模型被开发出来，我们的目标是开发细胞培养或分子生物学分析来测试病毒疫苗的神经毒性。随着以研究为基础的神经毒性测试的发展，我们寻求国际监管实验室合作，以评估测试范例的潜在监管用途。