Attenuated Strains of Human Metapneumovirus for Vaccines and Pathogenesis

描述(由申请人提供)：本申请的主要目标是开发人类偏肺炎病毒(HMPV)的候选疫苗，识别毒力的病毒决定因素，并确定HMPV的遗传多样性。HMPV是一种新近发现的副粘病毒，是全球婴儿和儿童下呼吸道疾病的主要原因，可导致住院和致命感染。HMPV还与需要住院的哮喘恶化有关，并在患有早产、心肺疾病和癌症等潜在疾病的人中导致严重疾病。这项工作建议开发针对HMPV的减毒活疫苗，并确定病毒毒力的决定因素。我们提出了三个具体目标：具体目标1.建立HMPV细胞培养传代株，并在动物模型中检测其致病性和免疫原性。明确目标2.确定有助于毒力和致病性的病毒因子。具体目标3.确定HMPV的遗传多样性和随时间的进化。这项研究将为HMPV提供潜在的候选疫苗，并为这一重要人类病原体的发病机制提供新的知识。拟议的实验结合了动物研究、经典病毒学技术、细胞免疫学工具和高通量测序，以定义HMPV毒力因子并识别减毒突变。这些发现将对反向工程HMPV疫苗的设计有用。相关呼吸道合胞病毒的主要候选疫苗使用反向遗传学来合并由类似方法确定的减毒突变，以及完全基因删除。高通量测序方法的使用将提供有关HMPV随着时间的推移遗传多样性的新信息。这些信息对于设计疫苗或预防性预防策略至关重要。我们假设，像其他副粘病毒一样，HMPV不会随着时间的推移而表现出实质性的遗传或抗原漂移。然而，这些数据尚不清楚，HMPV可能会表现出类似于流感病毒的持续变异，每年需要一种新的疫苗。HMPV对人类健康有重大影响，安全、有效的疫苗可以减轻与这种新病原体相关的疾病负担。与公共卫生相关：人类偏肺病毒(HMPV)是2001年发现的一种新病毒。HMPV是世界范围内呼吸道疾病的主要原因，并导致许多婴儿和儿童住院。这项提议的目的是开发针对hMPV的候选疫苗。这些研究将增加对hMPV如何导致人类疾病的理解，并可能有助于开发抗病毒药物和疫苗的靶标。

DESCRIPTION (provided by applicant): The major objectives of the proposed research in this application from a new investigator are to develop candidate vaccines for human metapneumovirus (HMPV), identify viral determinants of virulence and define genetic diversity of HMPV over time. HMPV is a recently discovered paramyxovirus that is a major cause of lower respiratory tract disease in infants and children worldwide, causing hospitalization and fatal infections. HMPV is also associated with asthma exacerbations requiring hospitalization and causes severe disease in persons with underlying conditions such as prematurity, cardiopulmonary disease, and cancer. This work proposes to develop live attenuated vaccines against HMPV and define viral determinants of virulence. We propose three specific aims: Specific Aim 1. Develop cell culture-passaged strains of HMPV and determine their pathogenicity and immunogenicity in animal models. Specific Aim 2. Define viral factors that contribute to virulence and pathogenicity. Specific Aim 3. Determine the genetic diversity and evolution of HMPV over time. This research will provide potential vaccine candidates for HMPV and provide new knowledge about pathogenesis of this important human pathogen. The proposed experiments use a combination of animal studies, classical virology techniques, cellular immunology tools, and high-throughput sequencing to define HMPV virulence factors and identify attenuating mutations. The findings will be useful for the design of reverse- engineered HMPV vaccines. Leading vaccine candidates for the related respiratory syncytial virus use reverse genetics to incorporate attenuating mutations identified by similar methods, as well as complete gene deletions. The use of high-throughput sequencing methods will provide novel information about the genetic diversity of HMPV over time. This information is essential for designing vaccines or prophylactic prevention strategies. We hypothesize that, like other paramyxoviruses, HMPV will not exhibit substantial genetic or antigenic drift over time. However, these data are not known and it is possible that HMPV would demonstrate continued mutation similar to influenza virus, requiring a new vaccine each year. HMPV has a major impact on human health and safe, effective vaccines could decrease the burden of disease associated with this novel pathogen. PUBLIC HEALTH RELEVANCE: Human metapneumovirus (hMPV) is an emerging virus that was discovered in 2001. hMPV is a major cause of respiratory tract disease worldwide, and leads to many hospitalizations of infants and children. The purpose of this proposal is to develop candidate vaccines for hMPV. These studies will increase understanding of how hMPV causes disease in humans, and may help develop targets for antiviral medicines and vaccines.