Development, Production and Testing of VLP based Respiratory Syncytial Virus (RSV

描述（由申请人提供）：本申请的目标是开发一种安全有效的基于病毒样颗粒（VLP）的呼吸道合胞病毒（RSV）疫苗，以预防该病原体引起的疾病。由呼吸道合胞病毒引起的婴儿、儿童和老年人呼吸道疾病具有全球性的经济和公共卫生影响。最近的一项全球估计表明，超过3300万5岁以下儿童患有与呼吸道合胞病毒相关的下呼吸道感染（ALRI），每年至少有300万人住院，约19.9万人死于该疾病。在美国，疾病预防控制中心估计，每年有超过12.6万例与呼吸道合胞病毒相关的儿科住院治疗，费用超过9亿美元。目前还没有获得许可的疫苗，针对这种疾病的治疗也很有限；预防性干预依赖于对有感染风险的婴儿施用中和性单克隆（Synagis）并给予支持性护理。一种安全有效的疫苗将是最理想和最具成本效益的预防性干预措施。然而，迄今为止还没有研制出这种疫苗，而且由于1960年代生产的一种福尔马林灭活疫苗引起的疾病增加，这种疫苗的研制受到阻碍。其他方法没有被证明是成功的，甚至是危险的。在这里，我们建议开发和测试一种显示RSV抗原的病毒样颗粒，作为创建安全有效的RSV疫苗的策略。VLPs是野生型病毒颗粒的模拟物，但不含病毒遗传物质，因此无法复制或引起感染。VLP表面的颗粒性和冗余的天然抗原阵列激发了免疫系统的更大识别。我们已经成功地产生了具有表面刺突和类似野生型病毒的天然rsv - vlp。我们基于RSV的VLP候选疫苗是通过共表达蛋白M、F和SH或M、F或M、F和G以及其他组合而制成的。它们诱导的免疫反应的类型和强度以及RSV-VLP候选疫苗的功效将在动物模型中进行评估。为了实现这些目标，我们设计了三个特异性目标：特异性目标一：产生并表征显示呼吸道合胞病毒表面抗原的病毒样颗粒（vlp）。特异性目的二：评价RSV-VLP疫苗引起的免疫原性（免疫反应的质量和强度），建立RSV-VLP疫苗替代组合物在呼吸道合胞病毒感染小鼠模型中的安全性和保护效果。将通过在小鼠中增加疫苗剂量来重新评估选定的候选疫苗。同时，开始开发稳定的细胞系，以便持续生产首选的VLP疫苗。目的三：在呼吸道合胞病毒感染棉花大鼠模型中重新检测具有有效性、效力和安全性的VLP组合物，探索两种RSV感染模型的有效性。这些研究将支持SBIR II期提案，并寻求FDA的IND申请。

DESCRIPTION (provided by applicant): The goal of this proposal is to develop a safe and efficacious virus-like particle (VLP) based-respiratory syncytial virus (RSV) vaccine to prevent the disease caused by this pathogen. The respiratory illnesses provoked by RSV in infants, children and the elderly are of global economical and public health impact. A recent worldwide estimate [5] indicates that over 33 million children under the age of five suffer RSV associated lower respiratory infections (ALRI) and at least 3 million are hospitalized and approximately 199,000 die of the disease each year. In the US, the CDC estimates that there are over 126,000 RSV associated pediatric hospitalizations at a cost of over $900 million per year. There is no vaccine currently licensed and treatments for the disease are limited; a prophylactic intervention relies on administering a neutralizing monoclonal (Synagis) to infants at risk of infection and to supportive care. A safe and effective vaccine would be the most desirable and cost effective preventive intervention. However, to date the creation of such a vaccine has not been attained and its development hindered by the enhancement of disease provoked by a formalin-inactivated vaccine produced in the 1960's. Other approaches have not proven successful and even dangerous. Here, we propose to develop and test a virus-like particle displaying RSV antigens as a strategy to create a safe and effective RSV vaccine. VLPs are mimics of wild type virus particles but do not contain viral genetic material making them unable to replicate or cause infection. The particulate nature and redundant array of native antigen on the surface of the VLP incites a greater recognition by the immune system. We have successfully produced native RSV-VLPs that display surface spikes and resemble wild type virus. Our RSV based VLP candidate vaccines are created by co-expressing the proteins M, F and SH or M, F or M, F and G as well as additional combinations. The type and magnitude of the immune response they induce as well as the efficacy afforded by the RSV-VLP candidate vaccines will be assessed in animal models. To fulfill these goals, we have designed three specific aims: Specific aim I: Produce and characterize virus-like particles (VLPs) displaying respiratory syncytial virus surface antigens.in alternative compositions F, F+SH, F+G and F+SH+G Specific aim II: Evaluate the immunogenicity (quality and magnitude of the immune response) elicited by the RSV-VLP vaccine and establish safety profile as well as the protective efficacy afforded by alternative compositions of RSV-VLP vaccines in a mouse model of respiratory syncytial virus infection. Selected candidates will be reevaluated by escalating doses of vaccine in mice. Also, initiate development of stable cell lines for the continuous production of the preferred VLP vaccine. Specific aim III: The VLP composition demonstrating efficacy, potency and safety will be retested in the cotton rat model of respiratory syncytial virus infection seeking probe of efficacy in two model of RSV infection. These studies will support a SBIR Phase II proposal and pursue an IND application with the FDA.