HA Surface Presented Yeast Flu Vaccine and Its Enhancement by CD154 Codisplay

描述（由申请人提供）：疫苗接种是目前唯一可以有效阻止流感病毒在人群中传播的方法。传统的基于鸡蛋的流感疫苗技术的缺点是，如果全球爆发，它们不能大规模和快速地生产针对流行流感的疫苗。在这里，提出了一种新型的有效流感疫苗的基础上PI的蛋白质表面展示的工作。这项新技术的核心是在酵母表面展示病毒蛋白，如禽流感H5N1血凝素（HA），使这些重组酵母可用作流感疫苗。已知酵母能够表达功能性HA。HA的表面展示可以显著促进宿主免疫系统对抗原的识别，并与酵母细胞膜组分介导免疫佐剂效应。尽管酵母与哺乳动物细胞相比具有不同的糖基化能力，但这种有限的糖基化实际上可能有利于配制酵母疫苗。据报道，人和标准疫苗中天然流感病毒的糖基化实际上通过阻止抗体接近HA表面而干扰免疫诱导。这项工作将彻底调查这种好处。或者，糖基化酵母将用于构建HA表面展示酵母疫苗，以评价这些疫苗的免疫改变。为了提高酵母疫苗的效力和免疫原性，将采用双蛋白表面展示技术来共展示HA和CD 154。HA与CD 154的共展示将进一步刺激抗原呈递细胞的成熟，促进适应性免疫应答。综上所述，提出了HA表面展示酵母疫苗可以引发针对流感的强保护性免疫的假设。此外，这些有效的疫苗可以通过共展示HA与CD 154来增强。PI实验室最近进行的一项动物疫苗接种研究支持了这一假设。本项目旨在进一步验证这一假设，提出了三个目标：目标1，制备HA表面呈递的酵母流感疫苗;目标2，表征酵母疫苗在动物（小鼠）中诱导的体液和细胞介导的免疫应答;目标3，证明酵母疫苗对小鼠的致死性禽流感的保护。该项目的长期目标是将动物研究转化为临床前研究，确定这些酵母疫苗在人类中的免疫原性，并增强该技术以开发用于治疗许多病毒感染相关疾病如艾滋病和癌症的其他疫苗。与基于病毒的疫苗不同，酵母疫苗可安全用于人类，并且疫苗储存不需要冷藏。此外，它们可以以低成本大规模和快速地生产。此外，这些疫苗不需要病毒通过鸡蛋，为疫苗种子株的开发提供了可能性，这些疫苗种子株与原始"野生"病毒更接近，并可能转化为更好的免疫原性和有效的反应。

DESCRIPTION (provided by applicant): Vaccination is currently the only method that can effectively impede the spread of influenza viruses among people. Traditional egg-based influenza vaccine technologies suffer from their incapability of massive and rapid production of vaccines against circulating influenza if a global outbreak occurs. Here, a new type of potent influenza vaccines is proposed based on the PI's previous works on protein surface display. The core of this new technology is to display a viral protein such as avian influenza H5N1 hemagglutinin (HA) on yeast surface in a manner such that these recombinant yeasts can serve as vaccines against influenza. Yeast is known of being able to express functional HA. The surface display of HA can significantly facilitate the recognition of antigens by host immune systems and mediate an immunoadjuvant effect with yeast cell membrane components. Although yeast has different glycosylation capability as compared to mammalian cells, this limited glycosylation may actually be a benefit to formulating a yeast vaccine. It has been reported that the glycosylation of natural influenza viruses in humans and in the standard vaccine actually interferes with induction of immunity by preventing access of antibodies to the HA surface. This benefit will be investigated thoroughly in this work. Alternatively, glycosylated yeast will be employed to construct HA surface-displayed yeast vaccines for evaluating the alteration of immunity of these vaccines. To enhance the efficacy and immunogenicity of the yeast vaccines, a dual-protein surface display technique will be adopted to codisplay the HA with CD154. The codisplay of HA with CD154 will further stimulate the maturation of antigen presenting cells and promote the adaptive immune response. Taken together, a hypothesis was developed that HA surface-displayed yeast vaccines can elicit strong and protective immunity against influenza. Furthermore, these potent vaccines can be enhanced by co-displaying HA with CD154. A recent animal vaccination study conducted in PI's lab supports this hypothesis. This project is proposed to further verify this hypothesis, three aims are proposed: Aim 1, Generate HA surface presented yeast influenza vaccines; Aim 2, Characterize both humoral and cell-mediated immune responses induced by yeast vaccines in animals (mice); Aim 3, Demonstrate the protection of mice from lethal avian influenza using yeast vaccines. The long-term goals of this project are to translate the animal studies into preclinical studies, determine the immunogenicity of these yeast vaccines in humans, and to augment this technology to develop other vaccines for treating many virus- infection related diseases such as AIDS and cancers. Unlike virus-based vaccines, yeast vaccines are safe for use in humans, and vaccine storage does not require refrigeration. Moreover, they can be massively and rapidly produced at a low cost. In addition, these vaccines do not require the passage of virus through eggs, offering a possibility for vaccine seed strain development that more closely matches the original "wild" virus and translating potentially into a better immunogenic and effective response.