A novel lactic acid bacteria-based norovirus vaccine

 描述（由申请方提供）：人类诺如病毒（HuNoV）感染是全球95%以上非细菌性急性胃肠炎和美国60%以上所有食源性疾病的原因。有证据表明，HuNoV和猪诺如病毒（PoNoV）具有较高的人畜共患病潜力，并且由于PoNoV与HuNoV GII毒株具有最高的同一性，这表明猪可作为HuNoV的储库，并出现新型HuNoV和猪/人GII重组体。尽管做出了重大努力，但疫苗或抗病毒药物仍然不可用。这主要是由于缺乏细胞培养系统或HuNoV发病机制的小动物模型。该提案的总体目标是开发乳酸乳球菌或乳酸菌（LAB）作为载体以递送NoV病毒样颗粒（VLP）和突起（P）颗粒，并开发基于LAB的“活”NoV疫苗用于临床试验。我们已经表明，表达来自HuNoV-GII.4的VLP和P颗粒的LAB菌株在经口接种到gnotobiotic（GN）仔猪中时诱导强烈的保护性免疫应答，GN仔猪是唯一准确复制HuNoV疾病的非灵长类动物模型。使用这种独特的动物模型，我们将确定LAB定殖的动力学和胃肠道中NoV VLP和P颗粒的表达、摄取以及由基于LAB的疫苗诱导的先天免疫。我们将确定基于LAB的疫苗是否提供针对同源（HuNoV-GII）或异源（PoNoV-GII）病毒攻击的保护。随后，我们将确定基于LAB的疫苗诱导NoV特异性粘膜、体液和细胞免疫应答的机制，并定义针对NoV毒株的同源和异源保护的免疫相关性。最后，我们将确定微囊化和特异性结合粘膜抗原呈递细胞（APC）的树突状细胞（DC）靶向肽是否会增强基于LAB的NoV疫苗的免疫原性，并保护GN仔猪免受强毒病毒攻击。这些研究的成功完成将导致开发安全、稳定和有效的疫苗，用于预防人类和猪的HuNoV/PoNoV胃肠炎。该项目还将为其他人类和家畜的不可培养的食源性和水媒病毒的疫苗开发提供新的途径。

 DESCRIPTION (provided by applicant): Human norovirus (HuNoV) infections are responsible for more than 95% of the non-bacterial acute gastroenteritis worldwide and more than 60% of all food-borne illnesses in the US. Evidence suggests that HuNoVs and porcine norovirus (PoNoV) possess high zoonotic potential and, since PoNoV shares the highest identity to HuNoV GII strains, suggesting that swine may serve as reservoirs HuNoV and for emergence of novel HuNoVs and porcine/human GII recombinants. Despite the major efforts, vaccines or antiviral drugs are not available. This is due in major part to the lack of a cell culture system or a small animal model for HuNoV pathogenesis. The overall goal of this proposal is to develop a Lactococcus lactis or lactic acid bacteria (LAB) as the vector to deliver NoV virus-like particles (VLPs) and protrusion (P) particles, and to develop LAB-based "live" NoV vaccines for clinical trials. We have shown that LAB strains expressing VLP and P particles derived from HuNoV-GII.4 induced strong protective immune responses when orally inoculated into gnotobiotic (GN) piglets, the only nonprimate animal model that accurately replicates HuNoV disease. Using this unique animal model, we will determine the dynamics of LAB colonization and the expression, uptake of the NoV VLP and P particles in gastrointestinal tract, and innate immunity induced by LAB-based vaccines. We will determine if LAB- based vaccines provide protection against challenge with homologous (HuNoV-GII) or heterologous (PoNoV-GII) viruses. Subsequently, we will determine the mechanism by which LAB-based vaccine induces NoV-specific mucosal, humoral, and cellular immune responses, and define immune correlates of homologous and heterologous protection against NoV strains. Finally, we will determine if microencapsulation and a dendritic cell (DC) targeting peptide that specifically binds mucosal antigen- presenting cells (APCs) will enhance the immunogenicity of LAB-based NoV vaccines and will protect GN piglets from virulent virus challenge. Successful completion of these studies will result in development of safe, stable and efficacious vaccine(s) for the prevention of HuNoV/PoNoV gastroenteritis in humans and swine. This project will also provide a new avenue for vaccine development for other non-cultivable food- and water-borne viruses of human and domestic animal significance.