A novel lactic acid bacteria-based norovirus vaccine

 描述(申请人提供)：人类诺如病毒(HuNoV)感染导致全球95%以上的非细菌性急性胃肠炎和美国60%以上的食源性疾病。有证据表明，HuNov和猪诺如病毒(PoNoV)具有很高的人畜共患病潜力，由于PoNoV与HuNov GII株有最高的同源性，这表明猪可能是HuNoV的宿主，并可能产生新的HuNov和猪/人GII重组体。尽管做出了重大努力，疫苗或抗病毒药物仍不可用。这在很大程度上是由于缺乏细胞培养系统或小动物模型来研究HuNoV的致病机理。这项提议的总体目标是开发一种乳球菌或乳酸菌(LAB)作为载体来运送NOV病毒样颗粒(VLP)和突起(P)颗粒，并开发基于实验室的用于临床试验的NOV活疫苗。我们已经证明，表达来自HuNoV-GII-4的VLP和P颗粒的实验室菌株在口服接种到GnotoBiotic(GN)仔猪时诱导了强大的保护性免疫反应，GN仔猪是唯一准确复制HuNoV疾病的非灵长类动物模型。利用这一独特的动物模型，我们将确定实验室定植的动态，以及NOV VLP和P颗粒在胃肠道的表达、摄取，以及实验室疫苗诱导的先天免疫。我们将确定基于实验室的疫苗是否提供针对同源(HuNoV-GII)或异源(PoNoV-GII)病毒的攻击的保护。随后，我们将确定基于实验室的疫苗诱导NOV特异性粘膜、体液和细胞免疫反应的机制，并定义针对NOV毒株的同源和异种保护的免疫相关性。最后，我们将确定微囊化和树突状细胞(DC)靶向多肽是否能与粘膜抗原提呈细胞(APC)特异性结合，从而提高基于实验室的新城疫疫苗的免疫原性，并保护GN仔猪免受强毒病毒的攻击。这些研究的成功完成将导致安全、稳定和有效的疫苗(S)的开发，以预防人和猪的人/猪新城疫胃肠炎。该项目还将为人类和家畜意义上的其他不可培养的食物和水传播病毒提供一种新的疫苗开发途径。

 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.