A novel DNA-launched live attenuated Chikungunya vaccine

描述（由申请方提供）：本申请的主要目标是设计、生产和评价一种抗基孔肯雅病毒（CHIKV）的概念性新型疫苗。我们提出了一种新的技术，“传染性”的DNA（i-DNA）作为CHIKV疫苗。该技术的一个独特特征是活减毒CHIKV疫苗在体内从i-DNA质粒启动。在i-DNA中，将修饰的减毒IND活疫苗181/25的RNA基因组的全长拷贝置于优化的真核启动子和调控序列背景下的质粒中。基因组病毒RNA在体内的转录导致减毒病毒在疫苗受体组织中的有限复制和保护性免疫应答的诱导。由于i-DNA代表一种分子克隆，它将产生一个均匀的减毒病毒群体，从而潜在地提高安全性。我们还将通过对C-E2-E1基因内的翻译密码子进行去优化来制备两种i-DNA变体，以增强遗传稳定性和疫苗安全性。 实验CHIKV i-DNA疫苗将与目前的181/25活减毒疫苗一起在体外和体内沿着进行评价。疫苗抗原将与印度Chennai的Sri Ramachandra大学合作，用来自最近临床CHIKV分离株的一组人抗血清进行探测。将在幼龄和老龄小鼠以及免疫抑制仓鼠中确定免疫原性和安全性特征。因此，将在各种年龄和免疫状态的临床前模型中评价候选i-DNA疫苗的特征，该模型模拟人类群体，并将提供疫苗安全性和免疫原性特征的准确测定。 总之，i-DNA疫苗接种将联合收割机结合DNA疫苗的简单性和减毒活疫苗的特殊功效。i-DNA可以潜在地提高安全性，不需要冷链，并且易于制造和在紧急情况下扩大规模。此外，细菌产生的i-DNA将含有CpG基序，预期其激活先天免疫应答并改善免疫原性。如果成功的话，这项技术可能代表了基孔肯雅热疫苗接种的革命性解决方案。 公共卫生相关性：基孔肯雅病毒（CHIKV）是一种新出现的病原体，是全球范围内的公共卫生问题。本研究的重点是设计、生产和评估一种概念上新颖的CHIKV疫苗。我们假设，通过使用“感染性”DNA技术（i-DNA），可以提高CHIKV减毒活疫苗的安全性和免疫原性。这将产生独特的CHIKV疫苗，其将联合收割机DNA疫苗的简单性与减毒活疫苗的卓越功效相结合。这种疫苗可以在疫情爆发期间迅速部署，并防止感染蔓延到未受影响的地区。

DESCRIPTION (provided by applicant): The main goal of this application is the design, production and evaluation of a conceptually novel vaccine against Chikungunya virus (CHIKV). We propose a novel technology of "infectious" DNA (i-DNA) as CHIKV vaccine. A unique feature of this technology is that live attenuated CHIKV vaccine is launched in vivo from the i-DNA plasmid. In the i-DNA, the full-length copy of RNA genome of modified live attenuated IND vaccine 181/25 is placed in the plasmid in the context of optimized eukaryotic promoter and regulatory sequences. Transcription of the genomic viral RNA in vivo results in limited replication of attenuated virus in the tissues of vaccine recipient and induction of a protective immune response. Since the i-DNA represents a molecular clone, it will generate a uniform population of attenuated virus thus potentially improving safety. We will also prepare two i-DNA variants by de-optimization of translational codons within C-E2-E1 genes with the view to enhance genetic stability and vaccine safety. Experimental CHIKV i-DNA vaccines will be evaluated in vitro and in vivo along with the current 181/25 live attenuated vaccine. The vaccine antigens will be probed with a panel of human antisera from recent clinical CHIKV isolates in partnership with Sri Ramachandra University, Chennai, India. Immunogenicity and safety profiles will be determined in the young and aged mice as well as in immunosuppressed hamsters. Thus, characteristics of candidate i-DNA vaccines will be evaluated in the preclinical models of various age and immune status, which mimics human population and will provide accurate determination of safety and immunogenicity profiles of the vaccines. In summary, i-DNA vaccination will combine the simplicity of DNA vaccines with the exceptional efficacy of live attenuated vaccines. The i-DNA can potentially improve safety, does not require cold chain and is easy to manufacture and scale-up in emergency scenarios. Further, bacterially generated i-DNA will contain CpG motifs, which are expected to activate innate immune responses and improve immunogenicity. If successful, this technology may represent a revolutionary solution for vaccination against Chikungunya fever. PUBLIC HEALTH RELEVANCE: Chikungunya virus (CHIKV) is an emerging pathogen and a public health concern worldwide. The focus of this study is the design, production and evaluation of a conceptually novel vaccine against CHIKV. We hypothesize that safety and immunogenicity of live attenuated CHIKV vaccine can be improved by using the "infectious" DNA technology (i-DNA). This will result in a unique CHIKV vaccine, which will combine the simplicity of DNA vaccines with the exceptional efficacy of live attenuated vaccine. Such vaccine can be rapidly deployed during outbreaks and prevent spread of infection to non-affected areas.