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Attenuation of a highly virulent oncogenic herpesvirus by computer-aided virus reengineering

通过计算机辅助病毒重组来减毒高毒力致癌疱疹病毒

基本信息

批准号：
240384313
负责人：
Professor Dr. Nikolaus Osterrieder
金额：
--
依托单位：
Institut für Virologie (WE05)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/240384313?language=en
关键词：
Attenuation highly virulent oncogenic herpesvirus

项目摘要

Vaccines are the most valuable and cost-effective tools to fight infectious diseases, particularly virus infections. The ´death by thousand cut´ is a new and revolutionary strategy that has enabled attenuation of viruses to a desired level, in a controlled manner, and with unprecedented efficiency and speed. This strategy, also known as synthetic attenuated virus engineering (SAVE), is based on introduction of several hundred nucleotide mutations into coding sequences without changing the amino acid composition of encoded proteins. Thus, the mutated virus, a modified live viral vaccine (MLV), is antigenically identical with the parental pathogenic virus, but its replication and pathogenic capacity is impaired. The actual encoding of amino acid in open reading frames (ORFs) is biased and some synonymous codons are used more often than others (codon bias). Consequently, utilization of rare codons results in suboptimal translation. Similarly, but independently of codon bias, codon pair combinations in ORFs are also not random. Some synonymous codon pairs are found in ORFs significantly more or less frequently than it would be expected based on the overall frequencies of two codons that form a codon pair (codon pair bias). Codon pair usage affects translational efficiency more than codon bias, and thus, unfavorable codon pairs are normally rarely used. Utilization of naturally underrepresented codon pairs creates unfavorable conditions for efficient protein translation, and this causes attenuation of a virus. The SAVE strategy has been successfully used in attenuation of two unrelated RNA viruses (poliovirus and influenza virus) and a pathogenic bacterium (Streptococcus pneumoniae), but it has not been tested on large double-stranded DNA viruses, such as asfarviruses, poxviruses or herpesviruses. Before this technology can be applied for production of viral vaccines, it must be comprehensively studied and tested.The proposed project will explore promising applications this technology for the first time on a large DNA virus. The overall goal of the proposed project is to determine how a herpesvirus can be attenuated most efficiently by the SAVE technology. To address this objective we will use a unique small animal model, which involves the highly virulent and oncogenic Marek´s disease herpesvirus (MDV), and the chicken. The central hypothesis for this project is that codon pair deoptimization of MDV genes will result in fully attenuated herpesviruses and that the attenuated viruses will be highly efficacious MLV vaccines. The mutant viruses will be first constructed and tested in vitro, and then evaluated for their ability to induce vaccinal protection without being virulent themselves by in vivo experiments.We expect that the proposed will have significant and positive impact on virology and vaccinology and that comprehensive understanding of the SAVE technology will ultimately lead the development of superior animal and human vaccines.

疫苗是对抗传染病，特别是病毒感染的最有价值和最具成本效益的工具。“千刀致命”是一种新的革命性战略，它以可控的方式，以前所未有的效率和速度将病毒衰减到所需的水平。这种策略，也称为合成减毒病毒工程（SAVE），是基于在编码序列中引入数百个核苷酸突变，而不改变编码蛋白质的氨基酸组成。因此，突变的病毒，一种改良的活病毒疫苗（MLV），在抗原性上与亲本致病病毒相同，但其复制和致病能力受损。开放阅读框（ORF）中氨基酸的实际编码是有偏向的，并且一些同义密码子比其他密码子使用得更频繁（密码子偏向）。因此，稀有密码子的利用导致次优翻译。类似地，但独立于密码子偏好，ORF中的密码子对组合也不是随机的。在ORF中发现的一些同义密码子对的频率明显高于或低于基于形成密码子对的两个密码子的总体频率所预期的频率（密码子对偏好）。密码子对使用比密码子偏好性更影响翻译效率，因此，通常很少使用不利的密码子对。天然代表性不足的密码子对的利用为有效的蛋白质翻译创造了不利的条件，并且这导致病毒的减毒。SAVE策略已成功用于两种不相关的RNA病毒（脊髓灰质炎病毒和流感病毒）和一种致病性细菌（肺炎链球菌）的减毒，但尚未在大型双链DNA病毒（如asfarviruses、痘病毒或疱疹病毒）上进行测试。在这项技术可以应用于生产病毒疫苗之前，它必须进行全面的研究和测试。拟议的项目将首次探索这项技术在大型DNA病毒上的有前途的应用。拟议项目的总体目标是确定如何通过SAVE技术最有效地减毒疱疹病毒。为了实现这一目标，我们将使用一种独特的小动物模型，其中包括高毒性和致癌性马立克氏病疱疹病毒（MDV）和鸡。该项目的中心假设是MDV基因的密码子对去优化将导致完全减毒的疱疹病毒，并且减毒病毒将是高效的MLV疫苗。我们将首先在体外构建和测试突变病毒，然后通过体内实验评估它们诱导疫苗保护的能力，而不是毒性本身。我们期望所提出的将对病毒学和疫苗学产生重大和积极的影响，并且对SAVE技术的全面理解将最终导致上级动物和人疫苗的开发。