A sequence-independent approach for attenuating hepaciviruses

一种与序列无关的减毒肝炎病毒方法

基本信息

批准号：
10598793
负责人：
Amit Kapoor
金额：
$ 19.5万
依托单位：
RESEARCH INST NATIONWIDE CHILDREN'S HOSP
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-11-07 至 2024-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10598793
关键词：
Acute Acute Disease Adenine Animal Model Attenuated Attenuated Live Virus Vaccine Attenuated Vaccines Bioinformatics Biological Assay Cell Culture System Cells Chronic Chronic Disease Chronic Hepatitis C Codon Nucleotides Communication CpG dinucleotide Cytosine Development Dinucleoside Phosphates Frequencies Future Genes Genome Genomic Segment Guanine Hepatitis C Hepatitis C Vaccine Hepatitis C virus Hepatitis C-Like Viruses Hepatology Human Immune Immune response Immunity Immunocompetent In Vitro Individual Infection Interferons Investments Journals Modeling Modernization Mutagenesis Mutate Mutation Natural Immunity Nature Nucleotides Outcome Pathogenesis Pathogenicity Pathway interactions Play RNA RNA Viruses Rattus Research Rodent Role Science Serial Passage Serum Solid Species Specificity Structure T-Lymphocyte Uracil Vaccines Variant Vertebral column Viral Viral Genome Viremia Virus Virus Diseases adaptive immunity attenuation biological systems chronic infection design in vivo interest mutant pathogen pathogenic virus preservation prevent recombinant virus transcriptome transcriptome sequencing vaccination strategy virology

项目摘要

Abstract Human hepacivirus or hepatitis C virus (HCV) establishes chronic hepatotropic infection in ~70% of infected individuals. In this project, the central question is: Can we mutate a hepacivirus genome to generate an attenuated virus to use as a vaccine? Serial passaging of pathogenic viruses in vitro or in vivo biological systems followed by the selection of less-pathogenic viral strains is the traditional way to generate an attenuated virus vaccine. HCV attenuation remained inconceivable since an efficient cell culture system was unavailable for decades after virus discovery, and an animal model is still elusive. Similarly, for many other chronic human viruses, their species specificity restricts the development of immunocompetent animal models critical for meaningful studies of immunity and pathogenesis. This project will use a rodent hepacivirus (RHV) that shares the hallmarks of HCV infection in humans. We will use a bioinformatics approach to alter the dinucleotide frequencies in RHV genomes to generate attenuated variants. Our preliminary results provided a solid rationale for the project and assured its feasibility. We determined that the RHV variant with high frequencies of UpA (uracil followed by adenine) failed to develop a chronic infection in rats. We propose two aims to refine our strategy of generating attenuated hepaciviruses and characterize the innate and adaptive immunity induced by their infection. Aim-1 is to optimize the design of the hepacivirus mutants that produce high-titer viremia and fail to develop chronic infection. Aim-2 is to characterize the innate and adaptive immunity induced by attenuated hepacivirus mutants. Since we will use a sequence-independent approach (only synonymous mutations) to attenuate RHV, the results can inform the design of an HCV vaccine. Additionally, successful attenuation of a chronic virus in its natural host will open new research avenues and yield new viral variants to define immune responses associated with viral clearance and persistence and immune correlates of protection for chronic viruses.

抽象的人类肝炎病毒或丙型肝炎病毒 (HCV) 在约 70% 的感染者中形成慢性嗜肝性感染个人。在这个项目中，核心问题是：我们能否突变肝炎病毒基因组以产生减毒病毒可以用作疫苗吗？病原病毒在体外或体内生物系统的连续传代其次选择致病性较低的病毒株是产生减毒病毒的传统方法疫苗。由于没有有效的细胞培养系统，HCV 减毒仍然是不可想象的。病毒发现几十年后，动物模型仍然难以捉摸。同样，对于许多其他慢性人类病毒，其物种特异性限制了免疫活性动物模型的发展，这对于免疫和发病机制的有意义的研究。该项目将使用啮齿动物肝炎病毒（RHV），该病毒共享人类 HCV 感染的特征。我们将使用生物信息学方法来改变二核苷酸 RHV 基因组中的频率以产生减毒变体。我们的初步结果提供了可靠的说明该项目的基本原理并保证其可行性。我们确定 RHV 变体具有高频率 UpA（尿嘧啶随后是腺嘌呤）未能在大鼠中形成慢性感染。我们提出了两个改进目标我们产生减毒肝炎病毒并表征先天性和适应性免疫的策略由他们的感染引起。 Aim-1 是优化产生高滴度的肝炎病毒突变体的设计病毒血症并且无法发展为慢性感染。 Aim-2 是表征先天性和适应性免疫的特征由减毒肝炎病毒突变体诱导。由于我们将使用与序列无关的方法（仅同义突变）来减弱 RHV，结果可以为 HCV 疫苗的设计提供信息。此外，慢性病毒在其自然宿主中的成功减毒将开辟新的研究途径并产生新的病毒定义与病毒清除和持久性相关的免疫反应以及免疫相关性的变体对慢性病毒的保护。