A sequence-independent approach for attenuating hepaciviruses

一种与序列无关的减毒肝炎病毒方法

• 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
• 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

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.

摘要