ABSTRACT
ADAR1-mediated deamination of adenosines in long double-stranded RNAs plays an important role in modulating the innate immune response. However, recent investigations based on metatranscriptomic samples of COVID-19 patients and SARS-COV-2-infected Vero cells have recovered contrasting findings. Using RNAseq data from time course experiments of infected human cell lines and transcriptome data from Vero cells and clinical samples, we prove that A-to-G changes observed in SARS-COV-2 genomes represent genuine RNA editing events, likely mediated by ADAR1. While the A-to-I editing rate is generally low, changes are distributed along the entire viral genome, are overrepresented in exonic regions, and are (in the majority of cases) nonsynonymous. The impact of RNA editing on virus-host interactions could be relevant to identify potential targets for therapeutic interventions.
Subject(s)
Adenosine Deaminase/genetics , COVID-19/genetics , Genome, Viral , Host-Pathogen Interactions/genetics , RNA Editing , RNA, Viral/genetics , RNA-Binding Proteins/genetics , SARS-CoV-2/genetics , Adenosine/metabolism , Adenosine Deaminase/immunology , Animals , COVID-19/metabolism , COVID-19/virology , Cell Line, Tumor , Chlorocebus aethiops , DEAD Box Protein 58/genetics , DEAD Box Protein 58/immunology , Deamination , Epithelial Cells/immunology , Epithelial Cells/virology , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate , Inosine/metabolism , Interferon-Induced Helicase, IFIH1/genetics , Interferon-Induced Helicase, IFIH1/immunology , Interferon-beta/genetics , Interferon-beta/immunology , RNA, Double-Stranded/genetics , RNA, Double-Stranded/immunology , RNA, Viral/immunology , RNA-Binding Proteins/immunology , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Transcriptome , Vero CellsABSTRACT
Various next generation sequencing (NGS) based strategies have been successfully used in the recent past for tracing origins and understanding the evolution of infectious agents, investigating the spread and transmission chains of outbreaks, as well as facilitating the development of effective and rapid molecular diagnostic tests and contributing to the hunt for treatments and vaccines. The ongoing COVID-19 pandemic poses one of the greatest global threats in modern history and has already caused severe social and economic costs. The development of efficient and rapid sequencing methods to reconstruct the genomic sequence of SARS-CoV-2, the etiological agent of COVID-19, has been fundamental for the design of diagnostic molecular tests and to devise effective measures and strategies to mitigate the diffusion of the pandemic. Diverse approaches and sequencing methods can, as testified by the number of available sequences, be applied to SARS-CoV-2 genomes. However, each technology and sequencing approach has its own advantages and limitations. In the current review, we will provide a brief, but hopefully comprehensive, account of currently available platforms and methodological approaches for the sequencing of SARS-CoV-2 genomes. We also present an outline of current repositories and databases that provide access to SARS-CoV-2 genomic data and associated metadata. Finally, we offer general advice and guidelines for the appropriate sharing and deposition of SARS-CoV-2 data and metadata, and suggest that more efficient and standardized integration of current and future SARS-CoV-2-related data would greatly facilitate the struggle against this new pathogen. We hope that our 'vademecum' for the production and handling of SARS-CoV-2-related sequencing data, will contribute to this objective.