Tracking the Transcription Kinetic of SARS-CoV-2 in Human Cells by Reverse Transcription-Droplet Digital PCR.

Ka-Ki Au,Chun-Kin Chow,Chunke Chen,Yee-Man Chan,Winsome Wing Sum Wong,Chris Ka Pun Mok,Huibin Lv

doi:10.3390/pathogens10101274

Abstract

Viral transcription is an essential step of SARS-CoV-2 infection after invasion into the target cells. Antiviral drugs such as remdesivir, which is used to treat COVID-19 patients, targets the viral RNA synthesis. Understanding the mechanism of viral transcription may help to develop new therapeutic treatment by perturbing virus replication. In this study, we established 28 ddPCR assays and designed specific primers/probe sets to detect the RNA levels of 15 NSP, 9 ORF, and 4 structural genes of SARS-CoV-2. The transcriptional kinetics of these viral genes were determined longitudinally from the beginning of infection to 12 h postinfection in Caco-2 cells. We found that SARS-CoV-2 takes around 6 h to hijack the cells before the initiation of viral transcription process in human cells. Our results may contribute to a deeper understanding of the mechanisms of SARS-CoV-2 infection.

Highlights

There have been more than 179 million COVID-19 cases around the globe and nearly4 million associated deaths since the initial disease outbreak in late 2019 [1]
SARS-CoV-2 belongs to the beta group of coronaviruses, which is in the family of Coronaviridae
To identify suitable target regions for the Droplet digital PCR (ddPCR), 61,013 of SARS-CoV-2 sequences were downloaded from GISAID and aligned

Summary

Introduction

There have been more than 179 million COVID-19 cases around the globe and nearly. 4 million associated deaths since the initial disease outbreak in late 2019 [1]. The causative agent that is responsible for the disease is a new and emerging strain of coronavirus, namely. SARS-CoV-2 [2,3]. SARS-CoV-2 belongs to the beta group of coronaviruses, which is in the family of Coronaviridae. The architecture of SARS-CoV-2 has been studied in detail [4]. There is a positive sense, single-stranded viral genome which is around. Its genome encodes for four major structural proteins: spike (S), envelope (E), matrix (M), and nucleocapsid (N); sixteen nonstructural proteins (nsp to nsp16); and ten accessory proteins (ORF1a/1ab, 3a/b, 6, 7a/b, 8, 9b, and 10) [4]

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Results

Conclusion