Scarless SARS-CoV-2 Genome Engineering and Variant Analysis
In addition to causing cold and flu-like symptoms, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can also cause chronic longer-term diseases. Antiviral drugs, especially used combinatorially, have the potential to reduce the severity of individual infections and prevent the development of chronic disease. One of the safest and most versatile reverse genetics systems for SARS-CoV-2…
SARS-CoV-2, responsible for colds and flu-like symptoms, can also lead to chronic diseases. Antiviral drugs, particularly in combination, may lessen infection severity and avert chronic disease development. A bacterial artificial chromosome (BAC)-based system carrying the full-length genome of the WA1 strain, with deletions in accessory proteins ORF3a and ORF7b, is a safe and versatile reverse genetics system for studying SARS-CoV-2.
In this system, a scarless genome engineering method called En Passant mutagenesis changed amino acid P132 in the main protease to the variant found in Omicron strains. This new recombinant, attenuated viral system measures antiviral EC50 values, revealing how well drugs like nirmatrelvir (Paxlovid) and ensitrelvir (Xocova) work, as well as drug efflux.
For example, nirmatrelvir's potency enhances 50-fold by inhibiting the P-Glycoprotein (P-Gp) transporter using ritonavir or tariquidar, while ensitrelvir's potency remains unchanged. This system also permits the secure identification and examination of drug-resistant viral variants; Mpro M49L reduces ensitrelvir's effectiveness.
Overall, these systems offer secure, dependable, and quantitative methods for analyzing Mpro variants and testing drugs without the biosafety risks associated with using wildtype isolates.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
