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13:04
A Protocol for Analyzing Hepatitis C Virus Replication
Published on: June 26, 2014
24.2K
Hepatitis C Virus Down-Regulates the Expression of Ribonucleotide Reductases to Promote Its Replication
Chee-Hing Yang1, Cheng-Hao Wu2, Shih-Yen Lo2,3
1Department of Microbiology and Immunology, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan.
Pathogens (Basel, Switzerland)
|July 29, 2023
Summary
Hepatitis C virus (HCV) down-regulates cellular ribonucleotide reductases (RRMs) to boost its replication. Inhibiting RRMs or knocking down RRM1/RRM2 enhances viral RNA replication, suggesting a novel viral strategy.
Area of Science:
- Virology
- Molecular Biology
- Biochemistry
Background:
- Ribonucleotide reductases (RRs) are essential for DNA synthesis by converting ribonucleotides (NTPs) to deoxyribonucleotides (dNTPs).
- While DNA viruses utilize viral RRs, the interaction between cellular RRs and RNA viruses like Hepatitis C virus (HCV) is poorly understood.
- Mammalian RRs consist of RRM1 and RRM2 subunits.
Purpose of the Study:
- To investigate the role of cellular ribonucleotide reductases (RRMs) in Hepatitis C virus (HCV) replication.
- To determine how HCV infection affects the expression of RRM1 and RRM2 subunits.
- To explore the impact of RRM modulation on HCV replication and identify viral factors involved.
Main Methods:
- Analyzing RRM1 and RRM2 expression in HCV-infected cells (Huh7.5 and Huh7 with HCV subgenomic RNAs).
- Measuring NTP/dNTP ratios in HCV-infected and RRM-knockdown cells.
- Assessing the effect of RRM knockdown (RRM1 or RRM2) and RRM inhibitors (Didox, Trimidox, hydroxyurea) on HCV replication.
- Investigating the role of HCV proteins (NS5A, NS3/4A) in regulating RRM expression.
Main Results:
- HCV infection down-regulates the expression of cellular RRM1 and RRM2 in cultured cells.
- HCV infection leads to an elevated NTP/dNTP ratio.
- Knockdown of RRM1 or RRM2, as well as treatment with RRM inhibitors, enhances HCV replication.
- HCV NS5A and/or NS3/4A proteins were identified as suppressors of RRM expression.
Conclusions:
- Hepatitis C virus actively down-regulates cellular ribonucleotide reductase expression to promote its own replication.
- This down-regulation is mediated by viral proteins NS5A and/or NS3/4A.
- Targeting cellular RRMs presents a potential avenue for antiviral strategies against HCV.
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