[Effect of remantadine on the deproteinization of influenza viruses in infected cells]
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Abstract:
The effect of remantadine on penetration of influenza virus (the WSN strain) structures into MDCK cells was studied. Autoradiography of remantadine-treated cells infected with 3H-uridine-labeled virus showed remantadine to block the penetration of the parental viral structures from the perinuclear cytoplasm into the nuclei resulting in the structures aggregating in the perinuclear cytoplasm. Biophysical analysis of the viral structures recovered from the cells and analysis of their proteins by polyacrylamide gel electrophoresis showed that in remantadine-treated cells the amount of virus nucleoids (ribonucleoproteins, RNP, surrounded by a layer of M protein) increased in the perinuclear bytoplasm while the amount of intranuclear viral plasm while the amount of intranuclear viral RNPs decreased. These data suggest that the effect of remantadine is due to blocking of the second stage of deproteinization, that is, deproteinization of viral nucleoids to viral RNPs occuring in the perinuclear cytoplasm (possibly, on nuclear membrans); remantadine did not affect penetration of viral structures into the cells or the first stage of deproteinization (formation of nucleoids from virus particles). In order to inhibit deproteinization of viral structures remantadine should be present in the process of infection and be added soon after innoculation. When added 30 min after inoculation, remantadine has no effect on the intracellular distribution of viral structures.
Insights
Remantadine blocks influenza virus (WSN strain) RNP deproteinization in MDCK cells, preventing nuclear entry. This antiviral effect requires early drug administration during infection.
Area of Science:
- Virology
- Cell Biology
- Antiviral Research
Context:
- Influenza virus infection involves complex intracellular transport and uncoating mechanisms.
- Understanding viral entry and deproteinization is crucial for developing effective antiviral therapies.
- MDCK cells are a standard model for studying influenza virus replication.
Purpose:
- To investigate the effect of remantadine on the intracellular penetration and deproteinization of influenza virus structures in MDCK cells.
- To elucidate the specific stage of viral deproteinization inhibited by remantadine.
- To determine the optimal timing for remantadine administration to achieve antiviral efficacy.
Summary:
- Remantadine treatment inhibited the penetration of influenza virus structures from the perinuclear cytoplasm into the nucleus of MDCK cells.
- Biophysical and biochemical analyses revealed that remantadine blocks the deproteinization of viral nucleoids into ribonucleoproteins (RNPs) in the perinuclear cytoplasm.
- The drug did not affect initial viral entry or the formation of nucleoids from virus particles, indicating a specific inhibition of the second deproteinization stage.
Impact:
- These findings suggest remantadine acts by preventing the uncoating of viral RNPs, a critical step for viral replication.
- The study highlights the importance of early administration of remantadine during the infection process for its antiviral activity.
- This research provides insights into the mechanism of action of remantadine and informs the development of new influenza antiviral strategies.