Related Experiment Videos
Influenza virus uncoating in infected cells and effect of rimantadine
Abstract:
Uncoating of influenza virus (strain WSN) in MDCK cells was studied by following the fate of the virus labelled with radioactive precursors. The accumulation of subviral components of input virus was observed in nuclear-associated cytoplasm (NAC) obtained by treatment of the nuclei with citric acid. Two types of subviral components were found there, ribonucleoproteins (RNPs) and larger subviral particles (SVP) containing RNPs in association with M protein. SVP, with different relative amounts of M protein, were revealed in NAC, suggesting that M protein was gradually released from RNPs. The released RNPs entered the nuclei while M protein accumulated within perinuclear membranes. Thus, SVP could be regarded as probable intermediates in virus uncoating. Rimantadine prevented the release of M protein from RNPs and their penetration into the nuclei provoking the accumulation of subviral components in NAC.
Insights
This study reveals how influenza virus components uncoat within host cells. Subviral particles (SVPs) appear to be intermediates, with M protein gradually separating from ribonucleoproteins (RNPs) during uncoating.
Area of Science:
- Virology
- Cell Biology
Background:
- Influenza virus uncoating is a critical early step in infection.
- Understanding the precise mechanisms of viral component release is essential for developing antiviral strategies.
Purpose of the Study:
- To investigate the uncoating process of influenza virus (strain WSN) in Madin-Darby canine kidney (MDCK) cells.
- To identify intermediate structures and molecular events during influenza virus uncoating.
Main Methods:
- Radioactive labeling of influenza virus (strain WSN).
- Isolation of nuclear-associated cytoplasm (NAC) from infected MDCK cells using citric acid treatment.
- Analysis of subviral components within NAC using biochemical methods.
Main Results:
- Accumulation of subviral components, including ribonucleoproteins (RNPs) and larger subviral particles (SVPs), was observed in NAC.
- SVPs contained RNPs associated with M protein, with varying M protein amounts, suggesting gradual M protein release.
- Released RNPs entered the nucleus, while M protein accumulated in perinuclear membranes.
- Rimantadine treatment inhibited M protein release and RNP nuclear entry, causing subviral component accumulation in NAC.
Conclusions:
- Larger subviral particles (SVPs) are likely intermediates in influenza virus uncoating.
- The uncoating process involves the sequential release of M protein from RNPs, followed by RNP nuclear entry.
- Rimantadine interferes with influenza virus uncoating by blocking M protein release and RNP nuclear translocation.