Sendai virus fusion activity as modulated by target membrane components

Area of Science:

• Virology
• Membrane Biology
• Biochemistry

Background:

• Sendai virus fusion is crucial for viral entry and replication.
• Erythrocytes and erythrocyte ghosts are commonly used model systems to study viral fusion.
• Understanding the factors influencing fusion efficiency is key to deciphering viral mechanisms.

Purpose of the Study:

• To compare the suitability of erythrocytes and erythrocyte ghosts as target membranes for Sendai virus fusion studies.
• To investigate the impact of prebinding and target membrane composition on fusion activity.
• To elucidate the roles of target membrane proteins and sialic acid residues in Sendai virus-mediated fusion.

Main Methods:

• Continuous monitoring of Sendai virus fusion using R18-labeled virus and fluorescence dequenching.
• Experiments conducted with and without virus/target membrane prebinding.
• Treatment of target membranes with proteinase K and neuraminidase to assess the role of proteins and receptors.

Main Results:

• Fusion activity was significantly higher with erythrocyte ghosts compared to intact erythrocytes, despite similar viral binding.
• Prebinding virus to target membranes in the cold enhanced fusion kinetics.
• Proteinase K treatment inhibited fusion, indicating a role for target membrane proteins.
• Neuraminidase treatment reduced viral binding by removing sialic acid but had minimal impact on the fusion process itself.

Conclusions:

• Erythrocyte ghosts are more effective target membranes than intact erythrocytes for studying Sendai virus fusion.
• Target membrane proteins are involved in the fusion process, while sialic acid residues are primarily involved in viral binding.
• Optimized experimental conditions, such as prebinding, can enhance fusion efficiency and provide rapid insights into viral fusion mechanisms.