Poliovirus mutant that does not selectively inhibit host cell protein synthesis

Area of Science:

• Virology
• Molecular Biology
• Cellular Biology

Background:

• Poliovirus infection typically inhibits host cell translation.
• This inhibition is crucial for efficient viral replication.
• The precise mechanisms, including P220 cleavage, are under investigation.

Purpose of the Study:

• To investigate the role of a specific poliovirus mutation in host cell translation inhibition.
• To understand the consequences of impaired translational control on viral replication.
• To elucidate the involvement of P220 cleavage in poliovirus-induced inhibition.

Main Methods:

• Generation of a poliovirus type I (Mahoney strain) mutant via cDNA insertion.
• Analysis of viral replication, plaque formation, and protein synthesis in infected cells (HeLa and CV-1).
• Assessment of host cell translation inhibition and P220 cleavage.

Main Results:

• The mutant virus produced small plaques and exhibited reduced viral protein synthesis.
• Mutant-infected cells showed impaired selective inhibition of host cell translation.
• Cleavage of the cap-binding complex protein P220 did not occur in mutant-infected cells.
• Mutant virus yielded low progeny virus titers despite normal RNA replication in CV-1 cells.

Conclusions:

• Wild-type poliovirus actively inhibits host cell translation and avoids early self-inhibition.
• P220 cleavage is critical for the selective inhibition of host cell mRNA translation by poliovirus.
• The mutant's phenotype provides insights into poliovirus replication strategies and host-pathogen interactions.