Distinct Attenuation Phenotypes Caused by Mutations in the Translational Starting Window of Theiler’s Murine Encephalomyelitis Virus
Autor: | Nadine Jarousse, Vadim I. Agol, Ekaterina G. Viktorova, Elena V. Khitrina, Michel Brahic, Evgeny V. Pilipenko, Maslova Sv |
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Rok vydání: | 1999 |
Předmět: |
Picornavirus
viruses Molecular Sequence Data Immunology Genome Viral Biology Microbiology Ribosome Virus Mice Theilovirus Virology Protein biosynthesis Animals Base Sequence RNA Translation (biology) biology.organism_classification Internal ribosome entry site Phenotype Protein Biosynthesis Insect Science Mutation Pathogenesis and Immunity |
Zdroj: | Journal of Virology. 73:3190-3196 |
ISSN: | 1098-5514 0022-538X |
DOI: | 10.1128/jvi.73.4.3190-3196.1999 |
Popis: | Upon initiation of translation of picornavirus RNA, the ribosome is believed to bind the internal ribosome entry site of the template and then to form a productive complex with a downstream RNA segment, the starting window. The presence or absence of an AUG triplet within the starting window of the RNA of Theiler’s murine encephalomyelitis virus (a picornavirus) is known to modulate its neurovirulence. In this study, mutants of this virus in which the starting windows, lying upstream of the viral polyprotein reading frame, had AUGs with different nonoptimal contexts were engineered. Upon intracerebral inoculation of mice, the mutants proved to be partially attenuated, as judged by a significant increase in the dose causing paralysis in 50% of the animals (PD 50 ). Mutants with similar PD 50 s might differ from one another by eliciting either a severe, fatal tetraplegy or only mild, recoverable neurologic lesions. Some of the mutants triggered a chronic inflammatory reaction in the white matter of the spinal cord in the absence of detectable viral RNA or antigen. Thus, point mutations changing the context of an AUG within the starting window outside the polyprotein reading frame may differently affect the morbidity and mortality caused by a viral infection and may result in distinct attenuation phenotypes. |
Databáze: | OpenAIRE |
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