The major structural proteins of MHV virion include the spike glycoprotein (S) the envelope protein (E) the membrane protein (M) and the nucleocapsid protein (N). The largely immunologically mediated demyelinating disease in mice serves as an extensively investigated model for demyelinating diseases such as multiple sclerosis (MS) ( Weiss and Leibowitz, 2007, Das Sarma et al., 2000). Infection of C57Bl/6 mice with MHV-A59 causes mild encephalitis, sub-acute demyelination, and acute hepatitis ( Weiss and Leibowitz, 2007, Weiss and Leibowitz, 2011). MHV has been widely utilized as a model for viral pathogenesis, particularly the two most commonly studied strains of MHV, MHV-A59 and MHV-JHM. It includes large single and positive stranded RNA viruses that induce a spectrum of acute and chronic diseases of the neurological, gastrointestinal and respiratory system in animals and humans, such as the human pathogens SARS-CoV and HCoV-OC43 ( Weiss and Leibowitz, 2011). ![]() Mouse Hepatitis Virus (MHV) is a member of the family coronaviridae. ![]() Replacing proline 939 with the corresponding HCoV-OC43 residue, leucine, decreased the ability MHV to induce cell–cell fusion, providing experimental support for an earlier proposal that residues 929–944 make up the fusion peptide of the MHV S protein. Mutation of the cysteine in position 547 to alanine and alanine replacements at residues 581–586 was lethal. Although we were unsuccessful in isolating mutant viruses which were specifically defective in that property, we identified several mutations with interesting phenotypes. In this work we undertook a mutational analysis to attempt to identify specific amino acid sequences within the spike glycoprotein crucial for molecular mimicry of FcγRII. This molecular mimicry of FcγRII by the MHV S protein is also exhibited by other lineage 2a betacoronaviruses, with the exception of the human coronavirus HCoV-OC43. ![]() The MHV spike protein (S) is a major virulence determinant which in addition to binding to cellular receptors to mediate cell entry and facilitate virus spread to adjacent cells by cell–cell fusion, also is a molecular mimic of the FcγRII receptor. Mouse Hepatitis Virus (MHV) is a single-stranded positive sense RNA virus with the ability to promote acute and chronic diseases in mice.
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