07-病毒学virus巴斯德研究所.ppt

Virus and host cell interaction and pathogenesisPaul ZhouInstitut Pasteur of Shanghai General consideration of virus and host cell interaction Importance A key understanding of virus replication An insight into basic cellular and molecular biology mechanisms A lead to understanding causes for viral pathogenesis A lead to the definition of antiviral strategies A lead to the better viral vectors for gene delivery Levels Molecular and cellular level Within a host organism spread from one cell to another In environment transmission among individual organisms Outcomes of viral infection of a cell Nonproductive infection – no viral replication and host cell survival with or without viral genome persistent as episomal DNA or integrated into host genome (potential oncogenesis and/or latent infection) Nonproductive infection – no viral replication but non-survival of host cell Productive infection results in cell death Productive infection without cell death (chronic infection) Cytopathic effects of virus infection Effect on host cell DNA replication Inhibit host cell DNA synthesis To provide the precursors for viral DNA synthesis such as vaccinia in cellular DNA degradation To provide host cell structure and replication proteins for viral DNA synthesis such as HSV can displace cellular DNA from nuclear cage and recruit cellular replication proteins to viral structure As a secondary effect of inhibiting cellular protein synthesis such as HSV and adenovirus Induce host cell DNA synthesis Induce host cell into S phase such as SV40 T antigen and adenovirus E1A and E1B Maintain viral DNA Integrate viral DNA into host cell chromosomes such as retrovirus Maintain viral DNA as an extra-chromosomal circular molecule such as EBV, HHV8, and KSAV in latently infected cells Effect on host cell RNA transcription and export Inhibition of cellular transcription and export DNA viruses compete for pol II polerase and transcription factors and inhibit Inhibit RNA exporting: Adenovirus