英文版 六年制总-3 Viralinfection,06。3.ppt

Section II Viral Infection and Pathogenicity  I. The pathogenesis mechanism of viral infection (I). virus – cell interactions: 1. cytocidal effect杀细胞感染 virus which infect and replicate within cells causing the cells to lyse when the progeny virions are released. Cytopathic effecte, CPE Normal cell 2. steady state infection稳定状态感染: viruses are produced from the infected cells but the cells are not killed by the process. --- integration of viral Ag in cell membranes. --- cell fusion. , produce multinucleated giant cells, such as CMV ： 3. inclusion body包涵体 inclusion bodies：round, oval, or irregular-shaped bodies occurring in the cytoplasm and nuclei of virus-infected cells, as in disease caused by filtrable virus infection such as rabies, smallpox, herpes, etc. 4. cell apoptosis 细胞凋亡 viruses have the potential to initiate or stay the onset of programmed cell death through the manipulation of a variety of key apoptotic proteins of the host cell. Such as HIV, adenovirus. 5. integration and cell transformation 基因整合与细胞转化: integration: integration of the viral genome into cellular DNA . cell transformation: the introduction of inheritable changes in a cell causing changes in the growth phenotype and immortalization. Infection with oncogenic viruses cause cell malignant transformation. The oncogenic virus associated with human tumors HBV --- hepatocellular carcinoma HPV --- cervical carcinoma HSV-II ----- cervical carcinoma? EBV --- Burkitt lymphoma , nasopharyngeal carcinoma HCV --- hepatocellular carcinoma HTLV --- T cell leukemia virus – immune system interaction: immunopathological reactions: killing of virus-infected cells by the attack of cytotoxin T cells; formation of virus-antibody complexes that are deposited in tissues. 2. the injury of immune system induced by virus infection: Viral infections are often immunosuppressive, e.g. measles viruses, HIV Auto-immunity can be induced by viral infections III. The pathways of vi