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MLT-DNA Virus I
Virology
Question | Answer |
---|---|
What are the 3 sub families of Human Herpesviridae? | 1.Alphaherpesvirinae 2.Betaherpesvirinae 3.Gammaherpesvirinae |
What are the examples of Alphaherpesvirinae and and growth rate? | Herpes simplex virus 1 and Varicella zoster virus, fast-growing |
What is the example of Betaherpesvirinae? | Cytomegalovirus, grow slowly |
What is the example of Gammaherpesvirinae? | Epstein Barr virus, poor replicating |
What is the structure of Herpesviridae? (ppt p.8) | 1.dsDNA 2.Icosahedral capsid 3.Amorphous tegument protein 4.Pleomorphic envelope |
DNA replication & encapsidation of Herpesviridae occur in host ________? | Nucleus |
dsDNA genome replicates by viral ______ polymerase? | DNA |
Gene expression by host RNA pol but regulated by _________? | viral factor |
What are the three proteins involved in immediate early, early and late transcription and translation stages of Herpesviridae? | 1.Immediate early: Alpha proteins 2.Early: Beta protein 3.Late: Gamma protein |
What are the function of alpha proteins? | As transcription factors |
What are the 2 function of beta proteins? | 1.enzymes for synthesis of nucleotides 2.enzymes for viral DNA replication |
What is the function of gamma proteins? | structural proteins for virus assembly |
What are the two kinds of viral infection? | 1.Productive infection 2.Latent infection |
What are the 3 examples of production infection? | 1.Cytocidal 2.Intranuclear inclusion 3.Syncytia |
In latent infection, Herpesviridae will be presist in the nuclei of _______ or ________ in the form of _______? | 1. neurons or lymphocytes 2. episome |
At the site of epidermal infection, virus is phagocytosed by ___A_____ & ______B_____; the viral antigen is then presented on dendritic cells & macrophages to ____C_____ T cells? | A.dendritic cells B.macrophages C.CD4 |
Epithelial infection is cleared but some viruses escapes & invade the local sensory neurones, how HSV escape antibody surveillance? | 1.binding of viral gE & gI to Fc receptor of IgG 2.protect HSV against immunological attack |
Viruses are transported to & establish latency in the _______ or _______? | spinal or cerebral ganglion |
What could reactivate Viruses? | 1.Immunosuppression 2.UV 3.Stress 4.Age |
What would be caused by HSV-1and example? | Oropharyngeal Herpes, herpes labialis (cold sore) |
What would be caused by HSV-2 and example? | Genital herpes |
What can be used to treat HSV? | Acycloguanosine (Acyclovir) |
How does Acyclovir work? | 1.Act ac analogue of GTP 2.Inhibit viral DNA polymerase |
What are the 2 most universal diseases caused by Varicella zoster virus? | 1.varicella (chicken pox) in child 2.zoster (shingles) in elderly |
What is life threatening Varicella zoster virus spp in adults? | Varicella pneumonia |
What would be given to pregnant women who has contacted a varicella case a few days before/ after delivery and to the baby as well? | ZIG (zoster immune globulin) |
Where would the Epstein Barr virus do replication? | Inside epithelial cells of nasopharynx & salivary glands |
What is the gene of EBV would be activated to immortalize the infected B cell? | EBNA-2 |
What would be caused by EBV infection in Cantonese and Eskimos? | Nasopharyngeal carcinoma |
What would be caused by EBV infection in African children? | Burkitt’s lymphoma |
What is the mechanism of Burkitt’s lymphoma? | 1.Translocation of c-myc(chr8) to Ig gene(chr14) 2.uncontrolled B cell proliferation & arrest differentiation |
EBV is spread through _______, ________, ________ and ________? | saliva, respiratory aerosol and utensils |
Cytomegalovirus is a __________ pathogen? | opportunistic |
Human Herpesvirus 8 is associated with the development of _________ in AIDS patients? | Kaposi’s Sarcoma |
What is the transmission route of Kaposi’s Sarcoma in AIDS patients | Sexually transmitted |