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48 Cards in this Set
- Front
- Back
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What are some diseases that Herpesviruses are responsible for
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Herpes simplex (fever blister)
Herpes zoster (chicken pox and shingles) Infectious mononucleosis Burkitt's lymphoma Nasopharyngeal carcinoma Childhood exanthema Kaposi's sarcoma Pleural effusion lymphoma |
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What virus family can be identified by the presence of double-stranded DNA in the core of the virion, and an icosahedral capsid containing 162 capsomeres assembled in the nucleus. The outer envelope is derived from nuclear membrane of the host. Relatively unstable at room temperature
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Herpesvirus family
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What three viruses are in the Herpesvirus alpha group
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HSV-1 Herpes simplex virus
HSV-2 VZV Varicella-zoster virus |
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What three Herpesviruses are in the Beta group
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CMV cytomegalovirus
HHV-6 Human herpesvirus HHV-7 |
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What two Herpesviruses are in the gamma group
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EBV Epstein-Barr virus
KSHV/HHV-8 Kaposis's sarcoma herpes virus or human herpes virus 8 |
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What Herpesvirus group has variable host range, relatively short reproductive cycle and is effective in the destruction of the infected cells. They also establish latency primarily in sensory ganglia
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Alpha group
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What herpesvirus group has a restricted host range, with a long reproductive cycle and the infected cells are frequently enlarged
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Beta group
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What Herpesvirus group efficiently infects lymphocytes and frequently enters latency after infection, resulting in the transformation of the cells
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Gamma group
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What does the herpesvirus tegument do
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It contains a trans-activator which turns on immediate early genes
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What virus causes labial lesions (cold sores), skin lesions, keratitis, and encephalitis
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HSV-1
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What virus causes genital lesions, severe diseases in neonates, during pregnancy, and in immunocompromised patients
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HSV-2
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What virus causes chicken pox (primary) and shingles or zoster (recurrence)
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VZV
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What virus is a major cause of birth defects (mental retardation), deafness, causes mononucleosis-like syndrome and causes retinitis, colitis and life-threatening pneumonitis in immunosuppressed patients
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HCMV
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What virus causes infectious mononucleosis and has a strong associating with Burkitt's lymphoma, nasopharyngeal carcinoma and lymphoproliferative disorders--polyclonal or monoclonal B-cell lymphoma (in immunosuppressed hosts), also hairy oral leukoplakia, a productive infection
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EBV
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What two viruses cause roseola infantum
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HHV-6
HHV-7 |
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What virus is a simian virus indigenous to Asian monkeys that can result in fatal encephalopathy in humans
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Herpes simiae (Herpes B)
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Do all herpesviruses establish latency
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Yes
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What virus docks by first binding to heparan sulfate molecules on the cell surface, then viral glycoproteins on the envelope associate with cell surface proteins, resulting in fusion of the virus envelope to the cellular membrane and entry of the capsid
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HSV
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What is the cell receptor for EBV
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CD21. Binding of EBV to cell surface receptors can induce cell signaling and activation which facilitates expression of cellular genes required for transcription, DNA replication, and virus production
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What is the temporal organization in replication and temporal transcription of HSV
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Immediate early genes (alpha) are expressed before the onset of protein synthesis, and delayed early (Beta) genes and late (gamma) genes, which require protein synthesis for their expression.
Alpha gene products turn on Beta gene products, which in turn activate gamma gene expressions, but at the same time shut off alpha gene expressions |
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What does the VP16 component of HSV do
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It serves as a transciptional factor to turn on alpha gene products
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What is unique about immediate early mRNA expression in Herpesviruses
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It requires no viral protein synthesis and proceeds in the presence of protein synthesis inhibitors
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What type of proteins do delayed early genes usually encode
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Proteins that are involved in DNA replication
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What type of genes are conserved in all herpesviruses
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Delayed early genes
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Where does Herpesvirus assembly take place
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In the nucleus of the infected cells
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What viral gene product can switch the EBV from latent to lytic
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Zebra or Zta. It is a trans-activator and may be a useful anti-viral target to prevent reactivation of EBV
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Where is HSV latency established
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Neurons. Virus enters axon and undergoes retrograde transport to the neuron's nucleus
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Where does HSV-1 latency occur
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Neurons in trigeminal and cervical ganglia
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Where does HSV-2 latency occur
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Neurons in sacral ganglia
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Where does VZV latency occur
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Neurons and non-neuronal cells in sensory ganglia, trigeminal and dorsal root ganglia
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Where does EBV latency develop
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B-lymphocytes
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Where does CMV latency occur
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Monocytes/macrophages and endothelial cells
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Where does HHV-6 latency occur
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Monocytes, CNS, Salivary glands
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Where does HHV-8 latency occur
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B-cells, vascular endothelial cells/spindle cells (KS tumors), prostate glands, saliva
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What are some things that can induce Herpes virus latency reactivation
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Tissue injuries, hormones, stress, and temperature, most likely via a transcriptional switch
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How is HSV-1 transmitted
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Close personal contact (mucosal surfaces/abraded skin)
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How is HSV-2 transmitted
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Close personal contact, sex
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How is VZV transmitted
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Airborne respiratory droplets, contact with lesional skin
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How is CMV transmitted
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During child delivery (perinatal infection), through breast feeding, close personal contacts, blood transfusion, organ transplantation
Primary infection during the first six months of pregnancy poses the greatest danger to the fetus via transplacental infection |
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How is EBV transmitted
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Salivary exchange, respiratory aerosols
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How is HHV-6 transmitted
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Intra-familial, mother to child, saliva
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How is KSHV/HHV-8 transmitted
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Sexual intercourse, whole blood transfusion, organ transplantation
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How does Acyclovir prevent Herpes infection
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Viral Thymidine kinase phosphorylates it, where it becomes ACG-ppp and inhibits viral DNA polymerase
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What is Acyclovir used for
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Recurrent HSV and VZV infection
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What antiviral is used in life-threatening CMV infection in immune-compromised patients
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Ganciclovir. It may cause neutropenia and thrombocytopenia
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What do Phosphonoacetic acid (PAA) and Phosphonofomate (PFA, Foscarnet) inhibit
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Herpes DNA polymerase
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What is Foscarnet used for
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HSV and CMV infection
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What two Herpes viruses don't have effective therapies available
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EBV and HHV-8/KSHV
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