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76 Cards in this Set
- Front
- Back
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Who discovered the 1st cancer causing virus? |
Peyton Rous (rous sarcoma virus) |
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What are the 6 viruses known to cause cancer? |
Hep B, Hep C, HPV, Epstein-Barr, Kaposi's Sarcoma-Associated Herpesvirus, and Human T-lymphotropic virus |
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Which DNA tumor virus was discovered by Richard Shope and he observed tumors on rabbits? |
Rabbit Fibroma |
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How do DNA tumor viruses differ from RNA tumor viruses? |
Structure, genome organization/replication strategies, and oncogenes of DNA tumor viruses are essential viral genes in replication. |
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Which DNA tumor virus is small, icosahedral symmetry, no envelope, over 100 serotypes, (2 cause cancer), and has a circular double stranded genome? |
Human Papillomavirus
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How does HPV replicate? |
In nucleus of metabolically active basal epithelial cells of skin. |
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Which 2 HPV serotypes cause cancer? |
16 & 18 |
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How is HPV detected? |
PCR, sequence analysis for serotype determination |
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What is the supposed co-factor with HPV for cervical cancer? |
HSV-2 because of the recurrent inflammation it brings due to genital herpes. |
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Which herpes virus causes Burkitt's lymphoma? |
Epstein Barr virus |
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Which cancer virus is associated with chromosomal translocation of the c-myc oncogene from 8 to 14? |
Epstein Barr |
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What condition other than Burkitt's Lymphoma is caused by Epstein Barr virus? |
Nasopharyngeal Carcinoma |
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Which cancer causing virus is due to human herpes virus 8? |
Kaposi's Sarcoma |
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Who are at most risk for developing Kaposi's sarcoma? |
Elderly men in of Mediterranean/Middle East and 50% of homosexual men. |
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Which cancer causing virus causes hepatocellular carcinoma? |
Hep B Virus |
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Which vaccine is the 1st to prevent cancer? |
Hep B vaccine |
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Can Hep C cause hepatocellular carcinoma? |
Yes but from a different mechanism than Hep B |
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What are the 3 main protein groups of RNA tumor virues? |
Gag (capsid), Pol (reverse transcriptase), Env (envelope) |
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How do RNA tumor viruses replicate? |
Attachment of envelope to receptor. Membrane fusion/entry. Uncoating. Reverse transcription causes RNA to double stranded DNA and it enters the cell nucleus. DNA inserted into host chromosome. Transcription of viral genes/oncogenes. |
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How can a virus accidentally pick up a proto-oncogene? |
1. provirus disintegrates from host chromosome & bring neighboring cell gene along 2. Mistakes during transcription 3. Progeny retrovirus include v-onc gene |
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Which retrovirus is endemic in japan/south america/Caribbean, infects CD-4 lymphocytes, and is transmitted via breast milk, placenta, or female to male sexual contact? |
HTLV-1 |
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Which disease caused by HTLV-1 is a cancer of the CD4 T-lymphocytes caused by viral tax proteins activating cellular interleukin 2 which causes abnormal cell growth and usually death? |
Adult T-cell Leukemia |
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Which retrovirus is found in a lot of the human genome but hasn't been proven to cause cancer due to defective viral sequences? |
Human Endogenous Retrovirus |
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What virus has been associated with obesity? |
Human Adenovirus 36 |
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Which virus is icosahedral, enveloped (has spikes), 2 copies of ssRNA (+) genome, has tRNAs that bind to each copy and act as reverse transcriptase, and has several accessory genes? |
HIV |
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How is HIV a weird RNA virus? |
Includes replication in the cell nucleus |
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What cells does HIV infect? |
CD4 (lyses too), CD8, macrophages, natural killer cells, nervous system cells, and dendritic cells. |
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What are the major receptors and co-receptors that enable HIV attachment? |
Major: CD4 & Macrophages Co: CXCR4 & CCR5 |
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What structure allows for the conformational changes which causes co-receptors to anchor the virus into membrane and pulls in for fusion? |
gp120 & gp41 spikes |
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What serves as a primer and initiates DNA synthesis for HIV? |
tRNAs |
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What is the final product of DNA synthesis? |
dsDNA flanked by long terminal repeat sequences |
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What integrates the HIV viral genome into the host cell's DNA? |
integrase protein (p32) |
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In HIV-1 what is proviral DNA transcribed from? What is it transcribed into and by what? |
a single promoter in 5' LTR viral RNA by RNA Pol 3 |
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How are HIV-1 viral particles assembled and released? |
They are assembled at budding sites at the plasma membrane--> gag and pol proteins are cleaved to form mature virus particle. Released by budding. |
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What are the 3 phases of infection by HIV-1? |
1. Primary HIV-1 infection 2. Chronic asymptomatic phase 3. Clinical AIDS |
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How is HIV diagnosed? |
ELISA test that is confirmed with Western Blot. |
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How is HIV-1 managed? |
CD4 T lymphocyte counts & virus-load monitoring |
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What are the common antivirals for HIV? |
Zidovudine (some resistance has emerged) Highly Active Retroviral Therapy uses 3 compounds at least at the same time (generally effective) |
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what are the 5 classes of HIV antiviral therapy? |
1. Non-nucleoside/nucloside reverse trancriptase inhibitors 2. Protease Inhibitors 3. Fusion Inhibitors 4. Integrase inhibitors 5. CCR5 Blocking Inhibitor |
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What are the 3 distinct groups of HIV? |
M (major), O (outlier), and N (nev) |
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What is the difference between HIV-2 and HIV-1? |
Typically less pathogenic, found more in Central Africa, and is rare in the U.S. |
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Some people seem to be born with resistance to HIV. Which gene is this associated with? |
CCR5 gene is missing 32 base pairs so it creates a truncated protein that isn't detectable in cell's surface so HIV can't attach |
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What type of virus causes Marburg and Ebola Viruses? |
Filoviruses |
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What is the Marburg virus? |
First encountered in 1967. Workers unknowingly exposed to infected chimps. Caused a hemorrhagic fever. |
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What are the 5 strains of the Ebola virus? |
Zaire, Sudan, Bundibungyo, Tai Forrest, Reston |
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Which is the only deadly Ebola strain in humans? |
Zaire |
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How does Ebola infect the body? |
Attacks/infects dendritic cells and monocytes causing them to secrete cytokines--> cytokine storm causing fever, increase vascular permeability, rash, hemorrhage, liver infection, multiple organ failure, and immune system collapse. |
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What are the initial symptoms and symptoms of acute disease? |
I: headache, fever, sore throat, muscle aches A: vomiting, diarrhea, skin rash, and internal bleeding |
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What treatments are given to Ebola patients? |
Supporting care. ZMapp is an experimental antiviral. |
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Which slow virus causes progressive mutlifocal leukoencephalopothy? |
JC papovavirus |
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What is progressive mutlifocal leukoencephalopothy? |
Found in immunosuppressed/AIDS patients. Infect oligodendrocytes. Presents with confusion, dementia, altered speech/vision, loss of coordination, no inflammation, paralysis and death. |
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Which slow virus disease is caused by the measles virus and causes gradual personality/behavioral/intellectual changes, mocyclical jerks, spasticity, blindness & death? |
Subacute Sclerosing Panencephalitis |
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What prion disease was studied by Dr. Gadjusek in New Guinea? |
Kuru |
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What are the 3 stages of Kuru? |
1. Ambulant: unsteady gait/voice/hands/eyes, tremors/shivering, slurred speech, loss of coordination. 2. Sedentary: can't walk w/o support, higher severity tremors, laughter outbursts, depression/mental slowing 3. Terminal: can't sit w/o help, incontinence, difficulty swallowing, death |
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Which prion disease has symptoms of progressive atxia, tremors, severe itching, and death and causes rod-like fibers in the brain tissue? |
Scrapie |
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Which prion disease has an incubation period upward of 30 years, presents as personality changes, decrease intellectual abilities, vision problems, myoclonal jerks, ataxia, & death within 9 months? |
Creutzfeldt-Jakob Disease |
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How is CJD diagnosed? |
Clinical signs and EEG abnormalities. |
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Which prion disease presents as unsteady gait, aggressiveness, issues getting up/down, itching, anorexia, excessive licking, and spans 2-6 months before death? |
Mad Cow Disease |
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Which prion disease causes its target animal to exhibit dramatic weight loss, blank expression, excessive drooling/thirst, sluggish behavior, isolation, and poor coats? |
Chronic Wasting Disease |
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What type of virus was discovered by Martinus Beijenicnk? |
Plant viruses (tobacco mosaic precisely) |
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How does infection via plant cells vary from animal? |
Plant cells have to typically be wounded before they can be infected |
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Contrast vertical and horizontal transfer? |
H: plant to plant V: parent to offspring |
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How are viruses transmitted via soil? |
They're present in soil which acts as an abrasive and infect via wind/rain action or through damaged roots |
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What are the symptoms of a plant virus? |
Dwarfing, leaf curling, reduced yield, fruit distortion, chlorosis, color deviations/mosaic patterns/rings, wilting/withering, necrosis, & bark scaling. |
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How are plant viruses diagnosed? |
electron microscopy, inclusion bodies, cell culture, ELISA for viral antigens, DNA/RNA probes |
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How to plant viruses appear morphologically? |
1. long, helical flexuous 2. rigid helical 3. short ALL are rods, all naked |
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What are the major genome types of plant viruses? |
+ ssRNA, dsRNA, ssDNA, and dsDNA |
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What are the disadvantages of a segmented genome? |
all segments need their own particle & single cell has to take all of those up or it won't produce an infection. |
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Due to lack of lysis what happens once a plant is infected with a virus? |
It is forever infected |
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What virus infects tobacco, is the most studied, has a wide variety of hosts, is helical, no envelope, ssRNA (+), is very stable, and self-assembles? |
Tobacco Mosaic virus |
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How does tobacco mosaic virus replicate? |
Has replication complexes that increase in size on the ER in association with the cytoskeleton so it can move through the cell via plasmodesmata.
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What are the symptoms of tobacco mosaic virus? |
light green color between veins, mosaic pattern, dead leaves, and stunted plants |
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What is tobacco mosaic virus's host range and transmission mechanism? |
can infect up to 500 flowering plants (peppers, tobacco, tomatoes, and potatoes mainly). Mainly spread crop to crop via mechanical mechanism. Cigarettes/cigars can also contribute. |
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Which cassava virus is ssDNA, only in africa, transmitted via white fly, most damaging, and causes leaf mosaic chlorosis/leaf distortion/stunting? |
Cassava Mosaic |
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Which cassava virus is + ssRNA, filamentous, in africa but causes severe chlorosis/necrosis of leaves and brown streaks on stems, and causes the cassava to become inedible? |
Cassava Brownstreak |
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Which plant virus occurs in citrus, is +ssRNA, transferred via aphids/grafting and presents as defoliation, small/poor fruit, stunting, decline/death, and is caused by starvation of the roots? |
Citrus Tristeza Virus |
