Term
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Definition
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Term
|
Definition
| icosahedral (outer) and helical (inner) |
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Term
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Definition
| 2 identical copies of +ssRNA ONLY VIRUS WITH DIPLOID GENOME +ssRNA's have a cap, poly A tail and 2 untranslated regions and repeat seq at each end and a gag, pol and ENV region |
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Term
| rotavirus polymerases make... |
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Definition
|
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Term
| unusual things about rotavirus = |
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Definition
1. only virus with diploid genome
2. only RNA virus that goes into vell and doesnt immediately start replicating
3. only viral RNA to be synth and replicate dby host enzymes |
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Term
| viral reverse transcriptase makes... |
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Definition
| ...dsDNA from +ssRNA This DNA is called cDNA (complimentary DNA) |
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Term
| viral reverse transcriptase has what polymease activity? |
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Definition
| RNA dependant DNA pol activity and DNA dependent DNA pol activity |
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Term
| where does viral reverse transcriptase bind to viral +ssRNA? |
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Definition
| the middle and repeated regions of +ssRNA bind = big circle of +ssRNA |
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Term
| can reverse transcriptase of +ssRNA occur in vitro? |
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Definition
|
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Term
| does retrovirus nucleocapsid contain everything it needs for reverse transcriptase of +ssRNA? |
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Definition
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Term
| reverse transcriptase of +ssRNA into ds cDNA occurs in... |
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Definition
| ...viral capsid = no IFN response/induction |
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Term
| what happens to cDNA of rotavirus? |
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Definition
several copies of cDNA are intergrated into host genome at random loci by viral integrase enzyme
all this time virus is invisible to immune system!!
NOt really random as can only insert cDNA where host cell DNA is unwound (and therefore active) |
|
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Term
| whats in rotavirus icosahedral nucelocapsid? |
|
Definition
2 identical strands of +ssRNA
integrase
reverse transcriptase
protease
nucleoprotein (helical capsid containing +ssRNA) |
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Term
| untranslated sequnecs at end of virus gene = |
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Definition
| promoters (strong if need alot of that protein, weak if dont) |
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Term
| once cDNA in host cell DNA get synth of cDNA into mRNA by... |
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Definition
| ...host cell mRNA pol = synth of new virus proteins and genome |
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Term
| exit of rotavirus from cell = |
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Definition
| budding from host cell surface |
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Term
|
Definition
viral genes that promote tumour development
-DONT have introns
-expressed out of their normal cellular context
-under control of strong viral promoters
-have high freq of mutations (due to cutting and pasting by viral integrase)
-generated during reverse transcriptase of +ssRNA |
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Term
|
Definition
1. promote virus growth
2. promotion of host cell growth genes = incr growth |
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Term
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Definition
| strong viral promoters inserted close to cellular oncogenes may induce overexpression of the cellular oncogene |
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Term
|
Definition
1. replication-competent
2. replication-defective rapidly transforming
3. replication-competent rapidly transforming
4. trans-acting
5. endogenous retrovirus (ERV) |
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Term
| what class of retrovirus doesnt have pol gene? |
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Definition
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Term
| rous sarcoma virus is what type of retrovirus? |
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Definition
| replication-competent rapidly transforming |
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Term
|
Definition
| effects expression of genes |
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Term
|
Definition
| effects transcription of genes |
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Term
| which class of retrovirus doesnt have any promoters? |
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Definition
|
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Term
| what can activate replication of ERV? |
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Definition
irradiation
mutagen
immune stimulus
other retroviruses nearby with promoters |
|
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Term
| name a transacting retrovirus |
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Definition
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Term
| viral transcription factor genes = |
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Definition
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Term
| what limits replicating-competent rapidly transforming retrovirus? |
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Definition
| its very big = constraint on virus = more likely to make mistakes and get mutations on replication |
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Term
| what limits replicating-competent rapidly transforming retrovirus? |
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Definition
| its very big = constraint on virus = more likely to make mistakes and get mutations on replication |
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Term
|
Definition
|
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Term
|
Definition
| ...ERV (rarely expressed, not pathogenic) |
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Term
|
Definition
exogenous virus
replication competent
no v-onc
cis-acting(slow forming)
cause dz sporadically in birds |
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Term
| infection with avian retrovirus = |
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Definition
transient viraemia
immunity
leukaemia (rare) |
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Term
| vertical transmission of retrovirus in poultry results in... |
|
Definition
...immune tolearnt chicks
-chronic virameia
-leukaemia (common)
-spreads infection to rest of flock |
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Term
| dz of avian retrovirus depends on... |
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Definition
| ...what cell type is infected (causes incr in this cell type/ growth) |
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Term
| most common dz caused by retrovirus in birds = |
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Definition
B cell lymphoblastoma
occurs following insertion of virus close to c-myc oncogene, which encodes a cellular transcription factor |
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Term
|
Definition
healthy chick
no viraemia
no leukamia
chick may not be immunotolerant to virus as virus isnt expressing any genes |
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Term
|
Definition
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Term
| infection of FeLV occurs in... |
|
Definition
| ...high density cat populations via resp, groomiing or bites |
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Term
| FeLV infection in adult cat = |
|
Definition
immune response and celar infection
neutralising Abs stop spread
cytotoxic Tcells
cant get rid of cell with viralDNA integrated into genome though!! |
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Term
| FeLV is what class of retrovirus? |
|
Definition
| replication-competent (no oncogene, cis-acting0 |
|
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Term
| infection of preg queen or newborn kittens = |
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Definition
50% of kittens = immune response and clear virus
50% of kittens = no immune response, persistant viral infection, immunotolerant = shed virus all the time and can develop tumours |
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Term
|
Definition
Feline Oncovirus Cell Mb Ag
an oncovirus that can cause cancer |
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Term
| FOCMA is an ENV gene product of what class of FeLV? |
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Definition
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|
Term
| lymphocytes ifected with virus containing FOCMA = |
|
Definition
| express FOCMA on cell surface |
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Term
| infection of immune cats with FeLV = |
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Definition
| self limitng as cat got Abs against viral Abs and FOCMA non-viraemic |
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Term
| FeLV infection of immunotolerant cats = |
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Definition
perisitant infection with viraemia
no Abs against viral Ags or FOCMA
carriers
(thereofre cant detect FeLV by looking for Abs) |
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Term
| 3 antigenic types of FeLV are recognised based on their ENV glycoprotein. WHat are these? |
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Definition
|
|
Term
| most common types of FeLV = |
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Definition
|
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Term
| what FeLV is present in all cases of FeLV> |
|
Definition
|
|
Term
| which FeLV is most readily transmitted? |
|
Definition
|
|
Term
|
Definition
| ...thiamine transport protein 1 (THTR1)-commonly expressed on replicating cells |
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Term
| most commonly FeLV A causes... |
|
Definition
...lymphosarcomas (=30% of feline tumours)
-thymic
-multicentric
-alimentary |
|
|
Term
| what other dz can you get with FeLV A? |
|
Definition
| myeloproliferative dz - XS BM prolif |
|
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Term
|
Definition
recombinant of FeLV A ENV genes with ENV genes of ERV = change R
new R = Pit1(or 2) phosphate transporter |
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Term
| FeLV B can only be transmitted with... |
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Definition
| ...FeLV A and dies out after passage |
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Term
| combined infectiond of FeLVA and FeLVB = |
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Definition
| more rapid ds progression |
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Term
|
Definition
| FeLVA mutaion of ENV GP70 = change R = haem exporter |
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Term
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Definition
| rapid and fatal anaemia as attacks RBCs |
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Term
| what FeLV is NOT transmitted? |
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Definition
|
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Term
|
Definition
detection of virus Ag in blood or serum via ELISA test
(Abs no gd for detection of FeLV as can get immunotolerant cats) |
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Term
|
Definition
|
|
Term
| how do fibrosarcomas in yound cats develop from FeLV? |
|
Definition
| FeLV oncogene fuses with gag protein and is inserted into cell mb = development of multicentric fibrosarcomas |
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|
Term
| feline sarcoma virus is what class of retrovirus? |
|
Definition
| replication-defective rapidly transforming retrovirus |
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|
Term
| feline sarcoma virus manages to survive and replicate due to... |
|
Definition
| ...packaging/ infection along with FeLV A |
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Term
|
Definition
| testing and removing infected cats from catteries to decr spreading, espec queens (due to vertical transmission) |
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Term
|
Definition
| 1. cell culture derived glycoprotein 70, FOCMA AG (from FeLVA) 2. E. coli expressed subunit vacc - leucogen 3. recombinant canary pox virus (big genome so can manipulate alot so can put FeLV in genoma so poxvirus expresses gp70 = viral specific immune response :)) -canary poxvirus doesnt grow well in mammals :) |
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Term
|
Definition
| ovine pulmonary adenomatosis (Jaggsiekte) |
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Term
| where is ovine pulmonary adenomatosis found in the world? |
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Definition
| everywhere except australia |
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|
Term
| ovine pulmonary adenomatosis causes... |
|
Definition
| ...neoplastic transformation of type II alveolar cells and non-cliated bronchial epi cells |
|
|
Term
| do beta retrovirus have oncogenes? |
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Definition
|
|
Term
| ENV protein of beta retrovirus binds to... |
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Definition
|
|
Term
|
Definition
| enzyme on surface of many types of cells |
|
|
Term
| Jaggsiekte/btea retrovirus ENV protein acts as an...... |
|
Definition
| ... oncogene through binding to phosphatidylinositol 3-kinases (PI3), espec when in lung cells |
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Term
| effected sheep AB RESPONSE TO beta retrovirus = |
|
Definition
| NO Ab response to ENV protein, as the presence of closely related ERV causes the sheep to be immunotolerant to the jaagsiekte virus |
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Term
|
Definition
| not usually expressed and dont bind to PI3 = lack transforming properties |
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Term
| why is there tolerance to ERV and thereofe exogenous jaagsiekte retrovirus as well? |
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Definition
| ERV ENV protein is expressed in placenta where it may have an imp function in development of multinucleated trophoblast cells essential fro implantation = essentail for sheep breeding! Explaining the development of tolerance to ERV and thereofre jaagsiekte virus too |
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Term
|
Definition
|
|
Term
| following of intro of jaagsiekte virus into herd dz incidence can be as high as... |
|
Definition
|
|
Term
| how many sheep become affecte by beta retrovirus in endemic flock? |
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Definition
|
|
Term
| beta retrovirus is v common in what breed of sheep? |
|
Definition
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|
Term
| clinical signs of jaagsiekte = |
|
Definition
breathlessness
lung sounds
large amount of pulm fluid (wheelbarrow test) |
|
|
Term
| adenocarcinomas/adenomas = |
|
Definition
secrete large amounts of surfactant
metastisize to LNS |
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|
Term
| test for proviral DNA of beta retrovirus = |
|
Definition
| PCR - amplifies LTR (long tandem repeat seq = gd as wont get false + result when just got ERV as ERV has no repeat seq/promoter regions) |
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|
Term
| in beta retrovirus infected flock many sheep have virus in peripheral blood lymphocytes than have lung lesions and dont get tumours, despite lack of Ab response. Why is this? |
|
Definition
| expression of mutant gag proteins from some ERVs disrupts assmebly and exit of mature wild type/virulent virus and thereofre limits spread in lungs and prevents tumour development |
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Term
|
Definition
FIV
maedi/visna
carpine arthritis
equine infectious anaemia |
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|
Term
|
Definition
|
|
Term
| how many healthy cats are + for FIV Abs? |
|
Definition
|
|
Term
| how many sick cats are + for FIV Abs? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| infection of FIv can occur by... |
|
Definition
...fighting
transplacental infection
at parturtion if mum viraemic |
|
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Term
|
Definition
|
|
Term
|
Definition
| activated CD4+ Thelper cells |
|
|
Term
| acute phase I of FIV (2months) = |
|
Definition
viraemia
infection spreads to more CD4+Tcells
replication
fever
malaise
lymphadenopathy (dz of LNs) |
|
|
Term
| initial immune response to FIV = |
|
Definition
Ab production and cytotoxic CD8+Tcells = reduce no of infected CD4+Tcells and apparent clinical recovery
BUT CD4+Tcells containing provirus (incorporated into host cell genome) cant be eliminated :( |
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Term
| Phase II of FIV (may last several yrs) |
|
Definition
mutation of virus epitopes allows it to escape CD8+Tcells
gradual derc in CD4+Tcells
recurrent cycles of expansion, immun elimination, mitation and expansion again..... |
|
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Term
|
Definition
impaired immune function:
-decr IL2
-decr Ab
-decr blastogenesis
-decr CMIR
=immunodeficiency and predisposition to opportunistic pathogens |
|
|
Term
| Phase III of FIV infection = |
|
Definition
-onset of symptoms due to immunosupression associated with opportunistic infections
-high freq fever, gingivitis and mouth ulcers
-strong association with FeLV and Bcell lymphomas
-neuro signs if astrocytes and microglial cell infection predominates (rare) |
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|
Term
|
Definition
|
|
Term
|
Definition
AZT = inhibit Reverse transcriptase
(partially effective) |
|
|
Term
|
Definition
| no effective vacc :( as virus persists in the presence of Ab and cytotoxic resposne |
|
|
Term
|
Definition
maedi/visna caprine arthritis/encephalitis equine infectious anaemia/swamp fever
FIV |
|
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Term
|
Definition
| monocytes and monocyte precursors |
|
|
Term
| infected monocyte activation = |
|
Definition
| activate virus replication |
|
|
Term
|
Definition
late onset
lifelong infection |
|
|
Term
|
Definition
-chronic inflam/fibrosis induced by infected monocytes
-breathlessness
-consolidation of lungs
-enlarged bronchial LNs
-hyperplasia of alveoalar septae
-monocyte infiltartionof alveolar septae |
|
|
Term
|
Definition
chronic demyelinating encephalitis with moncyte infection
rare |
|
|
Term
| why does maedi/visna persist in presence of Ab and CMIR? |
|
Definition
| poss due to constant mutation |
|
|
Term
| transmission of maedi/visna = |
|
Definition
-to lambs in mums colostrum
-aerosol (from symptomatic sheep)
-biting insects = mechanical vectors |
|
|
Term
|
Definition
eradication of...
...symptomatic sheep
...sero+ sheep
...PCR + sheep |
|
|
Term
| similar virus to maedi/visna seen in goats = |
|
Definition
| caprine arthritis/encephalitis |
|
|
Term
| caprine arthritis/encephalitis causes |
|
Definition
| proliferative synovitis lesions with lymphocyte, plasma cell and moncyte infiltration |
|
|
Term
| caprine arthritis/encephalitis spread in... |
|
Definition
|
|
Term
| kids infected with caprine arthritis/encephalitis develop... |
|
Definition
|
|
Term
| what lentivirus is a notifiable dz in UK? |
|
Definition
| equine infectious anamia/swamp fever |
|
|
Term
| equine infectious anamia infects |
|
Definition
|
|
Term
| equine infectious anamia signs = |
|
Definition
-freq assymptomatic, therefore hard to eradicate
-virulent strains of equine infectious anamia cause:
acute viraemia
anaemia
thrombocytopaenia |
|
|
Term
| pathology of equine infectious anamia infection - |
|
Definition
| cyclical. virus escapes immunity and causes dz, then immunity gets on top, then escapes immunity again etc...... |
|
|
Term
| prognosis of equine infectious anamia = |
|
Definition
| partial recovery with time |
|
|
Term
|
Definition
| looking for Abs in blood to test for equine infectious anamia |
|
|
Term
| vacc for equine infectious anamia? |
|
Definition
chinese attenuated vacc: to get over 1st phase, but then persistently infected
only china uses this vacc as other countries trying to eradictae equine infectious anamia |
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|
