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75 Cards in this Set
- Front
- Back
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what are required for a virus to aquire an envelope?
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transmembrane glycoproteins called peplomers
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what are small infectious RNA molecules that cause disease in plants? properties?
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viroids - no genes, does not encode proteins, replicates by viroid cRNA intermediate, does not need cellular DNA, dicer cuts siRNAs that disrupt host mRNA
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characteristics of prions?
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causes slow disease and a spongiform encephalopathy, maybe due to spontaneous mutation of the cell gene that encodes that protein or by transmission of the prion such as by contaminated meat, can convert the normal protein to the prion form, resistant to many things, no immune response
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diseases caused by prions in humans?
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creutzfeldt jacob,kuru, gerstsmann-straussler-scheinker, bovine spongiform enceph (mad cow), scrapie in sheep
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characteristics of DNA viruses?
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size varies from 2200bp to over350K bp!, can be linear or circular genomes, most are double stranded, some single, ALL only ONE DNA molecule, capsids are mainly icosahedral, can be complex NO helical, some have envelope but not all
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major viruses with a DNA genome?
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poxviridae, herpesviridae, adenovridae, papillomaviridae, polyomaviridae, parvoviridae (single stranded), hepadnaviridae (reverse DNA family), TT virus... (HHAPPPy viruses...)... note look at chart in first aid for strandedness and confirmation
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what circular DS DNA virus family have ORF's on both strands of their circular genome and overlap so that maximal info is achieved?
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polyomaviridae
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what DNA virus fam has multiple ORF's that overlap on both strands, is partially double stranded and has a 5' terminal protein on the negative DNA strand?
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hepadnaviridae
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what DS DNA virus is linear with two vivral proteins linked at each 5' end of the genome?
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adenoviridae
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what DS DNA virus has either 4 isomers or 2 isomers due to inverting repeats?
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herpesviridae
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what double stranded DNA virus is the largest genome of the animal viruses?
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poxviridae
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what DNA virus is SS DNA, associated with hep and has only two ORFs?
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TT
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what are the major regulators of txn in viruses?
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cis elements on the DNA and the trans factors that bind to them
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what DS linear DNA virus undergoes mRNA splicing?
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adenovirus
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what are the major RNA virus families?
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picornavirus, reovirus, togavirus, bunyavirus, orthomixovirus, paramyxovirus, rhabdovirus, arenavirus, coronavirus, retrovirus, calcivirus, flavirus, filovirus, astrovirus, deltavirus. (please remember that bc O'Cal prefers reflective audiences, catnappers repent! cogitate! forgo failure and disaster.)
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characteristics of RNA viruses?
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7500 to 35K NT's long, 4-12 proteins, MOST are only 1 RNA, some are segmented to multiple, most sre single stranded, only reoviridae are DS
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what RNA viruses have multi-molecule genomes?
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Arena (2), Bunya (3), Ortho (8), Reo (10,11,12), retro is diploid
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what are the plus stranded RNA viruses?
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astro, picorna, flavi, toga, corona, calici (pick cali ass to corona flava)
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what are all the negative stranded RNA viruses?
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rhabdo, paramyxo, orthomyxo, reo, arena, bunya, filo, and delta (aren't boonies filthy, disgusting ol' poo mixers of rabid rectums)
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describe the genome of picornaviridae...
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SS RNA (+), 1 protein made that is cleaved to others, 5'VPg and 3' poly A tail
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describe genome and protein of flavivirus
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hep C and yellow fever, enveloped, icosahedral, SS linear RNA (+), 5' cap, encodes one polyprotein.
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describe the genome of reoviridae.
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DS RNA, fragmented into 10-12 molecules, one strand is neg, other is pos, infantile diarrhea
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describe the genome of retroviridae
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2 molecules of SS RNA (it is diploid), 5' cap and 3'poly A, near 5' end is a molecule of cellular tRNA that is a primer to start synthesis of DNA from the genomic RNA. only 3 genes
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describe the viruses that use helical capsids?
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SS RNA genome, always enveloped, 1 species of viral protein, genome may be one or more molecules
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define pitch.
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distance between helical turns in a helical capsid virus
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length of the helical capsid is determined by what?
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size of SS RNA
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what type of bonds are between the repeated copies of the viral helical capsid protein and the genomic RNA?
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non covalent
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what RNA virus has helical capsid and H and F peplomers?
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paramyxo
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what RNA virus has 2 peplomers, M2 channel, matrix protein and 8 helical capsids?
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orthomyxo virus
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what virus (es) have one helical capsid and a matrix?
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paramyxo and rhabdo
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what RNA virus has one helical capsid and L and P proteins that are RNA polymerases?
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paramyxo
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what virus is a 1 SS RNA with an envelope and helical capsid?
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filovirus
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what virus has 1 SS RNA, big genome for RNA, large peplomers, matrix and envelope?
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coronavirus
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what virus has 3 SS RNA molecules with helical capsids and an envelope with peplomers?
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bunya
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describe the genome and envelope status of viruses that use an icosahedral capsule.
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DNA or RNA, envolope or no envelope
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how many edges, faces, and vertices do icosahedral capsids contain?
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30, 20, and 12
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if an icosohedral face is divided what is the structure called?
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icosadeltahedron containing capsomeres
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what virus uses an icosahedral capsule has a unique envelope with tegument?
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herpesviridae
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what virus has ~2000 protein molecules?
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herpes
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what kind of capsule do picornaviridae use?
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icosahedral
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how do capsid proteins arrange themselves around vertices? on faces?
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multiples of 5, multiples of 3
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poliovirus capsid proteins are arranged how? coxsackie?
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5 trimers of VP1, VP2, VP3, at each vertex. 5 VP2s at each vertex, and VP1, VP3 hexamers on the faces
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what virus is uses s double capsid icosahedral?
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reovirus?
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what RNA virus (es) uses an icosahedral capsid with no envelope??
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calcivirus, picorna, and astro
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what DNA viruses have no envelope, an icosahedral capsid, and 72 capsomeres?
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papilloma
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what virus has no envelope, an icosahedral capsid and fibers at each vertex?
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adeno
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what is the capsid and envelope status of hepadnaviridae?
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has envelope and icosahedral capsid
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describe complex symmetry capsids and the prototypical virus that uses it.
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brick shaped virion, several layers of envelope, core is dumbbell shaped, large DS DNA genome within the capsid
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what viruses did we learn about that use complex capsids?
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poxviruses and retroviruses
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where can viruses aquire envelopes and what does an envelope make the virion susceptable to?
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from golgi/ER complex, plasma membrane of cells, or from the nucleus (Herpes only)
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does the virus or the host encode peplomers? where are they glycosylated and what glycosylates them?
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viral encoded protein glycosilated in the ER/Golgi complex and will thus be susceptable to drying, detergents, soaps, disinfectants, high temps, etc
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what are some functions of specefic peplomers?
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both in influenza type A (orthomyxo), HA that must be cleaved that allows fusion activity. NA digests mucous in upper resp tract to allow virus to reach the epi cells.
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describe the F peplomer of paramyxovirus.
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Fusion peplomer that must be cleaved
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which viruses have matrix proteins and what is its purpose??
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some enveloped viruses and it binds the peplomers and capsids to give the virus structural integrity and serves a role in envelopment
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which virus has 12 fibers coming out from its vertices?
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adenovirus
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which virus traps ribosomes during envelopement?
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arenavirus
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what is the purpose of the M2 protein in Influenza type A and how can we exploit it?
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it is a channel that allows H+ ions to enter the endosome and cause uncoating by lowering the pH. treatment - amantadine binds and blocks M2
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what virus contain there own RNA transcriptase within the virion?
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all negative stranded RNA viruses
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which virus uses a unique dogma of DNA to RNA to DNA via a viral reverse transcriptase?
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hepadnavirus
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what are the theories of virus evolution?
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non joiner theory, retrograde evolution, cellular nucleic acid (originated from cells and spouted off)
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where do the viral pocks grow in the avian eggs? what are they good for creating?
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on the chorioallantoic membrane and they are good for vaccine production
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differentiate between the two types of cell cultures that can live beyond the primary culture and what are the uses of the cell culture?
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cell strain is not immortal and will die after about 50 passes, cell line is imortal. good for isolating viruses, quantitating, molecular studies, drug screens, antibodies for neutralization,, and vaccines`
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what are the four general ways to detect or quantify viruses?
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detect physical particles via electron micro or hemagglutination (do not need infectious virus), molecular assys for viral nucleotides or viral proteins, detect live infectious viruses via avian embryo (pocks) or cell culture (plaques), detect viruses as complex antigens
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describe how to interpret results of a hemagglutination assay.
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clear result means they hemagglutinated, find most dilute titer that caused hemagglutinatin and multiply that number by the number of virus particle to hemagglutinate the number of RBC's added
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do molecular assays for viral molecules tell you if the virus is infectious?
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no
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when taking serum samples to determine viral infection what is the first sample called? second sample?
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acute. convalescent. Need to show a four fold rise in antibody titer
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what are the immunologic ways of detecting viral infection?
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hemagglutination, EIA/ELIZA, neutralization, RIA, FAb, latex agglutination, and complement fixation
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when using hemagglutination to determine antibody presence, how are results interpreted?
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test dilutions of serum for ability to prevent the virus from causing RBCs to hemagglutinate, so more antibodies is indicated by less agglutination
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describe how to interpret complement fixation tests for viral detection.
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ok, commercial complement added to heated sera (inactivated endogenous complement) along with antigen of virus you are looking for. If sera has Ab's to the Ag it will bind the Ag and fix the comercial complement to it. Then add RBC-Ab + RBCs as indicator, if all the complement has been fixed to our original Ag+Ab then there will not be enough complement to bind to this new addition of RBC-Ab + RBC and thus the RBC's will not be lysed by complement. If there is no viral Ab in the serum then the commercial complement will be free to bind to the RBC-Ab and cause RBC lysis. Thus a positive test is no lysis and thus presence of viral Ab
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describe the RIA for detecting anti viral antibodies and its results...
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mix dilutions of sera with radio labelled viral antigen and centrifuge then measure CPM pellets that reflect the amount of antibodies present (thus the amount of radio antigens is the amount of antibody after centrifuge)
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describe the radio immuno assay for detecting antigen.
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add sera to anti viral antigen antibody, then add radiolabelled antigen, then add anti IG antibody, centrifuge and CPM, reduction in CPM (less radioactivity) means more antigen was present
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steps to screen for HIV?
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detect antibodies to HIV, EIA to detect Ab, if positive repeat it, if 2nd is positive do a western blot assay to show pt's serum has antibodies to two of the major HIV proteins
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describe the RIA for detecting anti viral antibodies and its results...
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mix dilutions of sera with radio labelled viral antigen and centrifuge then measure CPM pellets that reflect the amount of antibodies present (thus the amount of radio antigens is the amount of antibody after centrifuge)
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describe the radio immuno assay for detecting antigen.
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add sera to anti viral antigen antibody, then add radiolabelled antigen, then add anti IG antibody, centrifuge and CPM, reduction in CPM (less radioactivity) means more antigen was present
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steps to screen for HIV?
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detect antibodies to HIV, EIA to detect Ab, if positive repeat it, if 2nd is positive do a western blot assay to show pt's serum has antibodies to two of the major HIV proteins
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