Virologie Flashcards
2 smallest human infecting viruses
hepadnaviruses, circoviruses
largest sort of viruses that infects humans
herpesviruses
why are RNA viruses mostly small ?
because RNA is unstable
to what family does smallpox virus belong? and give the following of this family: is it enveloped, is it segmented, DNA or RNA?
- family: Poxviridae
- enveloped
- unsegmented
- dsDNA
what is a characteristic for dsDNA viruses, that poxviruses don’t have
normally they replicate in the host nucleus, poxviruses have their own machinery and replicate in the cytoplasm
how are non enveloped viruses released from a host cell
cell lysis
which 2 receptors does HIV bind on a T cell
CCR5 & CD4
give 6 examples of arboviruses
- Yellow fever virus (YFV)
- dengue fever virus (DFV)
- chikungunya virus (CHIKV)
- west nile virus (WNV)
- Zika virus (ZIKV)
- japanese encephalitis virus (JEV)
(all are flaviviruses, except for CHICKV; togavirus)
how do arboviruses spread?
via insects and ticks
which reservoire do Culex (mosquito) transmitted arboviruses have and what do they cause
- avian reservoire
- encephalitis
(e. g., WNV)
which reservoire do Aedes (mosquito) transmitted arboviruses have and what do they cause
- primate reservoirs
- haemorrhagic disease
how does a linear +ssRNA look like at its 3’ and 5’ ends
- 3’ –> no polyA tail but loop formation
- 5’ –> methylated nucleotide cap (to allow translation), or a genome linked protein (VPg)
what 3 structural proteins does dengue virus encode
- capsid (C)
- membrane (M)
- envelope (E)
what does CHIKV cause, and is it fatal
- arthritis
- no
what do CHIKV, ZIKV, DENV, YFV have in common, spread wise?
they all spread via Aedes mosquitoes
by what type of mosquito does WNV spread?
Culex species
what do SARS-CoV-2 and HCoV-NL63 have in common
they both infect ACE2+ epithelial cells
give genome and virus type of HIV
genome: RNA
virus type: retrovirus
what structure protects Reverse Transcriptase and Integrase?
capsid: made of gag proteins
what protein limits HIV viral DNA insertion in the genome
viral rev protein
what are the 2 envelope proteins in HIV
glycoproteins (gp) 120 & 41
what is the difference between simple and complex retroviruses
both have: gag-pol-env sequence
but complex has additional accessory proteins
difference latent and lytic infection
latent = silent; few replication lytic = active; much replication
what type of herpesvirus is varicella zoster virus (VZV), which 2 diseases does it cause and which is the primary infection
- alpha herpesvirus
- varicella –> primary infection
- herpes zoster –> secondary infection
what compound makes EBV oncogenic and which pathways can it interfere with
- latent membrane protein 1 (LMP1)
- MAPK, JNK, PI3K, NF-kB
where does gamma herpesvirus HHV-8 settle and how is it transmitted
oral cavity, transmitted via saliva
difference HHV-6 and 7
HHV-7 can’t integrate into host genome, because it lacks U94
how and which cells does norovirus infect
- intestinal bacteria
- binds to: membrane, pili, or HBGA
what is the role for FUT2 in norovirus spread
individuals who lack FUT2 are known as non-secretors, because HBGA A/B/C are not present in their bodily secretions
what is HBGA made of and what is it
- glycans expressed on surface of cells
- noro- and rotavirus receptors
how do A, B & H HBGAs form?
- FUT2 adds fucose group to HBGA precursors
- this generates H HBGA
- from H HBGA, A & B HBGAs can be formed
in which 2 genotypes are rotaviruses divided
- G : glycoprotein (VP7)
- P : protease sensitive protein (VP4)
what type of virus is rabies virus
enveloped -ssRNA
in which 2 ways can RABV infect neurons
- via muscle: binds nAchR, replicate, spread to neuron
2. direct: bind NCAM or p75NTR on nerve cell
which 2 vaccines are used for RABV
- live attenuated vaccine (animals)
2. inactivated vaccine (humans & pets)
what kind of virus is poliovirus
picornavirus
nonenveloped +RNA virus
what is the most frequent viral infection in mankind?
picorna infection
what is measles virus for kind of virus
enveloped non segmented -ssRNA
what is characteristic for measles surface proteins
high similarity (only 1 serotype)
what receptors does MV bind to
- CD150
- Nectin-4
- CD46
describe the 3 stages in MV infection
- infection, following latent period of 2 weeks for replication
- MV infected cells migrate to lymph nodes, where CD150+ cells are infected. immune cells infect nectin-4+ epithelial cells resulting in T cell response –> skin rash
- nectin-4+ cells in respiratory tract release new virions
which 3 neurological complications can come with MV infection
ADEM, MIBE, SSPE
what MV vaccination is given
live attenuated genotype A strain
