Picornaviruses Flashcards
What type of genome are picornaviruses
Small +ve sense RNA viruses
7.4kb long
Describe structure of picornaviruses
Non-enveloped
30nm in diameter
Composed of 60 protomers forming a symmetrical icosahedral particle
Each protomer is made of 4 proteins
What are the celullar receptors for picornaviruses
Type 1 glycosaminoglycans
What is at the 5’ end of the genome
THE IRES
How do picornaviruses shut down host protein synthesis
Viral Protease 2A cleaves the cap structure of mRNA that are needed to initiate synthesis
How many species of enterovises are there
13
Enterviruses A-J
Rhinoviruses 1-3
What gene mutant causes less MHC presentation and therefore less B cell destruction
IFH1 gene defects
4 variants of this gene reduce the chance of developint T1DM
What % of polio is asymptomatic
95%
What % of polio causes CNS infection
0.3-1%
What is the live attenuated polio virus called and what type of immunity does it induce
SABIN
IgA mucosal and IgG immunity
What is the inactivated polio virus called and what type of immunity does it induce
SALK
IgG humoral immunity
In 2011 what 4 countries still had a polio epidemic
India
Pakistan
Afghanistan
Nigeria
When was there an outbreak of polio in Nigeria
2003
Spread to 8 Polio free countries
What receptors does the rhinovirus access throguh
ICAM-1 and LDL receptors
What % of rhinoviruses are symptomatic
2/3
10-20% also get a febirle illness
Name the broad spectrum vaccine that aims to work against enteroviruses and rhinoviruses
Pleoconaril
What is the link between rhinovirus and asthma
90% of children who had a severe rhinovirus infection before the age of 3 had developed asthma by the age of 6
What mediates recovery from rhinovirus
Unlikely to mediated by Ab or cellular immune response as it takes a week to produce Ab
What IgG can cause protection
IgA and IgG
IgA appears most important and it decreases after time
What do antivirals targeting rhinovirus generally target
the capsid
what is a problem with antivirals for rhinovirus
Problems with optimal administration to the nasal mucosa
What % of viral hepatitis worldwide is caused by hep A
90%
How long is the hep A incubation period
2 weeks
What is the Ab response rate to the Hep A virus
> 95% vaccinees have a protective antibody response by 2-4 weeks
What % of people vaccianted with the Hep A virus within 2 weeks of infection can be prevented from getting Hep A
85%
