Rhabdoviruses Flashcards
Genome type
(-)ssRNA
capsid type
helical
enveloped?
enveloped
segmented?
nonsegmented
What is absolutely required to be packaged for full replication?
Must include Large polymerase (L) and phosphoprotein (P) for primary transcription since (-)ssRNA
VAP (VSV and Rabies)
Glycoprotein (G)
Nucleoprotein (N)
coats the genome
What’s required for primary transcription?
Large polymerase (L) and phosphoprotein (P)
Matrix (M)
connects the nucleocapsid to the membrane
What is the representative virus?
Vesicular Stomatitis Virus (VSV)
Host receptor for VSV
LDL-R
Does the VAP do fusion too?
Yes, G protein also does fusion
Host receptor for rabies
G protein binds Nicotinic Acetylcholine Receptor (NAR) on neurons
How does the host receptor confer a wide host range for rabies?
Extremely large host range because acetylcholine is an essential neurotransmitter in many organisms so NAR is very conserved
What’s weird about plant rhabdoviruses?
They are enveloped and get it from inner organelle membranes
What are some benefits for studying VSV instead of rabies virus?
Less pathogenic
Faster gene expression
Large host range due to LDL-R
How does LDL-R make VSV a useful tool in biotech?
Most cells have LDL-R and the cells do a tasty test of the environment every ~10 min so easy entry
Replacing a virus envelope with VSV G enables broad tropism
What is the primary reservoir of rabies virus?
bats
What are the main terrestrial incidental hosts?
dogs, foxes, skunks, racoons
What about bats allows for them to be primary reservoirs for rabies?
Can sustain the virus population long term due to lower mortality rates
Can terrestrial incidental hosts spread rabies to other hosts? If so, why aren’t they considered primary reservoirs as well?
They can spread it but its too fatal to them to sustain the viral population
Understand the pathogenesis of rabies from when it enters the body from the bite of an infected animal all the way to death of the host
a. Virus is inoculated via bite or scratch
b. Replication in muscle tissue at inoculation site
c. Virus binds to NAR at the neuromuscular junction
d. Replication in motor neurons and it travels towards the CNS
e. CNS infection = symptoms
f. Spread to salivary glands
g. Coma
h. Death
Why is rabies virus spread through saliva?
Builds up in salivary glands since they’re so close to the brain and makes the saliva infectious
What’s the time between exposure and onset of first symptoms?
20-90 days so you have that long to get the vaccine and not die
Know what kind of vaccine Louis Pasteur’s rabies vaccine is.
Nerve-cell derived vaccine from dried rabbit spinal cord
Why have we gone away from these animal produced vaccines in favor of cell-culture-derived vaccine?
Myelin from neural tissue in the vaccine could cause fatal encephalitis sometimes
Inactivated vaccines are safer
What is the most common terrestrial host that spreads rabies to humans? What would be the best host to vaccinate to eradicate terrestrial rabies from an area?
Dogs, vaccine the dogs
