Rhabdoviruses

Question 1

Genome type

Answer 1

(-)ssRNA

Question 2

capsid type

Answer 2

helical

Question 3

enveloped?

Answer 3

enveloped

Question 4

segmented?

Answer 4

nonsegmented

Question 5

What is absolutely required to be packaged for full replication?

Answer 5

Must include Large polymerase (L) and phosphoprotein (P) for primary transcription since (-)ssRNA

Question 6

VAP (VSV and Rabies)

Answer 6

Glycoprotein (G)

Question 7

Nucleoprotein (N)

Answer 7

coats the genome

Question 8

What’s required for primary transcription?

Answer 8

Large polymerase (L) and phosphoprotein (P)

Question 9

Matrix (M)

Answer 9

connects the nucleocapsid to the membrane

Question 10

What is the representative virus?

Answer 10

Vesicular Stomatitis Virus (VSV)

Question 11

Host receptor for VSV

Answer 11

LDL-R

Question 12

Does the VAP do fusion too?

Answer 12

Yes, G protein also does fusion

Question 13

Host receptor for rabies

Answer 13

G protein binds Nicotinic Acetylcholine Receptor (NAR) on neurons

Question 14

How does the host receptor confer a wide host range for rabies?

Answer 14

Extremely large host range because acetylcholine is an essential neurotransmitter in many organisms so NAR is very conserved

Question 15

What’s weird about plant rhabdoviruses?

Answer 15

They are enveloped and get it from inner organelle membranes

Question 16

What are some benefits for studying VSV instead of rabies virus?

Answer 16

Less pathogenic

Faster gene expression

Large host range due to LDL-R

Question 17

How does LDL-R make VSV a useful tool in biotech?

Answer 17

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

Question 18

What is the primary reservoir of rabies virus?

Answer 18

bats

Question 19

What are the main terrestrial incidental hosts?

Answer 19

dogs, foxes, skunks, racoons

Question 20

What about bats allows for them to be primary reservoirs for rabies?

Answer 20

Can sustain the virus population long term due to lower mortality rates

Question 21

Can terrestrial incidental hosts spread rabies to other hosts? If so, why aren’t they considered primary reservoirs as well?

Answer 21

They can spread it but its too fatal to them to sustain the viral population

Question 22

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

Answer 22

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

Question 23

Why is rabies virus spread through saliva?

Answer 23

Builds up in salivary glands since they’re so close to the brain and makes the saliva infectious

Question 24

What’s the time between exposure and onset of first symptoms?

Answer 24

20-90 days so you have that long to get the vaccine and not die

Question 25

Know what kind of vaccine Louis Pasteur’s rabies vaccine is.

Answer 25

Nerve-cell derived vaccine from dried rabbit spinal cord

Question 26

Why have we gone away from these animal produced vaccines in favor of cell-culture-derived vaccine?

Answer 26

Myelin from neural tissue in the vaccine could cause fatal encephalitis sometimes

Inactivated vaccines are safer

Question 27

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?

Answer 27

Dogs, vaccine the dogs