L79 Flashcards

1
Q

What disease does rhinovirus cause? Transmission?

A

The common cold is transmitted by resp droplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are unique replication requirements of rhinovirus?

A

Prefers the cold

Nose > lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why does rhinovirus make asthma worse?

A

Turns on Th2 response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the rhinovirus genome - what is unique?

A

IRES = internal ribosome entry site
- Ribosome knows to start here, don’t need to scan the genome for start codon
Means rhinovirus RNA genome doesn’t need to be capped like human RNA does

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Rhinovirus pathogenesis - how does it change host cell processes? Where in the host cell does it replicate?

A

Infects nasal epithelium
Shuts off all host translation to push viral translation - preferential replication
RNA genome = replicate in cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does rhinovirus leave host cells

A

Lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the timeframe of rhinovirus cold - what immunity is responsible for clearing the cold?

A
0 = infected
Day 2 = viral peak in serum 
Day 3-4 = symptom peak
Day 5 = virus gone from serum 
Innate immunity clears - entire infection moves too fast for Ab to be produced/effective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why isn’t there a rhinovirus vaccine?

A

Too many strains - recombination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What bug causes flu?

A

Orthomyxoviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
Orthomyxoviridae genetics:
- or + 
ss or ds 
Helical or icosahedral capsid
Enveloped?
A

-ssRNA in 8 indep segments
Helical
Enveloped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where does Orthomyxoviridae replicate in host cells?

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which proteins are present on Orthomyxoviridae envelope?

A

HA

NA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe flu nomenclature:

A/California/07/2001 (H1N1)

A
A = type of flu (A, B or C)
Cali = where first isolated
07 = isolate #
2001 = year of isolation 
H1N1 = major HA & NA type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What receptor does flu bind to enter host cells?

A

HA + sialic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is the flu genome release after being endocytosed?

A

Endosome turns ACIDIC via M2 channel
HA triggered virus/endosome membrane fusion
Release genetic material alone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does Orthomyxoviridae leave host cells?

A

Bud off

17
Q

How does Tamiflu work?

A

Neurominidase inhibitor

Block the release of new virions

18
Q

How does flu effect ciliated epithelium?

A

Kills them

No cilia - mucus isn’t moving to clear infection

19
Q

What is antigenic drift?

A

Minor HA & HA variations year to year

Due to mistakes made by RNA pol

20
Q

What is antigenic shift?

A

If 2 flu viruses infect a person at the same time, the virus that buds out has a combo the RNA genomes of both
Genetic reassortment

21
Q

Pandemic: antigenic shift or drift?

A

Shift = pandemic

22
Q

Epidemic: antigenic shift or drift?

A

Drift = epidemic

23
Q

What aspect of Orthomyxoviridae would a universal flu vaccine target?

A

HA

24
Q

Which bugs fall under the umbrella of Paramyxoviridae? Which diseases do they cause?

A

RSV - pna & bronchiolits
Parainfluenza - croup
Mumps
Measles

25
Q

Paramyxoviridae
- or + RNA
Helical or icosahedral capsid?
Enveloped?

A

All have -ssRNA -> has viral RNA pol to transcribe viral genome on own
Helical
Enveloped

26
Q

2 major proteins on Paramyxoviridae envelope - describe the fxn of both

A

HN = binds sialic acid on ciliated epithelial cells
F protein = fusion
*Must be at NEUTRAL pH

27
Q

Which parainflu serotypes cause croup? What is croup?

A

Serotypes 1-3

Croup = distinct barking cough

28
Q

Which parainflu serotype causes bronchiolitis?

A

4

29
Q

How does Paramyxoviridae leave host cells?

A

Budding

Therefore envelope is derived from host cell membrane

30
Q

Where in the host cell does viral replication and assembly take place for Paramyxoviridae?

A

RNA virus –> cytoplasm

  1. Uncoat genome
  2. Viral RNA transcribed
  3. +sense amde
  4. Viral proteins through ER/Golgi –> surface
  5. RNA to PM site –> budding
31
Q

How does Paramyxoviridae interact with host immunity?

A

Inhibits innate immunity

Cells cant fight the infection against them –> increases spread

32
Q

Parainflu transmission

A

P2P - small infectious dose

33
Q

What 2 diseases does RSV cause?

A

Pediatrics:
Pna
Bronchiolitis

34
Q

Why do you know human metapneumo?

A

Causes diseases that look a lot like RSV - less severe