L28: Virology

Question 1

____: Infectious, obligate, intracellular parasites

Answer 1

Viruses

Question 2

___ ___ derived from host cell harboring viral spike protein, which makes coronaviruses susceptible to hand sanitizers

__ is a viral attachment protein involves in receptor binding and fusion – major vaccine candidate

Answer 2

Lipid Envelope

Spike

Question 3

Why is the spike a good vaccine candidate?

Answer 3

1. Specific to virus that infects us
2. Outside of virus - easily recognized

Question 4

Coronavirus binds to ___ on host cells

Answer 4

ACE-2

Question 5

True or False: Genetic changes associated with antigenic drift happen continually over time

Answer 5

True

Question 6

ANTIGENIC SHIFT
____: occurs when two closely related viruses infect the same cell. The resulting shift causes abrupt change.

Example: Flu virus from animal population gains ability to interact with humans

______: can occur in ss nucleic acid viruses; when AT LEAST two viral genomes co-infect same host cell and exchange genetic segments

Answer 6

Ressortment

Recombination

Question 7

True or False: While viruses change all the time due to antigenic drift, antigenic shift happens less frequently

Answer 7

True

Question 8

True or False: Coronavirus has segmented genome

Answer 8

False - has a 1 single long stranded genome

Question 9

True or False: Coronavirus can use mechanism of recombination

Answer 9

true

Question 10

All major Sars-CoV-2 variants of concern contain a specific mutation ____, which results in enhanced binding affinity to _____, which cleaves spike + involved in virus internalization

Which type of evolution is this an example of?

Answer 10

D614G
TMPRSS2 (on host cell)

CONVERGENT evolution!!

Question 11

Mutation ____ on the spike protein allows virus to bind tighter to human cells, making new variants more contagious

Answer 11

N501Y

Question 12

True or False: E484K mutation may make it easier to re-infect someone who has been vaxxed

Answer 12

True

Question 13

Why was omicron less able to cause disease?

Answer 13

• less efficient replication
• many mutations

Question 14

True or False: Delta was associated with increased transmissibility and more severe disease

Answer 14

True

Question 15

True or False: Coronavirus genome is slowly mutation, has relatively stable genome

Answer 15

True

Question 16

Coronavirus has a proofreading mechanism, which means the mutation rate is lower than influenza and, therefore, subject to less __ ___

Answer 16

antigenic drift

Question 17

True or False: While infected individuals can produce variants, most do not survive. Only a few virions go on to infect another person – therefore, populations change relatively SLOW during ‘normal infections’

Answer 17

True - bottleneck effect

Question 18

IC patients do not clear infections - what does this allow for?

Answer 18

Continued selection for viruses capable of evading IR

Question 19

Where do pathogenic viruses come from?

Answer 19

1. Recombination or reassortment (Emergent Virus)
2. Zoonoses *
3. Disease Emergence

Question 20

True or False: All severe coronaviruses trace recent evolutionary history to bats

Answer 20

True

Question 21

___ ___: A primary pathology of COVID, in which there’s a combo of inflammation, development of thrombosis in lung capillary + systemically

Answer 21

Cytokine Storm

Question 22

Which host response contributes to flu-like symptoms seen with COVID?

Answer 22

Interferons

Question 23

True or False: Covid can suppress body’s ability to make interferons

Answer 23

True

Answer 24

Question 25

How do antibodies escape?

Answer 25

Mutations in the receptor binding domain of the spike protein reduce binding affinity of neutralizing antibodies to epitope on proteins