Lecture 39 - Virology Replication 1

Question 1

what are the 6 steps to viral replication

Answer 1

1. attachment
2. penetration
3. uncoating
4. biosynthesis
5. assembly
6. release

Question 2

what is TRUE of viral replication?

a. specifics of steps vary between viruses
b. specifics of steps determine pathogenesis
c. specific of steps determine antiviral strategies
d. all of the above

Answer 2

d. all of the above

Question 3

what do viral attachment proteins bind

Answer 3

cell receptors

Question 4

T/F: cell receptors are critical determinants of tropism

Answer 4

TRUE

Question 5

what would antivirals do to target the attachment step

Answer 5

block binding and therefore infection

Question 6

what are anti-virus antibody drugs

Answer 6

antibodies bind to virus

ex: rabies, zmapp (ebola)

Question 7

what are anti-cell antibody drugs? what is a potential downside?

Answer 7

antibodies bind to cell receptors

downside: inhibit normal function of cell

Question 8

what are excess soluble receptors? what is a potential downside?

Answer 8

free-floating antibodies bind virus

downside: dependent on concentrations

Question 9

what 2 locations does viral penetration occur?

Answer 9

1. cell surface
2. endocytosis

Question 10

T/F: penetration and uncoating always occur independently

Answer 10

FALSE

Question 11

what are the 3 steps of fusion penetration

Answer 11

1. activation of viral fusion protein
2. fusion of viral envelope w cell membrane
3. injection of contents into cell

Question 12

what 3 things can mediate fusion activation

Answer 12

1. cell protease activation
2. cell co-receptor activation
3. acid-induced change activation

Question 13

how can antivirals target viral fusion activation

Answer 13

by competing with specific cell co-receptors

Question 14

what is the disadvantage of drugs that target the virus

Answer 14

virus easily mutates to resistance

Question 15

what is the disadvantage of drugs that target the cell

Answer 15

disrupt normal cell functions

Question 16

how can we target the virus but reduce its mutating to resistance

Answer 16

1. target epitope
2. combo drugs increase resistance barrier
3. disrupt encoding of viral proteins

Question 17

if the virus needs to uncoat to access machinery for replication, it is brought intracellularly by a

Answer 17

endosome

Question 18

if viruses penetrate a cell directly at the cell surface, how are they activated

Answer 18

activation of fusion protein by protease, co-receptor, or acid

Question 19

what is viral uncoating

Answer 19

removal of the envelope and all or some viral protein to release nucleic acid/capsid for biosynthesis

Question 20

T/F: viral uncoating can be simultaneous with fusion or endosomal acidification

Answer 20

TRUE

Question 21

T/F: non-enveloped virus uncoating can occur only by endosomal proteases

Answer 21

FALSE - protease or acidification

Question 22

what does Pleconaril do

Answer 22

blocks uncoating by blocking conformational change