Lecture 39 - Virology Replication 1 Flashcards
what are the 6 steps to viral replication
- attachment
- penetration
- uncoating
- biosynthesis
- assembly
- release
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
d. all of the above
what do viral attachment proteins bind
cell receptors
T/F: cell receptors are critical determinants of tropism
TRUE
what would antivirals do to target the attachment step
block binding and therefore infection
what are anti-virus antibody drugs
antibodies bind to virus
ex: rabies, zmapp (ebola)
what are anti-cell antibody drugs? what is a potential downside?
antibodies bind to cell receptors
downside: inhibit normal function of cell
what are excess soluble receptors? what is a potential downside?
free-floating antibodies bind virus
downside: dependent on concentrations
what 2 locations does viral penetration occur?
- cell surface
- endocytosis
T/F: penetration and uncoating always occur independently
FALSE
what are the 3 steps of fusion penetration
- activation of viral fusion protein
- fusion of viral envelope w cell membrane
- injection of contents into cell
what 3 things can mediate fusion activation
- cell protease activation
- cell co-receptor activation
- acid-induced change activation
how can antivirals target viral fusion activation
by competing with specific cell co-receptors
what is the disadvantage of drugs that target the virus
virus easily mutates to resistance
what is the disadvantage of drugs that target the cell
disrupt normal cell functions
how can we target the virus but reduce its mutating to resistance
- target epitope
- combo drugs increase resistance barrier
- disrupt encoding of viral proteins
if the virus needs to uncoat to access machinery for replication, it is brought intracellularly by a
endosome
if viruses penetrate a cell directly at the cell surface, how are they activated
activation of fusion protein by protease, co-receptor, or acid
what is viral uncoating
removal of the envelope and all or some viral protein to release nucleic acid/capsid for biosynthesis
T/F: viral uncoating can be simultaneous with fusion or endosomal acidification
TRUE
T/F: non-enveloped virus uncoating can occur only by endosomal proteases
FALSE - protease or acidification
what does Pleconaril do
blocks uncoating by blocking conformational change
