Flashcards in RNA Viruses Deck (371)
what is the smallest RNA virus
What is the structure of picornavirus
Naked, + icosahedral ssRNA
Where does picornavirus replicate?
what is the picornavirus capsid made of?
60 copies of NON-GLYCOSYLATED proteins
how does picornavirus enter the cell?
What does a + genome mean?
the genome acts as mRNA
What does a - genome mean?
the genome is complementary to the mRNA that will eventually be made
What are picornaviruses released from the cell?
What does poliovirus use as a receptor?
What do most other picornaviruses use as a receptor?
What part of the picornavirus capsid binds to the receptor?
What else can bind to the picornavirus canyon regions?
Antibodies to neutralize virus
What is unique about the protein made by picornavirus?
It is translated as 1 protein, and cleaved by a VIRAL PROTEASE
What are (-) copies made by picornaviruses?
complementary template used to make more copies of the viral genome
What is found at the 5' end of picornavirus RNA?
What is cleaved terminally in picornavirus replication? what is made?
VP0 --> VP2 and 4 mature particles
What is VPg?
virally encoded protein that acts as a 5' cap; guides translation and packaging of proteins
How is picornavirus transmitted?
What is unique about rhinoviruses?
They are LABILE at acidic pH; like the upper airway
What is unique about the other enteroviruses?
STABLE at acidic pH, like the GI tract
What are the examples of the picornavirus family?
Coxsackie A and B
What is the most common cause of the common cold ?
Where do enteroviruses replicate?
mucosa and lymphoid tissue of tonsils and pharynx
M cells and lymphocytes of Peyer's patches
Enterocytes of intestinal mucosa
What causes the spread of virus to secondary tissues?
What determines the degree of paralysis in paralytic polio?
the type of neurons affected and degree of damage
Who is more severely affected by paralytic polio?
the young and elderly
What are the effects of spinal cord involvement in paralytic polio?
paralysis of limbs or complete flaccid paralysis
What is affected in bulbar paralysis?
cranial nerves and the respiratory center in the medulla
Where is replication of poliovirus restricted to?