Pharmacology Lecture 13_RNA Viruses Flashcards
What do antiviral agents typically target
maturation and polymerase activity.
What are three important things about Enteroviruses
- Replicate in wide pH range (ie, 3-10)
- The small intestine is the major site of enterovirus infection
- replicate best at 37°C
What are two important features of retroviruses?
They are envoloped, they have a diploid single strand plus sense RNA genome. (also they are evil)
What are two important features of Reoviruses
They have a dsRNA genome with 8-11 segments. They are naked
What three disease states are often caused by Paramyxoviruses?
Measles, mumps, respitory tract infections.
What are two important features of Picornaviruses
They are naked, they have a pluse sense single strand RNA genome
What does retrovirus do upon infecting a host?
despite having a plus sence genome, retro viruses use their own RNA reverse transcriptase to copy the genome into dsDNA which it then inserts into the hosts genome. This makes them super hard to get rid of.
What is the most common Reovirus? What does it cause
Rotavirus. It causes diarrhea in young children
What are the two large families of Picornaviruses
- Rhinoviruses
* Enteroviruses
What are three important things about Rhinoviruses
- replicate at a pH of 6-8
- optimally replicate at 33°C
- primarily infect the nasal mucosa (they are the most common cause of the common cold)
What are two important features of Paramyxoviruses
They have a negative sense single strand RNA genome, the are enveloped with fusion glycoproteins in the membrane (can cause syncytia)
What are 8 clinical manifestations of picornavirus
- aseptic meningitis
- Encephalitis
- the common cold
- febrile rash illnesses (hand-foot-and-mouth disease)
- Conjunctivitis
- Herpangina
- myositis and myocarditis
- hepatitis
What are two important features of Orthomyxoviruses
They have single strand negative sense segmented RNA genomes, they are enveloped ( glyco proteins are • Hemagglutinin - helps with adhesion
• Neuraminidase - helps with egress), despite being enveloped they are endocytosed
Why does influenza (an orthomyxovirus) replicate in the neucleus
It steals the 5’ cap structures from host mRNA. This makes the viral mRNA bind preferentially with the host ribosomes (because they now have a 5’ cap and host mRNA does not).
Why do RNA viruses have such a high mutation rate
Because, unlike DNA ploymerase, RNA polymerase does not have a proof reading mechanisium
