Virology Flashcards
What is the genetic makeup of a retrovirus?
+ssRNA
What is the genetic makeup corana and flavi viruses?
+ssRNA
What is the genetic makeup of orthomixo and paramyxo viruses?
-ssRNA
What is the genetic makeup of herpres, adeno, pox and hepanda viruses?
+DNA
What host molecule does a herpes virus use for attachment?
Heparan sulfate proteoglycan
What host molecule does an influenza virus use for attachment?
Sialic acid
Why can HIV only infect activated T cells?
CCR5 is present only on activated T cells
What receptor for Hepatitis B used to enter liver cells?
NTCP (bile receptor)
How does polio enter cells?
Endocytosis (stuck in vesicle and leaves via pH changes)
Where in the cell does polio replicate?
Cytoplasm
How does polio leave cells?
Lysis
How does Measles (paramyxoviridae) enter cells?
Membrane fusion
How does measles leave cells?
Budding
Where in the cell does measles replicate?
ER and Golgi
Is polio capsulated or enveloped?
Capsulated
How does herpes enter and leave cells?
Uncoating at membrane
Exocytosis
Where in the cell does the first wave of herpes replication occur?
Nucleus
Is polio RNA or DNA?
RNA
Is herpes RNA or DNA?
DNA
Is measles RNA or DNA?
RNA
Is HIV RNA or DNA?
RNA
Is smallpox RNA or DNA?
DNA
What are the four types of outcomes of viral infections?
Transformation (tumour formation)
Lytic (lysis)
Persistant (exocytosis)
Latent (integration)
Where are Toll-like receptors located?
Throughout and on the cell
What signalling pathway do Toll-like receptors activate?
Nf-kb
What are the 3 mechanisms of type I INF function?
Activate protein kinase R (PKR)
Upregulate 2’,5’-oligo A synthetase
Upregulate MxGTPase
What is the effect of protein kinase R (PKR)?
Phosphorylates elongation factor, which needs to be dephosphorylated for viral replication to occur
What is the effect of activating oligo A synthetase?
Stitches together oligo A, which activates RNAase
What is the effect of activating Mx GTPase?
Multimerisation and apoptosis
How does the influenza virus evade host defences?
Inactivates PKR via NS1
How do pox and herpes viruses evade host defences?
Target INF signalling, PKR and oligo-A synthetase