41 Herpes Flashcards
What is the genome like of herpes virus?
Large dsDNA (200nm)—LINEAR
T-F–herpes establishes a life long latency
True
T-F–herpes generally causes severe disease in healthy people?
False–severe in immunocompromised
HSV-1, HSV-2, VZV causes latency where?
in neurons
HCMV, HHV6, HHV7, EBV, KSHV causes latency where?
hematopoietic cells
What type of capsid does herpes have? enveloped?
icosehedral–Yes
What is tegument?
protein layer between capsid and envelope
T-F–herpes only contains one glycoprotein on surface of vision to facilitate entry?
False- several
What happens to herpes genome after it tracks to nucleus?
circularizes
Describe herpes virus genome transcription?
3 stages
1st- immediate genes needed for transcription
2nd-early- virus replication genes
3rd- late- virus particle genes
What is necessary for herpes virus to synthesize new viral DNA?
viral DNA polymerase
How does genome replicate in the herpes life cycle?
episomally and the episome is maintained in daughter cells
What is DNA that is able to replicate independent of the host chromosome and has an origin of replication?
episome
What is required for production of sufficient nucleotide substrates for virus replication? what is this a target for? What do they do?
1- viral nucleoside kinase
- antivirals
- phosphorylate nucleosides and nucleoside analogs
Does herpes have a lytic life cycle?
Yes
Where do herpes virus particles assemble? what does this mean? Where does it go next?
- In the nucleus
- Must transverse nuclear membrane
- Enters golgi and traffics to plasma membran
how do all herpes viruses enter an individual?
close contact with body secretions
Initiallly, herpes replication occurs in the cell type that is lytically infected. T cell response after a few weeks manages this. What happens next?
Virus passed to one or more secondary populations where latency occurs and remains there for hosts life
What are 3 steps/facts of herpes virus latency?
- viral lytic genes turned off
- late genes turned on- only a few genes
- resevoir population and productive viral factory population
T-F–HSV-1— is beta herpes virus, worldwide, close contact spread, and has asymptomatic and symptomatic shedding?
False- it is alpha herpesvirus–everything else is true
The initial HSV-1 infection and replication is at the mucocutaneous site—where is latency HSV-1?
Ganglion proximal to initial site (mouth initial infection will lead to trigeminal ganglion latent infection)
T-F–HSV-1 can traffic down the sensory neuron to infect epithelial cells at the site of the original infection- HSV-1?
True
T-F–the primary infection epidermal destruction is due to T cell infiltration and cytotoxic effects- HSV-1?
False- viral cytopathic effects—Reactivation is due to both
What is the cytopathic effect that gives away herpes HSV-1
- multinucleate giant cells
2. inclusion bodies
Where are the 4 sites of HSV-1 primary infection?
- gingivostomatitis
- ocular herpes
- herpetic whitlow
- genital herpes (mostly HSV-2)
What is conjunctivitis and corneal epithelial lesions stained with Rose bengal characteristic of?
primary herpes infection