Herpes- medical microbio Flashcards
what defines the subfamilies of herpesvirus?
sequence homology and tissue tropism
herpes virus is known for this type of life-cycle
latent: limited gene expression, genome maintenance, immune evasion
the subfamily of herpesvirus that causes cancer
gamma
structural characteristic unique to herpes virion
tegment: helps take over the host cell when it infects
gene expression cascade of herpesvirus lytic cycle
immediate-early, early, late
immediate-early genes are not inhibited..
not inhibited by cyclohexamide
early genes are inhibited by..
are inhibited by cyclohexamide
late genes are inhibited by..
inhibited by viral polymerase inhibitors
blocking protein synthesis in a cell blocks these genes
early genes, because they’re dependent on immediate early genes
what type of nucleic acid comprises the herpesvirus genome?
DNA
the main target for antiviral drugs
dna polymerase
what does alpha HV infect?
neurons
what does beta HV infect?
CD34+, monocytes
what does gamma HV infect?
B cells (B cell tumors)
reactivation is caused by
lytic replication
HV infectiosn are mediated by…// these immunocompromised patients are at risk
cell mediated immunity//neonates, ederly, HIV, transplant
these subfamilies of herpes virus are diseases of lytic replication
alpha and beta HV- Direct tissue injury
subfamily that is a disease of latency
gamma HV (EBV, KSHV)
prototype antiviral
acyclovir
acyclovir targets… so,…
viral DNA polymerase; not effective against latent virus
foscarnet (pyrophosphate analogs) bind to
pyrophosphate site of DNA polymerases thus preventing nucleotide binding
during long-term treatment of immunocompromised patients with acyclovir and its derivatives can cause..
drug resistance mutations in TK and DNA pol
“below the waist” herpes subfamily
HSV2
“above the waist” herpes subfamily
HSV1
HSV acute replication happens in ___; latency occurs in ____ for oral HSV, and _____ for genital HSV
epithelial cells
trigeminal ganglia
spinal ganglia
a viral non-coding RNA expressed during latency
latency-associated transcript (LAT)
lobe affected by HSV encephalitis
temporal
ELISA detects viral..
antigen
PCR or hybridization detects..
viral DNA in tissue
how varicella-zoster virus spreads
droplets into the respiratory tract
anti-chicken pox vaccine
varivax
vaccine given to elderly to prevent shingles
zostervax
