Herpes Flashcards
Herpes Baltimore classification and biosynthetic pathway
dsDNA
transcription, needs to get into the nucleus
Herpes virion
tegument, capsid, envelope
Herpes proteins
VP5, VP16 localizes to the nucleus and forms a complex with HCF to induce immediately early genes.
Bind, attach and fuse
Herpes attachment and entry
- HSV-1 binds to heparan sulfate (binding receptor) and then to TNFR (entry receptor)
- fuses to membrane so tegument proteins can release into the cytoplasm
- VP16 localizes to the nucleus and forms a complex with host cell factor to induce IEG transcription
VP 16
activates transcription
forms a complex with HCF to induce immediately early genes
Herpes Immediate Early genes
TS factors to express EG
Herpes Early genes
protein DNA synthesis to replicate viral genome
Herpes Late genes
structure and assembly
Herpes genome
concatemers. Doesnt need to push cell cycle so can divide in replicating or non- replicating cells.
Herpes assembly and exit
double membrane process (nuc mem-Golgi-plasma mem) then lyses cell
LATs, and thymidine kinase
LAT when virus RNA is synthesized during latency.
Thymidine kinase is a viral enzyme that increases the pool of nucleotides in host cell so they can replicate in slowly dividing and non-dividing cells.
Susceptible to acyclovir. Beneficial to herpes during the lytic phase cause virus needs to lyse to infect more cells
Herpes dTTPs
dTTPs can infect cells that aren’t actively undergoing replication
ACV acyclovir
acts as a chain terminator to pre vent DNA elongation
targets thymadine kinase
HSV-1 & HSV-2
-infect epithelial cells or oral (1) or genital (2) mucosa
-cause latency infections in neurons.
HSV-1 causes encephalitis.
VZV Varciella
causes chicken pox and shingles, latent in dorsal root ganglia and can reactivate later in life as shingles.
spread by airborne or contact
