Antiviral therapy Flashcards
examples of DNA viruses
herpes
CMV
chicken pox (varicella, VZV)
Hep B
examples of RNA retroviruses
HIV1 and HIV2 –> AIDS
examples of RNA viruses
Influenza A, B, and C
Hep C
RSV
modes of transmission
human to human
animal to human
food to human
equipment to human
viruses are not cells, they are
obligate intracellular parasites
CMV is a herpesviruses and 50-80% are infected by age 40 but don’t know because it only affects….
immunocompromised patients
or unborn babies infected during pregnancy
infection process steps
adsorption penetration/uncoating replication/transcription/translation assembly release of new virus secondary infection of other cells
what do retroviruses have that humans don’t that makes it a good target to attack
reverse transcriptase (RNA –>DNA)
what are the 2 effects of interferons?
activates killer cells (Natural and CD8+ T cells)
induces resistance of other host cells to virus
… immunization is accomplished by injecting antiviral immunoglobulins
passive
… immunization is accomplished by vaccination with antiviral vaccines (administering antigen to induce cellular and humoral immunity) but it takes time to develop
active
in the innate immune system, ….. cells express … receptors the secrete…. following viral stimulation
specialized intereferon producing cells
Toll-like receptor (TLR)-7 and TLR 9
interferon 1
intereferon circulates and activates interferon receptors on other cells and this induces expression of many genes that promote …. to many viruses
resistance
which interferon is currently used as a therapeutic
interferon alpha
the goal of chemotherapy is to have
selective toxicity to the virus
lqtent infection and reactivation of herpesvirus takes place in …
sensory neurons
what drugs inhibit viral DNA polymerase and/or Hep B reverse transcriptase
base analogs- resemble bases or parts of them
Acyclovir
Valacyclovir
Ganciclovir
Lamivudine
what initiates activating acyclovir to phosphorylate it to a monophosphate?
viral thymidine kinase (in a virus infected cell)
Acyclovir MOA:
- selective metabolic activation in virus infected cells by …
- … inhibition
- incorporation into …
- Viral DNA polymerase cannot add another base causing …
viral thymidine kinase
competitive
DNA
chain termination
when acyclovir is phosphorylated into a … (which lacks …) it inhibits DNA polymerase.
triphosphate
lacks 3’OH, irreversibly inactivates viral DNA polymerase
Which disease is better treated by Acyclovir? Herpes or CMV?
Herpes
Which disease is better treated by Ganciclovir?
Herpes or CMV
CMV
In CMV, what phosphorylates Ganciclovir?
UL97 kinase
hepatitis B is a DNA virus BUT replication proceeds through … of a pregenomic RNA intermediate
reverse transcriptase