2-How Viruses Replicate and How to Stop it - Antivirals Flashcards
What is the primary receptor in HIV?
CD4
What are the secondary receptors in HIV?
CCR5 or CXCR4
What does Influenza use as its receptor?
silica acid
The ability of a virus to only infect certain cells; the viral receptor helps determine what cells the virus can infect; also what species the virus can infect (zoonotic transmission).
Tropism
In one mode of entry, both enveloped and naked viruses can be endocytosed, what helps the virus enter the cell?
the lower pH of the endosome
What viruses have an early, middle, and late part of replication?
DNA viruses like Herpes
Which DNA viruses do not have viral DNA polymerase and have to use the cell DNA polymerase to replicate; can sometimes cause cell cycle dysregulation and doesn’t kill the cell, so now there is a chance for a cancer causing event?
Papilloma, Polyoma, Parvo
What is the only virus in the Hepadnavirus family?
HBV
What does HBV have that allows some HIV drugs to be used in HBV infections?
Reverse transcriptase - HIV reverse transcriptase inhibitors
What viruses all have a latent stage?
Herpes
What is mRNA the same as?
+ssRNA
What is the first thing a +ssRNA virus does when it enters a cell?
make a polyproteins (except retroviruses)
What do all +ssRNA viruses have in order to cleave the polyprotein to make individual viral proteins?
viral protease
What do all +ssRNA viruses need to make because they need to make more RNA from their own RNA?
viral RNA dependent RNA polymerase
What do all +ssRNA viruses have that are great targets for antiviral drugs?
viral protein, viral polymerase
What are +ssRNA viruses that have 2 copies of the same genetic material?
Retroviruses
What steps in RNA replication can be inhibited by antivirals?
- Entry Inhibitors
- Reverse Transcriptase Inhibitors
- Integrase Inhibitors
- Protease Inhibitors
Not Assembly (#4)
Retroviruses are unique because they make a DNA copy of themselves by … and integrate that copy into the host cell chromosome, the viral DNA copy is in the cell for the life of the cell - only way to get rid of virus is if the cell dies.
reverse transcriptase
What is the first thing -ssRNA viruses do when they enter the cell?
make mRNA from their -ssRNA using a viral polymerase they carry into the cell with them in their virus
What is a defective virus (no RNA polymerase) that absolutely needs to co-infect a cell with HBV to replicate?
HDV
What antiviral for HIV is the reverse transcriptase inhibitor that is a chain terminator?
(NRTI) Nucleoside Reverse Transcriptase Inhibitors
What antiviral for HIV is the reverse transcriptase inhibitor that binds to reverse transcriptase and prevents its ability to make DNA?
(NNRTI) Non-nucleoside Reverse Transcriptase Inhibitors
What do the antiviral drugs for HCV block?(3)
viral protease, viral polymerase, NS5A (viral protein)
What Influenza Antiviral drug, blocks uncoating, all current stains are resistant?
Amantidine
What Influenza Antiviral drug, blocks release of the virus by blocking neurominidase?
Oseltamivir (Tamiflu)
For Herpesviruses Acyclovir compounds block the …, and need to be activated by a …
viral polymerase; viral kinase
What Herpesvirus antiviral is activated in the body and will function like acyclovir but has a longer half-life in the body, used for HSV and VZV herpesviruses?
Valacyclovir
What Herpesvirus antiviral is oral and used for HSV and VZV herpesviruses?
Famciclovir
What Herpesvirus antiviral is topical and used for HSV and VZV herpesviruses?
Penciclovir
What Herpesvirus antiviral has more side effects and usually used for herpesviruses CMV?
Valganciclovir/Ganciclovir
