Anti-virals

Question 1

What surrounds the genetic material in viruses?

Answer 1

Capsid (protein shell surrounding the genetic material)

Question 2

What type of genetic material do the following viruses have:

a. Hepatitis B
b. Hepatits C
c. HIV
d. Herpes Simplex Virus
e. Influenza

Answer 2

Hepatitis B = Hepadnavirus – it is a DNA virus that also involves reverse transcriptase in its replication

Hepatitis C = RNA virus

HIV = Retrovirus

Herpes Simplex Virus = DNA virus

Influenza = RNA virus

Question 3

Describe the relative curability of Hep B and Hep C.

Answer 3

Hep B – not curable

Hep C – CURABLE

Question 4

At what point do you start treating someone who has recently got infected by Hep B or Hep C?

Answer 4

When the infection becomes chronic

The immune system, in some people, is able to clear Hep B and Hep C infections by itself

Question 5

What is the treatment for Hep B? What type of drug is this?

Answer 5

Tenofovir

Nucleotide reverse transcriptase inhibitor

Question 6

What are the treatment options for Hep C? State the drug types.

Answer 6

Ribavirin (+ pegylated interferon)
Ribavirin is a nucleoside analogue (purine analogue)
Boceprivir – protease inhibitor (only works on Hep C genotype 1)

Question 7

Describe the receptor interaction involved in HIV attachment and entry.

Answer 7

HIV GP120 binds to CD4 and CCR5 or CXCR4

Then HIV GP41 penetrates the host cell membrane and the viral capsid enters

Question 8

State two drugs that interfere with HIV attachment and entry and state their targets.

Answer 8

Enfuvirtide – GP41

Maraviroc –CCR5

Question 9

Name a nucleoside reverse transcriptase inhibitor. How are they activated?

Answer 9

Zidovudine
Emtricitabine
Three step phosphorylation

Question 10

Name a nucleotide reverse transcriptase inhibitor.

Answer 10

Tenofovir

Question 11

How do non-nucleoside reverse transcriptase inhibitors act? Give an example of an NNRTI.

Answer 11

They bind to the reverse transcriptase and cause a change in shape of the enzyme so it blocks HIV replication
Example: Efavirenz

Question 12

Give an example of an integrase inhibitor.

Answer 12

Raltegravir

Question 13

What viral gene encodes all the viral structural proteins?

Answer 13

Gag gene

Question 14

What must happen to the protein product of this gene, in order to produce fully functioning virus particles?

Answer 14

This must be cleaved by a protease into the constituent proteins so that it can make the fully formed virus

Question 15

Name a drug that acts a protease inhibitor and state one problem with its pharmacokinetics.

Answer 15

Saquinavir

It has a low bioavailability

Question 16

What drug can be given to boost the level of the protease inhibitor in the circulation?

Answer 16

Ritonavir

This decreases the metabolism of saquinavir

Question 17

What is the herpes virus surrounded by?

Answer 17

Tegument and a lipid bilayer

Question 18

What do the two different types of herpes cause?

Answer 18

HSV1 – cold sores

HSV2 – genital herpes

Question 19

What is the treatment for HSV?

Answer 19

Acyclovir

Nucleoside analogue that is specific because its activation requires viral kinases

Question 20

What envelope protein of influenza is important for the release of the virus into the host cell?

Answer 20

Neuraminidase

Question 21

Name an inhibitor of this envelope protein

Answer 21

Oseltamivir