L34_DNA Viruses 1

Question 1

Where does transcription and replication take place for DNA viruses?

Answer 1

The nucleus (except pox)

Question 2

Is the host or virus RNA polymerase used to transcribe mRNA?

Answer 2

Host (except pox)

Question 3

Does the host or viral DNA polymerases replicate the genome

Answer 3

either can.

Question 4

What are the two common viral transcription factors that help enhance ciral transcription?

Answer 4

X and Y

Question 5

Are promoters in viral genomes recognized by host or viral transcription factors, or both?

Answer 5

Both Biatch!

Question 6

Give some examples of viruses that use their own DNA polymerase.

Answer 6

Herpesviruses and Adenovirus

Question 7

Do DNA viruses mutate faster or slower than RNA viruses? Why?

Answer 7

Slower, DNA polymerases have much higher fidelity and are capable of proofreading. (Recombination can still happen when a Polymerase hops strands)

Question 8

What are some common symptoms of Adenovirus affecting the respiratory system? how about other sites?

Answer 8

Respiratory: A bad cold with a fever, pharyngoconjuctival fever, Laryngitis and cough, pneumonia
Other Sites: Acute hemorrhagic cystitis, epidemic keratoconjunctivitis, gastroenteritis

Question 9

How is adenovirus transmitted?

Answer 9

Aerosol, Fecal-oral, objects, poorly chlorinated swimming pools

Question 10

What are the susceptible populations for adenovirus?

Answer 10

Children (no experience with the virus)
Military Recruits (reactivates under stress)

Question 11

How does adenovirus enter the cell?

Answer 11

fiber proteins dock and cell is endocytosed (happens very quickly)

Question 12

How is adenovirus released into cytoplasm of a cell?

Answer 12

Sharp spikes are extremely lytic and lyse endosome and release capsid into cytoplasm

Question 13

Where does uncoating of adenovirus take place and how?

Answer 13

The slightly degraded capsid (from late endosome) docks with nuclear pore and uncoats, allowing the genome to enter the nucleus

Question 14

Which DNA pol replicates Adenovirus genome?

Answer 14

The Virus DNA pol

Question 15

Where does capsid assembly occur in adenovirus lifecycle?

Answer 15

In the nucleus

Question 16

How does adenovirus egress?

Answer 16

Most likely lysis

Question 17

Describe the gene expression of adenovirus?

Answer 17

Immediate early phase (transcription factors), Early phase (DNA polymerase), and Late phase (Capsid Proteins)

Question 18

Can Adenovirus be treated?

Answer 18

Yes, in severe situations when patient is immunosupressed a drug (cidofovir) can be given but is highly nephrotoxic

Question 19

Can we prevent Adenovirus?

Answer 19

Yes there is a vaccine, but it is only approved for the military.

Question 20

What epithelial diseases are caused by HPV?

Answer 20

Common warts, plantar warts, genital warts

Question 21

What malignancies is HPV associated with?

Answer 21

Head and neck cancer, Cervical Cancer, Penile cancer

Question 22

Where does HPV like to grow? describe its growth

Answer 22

In the basal lamina of epithelium. HPV is very fastidious.

Question 23

How is the circular DNA of HPV maintained in epithelial cells?

Answer 23

Usually as a episome (like a plasmid)

Question 24

How does a wart form (describe within context of HPV life cycle)?

Answer 24

HPV infect basal lamina, as skin proliferates the infected cell moves towards surface and begins phenotypical changes. The HPV senses these changes and goes nuts, causing hyperplasia and a wart. Warts are contagious!

Question 25

Describe HPV genome

Answer 25

dsDNA circular

Question 26

What replicates the HPV genome?

Answer 26

The host DNA polymerase

Question 27

What HPV viral factors are oncogenes?

Answer 27

E6 and E7 (E stands for early)

Question 28

What phases are HPV genes transcribed, what types of proteins are transcribed in each phase?

Answer 28

Early (functional proteins), Late (Structural capsid proteins)

Question 29

How can you diagnose HPV?

Answer 29

DNA tests for HPV types

Question 30

How can you treat warts?

Answer 30

Cryotherapy, chemical ablation, colposcopy (minor surgery)

Question 31

How can you prevent HPV

Answer 31

There are two approved vaccines that treat high risk strains, they are made of virus like particles composed of empty capsids. They are made up of the late genes and the body develops antibody against them (recognize 3D structure). You must vaccinate before the person has ever been exposed.

Question 32

What DNA viruses tend to use their own DNA polymerase and which tend to use the host DNA pol?

Answer 32

Larger genomes- use their own

Smaller Genomes- use the host