Lecture 4 Part 5: Papillomaviruses & Polyomaviruses

Question 1

Does HPV have an envelope?

Answer 1

no envelope

Question 2

What is the shape of HPV’s capsid?

Answer 2

icosahedral capsid

Question 3

What type of genetic material does HPV contain?

Answer 3

dsDNA

Question 4

Is HPV’s genome linear or circular?

Answer 4

circular

Question 5

Where in the host cell does HPV replicate and assemble?

Answer 5

in the nucleus

Question 6

True OR False
HPV is lytic in permissive cells

Answer 6

TRUE

Question 7

True OR False
HPV can lead to cancer in non-permissive cells.

Answer 7

TRUE

Question 8

True OR False
HPV can only cause short-term infections

Answer 8

FALSE
It can cause chronic and latent infections

Question 9

SLIDE 40

Question 10

How many types of HPV are there?

Answer 10

more than 100

Question 11

Which HPV types are considered high-risk for cervical cancer?

Answer 11

HPV-16 and HPV-18.

Question 12

True or False
HPV-16 and HPV-18 can NOT integrate into the host genome.

Answer 12

False
HPV-16 and HPV-18 can integrate into the host genome

Question 13

True or False
HPV is found in less than half of cervical cancer cases

Answer 13

False
It is found in over 99% of cervical cancer cases

Question 14

True or False
HPV can only be transmitted through sexual contact

Answer 14

False
It can also be transmitted via fomites, broken skin, and during birth canal transmisison and sexual contact

Question 15

True or False
HPV can infect any type of cell in the body

Answer 15

False — HPV has specific tissue tropism and infects permissive cells only

Question 16

Which cells does cutaneous HPV infect?

Answer 16

Squamous epithelial cells of the skin

Question 17

What areas are affected by mucosal HPV types?

Answer 17

Conjunctival (eye), genital, and oral mucous membranes

Question 18

What effect does HPV have on epithelial cells?

Answer 18

Induces epithelial proliferation – results in thickening of
skin layers

Question 19

What are some clinical conditions caused by HPV?

Answer 19

1. Warts, condyloma, papilloma
2. Benign head & neck tumors
3. Anogential warts
4. Cervical dysplasia & neoplasia

Question 20

What are some examples of polyomaviruses?

Answer 20

SV40, JC virus, BK virus, and Merkel cell polyomavirus

Question 21

How do polyomaviruses compare in complexity to papillomaviruses?

Answer 21

it is ubiquitous, asymptomatic infection

Question 22

What happens in permissive cells infected by polyomaviruses?

Answer 22

lytic in permissive cells

Question 23

What happens in non-permissive cells infected by polyomaviruses?

Answer 23

Only early genes are transcribed, which can lead to cell transformation

Question 24

Which cells do JC and BK viruses target?

Answer 24

tropism for lymphocytes

Question 25

Where do JC and BK viruses go after spreading through the blood?

Answer 25

They spread to the kidneys, where they can remain latent

Question 26

When can polyomaviruses become active again?

Answer 26

activated in immunocompromised patients

Question 27

What disease is caused by the JC virus?

Answer 27

Progressive Multifocal Leukoencephalopathy (PML)

Question 28

How does the JC virus cross the blood-brain barrier?

Answer 28

By infecting capillary endothelial cells

Question 29

True or False JC virus causes a lytic infection in oligodendrocytes

Answer 29

True and this causes demyelination

Question 30

True or False JC virus transforms astrocytes

Answer 30

TRUE

Question 31

True or False Primary JC virus infection usually causes severe symptom

Answer 31

False it is asymptomatic

Question 32

In which individuals is JC virus most likely to reactivate?

Answer 32

1. Immunocompromised patients (including transplant recipients) 2. Pregnancy