Microbio Week 11 - DNA viruses (Exam 3)

Question 1

How do papillomaviruses replicate?

Answer 1

By entering the cell cycle

(they don’t have viral DNA polymerase!)

Question 2

T/F: A small number of papillomavirus serotypes exist

Answer 2

FALSE, a LARGE number of papillomavirus serotypes exist

Question 3

What are the 2 main types of HPV?

Answer 3

Mucosal
Cutaneous

Question 4

Is HPV a localized or generalized/systemic infection?

Answer 4

Localized

(only on skin or mucosal surface)

Question 5

Does HPV have a viremic stage?

Answer 5

NO

Question 6

What does cutaneous HPV form on the skin that can persist and spread?

Answer 6

Benign warts

Question 7

Can benign warts from cutaneous HPV be cleared without treatment?

Answer 7

Yes

Question 8

Where can cutaneous warts spread through autoinoculation?

Answer 8

To oral or genital mucosa

Question 9

What is the most common STD in the US?

Answer 9

Anogenital warts

Question 10

What are the most common types of mucosal HPV? Are they low or high risk?

Answer 10

HPV 6 and 11 - low risk
HPV 16 and 18 - high risk

Question 11

What are HPV 6 and 11 associated with?

Answer 11

90% of genital warts

Question 12

What are HPV 16 and 18 associated with?

Answer 12

70% of anogenital cancers
Most cervical cancers

Question 13

What else can HPV 6 and 11 cause?

Answer 13

Recurrent respiratory papillomatitis

Question 14

How do children acquire oral HPV?

Answer 14

At birth from mother

Question 15

How do adults acquire oral HPV?

Answer 15

Oral sex

Question 16

Where can mucosal HPV warts be found? What is required if this occurs?

Answer 16

Larynx - requires surgical removal

Question 17

What is needed so the HPV virus can infect the basal cell layer?

Answer 17

Break in the skin/mucosa

Question 18

In HPV, the basal cell will then replicate to repair the wound, and the virus will establish several copies of itself in an _________ form

Answer 18

episomal

Question 19

As the HPV virus containing cell moves through the different epithelial layers, what will it express?

Answer 19

Different viral proteins

Question 20

In the upper epithelial layers, the HPV virus will prod the terminally differentiated cell to replicate so it can make thousands of copies of ________ ______ and lots of ____________ ____________.

It does this by the viral _____ protein binding and inactivating the cellular Rb protein, which causes the cell to go into the cell cycle

Answer 20

viral DNA; capsid protein; E7

Question 21

What is HPV cancer caused by?

Answer 21

Dysregulation of E6 and E7 genes of HPV

Question 22

How do E6 and E7 genes of HPV become dysregulated?

Answer 22

By integrating viral DNA episome into basal cells’ DNA

Question 23

Is genome integration a normal part of HPV’s replication?

Answer 23

NO

Question 24

What does the integration of viral HPV episome turn off? What does this lead to?

Answer 24

Turns off a viral protein that controls E6 and E7 levels -> leads to high levels of E6 and E7 in basal cells

Question 25

In the oncogenic forms of HPV, which protein will bind and degrade the Rb protein causing the cell to go into the cell cycle?

Answer 25

E7

Question 26

In oncogenic forms of HPV, which protein will cause the degradation of p53, allowing the cell to continue to cycle and accumulate mutations?

Answer 26

E6

Question 27

In most cases, HPV infections spontaneously ___________ (meaning they are cleared by the immune system).

Answer 27

regress

Question 28

When do problems with HPV infection occur?

Answer 28

If the infection is persistent and the patient is high risk (can result in cancer)

Question 29

T/F: Once the immune system is activated, most people are protected from reinfection from that strain of HPV. Some people might have cross-protection between different strains of HPV.

Answer 29

True

Question 30

Is it possible to be infected with more than one strain of HPV, either simultaneously or sequentially?

Answer 30

Yes!

Question 31

HPV is known to contribute to 6 different cancers. Name them

Answer 31

Cervical Anal Vulvar Vaginal Penile Oropharyngeal

Question 32

There are now more HPV __________ cancers per year than cervical cancers

Answer 32

oropharyngeal

Question 33

Which stain of HPV causes almost all oropharyngeal cancers?

Answer 33

HPV 16

Question 34

What can increase risk of cancer from HPV infection?

Answer 34

Smoking and drinking

Question 35

As the number of people smoking reduced, oropharyngeal cancers ___________

Answer 35

decreased

Question 36

_________ cancer cases have been on the rise, with more being caused by HPV in younger _______________

Answer 36

Oral; non-smokers

Question 37

What type of vaccine is the HPV vaccine?

Answer 37

Subunit

Question 38

What does the subunit vaccine for HPV have in it?

Answer 38

One coat protein of HPV

Question 39

It is recommended that girls and boys ages ________ get vaccinated with _____ doses of the HPV vaccine

Answer 39

9-14; 2

Question 40

How many doses of the HPV vaccine must be done after age 14?

Answer 40

3

Question 41

What age group seems to have the most durable response to the HPV vaccine?

Answer 41

9-14

Question 42

Describe the polyomavirus

Answer 42

dsDNA Circular Naked Icosahedral

Question 43

Do polyomaviruses have a viral DNA polymerase?

Answer 43

NO

Question 44

What is needed for polyomaviruses to replicate their viral DNA?

Answer 44

Cell must divide

Question 45

T/F: JC only causes problems in the immunocompromised

Answer 45

True

Question 46

Name the 4 types of patients JC causes problems in

Answer 46

AIDS Transplant recipients People taking immunosuppressive drugs Hematologic malignancies

Question 47

What is JC caused by?

Answer 47

Polyomavirus

Question 48

T/F: All of polyomaviruses are very common; most people have been exposed or are latent/chronically infected

Answer 48

True

Question 49

A large majority of people have been infected with the JC virus by adulthood. Many people are latently infected and sporadically shed virus in their __________

Answer 49

urine

Question 50

The problems with JC arise when the virus mutates and becomes _________, and the person is immunosuppressed

Answer 50

neurotropic

Question 51

What cells does the mutant JC virus infect and kill, causing CNS demyelination and Progressive Multifocal Leukoencephalopathy (PML)

Answer 51

Oligodendrocytes

Question 52

Before ART, ______ occurred in people living with AIDS. However, it can still occur in people with AIDS and other immunosuppressed people.

Answer 52

PML

Question 53

What is the treatment for JC virus induced PML?

Answer 53

Stop the immunosuppressive agent Start HIV therapy to make immune system more active

Question 54

T/F: There is not lasting damage from PML

Answer 54

FALSE, there is lasting damage from PML

Question 55

Describe parvovirus

Answer 55

ssDNA Linear Naked Icosahedral

Question 56

Does parvovirus have DNA polymerase?

Answer 56

NO

Question 57

Can parvovirus stimulate the cell to grow, like polyomavirus or papillomavirus?

Answer 57

NO

Question 58

How does parvovirus replicate?

Answer 58

Infects actively dividing cells

Question 59

What does parvovirus B19 cause?

Answer 59

Erythema infectiosum-fifth disease

Question 60

Is Erythema infectiosum-fifth disease a localized or generalized infection?

Answer 60

Generalized

Question 61

The “slapped cheek rash” characterizes which infections?

Answer 61

B19

Question 62

In B19 infections, the _______ develops because of the immune response and the person is no longer contagious

Answer 62

rash

Question 63

The B19 parvovirus needs to infect actively dividing cells and preferentially infects ________ precursor cells, killing those cells. What does this cause?

Answer 63

erythroid; causes transient anemia

Question 64

For people who already have an increase in RBC turnover due to hemoglobin disorders like sickle cell or chemotherapy, what can a B19 infection cause?

Answer 64

Transient aplastic crisis -> causing severe drop in RBCs

Question 65

If infected with parvovirus B19 in the 1st trimester, what is there a chance of?

Answer 65

Miscarriage

Question 66

If infected with parvovirus B19 anytime during pregnancy, what is there a chance of causing?

Answer 66

Hydrops fetalis

Question 67

Describe poxvirus

Answer 67

dsDNA Linear Enveloped

Question 68

Where do poxviruses replicate?

Answer 68

Cytoplasm

Question 69

What do poxviruses bring into the cell so it can make mRNA and not have to enter the nucleus?

Answer 69

DNA-dependent RNA polymerase

Question 70

Name the poxviruses

Answer 70

Molluscum virus Orthopoxviruses (variola, cowpox, mpox, vaccinia)

Question 71

What virus causes raised lesions of the skin that appear smooth with a dimple in the middle and are actively secreting the virus?

Answer 71

Molluscum virus

Question 72

Is molluscum contagiosum a local or generalized infection?

Answer 72

Local

Question 73

How is molluscum contagiosum spread?

Answer 73

Close contact Autoinoculation

Question 74

T/F: The molluscum contagiosum infection usually disappears without intervention by 2 to 12 months without scarring and affects children more than adults

Answer 74

True

Question 75

Orthopoxviruses (Variola, Cowpox, Mpox, Vaccinia)