Lecture 19 - Herpesvirus

Question 1

What virus is one of the most common ones found in humans?

Answer 1

herpesvirus

Question 2

Can herpesvirus cause cancer?

Answer 2

yes

Question 3

What genome does herpesvirus have?

Answer 3

dsDNA viruses

Question 4

In the herpesvirus virion, what are most viral structural proteins commonly called?

Answer 4

VP = viral protein (nucleocapsid)

Question 5

What is the HSV-1?

Answer 5

one most common herpesvirus strain

Question 6

Where do herpesviruses attach to?

Answer 6

cells of the epidermis/dermis of skin and epidermal mucosal cells

Question 7

How is viral attachment and entry of the herpesvirus achieved?

Answer 7

through a binding receptor and entry receptor

Question 8

What is the function of VP16?

Answer 8

initiates transcription

Question 9

What are the early genes herpesvirus transcribes?

Answer 9

genes for DNA synthesis

Question 10

What are the late genes herpesvirus transcribes?

Answer 10

structural and assembly proteins

Question 11

What mechanism does herpesvirus use to replicate their genome? What does this result in?

Answer 11

rolling circle replication resulting in linear concatemers of DNA

Question 12

What does thymidine kinase do and why is it important?

Answer 12

enzyme that increases the pool of dT(thymidine)TPs within a host cell | allow herpesvirus to replicate in slowly dividing or non-dividing cells

Question 13

What process does the herpes virus use to assemble?

Answer 13

double-envelope process

Question 14

What is the double-envelope process?

Answer 14

nucleocapsid buds out of nucleus membrane and then gets its second envelope from Golgi apparatus

Question 15

How can syncytia formation occur with herpesvirus?

Answer 15

glycoproteins can cause fusion between infected and non-infected cells

Question 16

What is the effect on the host cell due to the double-envelope process?

Answer 16

cell lyses

Question 17

What is the viral capsid enveloped by? And why?

Answer 17

nuclear membrane to translocate it to the cytoplasm

Question 18

Where does the nucleocapsid mature?

Answer 18

cytoplasm

Question 19

Where does the main envelope of the nucleocapsid of the herpesvirus derive from?

Answer 19

Golgi-derived vesicles

Question 20

After a productive primary infection, where does the herpesvirus travel to become latent?

Answer 20

enters sensory neuron axons and migrates along axon to the cell body in a ganglion in the CNS

Question 21

What are viral RNA transcripts that are synthesized during latency called?

Answer 21

LATs (Latency Associated Transcripts)

Question 22

How are LATs beneficial to the virus?

Answer 22

after it undergoes splicing, it plays an important biological role

Question 23

What type of transport direction is the virus moved within the neuron during latency?

Answer 23

retrograde transport, towards nucleus

Question 24

What type of transport direction is the virus moved within the neuron during reactivation?

Answer 24

anterograde, down the axon

Question 25

What 10 factors associate with reactivation of the herpesvirus?

Answer 25

immune suppression | sex | stress | temperature changes | UV light/sunburn | menstruation, pregnancy, lactation | malnutrition | excessive fatigue

Question 26

What does disease severity depend on (herpesvirus)?

Answer 26

interplay between the virus and its host, especially the host's immune status

Question 27

What are 2 methods of transmission of the herpesvirus?

Answer 27

saliva, vaginal secretions, secretions from oral/anogenital tracts (mouth and butthole) | eyes and skin lesions

Question 28

What are 2 diseases that occur due to infection from herpesvirus?

Answer 28

mucosal lesion | encephalitis

Question 29

What is the most commonly prescribed antiviral drug for HSV?

Answer 29

acyclovir (ACV)

Question 30

What does acyclovir do?

Answer 30

acts as a chain terminator, prevents DNA elongation

Question 31

Which epithelial cells do HSV-1 infect?

Answer 31

oral, skin, cornea

Question 32

Where in the nervous system do HSV-1 viruses establish latent infections?

Answer 32

trigeminal nerve = spine

Question 33

Where in the nervous system do HSV-2 viruses establish latent infections?

Answer 33

sacral ganglia

Question 34

What does the Varicella Zoster virus cause?

Answer 34

chickenpox and shingles

Question 35

What is chickenpox?

Answer 35

mild diseases affecting kids

Question 36

What are 3 symptoms of VZV?

Answer 36

fever, malaise, ~300 lesions

Question 37

What is the mode of transmission of Varicella-Zoster virus?

Answer 37

airborne via cough/sneeze

Question 38

What happens to the Varicella Zoster virus after the primary infection?

Answer 38

becomes latent in the dorsal root ganglia

Question 39

What factor increases the risk of reactivation of Varicella-Zoster virus?

Answer 39

aging

Question 40

List 4 symptoms of shingles.

Answer 40

pain, headache, rash, numb

Question 41

What are shingles?

Answer 41

reactivated Varicella-Zoster virus after 60yo | common/severe in immunocompromised people

Question 42

Is there a vaccine available for shingles?

Answer 42

yes

Question 43

What human herpesvirus causes cancer and 79% of infectious mononucleosis cases?

Answer 43

Epstein-Barr Virus

Question 44

What is the mode of transmission of EBV? What is it also called?

Answer 44

saliva; kissing disease

Question 45

What is associated with Burkitt's lymphoma?

Answer 45

Epstein-Barr Virus

Question 46

What is cytomegalovirus?

Answer 46

common but show asymptomatic or mild symptoms

Question 47

How can the cytomegalovirus affect pregnant women?

Answer 47

infect placenta >>> fetus

Question 48

What effects does cytomegalovirus have on the fetus

Answer 48

small brain size | enlarges liver and spleen

Question 49

What effects does cytomegalovirus have on adults?

Answer 49

hearing loss and mental disabilities

Question 50

What is Kaposi's Sarcoma-Associated Herpesvirus (KSAH)?

Answer 50

aggressive pigmented sarcoma on skin | transmitted by saliva