4.2 Papilloma and Herpes Virus

Question 1

Where does HPV replicate?

Answer 1

in the nucleus of host cells - uses its transcription machinery including splicing mechanisms

Question 2

In what layer does HPV link itself to the host?

Answer 2

Long lived basal layer skin cells

Question 3

What is the viral genome of HPV made of and what are their functions?

Answer 3

6 early open reading frame proteins (E1,2,3,4,6,7) which function as regulatory proteins
2 late open reading frame proteins (L1 and 2) which make the capsid

Question 4

What are the two phases of HPV replication?

Answer 4

1. infection of basal cells - persistence and evasion of immunity
2. Amplification - genome with virus proteins induce cell division and causes warts

Question 5

What are the herpes viruses that infect humans?

Answer 5

Herpes simplex virus 1 and 2
Varicella-Zoster 
Cytomegalovirus 
Epstein-Barr 
Human herpesvirus 6 
Karposis sarcoma associated herpes virus

Question 6

What do all herpes viruses have in common?

Answer 6

Large linear dsDNA
Capsid
Envelope
Tegument (between capsid and envelope which is packed with virus proteins)

Question 7

What is the important part of herpes virus that leads to infection?

Answer 7

Latency

Question 8

Where is the primary infection and latency of herpes simplex virus 1 and 2?

Answer 8

primary infection is in the primary sensory neurons and the latency is in neurons

Question 9

What is the most common cause of transmission of herpes simplex virus?

Answer 9

asymptomatic shedding

Question 10

Where does herpes simplex virus type 1 and 2 usually infect?

Answer 10

1: facial
2: genital

Question 11

What are the severe manifestations of HSV?

Answer 11

neonatal herpes
Herpes encephalitis
Eczema herpeticum

Question 12

How is Varicella Zoster spread?

Answer 12

Respiratory route - dissemination to lymph nodes and to skin via infected lymphocytes

Question 13

Where is the latency of Varicella zoster?

Answer 13

In the sensory neurons

Question 14

What is the reactivation of Varicella zoster?

Answer 14

Shingles which leads to neural and skin infection

Question 15

What are the 2 Varicella zoster vaccines and when would you use them?

Answer 15

1. Varivax: lower dose for VZV naive (children)

2. Zostervax: higher dose, for booting immunity to prevent zoster (>60)

Question 16

How is human cytomegalovirus spread?

Answer 16

Via close contact - urine saliva and breast milk

Question 17

What is the classic histopathology of human cytomegalovirus?

Answer 17

owl eyes intranuclear inclusions

Question 18

Where is the latency of human cytomegalovirus?

Answer 18

Myeloid progenitors in the bone marrow

Question 19

What is the prevalence of human cytomegalovirus?

Answer 19

50-80% infected by 40

Question 20

What are the groups at high risk of human cytomegalovirus complications and what are they?

Answer 20

Pregnancy: most common cause of congenital defects like blindness, deafness, mental retardation and growth retardation
Immunocompromised: pneumonia and retinitis

Question 21

How is Epstein Barr spread and where is its latency?

Answer 21

Spread via saliva and latency is in B lymphocytes (and some epithelial cells)

Question 22

What is acyclovir used for?

Answer 22

Herpes simplex virus and shingles (tablet and topical cream)

Question 23

What is Ganciclovir used for?

Answer 23

cytomegalovirus