CMV, EBV, KSHV

Question 1

What type of replication cycle does the herpes virus undergo?

Answer 1

Lytic replication

Question 2

Describe structure of herpesvirus?

Answer 2

Icosahedral, enveloped, tegument contains the bad stuff (viral proteins)

Question 3

Describe the attachment phase of the lytic replication cycle

Answer 3

herpes virus envlope fuses with the plasma membrane of the cell, nucleocapsid released and it goes to the nucleus

Question 4

What are the 3 phases of the lytic replication cycle

Answer 4

Immediate early, Early, Late

Question 5

What occurs during the immediate early phase?

Answer 5

viral transcription factors are transcribed.

Question 6

Is the host RNA polymerase II used for this?

Answer 6

Yes.

Question 7

What occurs during the early phase?

Answer 7

Replication proteins such as the viral DNA polymerase are transcribed. Thymidine kinase becomes thymidine

Question 8

Late Phase

Answer 8

Structural proteins (capsids, glycoproteins)
Viral glycoproteins are incorporated into virus envelope and transported to cell surface.

Question 9

SUmmarize herpes lytic replication

Answer 9

IE- transcrption factors
E- Replcation machinery (DNA poly)
L- Structural
Assembly occurs in nucleus.
Process is refered to as cascade regulation

Question 10

Where are gnomes maintained during herpesvirus latency

Answer 10

extrachromosomally

Question 11

Is virus produced during latency?

Answer 11

No

Question 12

Three stages of latency

Answer 12

Establishment, Maintenance, Reactivation

Question 13

When does reactivation occur?

Answer 13

During a lapse in immunity, results in the production of virus and recurrent infection

Question 14

How is CMV spread?

Answer 14

STI, through anything liquid in the body….also THROUGH TRANSPLANTS

Question 15

At risk populations?

Answer 15

neonates, day care workers, pregnant workers, gay men, immunocompromised patients

Question 16

WHere does the primary replication of CMV occur?

Answer 16

Epithelial cells of throat then spreads to lymphoid tissue

Question 17

Where does CMV become latent?

Answer 17

B and T cells, monocytes, lymphocytes.

Question 18

What are the symptoms?

Answer 18

In neonates, mostly asymptomatic but can cause deafness and retardation
In adults, mostly asymptomatic but can cause mono.

Question 19

Do most transplant patients develop CMV?

Answer 19

Yes.

Question 20

What is a serious aspect of transplant acquired CMV

Answer 20

pneumonitis can be life-threatening.

Question 21

How is it treated?

Answer 21

CMV Ig and Ganciclovir

Question 22

Diagnosis of CMV

Answer 22

PCR of ELISA….old way was SHell assay

Question 23

Three most common anti-virals for herpesvirus?

Answer 23

Acyclovir, Ganciclovir, Foscarnet

Question 24

WHich is most commonly used for CMV?

Answer 24

Ganciclovir- Guanosine analog, side effects are neutropenia and GI bleeds

Question 25

Is epstein barr virus common?

Answer 25

Yes

Question 26

What is one related symptom of EBV seen in AIDS patients

Answer 26

Oral hairy leukoplakia

Question 27

How is oral hairy leukoplakia caused by EBV treated?

Answer 27

Acyclovir.

Question 28

What two cancers is EBV associated with?

Answer 28

Nasopharyngeal carcinoma and Burkitts lymphoma

Question 29

How is EBV spread?

Answer 29

Saliva

Question 30

WHere does it lay latent?

Answer 30

Originally in the oropharyngeal epithehelium then moves to lymphocytes and then to liver and spleen

Question 31

Symptoms?

Answer 31

most asymptomatic. Some get mono.

Question 32

How is it diagnosed?

Answer 32

Monospot test or by symptoms and the appearance of 50% large lymphocytes with lobulated nuclei

Question 33

What is EBNA

Answer 33

Epstein barr nuclear antigen

Question 34

When does EBNA appear?

Answer 34

early in infection

Question 35

COnversion to what signals the end of primary infection?

Answer 35

Anti EBNA Ig

Question 36

What does VCA stand for

Answer 36

Viral capsid antigen

Question 37

Describe how VCA can help with diagnosis

Answer 37

Presence of Anti VCA IgM means primary infection Presence og anti vca IgG without Anti EBNA indicates primary infection Presence of anti vca IgG with anti EBNA IgG signals the end of primary infection.

Question 38

What does the monospot test look for?

Answer 38

Heterophile antibodies that agglutinate sheeps blood. This is the best test to differentiate EBV mono from CMV mono

Question 39

What is PTLD

Answer 39

Post transplant lymphoproliferative disorder

Question 40

What causes PTLD?

Answer 40

EBV modification of B cells causes them to proliferate out of control and in a post transplant patient taking immunosuppressive drugs, there is no immune response to these B cells.

Question 41

How do we treat PTLD

Answer 41

Take pt off immunosuppressive therapy...risky

Question 42

Burkitts lymphoma, describe it

Answer 42

Neoplasm of B cells that affects jaw bones. ENdemic in Central Africa and New Guinea. Three causes: EBV, Malaria, C-myc activation.

Question 43

Nasopharyngeal carcinoma affects what cells?

Answer 43

Epithelial cells. Most common insouth china. presents as painless lump in neck. very poor survival

Question 44

What is the role which KSHV plays in kaposi's sarcoma

Answer 44

It is necessary but not sufficient to cause KS.

Question 45

Where is KSHV latent?

Answer 45

B cells and endothelial cells

Question 46

Where do KS tumors arise?

Answer 46

lining of lymphatic system.

Question 47

Most KS patients in US are aids pts?

Answer 47

True

Question 48

How is it spread?

Answer 48

Not quite sure. Its an STI but the virus is present in saliva

Question 49

What other B cell abnormalities does KSHV cause?

Answer 49

Primary Effusion Lymphoma | Castelemans disease

Question 50

HBow does Ganciclovir work?

Answer 50

Inhibits viral polymerase

Question 51

How does Foscarnet work?

Answer 51

Inhibits DNA polymerase, does not have to be phosphorylated.

Question 52

Where does EBV lay latent? CMV KSHV

Answer 52

EBV- Throat epithelial and B CMV- B,T, mono, lymph KSHV- lining of lymphoid