Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cancer > Epstein-Barr Virus > Flashcards

Epstein-Barr Virus Flashcards

1
Q

What percentage of human cancers are estimated to be associated with viruses?

A

15-20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How can viruses contribute to cell transformation?

A

Carrying transforming genes within their own genome.

Causing host DNA damage during their life cycle and affecting host transforming genes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three subfamilies of human herpes viruses?

A
  1. Alphaperpesviruses (HSV-1, HSV-2, VZV)
  2. Betaherpesviruses (CMV, HHV-6, HHV-7)
  3. Gammaherpesviruses (EBV, HHV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When are reactivations of human herpes viruses most likely to occur?

A

When carrier is immunosuppressed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name 3 diseases associated with EBV primary infection.

A
  1. Infectious mononucleosis (glandular fever)
  2. Chronic active EBV infection
  3. X-linked lymphoproliferative disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the symptoms of glandular fever?

A

Fever, lymphadenopathy and pharyngitis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the symptoms of chronic active EBV infection?

A

Sever illness of more than 6 months, histologic evidence of organ disease, and demonstration of EBV antigens or EBV DNA in tissue (mimics fatigue syndrome).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the symptoms of X-linked lymphoproliferative disease?

A

Inherited disease of males, absence of functional SAP gene impairs the normal interaction of T and B cells resulting in unregulated growth of EBV-infected B cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give 3 EBV associated diseases related to reduced immunity.

A
  1. PTLD (post transplant lymphoproliferative disease) - a tumour often found in organ transplant patients.
  2. Oral hairy cell leukaemia - nonmalignant hyperplastic lesion of epithelial cells, usually in AIDS patients, but also in other immunosupressed patients.
  3. Chronic interstitial pneumonitis - in AIDS patients.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name 6 cancers which are associated with EBV infection.

A
  1. Nasopharyngeal carincoma
  2. Burkitt’s lymphoma
  3. Hodgkin’s disease
  4. Lymphoproliferative disease and lymphoma
  5. Gastric carcinoma
  6. Nasal NK/T-cell lymphoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the DNA of EBV.

A

Linear dsDNA molecule of about 175kbp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the structure of EBV.

A

Icosahedral capsid.
100-110nm in diameter.
Contains 162 capsomeres with a hole running down the long axis.
An amorphous, sometimes asymmetric material that surrounds the caspid designated as the tegument.
An enevlope containing viral glycoprotein spikes on its surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the main method of transmission for EBV?

A

Salivary contact

e.g. kissing, sharing food, babies toys, coughing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

At what age are the two peaks of infection seen in developed countries?

A

Ages 1-6 and 14-20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In developing countries, how many children are seropositive for EBV by the age of two?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What percentage of teenagers or young adults with primary EBV infection get glandular fever?

A

30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which cells does EBV infect?

A

B-lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the mechanism by which EBV infects B-lymphocytes?

A

By binding viral gp350 to CD21 and viral gp42 to MHCII.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In which area of the body can low grade virus replication and shedding be demonstrated in all seropositive individuals?

A

The epithelium of the pharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the replication origins of the lytic and latent life cycles?

A

oriLyt and oriP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens immediately after viral binding?

A

Endocytosis and transport to the nucleus.

Genome circularises and is maintained as an extrachromosomal plasmid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which area of the body does EBV tend to be active in?

A

Nasopharyngeal lymphoid system (including tonsils)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How many B cells are persistently infected in asymptomatic carriers?

A

0.5-50 B cells/million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the major envelope protein of EBV?

A

Gp350

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In the acute stage which cells control proliferative EBV infected cells?

A

NK cells
CD4
CD8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How many EBV genes are encoded during its latent phase?

A

About 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which nuclear antigens are encoded during the latent phase?

A

EBNAs 1, 2, 3A, 3B, 3C, and LP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which latent membrane proteins are encoded during EBV’s latent phase?

A

LMP1, LMP2A, LMP2B

29
Q

What is the difference between LMP2A and LMP2B?

A

LMP2B uses an internal promoter and is N-terminally truncated compared to A.

30
Q

What is a BART?

A

BamHI A rightward transcript

They include several microRNAs

31
Q

What is the function of EBNA-1?

A

Maintenance of EBV episome.

32
Q

Which genes up-regulate B cell proteins?

A

LMP-1, EBNA-2, EBNA-3

33
Q

What is the function of LMP-2?

A

Protection of reactivation from latency.

34
Q

Which genes cause apoptosis?

A

BHRF1 and LMP1

35
Q

What effect can EBNA1 have in cancer?

A

It can activate potential oncogenes or inhibit tumour suppressor genes.

36
Q

What is the role of USP7?

A

It associated with p53, de-ubiquitinates and therefore inhibits its destruction.
i.e. USP7 stabilises p53

37
Q

What association does EBNA1 have with p53?

A

EBNA1 can associate with p53, blocking the ability of USP7 to associate and stabilise it, resulting in either mutations or degradation of p53.

38
Q

Where is CD40 found?

A

On germinal centre B cells.

39
Q

What allows B cells to switch Ig isotype and/or become a memory B cell?

A

Binding to CD40L (or CD154).

40
Q

What results in NFkappaB expression?

A

Downstream signalling via TRAF-binding domains.

41
Q

What do LMP1 and LMP2 mimic?

A

Normal B-cell survival signals to allow the viral infected cell to persist.

42
Q

Which EBV genes are expressed in Burkitt’s lymphoma?

A

EBER, EBNA-1, BART

43
Q

Which EBV genes are expressed in nasopharyngeal carcinoma and Hodgkin’s lymphoma?

A

EBER, EBNA-1 LMP-1, LMP-2, BART

44
Q

Which EBV genes are expressed in lymphoproliferative disease?

A

EBER, EBNA-1, EBNA-2, EBNA-3s, LMP-1, LMP-2, BART

45
Q

In which instances can lymphoproliferative lesions and lymphomas develop in EBV infected patients?

A

When the patient is immunocompromised.

46
Q

Where in the body might lymphoproliferative lesions and lymphomas develop?

A

GI tract or CNS

47
Q

Which diseases is EBV associated with in AIDS patients?

A

Oral leukoplakia and various non-Hodgkin’s lymphomas.

48
Q

Which condition accounts for half of the fatal cases of infectious mononucleosis?

A

Duncan X-linked lymphoproliferative syndrome.

49
Q

What are the risk factors for PTLD?

A 
Degree of overall immunosuppression
EBV serostatus
Time post transplant
Recipient age
Ethnicity
50
Q

Is PTLD more common in children or adults?

A

Children

51
Q

Which transplants give a higher risk of developing PTLD?

A

Intestinal/multiorgan transplantation (11-33%)

52
Q

What is the clinical presentation of PTLD?

A

Fever
Lymphadenopathy
Allograft involvement
CNS symptoms

53
Q

How can PTLD be treated?

A 
Reduction of immunsuppresion
Antiviral therapy
Monoclonal antibodies
Chemotherapy and radiotherapy
Interferon α
Surgical resection
Adoptive immunotherapy
54
Q

What is rituximab?

A

An anti-CD20 monoclonal antibody.

55
Q

What are the survival rates for somebody with PTLD?

A

25-60%

56
Q

What is adoptive immunotherapy?

A

T-cells stimulated and clonally expanded ex-vivo using EBV transformed LCL.
This generates a panel of host derived EBV-specific cytotoxic T-cells.
Those with highest cytotoxic activity are then transfused back into the patient to try to prevent EBV-PTLD development.

57
Q

Which age range is Burkitt’s lymphoma most common in?

A

3-14 years

58
Q

Which regions have higher incidence of Burkitt’s lymphoma?

A

High malarial regions.

59
Q

Why is Burkitt’s lymphoma associated with malaria?

A

Malaria is thought to inhibit the T cell response to EBV from an early age.

60
Q

How does Burkitt’s lymphoma present?

A

As a rapidly growing tumour of the jaw, face or eye.

61
Q

How is Burkitt’s lymphoma treated?

A

Chemotherapy - responds well in 50-80% of cases.

62
Q

What is the association of EBV to endemic Burkitt’s lymphoma?

A

95%

63
Q

What is the association of EBV to sporadic Burkitt’s lymphoma?

A

20-30%

64
Q

What is the name of the EBV expression pattern found in Burkitt’s lymphoma?

A

Latency I

65
Q

Which chromosomal translocation is found in all BL tumours?

A

All BL tumours harbour a chromosomal translocation that takes the oncogene c-myc (chromosome 8) to an immunoglobulin locus (chromosomes 14, 2 or 22) resulting in deregulated c-myc expression

66
Q

In Hodgkin’s lymphoma what percentage of the tumour mass is made up of malignant cells?

A

1-2%

67
Q

What is the name given to the EBV expression pattern found in Hodgkin’s lymphoma?

A

Latency II

68
Q

How is a nasopharyngeal carcinoma (NPC) treated?

A

Radiation therapy

Chemotherapy

69
Q

Which populations is NPC common in?

A

Southern chinese
Arctic
African mediterranean

Cancer (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions