08 EBV Refresher

Question 0

EBNA1

Answer 0

Usually the only EBV protein expressed in latent life cycle

• poorly immunogenic
• maintains episome matinence

Question 1

EBV classification

Answer 1

Enveloped Gammaherpesvirus

Single Stranded DS +- DNA Genome

Question 2

EBV proteins causing cell cycle

Answer 2

EBNA 2,3
LMP1,2
BARF1

Question 3

EBV pathogenesis

Answer 3

Infectious EBV always in saliva
>95% in DEVELOPING infected by 3 years old- mild cold symptoms

in DEVELOPED countries 70% 12 y.o. positive
*EBV during adolescence causes MONONUCLEOSIS >95% infected before finishing college

Question 4

MONONUCLEOSIS

Answer 4

• Massive CD8(+) T cell reaction “Downy cells”

* B cell expansion with heterophile antibodies

Question 5

Clinical course of mono

Answer 5

*up to 2 month incubation (usually 2 weeks)
* 3 week syndrome:
Fever, Lymphadenopathy, splenomegaly, pharyngitis, malaise and fatigue, virus in saliva, ATYPICAL LYMPHOCYTES AND HETEROPHILE ANTIBODIES
*Anti EA at around 7 days
* Anti VCA IGM 7 days- 1 month, After that Anti VCA IgG
*Anti EBNA1 after a few months

Question 6

EBV oncogenesis mechanisms

Answer 6

Direct transformation, Hit-and-run, Bystander effect, Chronic inflammation

Question 7

EBV direct transformation

Answer 7

Possibly:
^EBV monos =^Bcells
Latency II, and IIIproteins oncogenic in mouse

Not probable:
Oncogenes weren’t necessary for transformation
Only select individuals acquire lymphomas

Question 8

EBV Hit and run

Answer 8

EBV causes replication and genomic instability which probably leads to endemic Burkitts t(8;22) translocation

Question 9

Chronic inflammation

Answer 9

Hodgkins lymphoma is associated with EBV and lots of non-transformed inflammatory cells

Question 10

Bystander effect

Answer 10

Do the EBV replicating cells release cytokines and GFs leading to transformation of nearby cells?