EBV

Question 1

How does EBV initiate infections?

Answer 1

Infects cells of the respiratory system and regional lymph nodes

Then spreads to secondary sites via B-cell lineage lymphocytes

Question 2

Describe the structural characteristics of EBV

Answer 2

Double stranded DNA

Icosahedral capsid

Envelope with glycoprotein spikes

Question 3

What is the receptor molecule present on B cells that is utilized by EBV?

Answer 3

CD21

Also binds MHCII

Question 4

What are the primary viral antigens found in EBV infected cells?

Answer 4

EBNA - DNA binding proteins

VCA - capsid

MA - membrane

EA- early antigens

Question 5

Where does EBV establish latent infection?

Answer 5

Memory B cells when competent T cells are present

Question 6

Where does replication of EBV take place?

Answer 6

Permissive cells, resting B cells in the tonsils

Question 7

What is the function of gp350/220?

Answer 7

Glycoproteins that enable attachment of the virus to CD21

Question 8

What genes are expressed during a latent EBV infection?

Answer 8

EB Nuclear Antigen-1 and latent proteins

Question 9

What proteins are important for B cell immortalization during EBV infection?

Answer 9

Latent membrane proteins (3) - stimulate the replication of B cells

Question 10

What diseases is EBV associated with?

Answer 10

Mononucleosis

Burkitts lymphoma

Nasopharyngeal carcinoma

Question 11

What are the three primary symptoms of infectious mononucleosis?

Answer 11

Lyphadenopathy

Splenomegaly

Exudative pharyngitis

Question 12

What are heterophile antibodies?

Answer 12

Polyclonal antibodies (IgM) produced by infected B cells

Detected with monospot test (some patients can be negative)

Question 13

What are Downey cells?

Answer 13

Atypical T lymphoctyes that are large, basophilic, and have foamy cytoplasm

Question 14

What are the best lab tests for EBV?

Answer 14

Virus neutralization

Immunofluoresence

CF for viral antibodies

Question 15

What is the treatment for EBV?

Answer 15

Symptomatic management

Valacyclovir for severe infections

Question 16

What is chronic EBV mononucleosis?

Answer 16

Chronic systemic mono symptoms, fatigue most common

Last months to years

Women most likely affected

Question 17

What does HHV6B cause?

Answer 17

Exanthem subitum (roseola)

Infections B and T cells, can also infect neurons

Can reactivate in transplant patients

Question 18

What do HHV6 and 7 cause?

Answer 18

Roseola - high fever with rash that starts on trunk and face first then spreads

Question 19

What is associated with HHV8 infection?

Answer 19

Kaposi sarcoma - found among AIDS patients

Also rare type of B cell lymphoma