EBV part II Flashcards
Characteristics of mono regarding viral shedding, infected B cells in periphery and lymphocyte counts?
1) high levels of iral shedding from the oropharynx.
2) high frequencies of latently infected B cells in periphery (circulation)
3) very very high lymphocyte count (particularly T cells)
in primary infection, which CD8+ T cell response is expanded more? CD* response against lytic or latent?
Against lytic.
What is thought to cause the symptoms of glandular fever?
Heavily expanded EBV-specific CD8+ T cells- (almost 50% are against lytic targets.
Do you get large expansion of CD4+ T cells in EBV primary infection?
Yes you do, but not as large versus the CD8+ T cell expansion against EBV epitopes.
Do expanded CD4+ T cells primarily target lytic or latent epitopes in the primary infection?
against latent epitopes.
Is the CD4 or CD8 T cell response broader in primary infection?
CD4 T cell response is broader.
What phenotype do CD8 T cells have in primary infection?
highly activated TEM phenotype: CCR7- CD62L- CD45RO+ CD45RA-.
Similarity and difference in the CD8 T cell response in asymptomatic vs symptomatic people.
Expanded CD8 EBV specific cells which have highly activatated phenotype.
But no overall extreme lymphocyte expansion seen.
What 2 things happen to T cells after primary infection?
They are culled to small memory populations whichch are no longer activated CD38- and have central (regain CCR7 expression) or effector memory phenotype.
Compare the cytokine profiles of T cells in primary and persistent infection.
primary: not very polyfunctional, predominated by IFN-y
persistent: polyfunctional includes TNF-a, IFN-y and IL-2, dominated by TNF-a.
Are CD8 and CD4 T cells cytotoxic in primary and persistent infection?
perforin and granzyme expressed by both CD8 and CD4 T cells during primary infection.
However CD4 T cells lose perforin and granzyme expression in persistence.
Why might B cells make good targets for cytotoxic CD4s?
Because they constitutively express MHC II.
What 3 things are seen with NK depletion and challenge with EBV?
increased plasma IFN-y and viral load. Increased CD8+ T cell count.
Coupled with large expansion of lyrically infected cells.
Does viral load in the throat or PBMCs fall faster after primary infection? What about T cell numbers?
much faster in PBMCs. Lytic viral load much slower in the throat.
EBV-specific responses are much lower in the throat than is seen in the blood.
6-months post-infection, EBV-specific T cells tend to accumulate in the tonsils,. Are latent or lytic specific responses enriched more?
Lytic specific CD8 T cells in the tonsils are enriched more.
