EBV Flashcards
gammaherpes virus
enveloped double stranded DNA virus
85 proteins
EBV associated diseases
infectious mononucleosis - glandular fever in teenagers
burkitts lymphoma
carcinoma
primary infection
oral transmission
replicates in the epithelial cells
lytic replication results in high titre of virus in throat
virus goes into lymphoid tissue to infect B cells
expansion of LCL-like cells in the extra-follicular areas of the tonsils
innate response
dendritic cells recognise EBERs - pamps - via TLR3.
secrete IL-12 and IFN-y
NKC recruited
NKC secrete IFNy activates phagocytosis and T cells
T cells
central to immune response
CD8 cells kill infected cells displaying MHC+ antigen and deliver toxic cargo
coreceptors stabilise interaction - immunological synapse
CD4 cells
TH1 secrete IFNy
LCLs
reservoir for latency
immortal
EBNA and LMP activate B cells into proliferating lymphoblast
LMP1 and 2 cause donstream signalling by binding to the BCR and CD40 promoting memory formation
Burkitts lymphoma
epigenetic mutation, translocation of the MYC oncogene with a heavy chain promoter region - uncontrolled expression
when cell is infected with EBV, EBV removes BIM (pro-apoptosis) so cell doesnt undergo apoptosis and continues to proliferate.
X linked lymphroliferative disease
mutation in the SHD1A gene which encodes SAP protein which binds to SLAM receptors on NK cells, reducing downstream signalling for cytotoxicity
reactivation
Rta and Zta transcription factors activate eachothers promoters
dendritic cells
secrete IFN-a/b which inhibit B cell transformation
immune evasion
IL-10 homologue dampens immune response
inhibits expression of co stimulatory molecules
decreases TAP protein expression, reducing antigen processing and inhibiting MHC presentation.
