T1D summary Flashcards
mediators of B cell death
CD8
CD4- Th1 and Th2
Macrophages
B cells
if B cells are infected with an enterovirus they will express
VP1
VP1 expression is also correlated with increased..
PKR and Mda5
PKR mediates
translational arrest
Mda5
unregulated IFN-1- stimulates other cells around to stop protein synthesis- apoptosis
both PKR and Mda5 stop labile proteins being produced e.g.
Mlc-2
Mlc-2
usually prevents apoptosis
concept of insulitiis
- autoantibodies
- B cell and antibody response
- destruction of cells which overexposes HLA-1 (binding region on MHC-1)
HLA-1
binding region on MHC I
autoantibodies in T1 diabetes do not themselves
cause β-cell destruction, but rather reflect autoimmune activity; the β-cell destruction is mediated through T-cell
enterovirus implicated
cocksackie virus B
how do virus’ infect B cells
hijack CAR receptors and enter the B cell (alpha cells have better immune response), because of insulin granules
CAR found on
insulin granules
virus convert RNA into
sdRNA
persistent infection
virus evades immune system- staying the B cell surviving
- doesn’t cause cell to die or evoke an immune response
how does persistent infection occur
viral replication complex
the viral replication complex
stops recognition of virus and avoids cellular response by stopping production of sdRNA
viral replication complex means that virus’ can
permits within B cell without triggering acute immune response
persistent infection is a reason for
late onset- something trigger virus to start replicating dsRNA, meaning it is recognised by the immune system
acute infection
virus starts producing dsRNA rapidly (no viral replication complex), meaning immune system destroys straight away
acute infections are characterised by
sudden onset
biology of +ve single stranded viruses
ssRNA uses reverse transcriptase to convert ssRNA to dsRNA
dsRNA
evokes a strong immune response- not human (unless within viral replication complex)
ssRNA has a specific surface protein which
binds to CAR receptor - increasing uptake