Immune Tolerance Flashcards
What causes auto immune diseases
No known causes, one susceptibility reasons
What property of the adaptive immune system causes these diseases to be chronic?
Memory
What are the three outcomes for immature lymphocytes that bind strongly to self antigen in primary lymphoid organs?
Apoptosis Bcr editing, t regs
What. Happens to mature reactive cells in the periphery
’ inactivated- anergy
Deleted apoptosis
Suppressed by treg
What allows thymic epithelial cells to express all antigen
‘AIRE- allows for clonal deletion ( central tolerance)
Production of natural t reg cells relay on expression of what?
Fox p3
What are the markers for tregs
CD 4
CD 25
Fox p3
CT LA 4
What is the purpose of T regs
Prevent auto immune reactions
What type of T cells regulate in the periphery
Induced T regs
What must be p resent to induce fox p3 in inducible T cells in periphery?
TGF-b
Describe what is need ed to induce differentiation into iT reg versus th17
In lymph node
, Itreg needs TGFb and IL-2
T17 needs TGFb and Il 6 and IL 1
How do t regs promote peripheral tolerance
Directly block apc ability to activate T cells
Prevent T cells from helping with B cell affinity mat and switching
Prevent CD 4 and 8 from differentiating into effector cells
Where do B cells expressing bcr for self antigen under go editing?
Bone marrow
What chain undergoes editing if B cells are self reactive?
Light chain
What inhibitory receptor on B cells is involved in induction of peripheral b tolerance to self antigen
CD22
Activate recruit SHP-1 tyrosine phosphotase which turns off b c cell s’ignaling
Binds Salic acid which is only on human cells
