T Cell Regulation Flashcards
what is the overall purpose of T reg cells
restrain the immune system
in the presence of what cytokine will a t cell become a T reg cell
TGFbeta
activated helper T cells secrete which cytokines to activate the immune system
TNF and IFN-y
activated T reg Cells secrete which cytokines to restrain the immune system
TFGbeta and IL-10
what does TFGbeta stand for
transforming growth factor beta
what does TFGbeta do
- binds to receptors on T cells
- reduces proliferation
- reduces CTL killing
what does IL-10 do
- binds to receptors on T cells
- blocks co-stim signals (CD28)
- reduces proliferation
does the intestines produce TGFbeta
yes (the epithelial cells)
TFGbeta does what in the Peyers Patch
causes T cells to become T reg cells
what do T reg cells do in the GI tract
encourage a calmer mucosal immune system
T/F T reg cells prevent allergies
true
For co-stim does the APC present the B7 or CD28
B7
what do very experienced T cells make more and more of
CTLA-4
what does CTLA-4 do
- binds to B7 and blocks CD28
- out competes CD28
what does CTLA-4 have very difficult for the T cell to do
become activated
what does PD1 stand for
Programmed Death 1 receptor
which cells express PD1
activated T cells
which cells express PD1-L
WBCs and inflamed tissue
what does the engagement of PD1 and PD1-L do
slows proliferation of T cells and may induce apoptosis
what is another name for the PD1-L
the down regulator
T/F any cell that expresses the PD1 receptor can be down regulated
true
T/F once activated, T cell longevity is greatly enhance
False
what does AICD stand for
Activation-Induced Cell Death
explain AICD
- older T cells Fas proteins become sensative
- Fas Ligand and Fas proteins on SAME cell can engage (apoptosis)
- Fas proteins from a younger T cell can engage Fas Ligand on an older T Cells and kill the older T cell
