restraining immune system Flashcards
what restrains the immune system?
activated regulatory T cells (Inducible TregsNatural Tregs)
what do regulatory T cells secrete?
TGFβ and IL-10
what do activated hyper T cells secrete?
TNF and IFN-γ which activate the immune system
Binds to receptors on T cells–Reduces proliferation–Reduces CTL killing
TGFβ
Binds to receptors on T cells–Blocks co-stimulatory signals (CD28) –more difficult to activate–Reduces proliferation
IL-10
CTLA-4 is binding all the B7 co-stimulatory molecule and…..:
blocks co stimulation and activation
B7 binding to naïve T cell’s CD28 causing:
co stimulation and activation
major antibody class in intestines & tissues below can bind & neutralize invaders
IgA
Develop in MALT, Function to restrain the immune system to keep it from over-reacting to foreign antigen, Function by producing cytokines that suppress the immune response•Two subtypes–Tr1–Th3
iTreg(adaptive)
Develop in the thymus•Function to provide protection against T cells with the potential to react against self antigens and cause autoimmune disease that escaped negative selection in the thymus•Thought to require direct cell to cell contactand are antigen specific
nTreg
a receptor molecule on the T cell. When activated, it amplifies the signal and lowers the number of TCR crosslinks needed for activation.
CD28
receptor molecule on the very experienced T cells. When brought to the membrane, it competes for B7, making co-stimulation and activation more difficult
CTLA4