5) T cells and Cell-Mediated Immunity Flashcards
What three signals are required for T cell signaling?
1) TCR-MHC interaction
2) co-stimulatory molecules
CD28/B7
CD40L/CD40
3) production and secretion of cytokines
Which T helper cells lead to cell-mediated immunity?
Th1
Which T helper cells lead to inflammatory response?
Th17
Which T helper cells lead to humoral immunity?
Th2
Which cytokine activates Th1?
IL-12
Which cytokine activates Th2?
IL-4
What cytokines activate Th17 (3)?
IL-1
IL-6
TGF-beta
What three things do Th1 do after it has been activated?
1) release IFN-gamma
2) release cytokines to activate CTL
3) enhance APCs to activate CTL
What do CTLs do after they have been activated?
they bind to infected cells via MHC class I and initiate the process of apoptosis
What are the two mechanisms used by CTL in killing infected cells?
1) degranulation of perforins and granzymes
2) Fas/FasL pathway
Fas is on which cell while FasL is on which cell?
Fas is on target cell, FasL is on CTL (notice the 2L’s)
What cytokines are released after Th2 activation (3)?
IL-4 –> IgE
IL-5
IL-13
What cytokines are released after Th17 activation (2)?
IL-17
IL-22
What transcription factor is induced by TCR’s signal transduction?
AP-1
What does AP-1 lead to?
IL-2 production along with expression of IL-2 receptor (autocrine). Proliferation!!
