Lecture 6A - Adaptive Immune Response to INTRAcellular Pathogens (Stiner) Flashcards
What type of cell produces IL-12?
macrophages.
what does IL-12 do?
one of its important functions is to tell NK cells to produce IFN-gamma (which activates macrophages)
NK cells have 2 types of receptors.
- Activating receptor
- binds to an NK cell ligand on a normal cell
- Inhibitory receptor
- binds to MHC I-self-peptide complex
How is an NK cell activated?
The ABSENCE of the inhibitor signal from the MHC I
-viruses can inhibit MHC I expression
What happens when an NK cell becomes activated?
degranulation of NK cell kills the infected cell.
Which cytokine helps switch a normal T cell into a Th1 cell?
IL-12
APCs secrete IL-12 in lymph nodes to switch T cells into…
Th1 cells
Where to APCs and T cells come into contact?
lymph nodes
What are the two steps of T cell activation?
- T cell receptor (TCR) binds w/ MHC on APC
- Costimulatory binding
- CD28 (on T cell) binds w/ B7 (on APC)
What does CD28 bind to?
B7
Where is CD28 located?
on T cell
Where is B7 located?
on APC
What two steps are involved when an T cell is activating a B cell?
- TCR binds w/ MHC on B cell
- Costimulatory binding
- CD40L (on T cell) binds w/ CD40 (on B cell)
Where is CD40L?
on a T cell that is working to activate a B cell
Where is CD40?
On a B cell (or a macrophage) that is being activated by a T cell
What are CD40 and CD40L involved in?
Activation of a B cell by a T cell
What do TNF-alpha and IL-1 do?
These cytokines activate endothelial cell sot express adhesion molecules.
_______ kill and ______ protect
macrophages; T cells
________ cells activate macrophages.
T cells activate macrophages by releasing IFN-gamma
Th1 immunity is induced by _______ infections.
viral (intracellular)
Th2 immunity is induced by ________ infections.
bacterial (extracellular)
What MHC does a CTL TCR recognize?
MHC 1
What are 2 accessory molecules on a CTL?
CD8
LFA-1
Where is LFA-1?
CTL
