2.7 - Cell Mediated Immunity Flashcards
(60 cards)
___ is the most important primary immune response
Dendritic cells
Dendritic cell function
Process antigen material and present it on the cell surface to T cells, especially in a primary response
Once T cells leave the thymus, they populate
Secondary lymphoid organs
Majority T cells express the ___ T cell receptor
alpha:beta receptor
T cells leave thymus as
Mature naive T cells
Effector cells
Mature naive T cell that has interacted with antigen on DC
Cytotoxic CD8+ location, antigen recognition, and effector action
- Cytosol
- MHC class I
- Killing of infected cell by apoptosis (cytotoxic T cell)
CD4+ TH1 location, antigen recognition, and effector action
- Macrophage vesicles
- MHC class II
- Activation of infected macrophage by cytokines
Class I molecules are located
All cell types, except RBC
Class II cells are located where
On APC (B cells, macrophages, dendritic cells)
What is an immature dendritic cell called?
Langerhans’ cells
Where can you find langerhans’ cells?
In the epithelial area of mucosal surfaces and skin
When do langherhans’ cells become dendritic cells?
When they enter the lymph node to become DC expressing B7
Mature DC can ___ antigens but ___ process
Present antigens but CAN’T process
Immature DC ___ process but ___ present
Can process but can’t present
T cells that don’t encounter specific antigen leave the lymph node in the ___
Efferent lymph
How do naive T cells enter the lymph node?
Across high endothelial venules in the cortex, in the blood or lymph
In the blood T cells interact w/ endothelium cells via ___ expressed by T cell and endothelium cell
Adhesion molecules
Steps for T cell entering lymph node
- T cell enters high endothelial venule (HEV)
- Binding of L-selectin to GlyCAM-1 and CD34 allows rolling
- LFA-1 is activated by chemokines
- LFA-1 binds to ICAM-1
- T cell enters lymph node between 2 endothelial cells (diapedesis)
What are important adhesion molecules?
Intergrin LFA-1 and it’s ligand ICAM-1
Adhesion molecules allow for what?
TCR to come in contact w/ the process antigen associated with the MHC
What are the signals involved in the activation of T cells?
- Signal 1 = MHC & TCR and co-receptors CD4 or CD8
- Signal 2 = co-stimulators B7 on APC and CD28 on the T cell
If the T cell recognized a self antigen, then the T cell would become ___. What does the APC not have?
Anergic
APC doesn’t have co-stimulator molecule (B7)
What does it mean if there is a co-stimulatory signal alone?
- T cell didn’t recognize antigen
- No effect on T cell
