T Cell Activation And Generation Of Effector T Cells Flashcards
Where do naive T cells end up?
In the lymph node
What happens when a naive T cell reaches the lymph node?
Migrate through the lymphatic system until they find an antigen
What happens once a naive T cell has been activated?
Move into circulation through the thoracic duct in the vena cava and are preferentially moved into the sites of infection
How does the activated T cell know where to move to?
Specific chemokines released from the site of infection
What do dendritic (/myeloid) cells do?
Detect the presence of infection, get primed and activated present MHC molecules
What do B cells pick up to become professional APCs?
Antigen soluble receptors
What do you need to be fully activated and differentiated into effector or memory cells?
Signal 1- Antigen recognition
Signal 2 - Costimulation
Signal 3 - Cytokines
What does the antigen recognition signal do?
Indicates the immune response
Where is the costimulation signal found?
On dendritic cells
Why is the costimulation signal used?
TCR signalling is not enough to activate a naive cell
What do dendritic cells do?
Upregulate B7, which activate T cells CD28
What does T cell recognition of the antigen cause?
Expression of CD40L on t cells
What does CD40L bind to and what does it lead to?
CD40 on dendritic cell leading to B7 expression and secretion of cytokines
What does CTLA-4 do?
Inhibits the downstream effector processes initiated by TCR MHC/peptide interaction
What does CTLA-4 cause?
Reduction in inflammation after the infection has cleared
