4. T cell development Flashcards
(37 cards)
What is a double negative T cell?
CD3- 4- 8-
What is a large active, double positive T cell?
CD3+ pTalpha:beta 4+ 8+
What is a small resting, double positive T cell?
CD3+ alpha:beta 4+ 8+
What is a small resting single positive T cell?
CD4+8- / CD4- 8+
In which order do T cells develop?
double negative
large active double pos
small resting double pos
small resting single pos
Which part of the thymus does positive and negative selection occur
medulla
What is pre Tau alpha?
A surrogate alpha chain
What is CD3 important for?
Signalling
Which stage does germline gene configuration occur?
DN1 and 2
Which stage does beta chain D-J rearrangement occur?
DN 2 and 4
Which stage does beta chain V-DJ rearrangement occur?
DN 3-4
At which stage is there a functional beta chain?
DN 4
What is the purpose of positive selection?
Ensures all TCR bearing cells can interact with self MHC
Where does positive selection take place
Thymis cortical epithelial cells
Where does negative selection take place
thymic cortex and medulla
CD8 T cell main function
Kill virus -infected cells
CD4 Th1 main function
Activate infected macrophages
Provide help to B cells for antibody production
CD4 Th2 main function
Drive antibody production, especially switching to IgE
CD4 Th17 main function
Enhance neutrophil recruitment
CD4 Tfh main function
B cell help - isotope switching
CD4 Treg main function
Suppress T cell responses
4 Stages of a T cell getting into lymph node
- Rolling
- Activation
- Adhesion
- Diapedesis
What does T cell express during rolling?
Selectins e.g. L selectin
What does T cell express during activation?
Chemokines e.g. CCL21