Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
14 Cards in this Set
- Front
- Back
|
Where do T cells originate and where do they mature?
|
They originate in the Bone Marrow and they mature in the Thymus.
|
|
|
What are little baby t-cells called?
|
thymocytes
|
|
|
What are the two main compartments of the Thymus?
|
The Cortex (outer)
The Medulla (inner ) |
|
|
What is a hemopoetic stem cell marker?
|
CD34
|
|
|
What cytokine stimulates T-cell differentiation?
|
IL-7
|
|
|
What's Notch and how does it function?
|
Notch is necessary for T cell development. Notch ligand is on the Thymic epithellium. The ligand binds to the Notch Receptor on the T-cell. Notch-1 is cleaved and binds to a transcription factor.
|
|
|
What are gamma delta cells? What do they do?
|
They're a small minority (1-5%) of T cells. They don't need MHC presentation. similar to innate immune response.
|
|
|
What's positive selection?
|
Only for alpha beta cells. When T-cell can recognize self MHC in thymus it gets signals to continue development. CD4 and CD8 expression is chosen.
|
|
|
What cells express MHC used for positive selection?
|
Cortical epithelial cells in thymus.
|
|
|
What's negative selection?
|
If a t-cell has a tcr that binds too tightly to self peptide/mhc complex it is signaled to apoptose.
|
|
|
Where does negative selection happen?
|
Happens in cortico-medullary junction. Is mediated by dendritic cells.
|
|
|
How do dendritic cells express self protein?
|
AIRE autoimmune-regulator. A transcription factor that allows for expression of all kinds of self genes in thymus.
|
|
|
How is TCR variability generated?
|
V(D for beta)J recombination.
|
|
|
Where do mature naive T cells go?
|
secondary lymphoid tissues
|
