Thymic Education Flashcards
a:b T cells are found where?
In circulation; they participate in main immune responses
y:d T cells are found where?
In tissues; they help get immune response started
T cells start out in the sub capsular space and they start to:
rearrange their beta chain
Once beta chain rearrangement occurs, the T cells then turn on what genes?
CD4 and CD8
they become double positive
After the T cell is double positive, what is the next step?
Alpha chain arrangement
after alpha chain is done, they move into corticomedullary junction
How many attempts can be made for beta chain rearrangement?
2
beta chain has three - V, D, and J
How many attempts can be made for alpha chain rearrangement?
Many attempts
alpha chain had 2 segments - V and J
The principle that drives positive selection is:
affinity
In healthy cells, you have self-peptide in class __ and clip in class __.
Self-peptide = class 1 Clip = class 2
If a double positive thymocyte binds to an MHC 1, what does is the single positive thymocyte result?
CD8
If a double positive thymocyte binds to an MHC 2, what does is the single positive thymocyte result?
CD4
The principle that drives negative selection is:
avidity
Negative selection occurs in what part of the thymus?
medulla
Where does central tolerance occur?
developmental organ (thymus or bone marrow)
___ is a binding site and plays a role in HIV
GP130
Yc and Bc are also binding sites but are not in HIV
