PCB 3233 Immunology Exam 4 Questions with Correct Answers
Chpt.7
1) Development (maturation) of T cells, where does it take place
Maturation of T cells take place in the Thymus
2) What gene segments are rearranged for the alpha and beta chains?
Alpha: V J Beta:
VDJ
3) Are the RAG genes used in the rearrangement?
Yes
4) What makes up a pre-TCR.
CD3 Complex, Zeta Chains, Beta chain, and surrogate alpha chain (PT alpha)
5) Know what IL-7 and Notch-1 do and when they exert their influence on
developing T-cells.
Il-7 is used for proliferation of lymphocytes. It helps T cells know what to do next
in its maturation. IL-7 receptor is essential for binding IL-7 secreted by thymic
stromal cells
Notch 1 is a signaling pathway, the easiest one. It is what keeps these cells on the
T cell patch. It is essential for T cells and makes sure we do not rearrange BCR
genes on a T cell. It opens up the chromatin of T cell genes and begins
transcription inside the nucleus
They are both involved in the maturation of both CD8 and CD4 cells
, 6) DiGeorge’s syndrome. What is the cause? What chromosome is involved
and what organ is involved.
DiGeorge’s Syndrome is nonfunctional and undeveloped Thymus. Part of
chromosome 22 is deleted. Similar to SCID
7) “Double negative” thymocytes; Why are they called this and where would
you find them in the body?
They are called double negative because they do not have CD4 and CD8 on their
surface. They are located in thymic stromal cells inside the cortical region of the
thymus
8) Are RAG-1 and 2 working in somatic recombination of T-cells genes also?
What about the 12/23 rule (1/2 turn rule)?
Yes, they are. Both of them are.
9) Which takes place first positive or negative selection? Where does
positive selection take place and where does negative selection take place?
Positive selection takes place first. Positive takes place in the Cortex of the Thymus
while negative selection takes place in the medulla.
10) Lifespan of a T cell, short or long compared to a B-cell.
T cells are long lived compared to B cells since they are self-renewing.
11) If you are heterozygous for the MHC (HLA) genes how many presenting
MHC (HLA) molecules do you have?
You have 12 MHC (HLA) molecules
Chpt.7
1) Development (maturation) of T cells, where does it take place
Maturation of T cells take place in the Thymus
2) What gene segments are rearranged for the alpha and beta chains?
Alpha: V J Beta:
VDJ
3) Are the RAG genes used in the rearrangement?
Yes
4) What makes up a pre-TCR.
CD3 Complex, Zeta Chains, Beta chain, and surrogate alpha chain (PT alpha)
5) Know what IL-7 and Notch-1 do and when they exert their influence on
developing T-cells.
Il-7 is used for proliferation of lymphocytes. It helps T cells know what to do next
in its maturation. IL-7 receptor is essential for binding IL-7 secreted by thymic
stromal cells
Notch 1 is a signaling pathway, the easiest one. It is what keeps these cells on the
T cell patch. It is essential for T cells and makes sure we do not rearrange BCR
genes on a T cell. It opens up the chromatin of T cell genes and begins
transcription inside the nucleus
They are both involved in the maturation of both CD8 and CD4 cells
, 6) DiGeorge’s syndrome. What is the cause? What chromosome is involved
and what organ is involved.
DiGeorge’s Syndrome is nonfunctional and undeveloped Thymus. Part of
chromosome 22 is deleted. Similar to SCID
7) “Double negative” thymocytes; Why are they called this and where would
you find them in the body?
They are called double negative because they do not have CD4 and CD8 on their
surface. They are located in thymic stromal cells inside the cortical region of the
thymus
8) Are RAG-1 and 2 working in somatic recombination of T-cells genes also?
What about the 12/23 rule (1/2 turn rule)?
Yes, they are. Both of them are.
9) Which takes place first positive or negative selection? Where does
positive selection take place and where does negative selection take place?
Positive selection takes place first. Positive takes place in the Cortex of the Thymus
while negative selection takes place in the medulla.
10) Lifespan of a T cell, short or long compared to a B-cell.
T cells are long lived compared to B cells since they are self-renewing.
11) If you are heterozygous for the MHC (HLA) genes how many presenting
MHC (HLA) molecules do you have?
You have 12 MHC (HLA) molecules
