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PCB 3233 IMMUNOLOGY EXAM 4
QUESTIONS WITH DETAILED VERIFIED
ANSWERS
Positive Selection Ans: makes sure that your T-Cell recognizes one of
your MHC.
If it does not, then apoptosis
Negative Selection Ans: Makes sure it does not recognize your
peptide:MHC too strongly
Does gamma: delta T-cells have to go through positive selection? Ans:
No
What does turning off RAG 1&2 do to your gene rearrangement? Ans:
Preserve the current rearrangement
Primary Lymphoid Tissue Ans: bone marrow and thymus
What does TH1 cells do? Ans: Activate macrophages
Thymal Stromal Cells Ans: Keeps BCR genes closed and opens TCR
genes
IgM activates? Ans: complement
Notch-1 Ans: The signal for survival. It drives the cell on the T-cell path
— signals to open up T-cell rearrangement.
Signaling rearrangement keeps T-cel on T-cell pathway
Where does Maturation and Positive Selection occur? Ans: Cortex of the
thymus
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Can negative selection also take place in the Cortex? Ans: Yes, negative
selection can take place in the cortex at the same time as positive
selection
Where does negative selection take place? Ans: medulla of thymus
Where are mature thymocytes located? Ans: Medulla
Where are immature thymocytes located? Ans: Cortex
What special cells are in the Medulla Ans: Dendritic cells, macrophages,
and medullary epithelial cells
What special cells are in the cortex? Ans: Cortical epithelial cells and
macrophages
Where can you find AIRE? Ans: in the medullary epithelial cells
AIRE Ans: Autoimmune regulator
made by medullary epithelial cells
Creates a couple hundred peripheral peptides that can be used to test T-
cells for negative selection
DiGeorge's syndrome Ans: deletion in chromosome 22 in which thymus
fails to develop and T-cells are absent
Hassall's corpuscles Ans: macrophages in both cortex and medulla
remove the many thymocytes that fail to mature properly
Involution of the Thymus Ans: Progressively shrinks, fat gradually
claiming areas once packed with thymocytes
-reduces production of new T-cells
Double negative Ans: No CD4 and CD8
Double Positive Ans: CD4 and CD8 are present
PCB 3233 IMMUNOLOGY EXAM 4
QUESTIONS WITH DETAILED VERIFIED
ANSWERS
Positive Selection Ans: makes sure that your T-Cell recognizes one of
your MHC.
If it does not, then apoptosis
Negative Selection Ans: Makes sure it does not recognize your
peptide:MHC too strongly
Does gamma: delta T-cells have to go through positive selection? Ans:
No
What does turning off RAG 1&2 do to your gene rearrangement? Ans:
Preserve the current rearrangement
Primary Lymphoid Tissue Ans: bone marrow and thymus
What does TH1 cells do? Ans: Activate macrophages
Thymal Stromal Cells Ans: Keeps BCR genes closed and opens TCR
genes
IgM activates? Ans: complement
Notch-1 Ans: The signal for survival. It drives the cell on the T-cell path
— signals to open up T-cell rearrangement.
Signaling rearrangement keeps T-cel on T-cell pathway
Where does Maturation and Positive Selection occur? Ans: Cortex of the
thymus
, Page | 2
Can negative selection also take place in the Cortex? Ans: Yes, negative
selection can take place in the cortex at the same time as positive
selection
Where does negative selection take place? Ans: medulla of thymus
Where are mature thymocytes located? Ans: Medulla
Where are immature thymocytes located? Ans: Cortex
What special cells are in the Medulla Ans: Dendritic cells, macrophages,
and medullary epithelial cells
What special cells are in the cortex? Ans: Cortical epithelial cells and
macrophages
Where can you find AIRE? Ans: in the medullary epithelial cells
AIRE Ans: Autoimmune regulator
made by medullary epithelial cells
Creates a couple hundred peripheral peptides that can be used to test T-
cells for negative selection
DiGeorge's syndrome Ans: deletion in chromosome 22 in which thymus
fails to develop and T-cells are absent
Hassall's corpuscles Ans: macrophages in both cortex and medulla
remove the many thymocytes that fail to mature properly
Involution of the Thymus Ans: Progressively shrinks, fat gradually
claiming areas once packed with thymocytes
-reduces production of new T-cells
Double negative Ans: No CD4 and CD8
Double Positive Ans: CD4 and CD8 are present
