PCB 3233 Immunology Exam 4 questions with correct answers

PCB 3233 Immunology Exam 4 questions with correct
answers


Positive Selection - ** VERIFIED ANSWERS **✔✔makes sure that your T-Cell recognizes one of
your MHC.



If it does not, then apoptosis



Negative Selection - ** VERIFIED ANSWERS **✔✔Makes sure it does not recognize your
peptide:MHC too strongly



Does gamma: delta T-cells have to go through positive selection? - ** VERIFIED ANSWERS **✔✔No



What does turning off RAG 1&2 do to your gene rearrangement? - ** VERIFIED ANSWERS
**✔✔Preserve the current rearrangement



Primary Lymphoid Tissue - ** VERIFIED ANSWERS **✔✔bone marrow and thymus



What does TH1 cells do? - ** VERIFIED ANSWERS **✔✔Activate macrophages



Thymal Stromal Cells - ** VERIFIED ANSWERS **✔✔Keeps BCR genes closed and opens TCR
genes



IgM activates? - ** VERIFIED ANSWERS **✔✔complement



Notch-1 - ** VERIFIED ANSWERS **✔✔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? - ** VERIFIED ANSWERS **✔✔Cortex of the
thymus



Can negative selection also take place in the Cortex? - ** VERIFIED ANSWERS **✔✔Yes, negative
selection can take place in the cortex at the same time as positive selection



Where does negative selection take place? - ** VERIFIED ANSWERS **✔✔medulla of thymus



Where are mature thymocytes located? - ** VERIFIED ANSWERS **✔✔Medulla



Where are immature thymocytes located? - ** VERIFIED ANSWERS **✔✔Cortex



What special cells are in the Medulla - ** VERIFIED ANSWERS **✔✔Dendritic cells, macrophages,
and medullary epithelial cells



What special cells are in the cortex? - ** VERIFIED ANSWERS **✔✔Cortical epithelial cells and
macrophages



Where can you find AIRE? - ** VERIFIED ANSWERS **✔✔in the medullary epithelial cells



AIRE - ** VERIFIED ANSWERS **✔✔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 - ** VERIFIED ANSWERS **✔✔deletion in chromosome 22 in which thymus
fails to develop and T-cells are absent

, Hassall's corpuscles - ** VERIFIED ANSWERS **✔✔macrophages in both cortex and medulla
remove the many thymocytes that fail to mature properly



Involution of the Thymus - ** VERIFIED ANSWERS **✔✔Progressively shrinks, fat gradually
claiming areas once packed with thymocytes



-reduces production of new T-cells



Double negative - ** VERIFIED ANSWERS **✔✔No CD4 and CD8



Double Positive - ** VERIFIED ANSWERS **✔✔CD4 and CD8 are present



Single Positive - ** VERIFIED ANSWERS **✔✔has either CD4 or CD8



CD2 and CD5 - ** VERIFIED ANSWERS **✔✔perform adhesion and signaling. They are present
during double negative stage



Thymocytes rearrange which 3 genes at the same time? - ** VERIFIED ANSWERS **✔✔Beta,
gamma, and delta



pTalpha - ** VERIFIED ANSWERS **✔✔surrogate alpha chain. signals cell to halt gamma, delta,
Beta chains, gene rearrangement and begin proliferation.



What do macrophages do in the thymus? - ** VERIFIED ANSWERS **✔✔continually remove dead
cells



How many rearrangements can successfully make a Beta chain? - ** VERIFIED ANSWERS **✔✔up
to 4 attempts



d:k light chain can have a minimum of how many rearrangements? - ** VERIFIED ANSWERS
**✔✔4 minimum attempts