Chapter 9 Flashcards
Committed lymphocyte progenitors originate in the:
bone marrow.
Hematopoietic stem cells cultured in the presence of which receptor differentiate into T cells rather than B cells?
Notch-ligand
Which of the following molecules would double-negative T cells fail to express?
CD4
Signaling through the pre-TCR occurs as a result of:
successful assembly of the pre-TCR
At what stage of T cell development is the pre-TCR expressed?
DN
Signaling through the pre-TCR results in:
All of the above
Which of the following represents the earliest stage in T-cell development?
DN
T cells selected on a b haplotype thymus would be able to respond to antigen presenting on which of the following haplotype antigen presenting cells?
B and C
Injecting a TCR transgenic mouse with the peptide that it recognizes would result in an increase in which process?
Negative selection
MHCa mice that are irradiated and reconstituted with MHCa × b bone marrow would accept grafts from which of the following donors?
A, B, and C
In negative selection, cells that receive _____________ signal through their antigen receptors die.
a strong
What happens to autoreactive cells that escape the thymus?
All of the above
How do self-antigens that are specific to tissues away from the thymus (like insulin or keratin for example) get in the thymus so that developing T cells that react to them can be deleted?
A transcription factor, AIRE is expressed in thymic medullary epithelial cells, which allows these cells to express proteins normally found in other tissues.
Superantigens differ from regular peptide antigens because they:
All of the above
What is currently the best explanation for what determines whether a T cell develops into a CD8+ T cell or a CD4+ T cell?
CD4 or CD8 expression is determined by the strength and duration of the TCR/MHC interaction.
Which of the following BEST describes the relationship between natural TREGs and induced TREGs?
Natural TREGs develop in the thymus, and induced TREGs develop in the periphery.
Which transcription factor is characteristic of TREG cells?
FOXP3
TREGs have been shown to be protective against which of the following conditions?
Inflammatory bowel disease
Which of the following are characteristics of apoptosis?
Membrane blebbing
Ligation of which of the following cell-surface receptors leads to cell death?
Fas
In some cases of B-cell lymphoma, translocation of bcl-2 into the Ig locus results in overexpression of this gene. Knowing what you do about lymphoma and cancer, what do you predict is the function of bcl-2?
It inhibits apoptosis.
