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30 Cards in this Set
- Front
- Back
What interactions are required for WBC progenitors from BM for T-cell commitment |
Notch-Notch1 |
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T/F The most immature thymocytes are DP |
F; DN |
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T/F The 2nd stage of thymocyte development is DN, then go onto become SP |
t |
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What 3 markers define the (DN1-4) and what do they do? |
CD44, CD25, c-kit Rearrange TCR B, D, and G |
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T/F alpha rearrangement occurs first in TCR develpment? |
F; Beta B selection occurs with invariant TCRa + Cd3 |
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What processes is responsible for self tolerance |
Positive Selection |
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What process is responsible for Self-MHC restriction |
Negative selection |
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T/F Low/Intermediate-affinity signals lead to apoptosis |
F; positive selection and onto SP status |
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95% of Thymocytes do not interact with _____ expressed by thymic epithelium and die by neglect |
MHC/Self peptide |
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What determines whether or not a DP becomes CD4 vs CD8 |
signal continuity: Continuous interaction with MHC2 --> CD4 Interrupted MHC1 --> CD8 (CD8 is down-regualted so Interrupted) |
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What TF is expressed in medulla but not cortext and what is it for? |
AIRE; lets Thymic tissue express tissue-specific Ag for T cell selection/Removal |
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Death by neglect occurs because: |
No sufficient TCR signaling |
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Extrinsic pathway |
Activated death receptors |
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Intrinsic pathway |
Mitochondrial Cyt C release |
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T/F BH3 family have only Pro-Apop factors |
T; Bim/Bad/Puma |
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T/F Bcl-2 has both Anti and Pro Apop factors |
T; Pro is BAX/BAK Anti are the Bcls |
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Beta selection initiates progression to ____ (5) |
DN4 stage Proliferation Allelic exclusion Progression to DP stage And TCR alpha rearrangment |
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Neg selection occurs in the _____ |
medulla of thymus |
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Why do most thymocytes die in the thymus? |
1) Do not make viable TCR 2) Do not bind self-MHC |
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Cytochrome C is in intrinsic or extrinsic pathway? |
Intrinsic |
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T/F Bcl2 inhibits apop by inhibiting Bax |
F; inhibits Cyt C release |
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Do g/d TCR require MHC? If not what are consequnces |
no; able to bind non peptides similar to innate IS recognition |
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What kind of CD4/8 cells are in Thymus of normal mice? RAG1/2 KO? Same for LN? |
|
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What kind of Thymocytes are in mice that don't have MHC 2 |
Everything but CD4 SP; DN, DP, CD8+ |
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What kind of Thymocytes are in mice that don't have AIRE |
All stages but there would be self-reactive cells |
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What kind of Thymocytes are in mice that don't have TCR alpha |
DN and DP only; cant positively select for A/B Will have some gamma delta |
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What kind of thymocytes wouldn't stain for CD3 and TCRB |
DNs |
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What kind of thymocytes wouldn't stain for TCRb but do for CD3? |
G/D T cells |
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T/F When MHC and TCR match lysis occurs, and doesn't occur when they differ |
T; ignore other MHCs |
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T/F Only TC with mature TCR express CD3 |
F; Pre-TCR also do |