Term
| Are CD4 and CD8 polymporphic? What do they do? |
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Definition
| No; provide specificity for Tc Cells when they interact with MHC |
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Term
| What are the functions of Cytotoxic T Cells (CTL's)? |
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Definition
| Kill virally infected cells, kill cells containing cytosolic bacteria, and kill tumor cells |
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Term
| What is the function of Inflammatory T cells (TH1)? |
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Definition
| Activate macrophages to kill intracellular bacteria |
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Term
| What is the function of Helper T cells (TH2)? |
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Definition
| Activate B cells to make antibody |
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Term
| What part of the MHC molecule is polymorphic? What is the function of this portion? |
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Definition
Class I=α1 & α2
Class II=α1 & β1
Peptide binding site |
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Term
| How do peptides interact with MHC molecules? |
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Definition
| Hydrophobic & Ionic Interactions (high affinity) - NO covalent bonds |
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Term
| How many class I MHC's does each person get? What about class II? |
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Definition
| 6 of each (3 maternal & 3 paternal) |
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Term
| Is there more diversity in Class I or Class II MHC molecules? |
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Definition
| Class II, b/c they can have different combinations of alpha & beta chains |
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Term
| T/F MHC I's can bind hundreds of different peptides as long as they have very similar primary structure. |
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Definition
| False; they can vary greatly |
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Term
| Which end of the MHC molecule is most consistent? |
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Definition
| C terminus - almost always hydrophobic |
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Term
| T/F A low affinity MHC interaction causes a weaker response. |
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Definition
| False; low affinity interaction causes NO response |
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Term
| Once activated what can a T helper cell do? |
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Definition
| proliferate or secrete IL-2 |
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Term
| What are proteins degraded by, and how are they signaled to be degraded? |
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Definition
| Proteasome; tagged by ubiquitin |
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Term
| What is the function of Transporter associated with Antigen Processing (TAPs)? |
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Definition
| TAP takes a sample of the degraded material from the proteasome and sends it to the lumen of the ER to be used for the MHC Class I molecule |
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Term
| When and where do peptides associate with MHC Class I molecules? What type of Ag is used in this case? |
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Definition
| peptide is associated as the MHC is being formed in the ER lumen; endogenous Ag (made in cell) |
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Term
| When and where does the peptide associate with MHC Class II molecules? What type of Ag is used? |
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Definition
| in the cytoplasm after the MHC II has been formed; uses exogenous Ag |
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Term
| Describe the function of the invariant chain. |
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Definition
| Invaraint chain on MHC Class II blocks the peptide binding site so that peptides are not associated with class II as it forms; proteases degrade both the protein and invariant chain to load MHC |
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Term
| What are HLA-DO & HLA-DM? |
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Definition
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