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33 Cards in this Set
- Front
- Back
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25. What are superantigens?
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a. Bridge T-cell receptors and MHC molecules
b. Leads to nonspecific T-cell activation (leading to inflammatory cytokines which can lead to immune pathology) |
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Do superantigens bind in the MHC groove?
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They DO NOT bind in the MHC peptide groove but bind to the lateral surface of the MHC and to the V-beta region of the TCR, effectively bridging the two
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What is Staphylococcal Toxic Shock Syndrome an example of?
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superantigen activation of T-cell cytokines leading to pathology
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1. What are the essential elements involved in antigen recognition by T cells?
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a. T-Cell receptor complex (on T cell)
b. Antigenic peptide (on APC) c. MHC proteins (on APC) |
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2. Where are Class one MHC
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a. On all nucleated cells
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3. Where are class II MHCs?
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a. On APCs
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4. How do antigens end up being presented on MHC class II cells?
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a. Extracellular antigen is taken into cell
b. Chopped up into peptides c. Bound to MHC class II d. MHC class II presents the peptide at the cell surface |
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5. How do antigens end up getting presented on MHC class I cells?
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a. Antigen starts from within the cell (such as a proliferating virus)
b. Gets chopped up be proteasome in the cell into peptides c. Bind to MHC I d. MHC class I presents peptide at cell surface |
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6. Review: What are the 3 antigen-presenting cells
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a. Dendritic cells
b. B-lymphocytes c. Macrophages |
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7. What antigen presenting cell is most responsible for presenting antigen to T cells?
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a. Dendritic cells
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8. How does antigen uptake occur in the 3 main APCs?
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a. Dendritic: phagocytosis and other
b. Macrophages: Phagocytosis c. B Cells: antigen specific receptor |
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9. Why are dendritic cells the most prevalent APC
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a. They have high surface area
b. Easily move to the T-cells for presentation c. Example: Langerhan cells of the skin |
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10. In a lymph node, where are dendritic cells going to coalesce?
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a. Where the T cells are…so where was that?
b. Pericortical area you smarty pants! |
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11. What allows dendritic cells to present to T-cells (4 factors)
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a. B7: co-stimulatory signal necessary for proper T cell activation
b. MHC Class I and II c. CAMs |
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12. What is B7, where is it located, what does it do and what cell expresses it?
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a. co-stimulatory signal necessary for proper T cell activation
b. located on dendritic cell |
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13. What is an immunological synapse?
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a. Where an APC and a T cell bind
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14. What is CTLA-4? What does it do?
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a. Co stimulatory molecule on activated T Cell
b. Shuts down the T-cell response |
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15. Do B cells need to be stimulated by T-Cell dependent or T-cell independent antigens?
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a. Can be either
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16. For TD antigen vs. TI antigen, are T cells required for AB production?
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a. TD: Yes
b. TI: No |
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17. For TD antigen vs. TI antigen, What type of antigens are involved?
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a. TD: proetien, glycoprotein
b. TI: polysaccharide |
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18. For TD antigen vs. TI antigen, What type of Ab is produced?
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a. TD: IgM, IgG, IgE, IgA
b. TI: IgM |
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19. For TD antigen vs. TI antigen, Which has memory? Do either?
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a. TD: has memory
b. TI: does not |
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what is a TD vs. TI antigen?
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T Cell Dependent vs. T Cell Independent
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20. What is the nature of this T-cell help for B-cell differentiation? That allows for complete expression of B cell antibody response (what molecules?) ***
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a. B-cell CD40 binds to T-cell CD40 ligand (also known as CD154)
b. This is what sends the accessory signal to give the full response of the B cell |
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21. What is one of the main jobs of the T-cells with respect to the B cell?
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a. To help them undergo isotype switching
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22. INF gamma tends to switch B cells to?
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a. IgG for phagocytosis (opsinization)
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23. TH2 releases IL4 causes what isotype switching in B cells?
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a. IgE for parasites and hypersensitivity reaction
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24. TGF Beta causes what isotype switch for B cells?
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a. IgA for mucosal immunity
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25. What are superantigens?
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a. Bridge T-cell receptors and MHC molecules
b. Leads to nonspecific T-cell activation (leading to inflammatory cytokines which can lead to immune pathology) |
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CD4+ T cells recognize what kind of peptide? where on the APC? what kind of MHC is involved?
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exogenous peptide
on the surface of the APC in binding groove of MHC Class II |
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CD8+ T cells recognize what kind of peptide antigens? Where on the APC? Which MHC class is involved?
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Endogenous peptide
Surface of APC MHC Class I |
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CD8 are what kind of T cells (review)
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Cytotoxic
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when macrophages are activated, what MHC class is more highly expressed?
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MHC II
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