PHRD5015 Lecture 23 - Anti-Tumor Defenses

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PHRD5015 Lecture 23 - Anti-Tumor Defenses
2013-12-04 06:15:35
Anti Tumor Defenses

Anti-Tumor Defenses
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  1. what was destruction of tumors by the immune system when tumors were transplanted due to?
    allograft rejection (NOT immune surveillance)
  2. percentage of TCR able to bind to a foreign MHC class I molecule with high affinity (to activate) no matter what antigen is loaded
  3. what nude mice lack
    functional thymus (also means no T cells)
  4. cancer rate in nude mice compared to other mice
    no increase in susceptibility to cancer
  5. what nude mouse cancer rates suggest
    NK cells play a very important part in tumor killing
  6. 2 events leading to the generation of large numbers of immunosuppressed individuals
    • 1) organ transplants
    • 2) HIV infection
  7. increases virally transmitted cancer risk
    immune suppression
  8. cancer survival correlation to high CD4 T-cell infiltration
    low survival
  9. cancer survival correlation to high CD8 T-cell infiltration
    high survival
  10. endogenous antigens are presented by ____
    MHC class I
  11. CD8 T-cells cannot kill without...
    licensing permission from CD4 T-cells
  12. only thing CD4 T-cell can react to
    antigen that comes from a phagocytosis event (necrotic/apoptotic tumor cells)
  13. how CTL kill (2)
    • 1) deliver granzymes to target cell
    • 2) activate Fas (death R -> induces caspase cascade)
  14. how granzymes are delivered
    through pores made by perforin
  15. where NK cells derive from
    lymphoid progenitors in bone marrow
  16. T/F: NK cell receptors undergo recombination like B cells and T cells.
  17. immune system NK cells are part of
  18. 2 NK cell targets
    • 1) cells not expressing MHC class I
    • 2) cells undergoing dangerous levels of stress
  19. absence of inhibitory signal
  20. targeting self cells expressing large amounts of stress proteins
    "induced self"
  21. family of receptors that primarily recognize different HLA alleles
    KIR (Killer Ig-like Receptors)
  22. what expresses KIR
    NK cells
  23. types of KIR that bind HLA alleles
    inhibitory receptors
  24. NK receptor ligands
    representative PAMPS/DAMPS upregulated by cells undergoing stress response
  25. M2-like macrophages that secrete IL-10 & downregulate the immune response
    TAM (tumor-associated macrophages)
  26. M1-like macrophages that secrete cytokines to attract/activate CD8 T-cells & NK cells
    inflammatory macrophages
  27. presence of these T cells in the tumor correlate with a poor prognosis
    CD4/CD25+ T cells (enriched for regulatory T-cell phenotype)