Lecture 23.txt

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Lecture 23.txt
2010-04-27 15:16:22
Micro Lecture

Micro 221 Lecture 23
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  1. Tcell receptor
    has variable and constant regions, alpha and beta chains, undergoes somatic recombination, only has ONE antigen binding site
  2. Helper T cel
    have CD4 receptors, bind to MHC II receptors, secrete cytokines (mainly interluekins)
  3. CD4
    Receptor that helps Tcell receptor bind
  4. Autostimulation Cytokines
    secreted by Th Cells to cause Th cell proliferation; they then differentiate into memory T cells supressor T cells
  5. Cytotoxic T cell
    have CD8 receptor, bind to MHC I, secrete perforin for apoptosis
  6. CD8
    helps T cell receptor bind to MHC I
  7. Perforin
    secreted by Tc to kill infected cell by apoptosis
  8. Granzymes
    released by activated Tc cell to induce apoptosis
  9. First Signal
    Binding of TCR to MHC and antigen; binding of CD 4 or 8 to MHC
  10. Second Signal
    binding of CD 28 to B7
  11. Co-Stimulatory peptide B7
    produced once the phagocyte has bound a PaMP; ensures dendritic cells have seen a pathogen
  12. CD28
    receptor on Tcell which binds B7
  13. Interlukin-2
    stimulates the Tc cell as a second signal to activate a Tc cell
  14. Naive T cell
    T cell that hasn't seen a pathogen
  15. Effector T cell
    T cell that has bound to pathogen on MHC and CD28
  16. T dependent Antigen
    must be stimulated by T cell to make antibodies
  17. T independent Antigen
    B cells that can proliferate without a Th cel by binding an antigen to many receptors n the B cell at once
  18. Protein Conjugate vaccine
    T independent antigen is attached to a proein; b cell has typical response and makes antibodies and memory B cells
  19. T regulatory cells
    shut off immune response once the antigen is gone
  20. T memory cells
    reactivated just by binding the antigen; do not need to bind CD28/B7; last 5-10 years
  21. Clonal deletion
    occurs in thymus during T cell development to delete T cells that recognize self antigens
  22. Positive selection
    T cells must bind to MHC I in thymus to get nutrients to develop; if they don't they die
  23. Negative Selection
    If binding to a self antigen in thymus occurs they die
  24. Natural Killer Cells
    Binds to the Fc part of an antibody bound to a pathogen; releases perforins to cause apoptosis
  25. Cancel Kill Signal
    If a MHC I receptor is present on a cell, it isn't killed by NK cells