Chapter 3

  1. Humoral Immunity
    • Induction of antibodies
    • Extracellular bacteria > B lymphocytes > elimination of bacteria by antibodies
    • Transferred by serum
  2. Cell-mediated immunity
    • Phagocytosed microbes in macrophage > T cell > activation of macrophage leading to microbial killing
    • Virus infected cell > T cell > lysis of infected cel
    • Transferred by lymphocytes
  3. Classes of lymphocytes
    • 1. B-cells
    • Antibody factories
    • Prevent infection
    • Target pathogens/toxins for destruction
    • 2. T-cells
    • Kill infected cells
    • Direct innate and lymphocyte responses
  4. B cells
    • Secrete their antigen receptor = antibody
    • Antigen = antibody generating, target of immune system
  5. T cells
    • Kill infected cells OR
    • Activate other cells to do so
    • Do not secrete their antigen receptor
  6. Cytotoxic lymphocytes (CTL)
    • CD8 T-cell
    • Defend against intracellular infection
    • By killing infected cells they prevent replication and spreading of infection
  7. T helper lymphocyte (TH)
    • CD4 T cell (co-receptor)
    • Defend against extracellular pathogens by enhancing phagocytosis by macrophages and neutrophils
    • Help B cells make antibodies
  8. B Cell Receptor
    Image Upload 2
  9. T cell receptor
    Image Upload 4
  10. How is specificity of antibody generated?
    Combining receptors generated by uniquely rearranged segments of DNA andother tricks
  11. MHC Class I
    Recognized by CD8
  12. MHC Class II
    Bind to CD4 T cells
  13. Functional outcome of B cell activation
    • Binding of antibody leads to...
    • 1. Neutralization
    • 2. Opsonization
    • 3. Complement activation
    • Ultimately leads to degradatoin by macrophage
  14. Function outcome of Cytotoxic T cell activation
    • Lysis of infected cells
    • Secretion of cytokines (interferon gama)
    • Image Upload 6
  15. Functional outcome of T helper cell activation
    Activation of other cell types (macrophages and B cells)
  16. Principle antigen presenting cells for T cells
    • Dendritic cells
    • Macrophages
    • Circulating mononuclear cells
    • B cells
  17. Principle antigen presenting cells for B cells
    Follicular dendritic cells
  18. Neutralization
    • Way antibody reduces infection
    • Binding to pathogen to inhibit growth, replication, or interaction with humans cells
  19. Opsonization
    • 1. Coating it with antibodies
    • When coated with IgG anitbodies, they bind to receptors on a phagoctye
    • 2. Coating with complement
    • Activation of classical pathway of complement activation
    • Pathogen becomes coated with C3b > increase phagocytosis by macrophages
Author
LT24
ID
5072
Card Set
Chapter 3
Description
Adaptive Immunity
Updated