Chapter 16

  1. Humoral response
    • Response against antigen circulating in body fluids
    • Mediated by antibodies produced by B lymphocytes
  2. Cell mediated response
    • Effective against intracellular pathogens and tumor cells
    • Mediated mainly by T lymphocytes (cytotoxic T cells)
  3. Specific Immune response
    • Acquired during life time on exposure of an antigen
    • Has memory
    • Slower immune response
    • Mediated by lymphocytes
  4. Antigen (Ag)
    • A foreign substances that induces immune response
    • Bind to antibody (or T cells) produced against it
  5. Chemical nature of antigen
    Portein, glycoprotein, polysaccharide, nucleic acid in nature
  6. Examples of antigens
    • Cell wall componenets
    • Flagella
    • Frimbrae of bacteria
    • Spike or protein coat of viruses
    • Pollen
    • Fungal spores
    • Metals
    • Certain food items
    • Drugs
  7. Self antigens
    • Antigens present on surfaces of our own cells
    • Not attacked by immune system
  8. Non self (foreign) antigens
    Antigens present on microbes, any foreign cells, or foreign material (food, drugs, spores, pollens, ect.)
  9. Exogenous Antigen
    • Present on the microbes taht are circulating in body fluids
    • (outside the cells)
  10. Endogenous Antigen
    • Present on microbes present inside cells
    • Tumor cells also carry these
    • Present on grafted tissue
  11. Epitope (antigenic determinant)
    3-D Part of an antigen that actually initiates antibody production
  12. Antibody (Ab)
    • Protein produced by B lymphocytes in reponse to specific epitope
    • AKA immunoglobulins (IG)
  13. Structure of an Antibody
    • 2 Heavy and 2 Light chains linked by disulfide bridges (hinge region)
    • Antigen-binding site (epitope)- has variable and constant region
  14. IgG
    • Monomer
    • 80% of serum antibodies
    • Complement activation
    • Opsonization, neutralize toxins & viruses
    • Crosses placenta: protects fetus
  15. IgM
    • Pentamer: Larger antibody
    • Complement activation
    • Agglutinates microbes
    • Neutralization of microbes
    • First Ab produced in response to infection: a high concentration in serum indicates current infection
Card Set
Chapter 16
Specific Immune response