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innate immunity: defenses against any pathogen. adaptive immunity: specific antibody and lymphocyte response to an antig

Innate immunity: Defenses against any pathogen.Adaptive immunity: Specific antibody and lymphocyte response to an antigen.. Historical Development. Pasteur observed immunity in chickens injected with weakened pathogens.Von Behring received the Nobel Prize for development of antitoxin.Ehrlich's work led to the identification of antibodies in serum..

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innate immunity: defenses against any pathogen. adaptive immunity: specific antibody and lymphocyte response to an antig

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    3. Historical Development Pasteur observed immunity in chickens injected with weakened pathogens. Von Behring received the Nobel Prize for development of antitoxin. Ehrlich’s work led to the identification of antibodies in serum.

    4. Terminology Antigen (Ag): A substance that causes the body to produce specific antibodies or sensitized T cells. Antibody (Ab): Proteins made in response to an Ag; can combine with that Ag. Complement: Serum proteins that bind to Ab in an Ag–Ab reaction; cause cell lysis.

    5. Dual Nature of Adaptive Immunity Adaptive immunity develops during an individual’s lifetime.

    6. Dual Nature of Adaptive Immunity Humoral immunity involves antibodies produced by B cells. B cells recognize antigens by antibodies on their surfaces. humoral

    7. Dual Nature of Adaptive Immunity Cell-mediated immunity involved T cells. T cells recognize antigens by TCRs on their surfaces.

    8. Terminology Serology: The study of reactions between antibodies and antigens. Antiserum: The generic term for serum because it contains Ab. Globulins: Serum proteins Immunoglobulins: Antibodies Gamma (?) globulin: Serum fraction containing Ab.

    9. Serum Proteins

    10. Antigenic Determinants Antibodies recognize and react with antigenic determinants or epitopes on an antigen.

    11. Haptens React with antibodies. How is this different from an antibody?

    12. Antibody Structure

    13. IgG antibodies Monomer 80% of serum antibodies Fix complement In blood, lymph, and intestine Cross placenta Enhance phagocytosis; neutralize toxins and viruses; protects fetus and newborn Half-life = 23 days

    14. IgM Antibodies Pentamer 5-10% of serum antibodies Fix complement In blood, lymph, and on B cells Agglutinates microbes; first Ab produced in response to infection Half-life = 5 days

    15. IgA Antibodies Dimer 10-15% of serum antibodies In secretions Mucosal protection Half-life = 6 days

    16. IgD Antibodies Monomer 0.2% of serum antibodies In blood, lymph, and on B cells On B cells, initiate immune response Half-life = 3 days

    17. IgE Antibodies Monomer 0.002% of serum antibodies On mast cells, basophils, and in blood Allergic reactions; lysis of parasitic worms Half-life = 2 days

    18. Activation of B Cells

    19. Clonal Selection

    20. Activation of B Cells T-independent antigen T-dependent antigen

    21. T-Dependent Antigens Activated TH cell secretes cytokines TH cell recognizes antigen

    22. Self-Tolerance Body doesn't make Ab against self. Clonal deletion The process of destroying B and T cells that react to self antigens.

    23. The Diversity of Antibodies During embryonic development, regions of V genes combine with C genes to produce ? 1015 different antibodies.

    24. Antigen—Antibody Binding Affinity: Strength of bond between Ag and Ag. Specificity: Ab recognizes a specific epitope.

    25. The Results of Ag-Ab Binding

    26. M (microfold) cells over Peyer’s patches which contain Antigen-presenting cells and T cells

    27. T Cells Helper T Cells (CD4, TH) TCRs: Recognize antigens and MHC II. TH1: Activate cells related to cell-mediated immunity (TOLL). TH2: Activate B cells to produce eosinophils, IgM, and IgE.

    28. Activation of TH

    29. T Cells Cytotoxic T Cells (CD8, TC) activated in cytotoxic T lymphocytes. CTLs recognize Ag + MHC I. Induce apoptosis in target cell.

    30. Activation of TC into CTL

    31. T Cells Regulatory T Cells (TR) Suppress other T cells

    32. Antigen-Presenting Cells Digest antigen Ag fragments on APC surface with MHC B cells Dendritic Cells

    33. Antigen-Presenting Cells Activated macrophages: Macrophages stimulated by ingesting Ag or by cytokines.

    34. Extracellular Killing Antibody-dependent cells-mediated cytotoxicity. Natural killer cells destroy cells which don’t express MHC I.

    35. Extracellular Killing

    36. Immune System Cells Communicate via Cytokines Interleukin-1: Stimulates TH cells. Interleukin-2: Activates TH, B, TC, and NK cells. Interleukin-8: Attracts phagocytes. Interleukin-10: Intereferes with TH1 cell activation. Interleukin-12: Differentiation of CD4 cells. ?-Interferon: Increase activity of macrophages. Chemokines: Cause leukocytes to move to an infection.

    37. Immunological Memory Antibody titer is the amount of Ab in serum.

    38. Adaptive Immunity Naturally acquired active immunity Resulting from infection Naturally acquired passive immunity Transplacental or via colostrum Artificially acquired active immunity Injection of Ag (vaccination) Artificially acquired passive immunity Injection of Ab

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