Adaptive Immunity: Specific Defenses of the host

1. Adaptive Immunity: Specific Defenses of the host Ch 17

2. Innate resistance • Immunity: ability of the body to resist pathogens • Due to production of specific lymphocytes and antibodies • Acquired immunity • Naturally – active immunity – get it, get over it • Passive immunity – Mother to child, AB from mother (short term)

3. Dual Nature of Adaptive Immunity Figure 17.8

4. Dual Nature of Adaptive Immunity • T and B cells develop from stem cells in red bone marrow • Humoral immunity • B cells mature in the bone marrow • Chickens: Bursa of Fabricius • Due to antibodies • Cellular immunity • Due to T cells • T cells mature in the thymus ANIMATION Humoral Immunity: Overview

5. Artificially acquired immunity • Vaccination • Antiserum • Gamma globulin (IgG purified)

7. Antigen, anything that can cause an immunological response • Examples

8. Humoral vs.. cell mediated immunity • Humoral is serum immunity • Cell mediated depends on T cells

9. Antibody Structure • The monomer is bivalent • 4 ppt chains, 2 light and 2 heavy • All contain a V region where antibody binding occurs • Y or T shaped know where ab binds, know constant region. • Fc or constant region binds to host cell or complement.

11. Epitopes

12. Haptens: example penicillin Figure 17.2

13. Classes of Immunoglobulin • IgG serum, passive immunity, neutralize, precipitate, opsonize • IgM 5monomers on a chain, agglutination and complement • IgA monomer in serum, dimmers in mucus, protects outer surfaces. • IgD antigen receptors on B cells • IgE antigen receptors on mast cells and basophiles.

14. Apoptosis: programmed cell death, Lymphocytes that are no longer needed destroy themselves. • Clonal selection: during fetal development, self reacting AB is destroyed. During sickness more AB is produced (will review later)

15. Types of WBC

16. Clonal Selection and differentiation of B cells

17. Results of antigen binding • Neutralize • Opsonizaiton • Agglutination • Fixing complement • Precipitation

19. Immunological memory • Ab titer • Plasma cells • Memory cells

22. Monoclonal Antibodies • Immortal cells that produce an antibody that binds to one haptin.

23. Production of Monoclonal AB (fig 18.2)

25. Antibodies can now be manufactured • Used to tread diseases like cancer • How are antibodies treated so that they do not produce an immune response?

26. All of the previous activities are due to B cells.

27. T cells and cell mediated Immunity • Differentiate in the thymus gland (and others) • Classified by cell surface receptors (CD4) • Binds to antigen and APC by MHC

28. Practical applications of Immunology (ch 19) • Vaccines • Heard immunity: if > 85% are immune to a disease, the pathogen has difficulty spreading • Types • Attenuated whole agent – non pathogenic • Inactivated whole agent – dead • Toxoids – inactivated toxin • Subunit vaccine –purified protein • Conjugated vaccine • DNA vaccine – MHC1 associated responses

29. How to make vaccines • Animals • Cell culture • Chick embryos • Recombinant vaccines are much safer

30. Disorders of the Human immune system

31. Defects • Hay fever • Transplant rejection • Autoimmunity • Infection • carriers

32. Hypersensitivity • Rx that lead to tissue damage • Occur when person is sensitized • 4 types

33. Autoimmune disease • From loss of self tolerance • Self tolerance occurs during fetal development • Clonal deletion • Clonal anergy • Graves disease • Myasthenia gravis • Systemic lupus • Rheumatoid arthritis • Hashimotas disease • Insulin dependent diabetes

34. Types of T cells • Classified by certain glycoproteins on surface (clusters of differentiation (CD)) • Th –T helper-CD4 • Recognise an antigen presented on the surface of a macrophage and activate it. • Tc – Cytotoxic T cells –CD8 • When activated by cytokines from the Th cell will change to kill self altered cells

35. Tr – Regulatory T cells – (turn down immune response)

36. Cytotoxic T cells are transformed into CTL’s by a cell with markers on it.

37. The MHC antigen complex induces a toll-like receptor

38. Organisms like large paracites that are too large for ingestion by phagocytic cells must be attacked externally