1. Overview of the Immune System
The bottom line: You are one bad monkey!

2. A closer look at general (Innate) Immune Response
Skin
Mucous Membranes
Mucus, Fluids
Cillia, hairs
Inflammation
Fever!
Serum Proteins: Complement System. Infection - cell lysis
Interferons
Natural Killer Cells (NK) Cells: Apoptosis, general fighters against Cancer and Viruses

3. Phagocytosis: A major player in Immunity (General and Specific)
Phagocytes…

4. Meet the Leukocytes Neutrophils Monocytes/ Macrophages Eosinophils
Basophils

5. Where can we find these cells and proteins?

6. Where else can we find these cells?

7. Inflammation: a General Immune Response
Chemokines
Vasodilation pre/vascoconstriction post
Histamine (from mast cells in connective tissue) increase capillary permiability
Chemokines attact WBC (Neutrophils then Monocytes) = phagocytosis
When antigens are “mopped up” and clot has stopped bleeding, inflamation dies down.
Fever often associated with inflammation:

8. An overview of Specific Immunity:
Four Characteristics/Attributes of Immunity
Specificity
Diversity
Memory (Effective Response)
Capacity to distinguish self from non-self
Two types of immunity
Humoral:
Cellular:

9. Specific Immune Response: Mediated by Lymphocytes

10. Lymphocyte development

11. Four Characteristics/Attributes of Immunity
Specificity: Each Lymphocyte is specific for a specific antigen
Diversity
Memory
Capacity to distinguish self from non-self

12. An Example of Specificity: A bacteria has multiple antigens (epitopes)

13. A VIRUS HAS MUTLIPLE EPITOPES AS WELL!

14. Lymphocyte Receptor Diversity
1 million
10 million

15. Four Characteristics/Attributes of Immunity
Specificity
Diversity: Your immune system can respond to millions of antigens
Memory (Effective Response)
Capacity to distinguish self from non-self

16. Lymphocytes are Diverse
Why: receptors (B & T Cell) are polymorphic proteins based on a similar structure which are translated from polymorphic, recombined genes.
This occurs during lymphocyte development.
These receptors hook up with other diverse, specific proteins found in other cells called MHC molecules
These other proteins arise from Multi Histonecompatibility Complex (MHC) genes
(these genes are in your cells, and produce proteins as needed)

17. How does this specificity arise?
Lymphocytes (T cells) become activated for an antigen when they interact with infected cells or with macrophages or dedritic cells.
This specificity is made possible by:
Class I MHC
Class II MHC

18. T-cell + MHC = Specificity

19. A closer look at T-cells

20. Lymphocytes: T cells and B cells
Antibodies
Macrophages
Killer T-cells
Activate B-cells to make antibodies
Activate and recruit other immune cells during infection
CD4 Helper T-cells
Images by The Museum of Science and Industry, Chicago
and The Chedd-Angier Production Company, Watertown, MA.

21. Four Characteristics/Attributes of Immunity
Specificity
Diversity
Memory (Effective Response)
Capacity to distinguish self from non-self

22. Clonal Selection: Antigen-driven cloning of lymphocytes
DPL
Short life (effective)
Long life (memory)

23. In other words…
Each antigen, by binding to specific receptors, selectively activates a tiny fraction of cells from the body’s diverse pool of lymphocytes: this relatively small number of selected cells gives rise to clones of 1000s of cells, all specific for -- and dedicated to -- eliminating that antigen.

24. One more look at Immune Memory
Exposure 2
Exposure 1
…This is the principle behind vaccinations

25. Four Characteristics/Attributes of Immunity
Specificity
Diversity
Memory (Effective Response)
Capacity to distinguish self from non-self

26. Acquired Immunity: An Overview

27. Acquired Immunity: An Overview

28. Acquired Immunity: An Overview

29. Helper T-Cells: A closer look

30. Killer T-cells: A closer Look

31. Humoral Immunity 1: Activation of Helper T cells
APC

32. Humoral Immunity 2: T cells activate B cells

33. Humoral Immunity 3: Clonal Selection, and Secretion of Antibodies
2000 Ab/second!

34. Immunoglobins: Globular Proteins secreted by Plasma B-cells
Neutralization,
agglutination
Help with MAC
Confers immunity to fetus,
Promotes Neutralization,
agglutination
General defense,
found in mucous membranes
Promotes histamine release,
Allergic response
May help with B cell differentiation
and clonal selection

35. How do Antibodies Work?
Membrane Attack Complex

36. Blood Groups: An application of Humoral Immunity

37. Allergic Response