1. Antigens (foreign cells and molecules)
~ viruses ~ bacteria ~ foreign tissue ~ molecules
Some cause disease

2. 3 Lines of defense against disease
Skin and mucous membranes (non- specific)
Inflammatory response (non-specific)
Immune Response (specific)
Exam

3. Skin cells with bacteria (green rods)
hair
Skin cells with bacteria (green rods)

4. 3 Lines of defense against antigens
Skin and mucous membranes (non-specific)
Inflammatory response (non-specific)
Immune Response (specific)

5. Neutrophil, a type of lymphocyte which scavenges for antigens

6. Lymphocytes on wall of blood vessel

7. Inflammatory Response
Histamine released by damaged cells
Inflammatory Response
Antigens
Skin cells
Bacteria and other antigens
Neutrophils leak out and eat antigens
Histamine causes blood vessels to leak
Capillary with Neutrophils and other blood cells
Same process in allergic reactions to pollen, chocolate, etc.

8. Inflammatory Response
Cut in skin
Damaged cells releases histamine
Neutrophils (WBC) eat bacteria by phagocytosis
Histamine causes capillaries to open up (distended)
White blood cells go to injury site.

9. Neutrophil or macrophage eating bacteria

10. 3 Lines of defense against antigens
Skin and mucous membranes (non-specific)
Inflammatory response (non-specific)
Immune Response (specific)

11. Immune Response – specific antigen
Bone
EXAM
Immune Response – specific antigen
Bone marrow
Unspecialized stem cell
Thymus Gland
B-cell
T-cell
macrophage

12. 30,000 antibodies seconds / cell
Antigen
Helper T cell
Macrophage
Suppressor T cell
B cell
Killer T cell
plasmacyte
Complex formed = antigen + macrophage + B cell + Helper T cell
EXAM
30,000 antibodies seconds / cell

13. Antigen – antibody complex reduces capacity of antigen to cause disease

14. Rhinovirus with antigenic sites brightly colored

15. Antibodies attached to the antigenic sites of the Rhinovirus

16. Specific antibody against specific virus
Specific antibody-antigen (virus) complex – neutralizes virus

17. How can 35000 genes make millions of protein antibodies?
Pre-existing in the human body is at least one specific pre-antibody producing cell (B-Cell) for every possible antigen – literally millions.
How?
How can genes make millions of protein antibodies?
One gene = one protein

18. How do we make so many antibodies or proteins?
Humans and other mammals can make a specific antibody for every antigen to which it is exposed
1000 antigens = 1000 antibodies
1,000,000 antigens = 1,000,000 antibodies
1,000,000,000 antigens = 1,000,000,000 antibodies
1 gene = 1 protein (antibody)
1,000,000 antibodies = 1,000,000 genes
Humans have about 35,000 genes
How do we make so many antibodies or proteins?

19. Barbara McClintock proposes (1948) that DNA shuffling makes new genes
Makes protein or antibody X
DNA
New arrangement makes protein or antibody Y
EXAM
Barbara McClintock proposes (1948) that DNA shuffling makes new genes

20. Watson, Crick, Wilkins get Nobel Prize for DNA Rosalind Franklin
Otto Hahn gets Nobel Prize for discovery of nuclear fission
Barbara gets Nobel Prize (1983) for gene shuffling……………. and a postage stamp
Barbara McClintock
Lise Meitner

21. Clonal Selection theory
B cells for Viruses A, B, C, D, E……………X, and billions more antigens
Virus X
B-cell for Virus X
Virus X + B cell for Virus X combine
Clonal Selection theory
B cell X is cloned
memory B cell X for Virus X
Plasmacyte (formed from B-cell X) makes Antibody X specific for virus X
Antibody X neutralizes Virus X

22. Memory B-cells specific for antigen X
Pre-existing specific B-cells for all antigens
Clonal Selection Theory
Specific antigen X
Cloning of specific B-cell for antigen X
Memory B-cells specific for antigen X
Figure: 27-04
Title: B Cells and Antibody-Mediated Immunity
Caption: B Cells and Antibody-Mediated Immunity.
Cloned plasmacytes make only antibodies for antigen X
Antigen X + Antibody X complex

23. Days EXAM Second exposure First exposure Amount of antibody 0 7 14
Days

24. Figure: 27-05
Title: Prepared for an Invasion
Caption: The memory cells produced by the body during a first attack by an invader allow it to mount a faster, more vigorous defense should the same invader attack a second time.

25. No antibody production Day 1
B cell meets antigen
No antibody production
Day 1
Ribosomes start to appear
Day 2
Endoplasmic reticulum appears
Day 3
More ribosomes and E.R.
Day 4
Antibodies produced
Day 5

26. B cell before contact with antigen – little or no rough endoplasmic reticulum or ribosomes
B cell 5 days after contact with antigen – extensive Rough Endoplasmic Reticulum and ribosomes

27. Macrophage eating cancer cell (yellow)
T cell killing cancer cell (yellow)
Notice all that’s left is cytoskeleton (yellow)

28. Why is cancer a disease of aging?

29. Human age Immune system Incidence of cancer Relative activity
Human age

30. Autoimmune disease – immune system attacks self = rheumatoid arthritis = immune system attacks joints
EXAM
Figure: 27-09
Title: When the Body Attacks Itself
Caption: Rheumatoid arthritis has so disfigured this person’s hands that simply signing a greeting card has become a difficult act. Rheumatoid arthritis is an autoimmune condition.

31. Multiple sclerosis = Autoimmune disease = T cells attack nerve cells

32. Immune cells release histamine when they encounter allergen (antigen such as pollen, chocolate, peanuts, etc.)
allergen
Immune cell
Allergy = overreaction to antigen
Histamine causes sneezing, runny nose, swollen eyes, swollen throat, etc.