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

Antigens (foreign cells and molecules)

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Page 1: Antigens (foreign cells and molecules)

Antigens (foreign cells and molecules)

~ viruses ~ bacteria ~ foreign tissue ~ molecules

Some cause disease

Page 2: Antigens (foreign cells and molecules)

3 Lines of defense against disease1. Skin and mucous membranes (non- specific)

2. Inflammatory response (non-specific)

3. Immune Response (specific)

Exam

Page 3: Antigens (foreign cells and molecules)

Skin cells with bacteria (green rods)

hair

Page 4: Antigens (foreign cells and molecules)

3 Lines of defense against antigens1. Skin and mucous membranes (non-specific)

2. Inflammatory response (non-specific)

3. Immune Response (specific)

Page 5: Antigens (foreign cells and molecules)

http://www.beyondbooks.com/lif71/images/00016305.jpg

Neutrophil, a type of lymphocyte which scavenges for antigens

Page 6: Antigens (foreign cells and molecules)

http://darwin.bio.uci.edu/~cchughes/Media/VessSEM.jpg

Lymphocytes on wall of blood vessel

Page 7: Antigens (foreign cells and molecules)

Inflammatory Response

Skin cells

Bacteria and other antigens

Histamine released by damaged cells

Histamine causes blood vessels to leak

Neutrophils leak out and eat antigens

Capillary with Neutrophils and other blood cells

Same process in allergic reactions to pollen, chocolate, etc.

Antigens

Page 8: Antigens (foreign cells and molecules)

Cut in skin

Histamine causes capillaries to open up (distended)

White blood cells go to injury site.

Neutrophils (WBC) eat bacteria by phagocytosis

Inflammatory Response

Damaged cells releases histamine

Page 9: Antigens (foreign cells and molecules)

Neutrophil or macrophage eating bacteria

Page 10: Antigens (foreign cells and molecules)

3 Lines of defense against antigens1. Skin and mucous membranes (non-specific)

2. Inflammatory response (non-specific)

3. Immune Response (specific)

Page 11: Antigens (foreign cells and molecules)

Unspecialized stem cell

Thymus Gland

macrophageT-cell

Bone marrowImmune Response –

specific antigen

Bone

B-cell

EXAM

Page 12: Antigens (foreign cells and molecules)

B cell

Macrophage

plasmacyte

Killer T cell

Suppressor T cell

Helper T cell

Complex formed = antigen + macrophage + B cell + Helper T cell

Antigen

EXAM 30,000 antibodies seconds / cell

Page 13: Antigens (foreign cells and molecules)

Antigen – antibody complex reduces capacity of antigen to cause disease

Page 14: Antigens (foreign cells and molecules)

Rhinovirus with

antigenic sites

brightly colored

Page 15: Antigens (foreign cells and molecules)

Antibodies attached to the antigenic sites of the Rhinovirus

Page 16: Antigens (foreign cells and molecules)

Specific virus

Specific antibody against specific virus

Specific antibody-antigen (virus) complex – neutralizes virus

Page 17: Antigens (foreign cells and molecules)

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 35000

genes make millions of protein

antibodies?

One gene = one protein

Page 18: Antigens (foreign cells and molecules)

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?

Page 19: Antigens (foreign cells and molecules)

Makes protein or antibody X

New arrangement makes protein or antibody Y

DNA

DNA

Barbara McClintock proposes (1948) that DNA shuffling makes

new genes

EXAM

Page 20: Antigens (foreign cells and molecules)

Lise Meitner

Otto Hahn gets Nobel Prize for

discovery of nuclear fission

Rosalind FranklinWatson, Crick, Wilkins get Nobel

Prize for DNA

Barbara McClintockBarbara gets Nobel Prize (1983) for gene shuffling……………. and a postage stamp

Page 21: Antigens (foreign cells and molecules)

memory B cell X for Virus X

B cell X is cloned

B cells for Viruses A, B, C, D, E……………X, and billions more antigens

Virus X + B cell for Virus X combine

Virus X

Clonal Selection

theory

B-cell for Virus X

Plasmacyte (formed from B-cell X) makes Antibody X specific

for virus X

Antibody X neutralizes Virus X

Page 22: Antigens (foreign cells and molecules)

Clonal Selection Theory

Pre-existing specific B-cells for all antigens

Specific antigen X

Cloning of specific B-cell for

antigen XMemory B-cells specific

for antigen X

Cloned plasmacytes make only antibodies

for antigen XAntigen X + Antibody X complex

Page 23: Antigens (foreign cells and molecules)

0 7 14

First exposure

Second exposure

Days

Amount of

antibody

0 7 14

EXAM

Page 24: Antigens (foreign cells and molecules)
Page 25: Antigens (foreign cells and molecules)

Day 1No antibody production

Day 2

Day 3

Day 4

Day 5

B cell meets antigen

Ribosomes start to appear

Endoplasmic reticulum appears

More ribosomes and E.R.

Antibodies produced

Page 26: Antigens (foreign cells and molecules)

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

Page 27: Antigens (foreign cells and molecules)

T cell killing cancer cell (yellow)

Notice all that’s left is cytoskeleton (yellow)

Macrophage eating cancer cell (yellow)

Page 28: Antigens (foreign cells and molecules)

Why is cancer a disease of aging?

Page 29: Antigens (foreign cells and molecules)

1 10 20 30 40 50 60 70 80

Immune system

Incidence of cancer

Relative activity

Human age

Page 30: Antigens (foreign cells and molecules)

Autoimmune disease – immune system attacks self = rheumatoid arthritis = immune system attacks joints

EXAM

Page 31: Antigens (foreign cells and molecules)

Multiple sclerosis = Autoimmune disease = T cells attack nerve cells

Page 32: Antigens (foreign cells and molecules)

Immune cells release histamine when they encounter allergen (antigen such as pollen, chocolate, peanuts, etc.)

Immune cell

allergen

Histamine causes sneezing, runny nose, swollen eyes, swollen throat, etc.

Allergy = overreaction to antigen