Antigens (foreign cells and molecules)

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Antigens (foreign cells and molecules) viruses


bacteria

foreign tissue

molecules
Some cause disease
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• 3 Lines of defense against disease
• Skin and mucous membranes (non- specific)
• Inflammatory response (non-specific)
• Immune Response (specific)

Exam
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hair
Skin cells with bacteria (green rods)
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• 3 Lines of defense against antigens
• Skin and mucous membranes (non-specific)
• Inflammatory response (non-specific)
• Immune Response (specific)

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Neutrophil, a type of lymphocyte which scavenges
for antigens
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Lymphocytes on wall of blood vessel
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jpg
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Inflammatory Response
Histamine released by damaged cells
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.
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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.
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Neutrophil or macrophage eating bacteria
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• 3 Lines of defense against antigens
• Skin and mucous membranes (non-specific)
• Inflammatory response (non-specific)
• Immune Response (specific)

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Bone
EXAM
Immune Response specific antigen
Bone marrow
Unspecialized stem cell
Thymus Gland
B-cell
T-cell
macrophage
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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
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Antigen antibody complex reduces capacity of
antigen to cause disease
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Rhinovirus with antigenic sites brightly colored
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Antibodies attached to the antigenic sites of the
Rhinovirus
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Specific virus
Specific antibody against specific virus
Specific antibody-antigen (virus) complex
neutralizes virus
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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
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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?
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DNA
Makes protein or antibody X
DNA
New arrangement makes protein or antibody Y
EXAM
Barbara McClintock proposes (1948) that DNA
shuffling makes new genes
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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
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B cells for Viruses A, B, C, D, EX, and
billions more antigens
Virus X
B-cell for Virus X
Virus X B cell for Virus X combine
B cell X is cloned
Clonal Selection theory
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
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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
Cloned plasmacytes make only antibodies for
antigen X
Antigen X Antibody X complex
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Second exposure
EXAM
Amount of antibody
First exposure
0 7 14
0 7 14
Days
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(No Transcript)
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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
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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
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Macrophage eating cancer cell (yellow)
T cell killing cancer cell (yellow) Notice all
thats left is cytoskeleton (yellow)
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Why is cancer a disease of aging?
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Immune system
Relative activity
Incidence of cancer
1 10 20 30 40 50 60 70 80
Human age
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Autoimmune disease immune system attacks self
rheumatoid arthritis

immune system attacks joints
EXAM
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Multiple sclerosis Autoimmune disease T cells
attack nerve cells
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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.