Immune Response
Nonspecific Immune
Response
• Inflammation– Swelling, redness, pain, itching, warmth– Histamines cause the blood vessels to spread open
• WBCs squeeze out of the bloodstream– WBCs attack the pathogen
Blood stream
Nonspecific Immune Response
• Fever– Chemicals cause the hypothalamus to increase
body temp– Stimulates interferon production
• Prevents virus reproduction
– Increases rate of WBC maturity
Specific Immune Response• Body must be able
to identify its own cells
• Antigens: proteins markers on the surface of pathogens (uniforms)
• Immunity: body produces memory cells to “remember” specific antigens
pathogenphagocyte
• Phagocyte engulfs the pathogen via phagocytosis
• Antigens from the pathogen are displayed on cell membrane
Antigenpresentingphagocyte
AntigenPresentingphagocyte
• T cell binds to the antigen presenting cell.
• Protein activates T cell
T cellT cell
• T cell begins to divide into two types of cells:– Memory T Cells– Activated T Cells
T cell
T cellT cell T cell
T cell T cell T cell T cell
Memory T Cells: used at a later date if the pathogen returns
Activated T Cells: fight current pathogen
• Activated T cells bind to infected body cells that show the proper antigens
T cellT cellT cell T cell
T cell T cell T cell T cell
Memory T CellsActivated T Cells
Infectedbody cell showingantigens
• Infected body cell bursts
T cell
T cellT cell
T cell
T cell T cell T cell T cell
Memory T CellsActivated T Cells
Infected bodycell showingantigens
InactivatedB cell
pathogen
• Pathogen binds to the antibodies of a B-cell
pathogen
InactivatedB cell
• B-cell engulfs the pathogen
InactivatedB cell
• Pathogen antigens displayed on cell membrane
InactivatedB cell
• T-cell attaches to the antigens of the B-cell
T cell
InactivatedB cell
• B-cell becomes activated
T cell
ActivatedB cell
• B-cell divides into two types of cells:– Memory B-cells– Activated B-cells
ActivatedB cell
ActivatedB cell
ActivatedB cell
ActivatedB cell
• Activated B-cells produce and release thousands of antibodies each
ActivatedB cell
ActivatedB cell
ActivatedB cell
ActivatedB cell
Memory B-cells: Reserve cells to be used at a later date if the pathogen returns
Activated B-Cells: used to fight the current pathogen
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ody
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ody
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ody
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ody
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ody
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ody
pathogenpathogen
pathogen
• Activated B-cells produce and release thousands of antibodies each
ActivatedB cell
ActivatedB cell
ActivatedB cell
Activated B cell
Memory B-cells: Reserve cells to be used at a later date if the pathogen returns
Activated B-Cells: used to fight the current pathogen
antib
ody
antib
ody
antib
ody
antib
ody
antib
ody
antib
ody
pathogenpathogen
pathogen
• Antibodies bind to pathogens
ActivatedB cell
ActivatedB cell
Activated B-Cells: used to fight the current pathogen
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ody
antib
ody
antib
ody
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ody
antib
ody
antib
odypathogen
pathogen
pathogen
• Phagocytes eat the pathogen clump
ActivatedB cell
ActivatedB cell
Activated B-Cells: used to fight the current pathogen
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ody
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ody
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odyan
tibod
y
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ody
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ody
PHAGOCYTE
Khan Academy: Humoral Immunity
http://www.youtube.com/watch?v=Z36dUduOk1Y
Vaccination• Prevention (not a cure)• Vaccination process
– Weakened pathogen introduced
– Immune system produces…• Antibodies to
fight the weakened pathogen
• Memory cells for future infections
• Goal: Speed up immune response if you encounter the actual virus