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

antib

ody

antib

ody

antib

ody

antib

ody

antib

ody

antib

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

antib

ody

antib

ody

antib

ody

antib

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

antib

ody

antib

ody

antib

odyan

tibod

y

antib

ody

antib

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