1. Biotechnology I
Immunity

2. Introductory Question
Your body is attacked by microorganisms 24 hours, 7 days a week. Microorganisms are looking to find shelter and nutrients to sustain their life and reproduce.
Given this, why are you not constantly sick?

3. Essential Questions
What distinguishes non-specific immunity from specific-immunity
When does humoral immunity, cell-specific immunity come into play when defending against invading pathogens?

4. Immunity
Definition
Ability of an organism to make chemicals and specific cells that protect the organism from foreign invaders
Analogous to your own Navy Seal Team

5. Resistance Definition
Organism’s ability to defend itself from invading microorganisms

6. Two-Types of Resistance
Non-specific
First and second-line of defense
Prevents pathogens from invading the body
Treats all invading pathogens the same
Most animals have this form of immunity
Specific
Third line of defense
Activated after pathogen enters the body
Defense response specific to invading organism

7. Self versus Non-self
Immune system must distinguish between self and non-self
Self – any component that belongs to the organism
Non-Self- anything that doesn’t belong to the organism

8. Specific immunity
Comes into play when non-specific defense mechanisms fail to ward off infectious agent
Specific defense mechanisms activated with presence of foreign invader

9. Specific Immunity Four key features
Specific- responds to pathogens actually present
Diverse – can respond to wide variety of pathogens
Distinguishes self from non-self- prevents destroying self cells
Immunological memory- effectiveness improves with later exposures

10. Specific Immunity Development of resistance to specific invaders
Development of immunity occur in two ways:
Natural infection – infected with virus or bacteria
Vaccination - injected with inactive form of the microorganism

11. Two Types of Specific Immunity
Humoral Immunity
White blood cells involved – B-lymphocytes (B cells)
Involved in producing antibodies
Attack pathogens floating around in body fluids
Cell-mediated Immunity
White blood cells involved – T-lymphocytes (T cells)
Attack cells infected with pathogen

12. Antigen A molecule that is recognized by the body as non-self
Possesses three characteristics
High molecular weight- large molecule
Chemically complex –typically proteins and polysaccharides
Foreignness (recognized as non-self)

13. Antibody production Antigen stimulate the production of an antibody
Antibody is a protein in the blood plasma that attaches to the antigen and counters its effects
Antibody-antigen complex –insoluble
Ingested and destroyed by macrophages

14. Humoral Immunity Involves B-lymphocytes
Antibodies produced by B-lymphocytes are carried to infection site
Antibodies bind to foreign antigen and neutralize their effect by having the antibody-antigen complex broken down

15. PROPERTY OF PIMA COUNTY JTED, 2010
Think-Pair-Share
Speculate why keeping our environment too clean would be bad for our immune system
Which immune system would most benefit –non-specific or specific immunity? Why?
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class
PROPERTY OF PIMA COUNTY JTED, 2010 3

16. Humoral Response Takes two exposures to trigger the strongest defense
Primary immune response- first exposure to antigen;
triggers formation of effector cells and memory cells
Antibodies produced by effector cells appear in the blood
peaks about two weeks after initial exposure
Secondary immune response –second exposure to the antigen
triggers a faster and stronger response have higher levels of antibodies
response lasts longer

17. Humoral Response

18. Creation of Memory cells
Each exposure to antigen triggers formation of two cells
B cells – survive only a few days; produce antibodies
Memory cells- last a long time; e.g. decades
Memory cells initiate the secondary immune response
Multiply quickly producing a new clone of B cells;
these B cells produce the antibodies

19. PROPERTY OF PIMA COUNTY JTED, 2010
Think-Pair-Share
What do you think the purpose of booster shots when you got vaccinated for childhood diseases like measles, mumps, whooping cough?
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class
PROPERTY OF PIMA COUNTY JTED, 2010 3

20. Creation of Memory Cells