1. 3rd Line – Immune Response B11-5-02 – Body’s response to viruses/bacteria

2. Immune System Video

3. The 3 Lines of Defense The 1 st line of Defense Barriers Barriers The 2 nd line of Defense Inflammatory response Inflammatory response The 3 rd line of Defense Immune response Immune response

4. Immune system distinguishes “self” from “non-self” Do not react with our own cells Do not react with our own cells

5. Generates specific response to specific invaders Builds up resistance against Pathogens Antigen Antigen Tailored to an individual threat

6. Most effective Memory component Memory component Improves response time

7. Immune Response Two types of specific immune response Antibody-mediated Antibody-mediated Cell-mediated Cell-mediated

8. Antibody-Mediated Immunity

9. Production of antibodies specific to a given antigen Antibodies bind to the antigens on invaders and kill or inactivate them Antibodies bind to the antigens on invaders and kill or inactivate them Antigens are molecules that cause antibody production Antigens are molecules that cause antibody production Response provided by B cells (lymphocytes derived from bone marrow)

10. Lymphocyste Video

11. In Response to Infection A few days after an infection Antigens cause the production of large amount of the antibody capable of interacting with it Antigens cause the production of large amount of the antibody capable of interacting with it Specific antibodies bind specific antigens Specific antibodies bind specific antigens

12. Antibodies Antibodies bind antigens in a lock-and-key fashion Forming antigen-antibody complex Forming antigen-antibody complex Type of protein Immunoglobulin Immunoglobulin Y shaped molecules with Two heavy chains Two heavy chains Two light chains Two light chains

13. Antibodies Cont. Identify Antigens as either Self Self Nonself Nonself Bind non-self antigens clumping them together making them inactive

14. Body only has antibodies for pathogens that a host has encountered When a new pathogen invades the body, B-cells “learn” about new antigens and develop appropriate antibodies The B-Cells then circulate though the body, releasing antibodies that bind to new antigen Antibodies Cont.

15. Antibodies Video 1

16. Antibodies Video 2

17. Antigens Protein or polysaccharide that is present on the plasma membrane

18. Cell-Mediated Immunity

19. Cell-mediated Immunity Require direct physical contact with antigens Does not involve the production of antibodies Response provided by T-Cells (lymphocytes derived from the thymus) Four types Four types

20. 1. Cytotoxic (Killer) T-Cells Defend the body by destroying Foreign cells Foreign cells Infected cells Infected cells Cancerous cells Cancerous cells Recognizes viral antigens on plasma membrane of host cell Attaches to plasma membrane of host cell

21. Secrete enzymes that digest host plasma membrane Punching holes Punching holes Infected cell’s cytoplasm leaks out and the cell dies The dead cell and its contents are removed by phagocytes

22. 2. Helper T-Cells Regulate immune response by … Secreting messenger proteins Secreting messenger proteins Direct contact with other cells Direct contact with other cells Helps Killer T-Cells and B-Cells to perform their function Are destroyed by the HIV virus in patients with Acquired Immune Deficiency Syndrome (AIDS)

23. 3. Suppressor T Cells Reduce the immune response of B cells and T cells to keep them in check

24. 4. Memory T Cells Remain in the body awaiting the reintroduction of the antigen

25. Grab a Text Read and Make Notes 13.3 INDUCED IMMUNITY 13.3 INDUCED IMMUNITY Active Immunity (250) Passive Immunity (251)