1. Immune System Cells and Cell Products That Protect the Body Against Disease

2. T cells B cells

3. Properties of the Immune Response A.Specificity: Unique response against each each invader B. Memory: Increased response at next invasion C. Discrimination: Ability to distinguish “self” from “non-self”

4. Applying Your Knowledge Which property of the immune response: A.keeps you from developing chicken pox a second time? (Assume you had a severe case at age six.) B.helps you successfully recover from a cold? C.causes you to reject a donated organ? 1.Specificity 2.Memory 3.Discrimination between Self and Non-self

5. Sources and Transport of Immune System Cells Sites of immune cell production or maturationSites of immune cell production or maturation bone marrowbone marrow spleenspleen thymusthymus tonsilstonsils CirculationCirculation –lymphatic system lymph vesselslymph vessels lymph nodeslymph nodes –bloodstream

6. Cells of the Immune System B cells produce antibodies that bind to antigens on the surface of the invader T cells carry out cell-cell interactions Macrophages engulf invaders and provide signals for other immune system cells

7. Activities of Macrophages Surround invader with plasma membrane and bring it into cell (phagocytosis)Surround invader with plasma membrane and bring it into cell (phagocytosis) Display antigen on surface by making a complex with MHC proteinDisplay antigen on surface by making a complex with MHC protein MHC= major histocompatibility complex, 70 genes that code for cell surface proteins

8. B Cells Fight Against Viruses and Bacteria Each B cell carries a unique antibody on its surfaceEach B cell carries a unique antibody on its surface When antigen on surface of invader binds to antibody on B cell, the B cell divides and gives rise to two types of cellsWhen antigen on surface of invader binds to antibody on B cell, the B cell divides and gives rise to two types of cells --plasma cell: actively secretes antibody into bloodstream --memory B cell: responds on second invasion

9. Primary Response: initial activation of immune system and destruction of invader Secondary Response: faster and stronger activation of immune system due to memory cells Memory Cells and the Immune Response

10. Antibody Structure  Antibody has 2 heavy chains and 2 light chains.  Each chain has variable (V) and constant (C) region.  Variable regions bind to antigen.  Constant regions bind to cells or other antibodies.

11. Gene for constant region of light chain Genes for variable region of light chain Gene for constant region of heavy chain Genes for variable region of heavy chain Recombination during Construction of Antibody Genes

12. Antibodies Mark Invaders for Destruction Phagocytosis by a Macrophage

13. Applying Your Knowledge A.Which part of the antibody binds to the antigen? (choices on left) B.Which type of protein structure is seen in a functional antibody molecule? (choices on right) 1.Light Chain 2.Heavy Chain 3.Variable Region 4.Constant Region 1.Primary Structure 2.Secondary Structure 3.Tertiary Structure 4.Quaternary Structure

14. Classes of T Cells 1.Helper T cells: activate B cells and cytotoxic T cells 2.Cytotoxic T cells: rupture infected body cells or cancer cells T cell Cancer cell Cytotoxic T cell attacks a cancer cell

15. Communication Among Cells 1. Macrophage engulfs invader 2. Macrophage displays “processed” antigen 5. Macrophage releases cytokines to activate Helper T cell 4. Helper T Cell binds to Macrophage 3. Invader binds to B cell that carries antibody matching the antigen 6. Activated Helper T cell stimulates division of selected B cell 7. Dividing B cell gives rise to memory B cells and plasma cells

16. Applying Your Knowledge Which immune system cell: A.keeps you from developing chicken pox a second time? (Assume you had a severe case at age six.) B.helps you successfully recover from a cold? C.causes you to reject a donated organ? 1.Macrophage 2.Plasma Cell 3.Memory B Cell 4.Helper T Cell 5.Cytotoxic T Cell

17. Humoral and Cellular Immunity Humoral(Antibody-mediated)Cellular (T-cell mediated) Hay fever Reaction to poison ivy Transfusion reactions Tuberculin Test Rh disease Reaction to bee stings Immunization Graft (organ) rejection Viral and Bacterial infections Cancer Prevention

18. Diseases of the Immune System A.Inherited Immune Deficiencies eg. SCID: Severe Combined Immune Deficiency B. AIDS: Acquired Immune Deficiency Syndrome C. Autoimmune diseases 1. Scleroderma 2. Rheumatiod arthritis D. Allergies

19. Allergies Produces antibodies with unique constant region (IgE) IgE antibodies bind to mast cells Mast cells release histamines Antigen binds to IgE on mast cells Antigen binds to B cell and activates it

20. HIV Glycoproteins Glycoproteins Envelope (lipid bilayer) Envelope (lipid bilayer) Protein Coat Protein Coat Core Proteins Core Proteins Reverse Transcriptase Reverse Transcriptase Viral RNA in protein coat Viral RNA in protein coat

21. Entry of HIV Retrovirus into Host Cell DNA copy of retroviral genome

22. Production of New Viral Particles Contains more than one protein product; individual proteins are separated by protease

24. HIV Binds to CD4 and CCR5 Co-receptors on Helper T cells Individuals that are homozygous for a deletion mutation in the CCR5 gene are resistant to HIV infection.

25. HIV Destroys T cells

26. Use of ELISA to detect Antibodies to HIV ELISA = Enzyme-Linked Immunosorbent Assay Tests serum for the presence of antibodies directed against HIV

27. ELISA Procedure HIV antigen Infected Person Uninfected Person No Anti-HIV in serum of uninfected person Anti-HIV in serum of infected person Anti-IgG with horseradish peroxidase enzyme Anti-IgG with enzyme does not bind Substrate:Salicylate(colorless)Product:OxidizedSalicylate (brown) No brown product formed ResultResult

28. Instructions for ELISA Follow ALL directions on pages 90-101 of workbook (summarized in these slides)Follow ALL directions on pages 90-101 of workbook (summarized in these slides) Label the vertical side of a microtiter plate as Rows 1, 2, 3, 4 so that there are three wells per row.Label the vertical side of a microtiter plate as Rows 1, 2, 3, 4 so that there are three wells per row. Add the antigen: Use a micropipettor and a CLEAN tip to add 0.1 mL (100 uL) of HIV antigen (viral antigens) to all wells.Add the antigen: Use a micropipettor and a CLEAN tip to add 0.1 mL (100 uL) of HIV antigen (viral antigens) to all wells. Incubate at room temperature for 5 minutes then empty the wells with the “flip and bang” method.Incubate at room temperature for 5 minutes then empty the wells with the “flip and bang” method. Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method.Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method.

29. Instructions for ELISA Add the test sera: (use clean tip for each)Add the test sera: (use clean tip for each) –100 uL PBS buffer to the three wells in row 1 (negative control). –100 uL of “+” (positive control: antibody to the HIV antigen) to the three wells in row 2. –100 uL of Donor Serum 1 to the three wells in row 3. –100 uL of Donor Serum 2 to the three wells in row 4. Incubate at 37 o (oven on side bench) for 15 minutes then empty the wells with the “flip and bang” method.Incubate at 37 o (oven on side bench) for 15 minutes then empty the wells with the “flip and bang” method. Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method.Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method.

30. Instructions for ELISA Add the 2 o Ab: Place 100 uL of the anti-IgG peroxidase conjugate in all 12 wells.Add the 2 o Ab: Place 100 uL of the anti-IgG peroxidase conjugate in all 12 wells. Incubate at 37 o (oven on side bench) for 15 minutes then empty the wells with the “flip and bang” method.Incubate at 37 o (oven on side bench) for 15 minutes then empty the wells with the “flip and bang” method. Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method.Wash the wells: Add PBS buffer with transfer pipette, empty wells with “flip and bang” method. Add the substrate: Place 100 uL of the substrate in all 12 wells.Add the substrate: Place 100 uL of the substrate in all 12 wells. Incubate at 37 o (oven on side bench) for 5 minutes.Incubate at 37 o (oven on side bench) for 5 minutes. Evaluate the plate for color changeEvaluate the plate for color change