1. Antigen fits with this B cell Different B cell clones Making antibodies Many plasma cells Some memory cells When specific B cells are activated, they multiply Some cells become memory cells, stored in case of a subsequent infection B cell response

2. Immunological Memory Memory cells are activated on second exposure to bacteria, virus  response is larger and faster  vaccines introduce antigen vaccination

3. What about T cells? T cells recognize virus-infected or cancerous body cells (cell-mediated)  When triggered, specific T cells divide. Killer T cells contact and release chemicals to kill the affected cells

4. What triggers T cells? Macrophages “wear what they eat” (in this case, self marker plus antigen from pathogen, or cancer- modified self markers) Helper T cells are triggered and activate B cells, killer T cells and memory T cells

5. Antigen-presenting cell Body cell Foreign microbe Processed antigen Antigen MHC protein

6. Helper T-cell activation and the B and T cells formed as a result

7. Protein coat has antigen Virus invades host cell Host cell Virus How Killer T-cells kill body cells

8. Foreign viral antigen Viral antigen is displayed on surface of host cell with self-antigen Virus invaded host cell Self-antigen How Killer T-cells kill body cells

9. Host cell with virus Killer T cell recognizes and binds with a specific foreign antigen complex Killer T cell Antigen complex How Killer T-cells kill body cells

10. Killer T cell releases chemicals that destroy cell How Killer T-cells kill body cells

11. Helper T cells do not kill cells, but amplify effects of other WBCs:  Enhance production of T and B cells, make chemotaxins for phagocytes  “Master switch” for immune response Helper T cells T-lymphocyte

12. Helper T cells are involved with B cell response as well Helper T cells

13. The MHC is a set of genes that code for glycoproteins on cell membranes and mark cells as “self” What are self markers?

14. Matching MHC markers is important when transplanting organs What are self markers?

15. ABO blood types are named by antigens on the surface of RBCs: A, B, AB, or O (neither antigen). People acquire antibodies for the blood antigens they do not have on their RBCs. Blood type O : universal donor (no antigens). Blood type AB : universal recipient (no antibodies) Blood groups

16. Reactivity to a harmless substance in environment Common triggers: pollen, molds, bee stings, dust, fur, mites, penicillin Allergies: adaptive immunity gone wrong

17. Allergens IgE antibodies  Allergies involve a particular type of antibody – IgE antibodies  IgE antibodies trigger mast cells and basophils to produce histamine and other chemicals at the site of the allergens Specific B cell clones Allergies: why in some people and not others?

18.  Hives - allergens on skin  Hay fever - allergens in nasal passages  Asthma - allergens in airway Allergies: adaptive immunity gone wrong