1. The Immune System 2 1

2. Adaptive Specific immunity (acquired) = the ability of the body to defend itself against specific invading agents such as bacteria, toxins, viruses, and foreign tissues. Specificity Specificity Memory Memory Lymphocytes T-cells and B-cells Pluripotent stem cells 2

3. Dual Nature of the Immune System Lymphocytes give rise to two major types of immune responses 1.Cell mediated immunity 2.Humoral ( Antibody mediated ) immunity 3

4.  Antigens  Immunogenicity  Reactivity  Hapten  Antigen Receptors 4

5. Cell Mediated Immunity 5

6. Antigen Processing By Antigen Presenting Cells 1. Breakdown the pathogen 2. Place part of the foreign antigen on the MHC molecule Major Histocompatibility Complex  MHC I  MHC II 6

7. FIRST SIGNAL T-cell Receptors TCRs TCRs SECOND SIGNAL o Costimulation T-cell Activation 7

8. Clonal Selection Lymphocyte Differentiation Lymphocyte Differentiation Lymphocyte Proliferation Lymphocyte Proliferation CLONES: CLONES: Effector cells Memory cells 8

9. Antibody Mediated Immunity B-cells gets a little help from her friends – Helper T-cell gets a little help from her friends – Helper T-cell Clonal selection Clonal selectionClones: Plasma cells and memory B cells Plasma cells and memory B cells 9

10. Classes of Immunoglobulins 1.IgG 2.IgA 3.IgM 4.IgE 5.IgD 10

11. Primary Response Secondary Response Autoimmune Disorders 11

12. Study Questions: 21.21 Where do T cells and B cells develop? 21.22 What are the functions of cell-mediated immunity and antibody mediated immunity? 21.23 How do antigens induce an immune response? Use the terms antigen processing and antigen presentation in your answer. 21.24 What is the normal function of major histocompatibility complex self- antigens? 21.32 Outline the steps of antibody production. 21.34 How do the five classes of antibodies differ in function? 21.35 How do antibodies disable antigens? 21.37 How does the complement system destroy microbes? 12