Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings About this Chapter  Anatomy and function of immune system  Response to different pathogens  Innate immunity: nonspecific body defenses  Acquired immunity: specific defenses that target one pathogen  Combined defenses against bacteria and viruses  Neuro-endocrine-immune interactions

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune System: Functions  Protects from pathogens and foreign molecules  Parasites  Bacteria  Viruses  Removes dead or damaged cells  Attempts to recognize and remove abnormal cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune System: Pathologies  Incorrect responses  Autoimmune disease (Type 1 diabetes)  Overactive responses  Allergies  Lack of response  Immunodeficiency disease (AIDS)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Pathogens: Bacteria and Viruses

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Viral Structure and Replication Figure 24-1a

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-1b Viral Structure and Replication

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Body Defenses: Two Lines  Physical and chemical barriers  First line of defense  Skin, epithelial linings, and cilia  Acids, mucous, and lysozymes  Immune defenses  Second line of defense  Innate, non-specific, immediate response  Acquired; attack a specific pathogen (antigen)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Steps in an Immune Response  Detect and identify invader/foreign cells  Communicate, alarm, and recruit immune cells  Coordinate response among all participants  Suppress or destroy invader

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System  Primary tissues  Bone marrow and thymus  Encapsulated tissues  Lymph nodes and spleen  Lymph vessels  Diffuse tissues

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-2a Lymphatic System: Anatomy

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-2b Lymphatic System: Anatomy

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Key Cells of the Immune System  Leukocytes (white blood cells)  Eosinophils  Basophils and mast cells  Neutrophils  Monocytes and macrophages  Lymphocytes and plasma cells  Dendritic cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-4 Key Cells of the Immune System

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune Cell Groups  Morphological group  Granulocytes  Functional group  Phagocytes, cytotoxic cells, and antigen-presenting cells (APCs)  Mononuclear phagocyte system

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune Cells: Function  Eosinophils  Allergic reactions  Parasitic diseases  Basophils  Release histamine  Inflammation

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune Cells: Function  Neutrophils  Ingest bacteria  Release cytokines  Monocytes  Mature to macrophages  Phagocytic  APCs

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune Cells: Function  Lymphocytes  Acquired immunity  Dendritic cells  Activate lymphocytes

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-5 (1 of 3) Antigen-Presenting Cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-5 (2 of 3) Antigen-Presenting Cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-5 (3 of 3) Antigen-Presenting Cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-5 Antigen-Presenting Cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Innate Immunity: Nonspecific  Physical and chemical barriers  Phagocytosis: macrophages, neutrophils, natural killer (NK) cells  Engulf and digest “tagged” cells  Inflammatory response

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-6a Innate Immunity: Phagocytosis

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-6b Innate Immunity: Phagocytosis

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-7 Phagosomes Lysosomal enzymes digest pathogens that have been enclosed in phagosomes

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings NK cells  Eliminate virus-infected and tumor cells  Secrete interferons  Interferon-alpha and interferon-beta  Prevent viral replication  Interferon-gamma  Activates macrophages and other immune cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory Response: Roles  Attract immune cells and chemical mediators to site of infection  Produce physical barrier to prevent infection from spreading  Promote tissue repair

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory Response: Players  Histamines from mast cells  Swelling, edema, vasodilation  Interleukins  Fever, blood vessels more permeable to white blood cells and proteins, acute-phase proteins

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory Response: Players  Bradykinin  Pain and swelling  Complement cascade  Membrane attack complex

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-8 Inflammatory Response: Players Action of a membrane attack complex

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Chemicals of the Immune Response

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Chemicals of the Immune Response

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Acquired Immunity: Antigen-Specific  T lymphocytes  Helper T cells  Cytotoxic T cells  B lymphocytes  Plasma cells  Memory cells  NK cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Acquired Immunity: Antigen-Specific  Naïve lymphocytes  Clonal expansion  Effector cells  Memory cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (1 of 4) Acquired Immunity: Antigen-Specific How clonal expansion leads to immunologic memory

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (2 of 4) Acquired Immunity: Antigen-Specific

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (3 of 4) Acquired Immunity: Antigen-Specific

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (4 of 4) Acquired Immunity: Antigen-Specific

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings B lymphocytes: Humoral Immunity  Immunoglobulins  Plasma and memory cells  Primary and secondary response

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure B lymphocytes: Humoral Immunity Memory in the immune system

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Plasma Cells: Antibodies  Five classes  IgG, IgA, IgE, IgM, IgD  Light and heavy chain  Fab region  Fc region

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Plasma Cells: Antibody Structure

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Activates antibody- dependent cellular activity Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Triggers mast cell degranulation Memory cells Plasma cells NK cell or eosinophil Antibody Secrete antibodies Activates complement Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, step 1 Activates B lymphocytes Antigen binds to antibody Antigen binding site Memory cells Plasma cells Antibody Secrete antibodies 1 Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–2 Activates B lymphocytes Antigen binds to antibody Antigen binding site Acts as opsonins Memory cells Plasma cells Antibody Secrete antibodies phagocytosis 1 2 Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–3 Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Memory cells Plasma cells Antibody Secrete antibodies Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–4 Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Activates antibody- dependent cellular activity Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Memory cells Plasma cells NK cell or eosinophil Antibody Secrete antibodies Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–5 Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Activates antibody- dependent cellular activity Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Triggers mast cell degranulation Memory cells Plasma cells NK cell or eosinophil Antibody Secrete antibodies Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–6 Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Activates antibody- dependent cellular activity Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Triggers mast cell degranulation Memory cells Plasma cells NK cell or eosinophil Antibody Secrete antibodies Activates complement Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings T Lymphocytes: Cell-Mediated  T cell receptors  Cell activated by antigen  Major histocompatibility complex (MHC)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure T Lymphocytes : Cell-Mediated Activation of T lymphocytes

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Major Histocompatibility Complex  Incorporates antigen fragments  MHC class I  Cytotoxic T cells  MHC class II  Helper T cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure T Lymphocytes: Cell-Mediated Roles of T lymphocytes and NK cells in cell-mediated immunity

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Defenses against Bacteria Immune responses to extracellular bacteria Bacteria enter extracellular fluid from outside SKIN OR MUCOUS MEMBRANE ECF Bacteria activate secrete attract present antigens to ingest and disable increases permeability Opsonins Acute phase proteins Circulating leukocytes Antibodies Histamine CAPILLARY Plasma proteins Chemotaxins Membrane attack complex act as coat lyses make activate are EXTERNAL ENVIRONMENT Complement proteins Mast cells B lymphocytes Phagocytes T H cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (1 of 4) Defenses against Bacteria Bacteria enter extracellular fluid from outside SKIN OR MUCOUS MEMBRANE ECF Bacteria CAPILLARY EXTERNAL ENVIRONMENT

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (2 of 4) Defenses against Bacteria Bacteria enter extracellular fluid from outside SKIN OR MUCOUS MEMBRANE ECF Bacteria activate secrete attract increases permeability Acute phase proteins Circulating leukocytes Antibodies Histamine CAPILLARY Plasma proteins Chemotaxins Membrane attack complex act as lyses make activate are EXTERNAL ENVIRONMENT Complement proteins Mast cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (3 of 4) Defenses against Bacteria Bacteria enter extracellular fluid from outside SKIN OR MUCOUS MEMBRANE ECF Bacteria activate secrete attract ingest and disable increases permeability Opsonins Acute phase proteins Circulating leukocytes Antibodies Histamine CAPILLARY Plasma proteins Chemotaxins Membrane attack complex act as coat lyses make activate are EXTERNAL ENVIRONMENT Complement proteins Mast cells Phagocytes

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (4 of 4) Defenses against Bacteria Bacteria enter extracellular fluid from outside SKIN OR MUCOUS MEMBRANE ECF Bacteria activate secrete attract present antigens to ingest and disable increases permeability Opsonins Acute phase proteins Circulating leukocytes Antibodies Histamine CAPILLARY Plasma proteins Chemotaxins Membrane attack complex act as coat lyses make activate are EXTERNAL ENVIRONMENT Complement proteins Mast cells B lymphocytes Phagocytes T H cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Defenses against Viruses Immune responses to viruses MHC-II Natural killer cell Preexisting antibodies MHC-II secretes activates activate Cytokines Viral antigen Helper T cell Macrophage presents antigen fragments. Activates helper T cell Macrophage ingests virus. Cytokines for inflammatory response Cytotoxic T cell T-cell receptor become B lymphocytes secrete Plasma cells Virus Antibodies Perforins, granzymes Attacked by cytotoxic T and natural killer cells Infected cell undergoes aptosis and die. MHC-I Infected host cell Viral antigen MHC-I Uninfected host cell Alpha-interferon protects uninfected cell. Virus invades host cannot infect cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (1 of 5) Defenses against Viruses Virus invades host Preexisting antibodies

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (2 of 5) Defenses against Viruses MHC-I Infected host cell Viral antigen MHC-I Uninfected host cell Virus invades host Preexisting antibodies cannot infect cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (3 of 5) Defenses against Viruses MHC-II Natural killer cell MHC-II secretes activate Cytokines Viral antigen Helper T cell Macrophage presents antigen fragments. Activates helper T cell Macrophage ingests virus. Cytokines for inflammatory response MHC-I Infected host cell Viral antigen MHC-I Uninfected host cell Alpha-interferon protects uninfected cell. Virus invades host Preexisting antibodies cannot infect cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (4 of 5) Defenses against Viruses MHC-II Natural killer cell MHC-II secretes activates activate Cytokines Viral antigen Helper T cell Macrophage presents antigen fragments. Activates helper T cell Macrophage ingests virus. Cytokines for inflammatory response become B lymphocytes secrete Plasma cells Virus Antibodies MHC-I Infected host cell Viral antigen MHC-I Uninfected host cell Alpha-interferon protects uninfected cell. Virus invades host Preexisting antibodies cannot infect cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure (5 of 5) Defenses against Viruses MHC-II Natural killer cell MHC-II secretes activates activate Cytokines Viral antigen Helper T cell Macrophage presents antigen fragments. Activates helper T cell Macrophage ingests virus. Cytokines for inflammatory response Cytotoxic T cell T-cell receptor become B lymphocytes secrete Plasma cells Virus Antibodies Perforins, granzymes Attacked by cytotoxic T and natural killer cells Infected cell undergoes aptosis and die. MHC-I Infected host cell Viral antigen MHC-I Uninfected host cell Alpha-interferon protects uninfected cell. Virus invades host Preexisting antibodies cannot infect cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Allergic Responses  First exposure  Sensitization  Activation, clone B cells, form antibodies and memory cells  Re-exposure  Many antibodies, activated T cells, intensified response, inflammation

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Allergic Responses Figure becomes Allergen B lymphocyte MCH-II First exposure activates Allergen ingested and processed by antigen-presenting cell Antigen-presenting cell activates helper T cell Helper T cell Plasma cell secretes Inflammation Antibodies IgE IgG Mast cell Memory B and T cells retain memory of exposure to allergen Vasodilation Bronchoconstriction Vascular permeability Activation of complement proteins Activated T cells Cytokines Cytokines, histamine, etc Reexposure Degranulation 1 2

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Allergic Responses Figure 24-19, step 1 becomes Allergen B lymphocyte MCH-II First exposure activates Allergen ingested and processed by antigen-presenting cell Antigen-presenting cell activates helper T cell Helper T cell Plasma cell secretes Antibodies Memory B and T cells retain memory of exposure to allergen Activated T cells 1

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Allergic Responses Figure 24-19, steps 1–2 becomes Allergen B lymphocyte MCH-II First exposure activates Allergen ingested and processed by antigen-presenting cell Antigen-presenting cell activates helper T cell Helper T cell Plasma cell secretes Inflammation Antibodies IgE IgG Mast cell Memory B and T cells retain memory of exposure to allergen Vasodilation Bronchoconstriction Vascular permeability Activation of complement proteins Activated T cells Cytokines Cytokines, histamine, etc Reexposure Degranulation 1 2

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Blood Types  Antigens on RBCs  A, B, AB or none (O)  Antibodies in plasma  Anti A, anti B, anti AB  Rh antigens and antibodies

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-20a Blood Types: ABO Blood Groups

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-20b Blood Types: ABO Blood Groups

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Autoimmune Diseases

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Neuro-Endocrine-Immune Interaction  Not fully understood  Neuroimmunomodulation  Common signal molecules and receptors  Overlapping responses  Fight or flight  Chronic stress

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Neuro-Endocrine-Immune Interaction  Model for interaction between nervous, endocrine, and immune systems

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Summary  Two primary lines of defense  Diversity of pathogens  Immune response  Innate and acquired  Lymphatic and circulatory systems  Leukocytes and lymphocytes  Inflammation and allergies  Interactions between systems