Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation prepared by Christine L. Case Microbiology B.E Pruitt & Jane J. Stein AN INTRODUCTION EIGHTH EDITION TORTORA FUNKE CASE Ch. 8 Specific defense of the host
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Specific Defenses of the Host: The Immune Response Innate (nonspecific)Defenses against any pathogen ImmunitySpecific antibody and lymphocyte response to an antigen Antigen (Ag)A substances that causes the body to produce specific antibodies or sensitized T cells Antibody (Ab)Proteins made in response to an antigen
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Terminology SerologyStudy of reactions between antibodies and antigens AntiserumGeneric term for serum because it contains Ab GlobulinsSerum proteins Gamma ( ) globulinSerum fraction containing Ab
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Serum Proteins Figure 17.2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Immune Response Acquired immunityDeveloped during an individual's lifetime Humoral immunityInvolves Ab produced by B cells Cell-mediated immunityInvolves T cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Acquired Immunity Naturally acquired active immunity Resulting from infection Naturally acquired passive immunity Transplacental or via colostrum Artificially acquired active immunity Injection of Ag (vaccination) Artificially acquired passive immunity Injection of Ab
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Antigenic Determinants Antibodies recognize and react with antigenic determinants or epitopes. Figure 17.3
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Haptens Figure 17.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Antibody Structure Figure 17.5a-c
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monomer 80% of serum antibodies Fix complement In blood, lymph, intestine Cross placenta Enhance phagocytosis; neutralize toxins & viruses; protects fetus & newborn Half-life = 23 days IgG antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pentamer 5-10% of serum antibodies Fix complement In blood, lymph, on B cells Agglutinates microbes; first Ab produced in response to infection Half-life = 5 days IgM antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dimer 10-15% of serum antibodies In secretions Mucosal protection Half-life = 6 days IgA antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monomer 0.2% of serum antibodies In blood, lymph, on B cells On B cells, initiate immune response Half-life = 3 days IgD antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monomer 0.002% of serum antibodies On mast cells and basophils, in blood Allergic reactions; lysis of parasitic worms Half-life = 2 days IgE antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Bone marrow gives rise to B cells. Mature B cells migrate to lymphoid organs. A mature B cells recognizes epitopes. Clonal Selection
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Clonal Selection Figure 17.8
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Self-tolerance Body doesn't make Ab against self Clonal deletion The process of destroying B and T cells that react to self antigens
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Results of Ag-Ab Binding Figure 17.9
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monoclonal Antibodies Hybridomas are produced by fusing a cancer cell with an Ab-secreting plasma cells The hybridoma cell culture is immortal and produces monoclonal Abs (Mabs) Immunotoxins: Mabs conjugated with a toxin to target cancer cells Chimeric Mabs:Genetically modified mice that produce Ab with a human constant region Humanized Mabs: Mabs that are mostly human, except for mouse antigen-binding
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monoclonal Antibodies Figure 17.11
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Interleukin-1Stimulates T H cells Interleukin-2Activates T H, B, T C, and NK cells Interleukin-12Differentiation of CD4 cells -InterferonIncrease activity of macrophages ChemokinesCause leukocytes to move to an infection Immune system cells communicate via cytokines
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Specialized lymphocytes, mostly T cells, respond to intracellular Ags After differentiating in the thymus, T cells migrate to lymphoid tissue T cells differentiate into effector T cells when stimulated by an Ag Some effector T cells become memory cells Cell-Mediated Immunity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings M (microfold) cells in Peyer's patches which contains Dendritic cells which are antigen-presenting cells (APS) and T cells Pathogens entering the gastrointestinal or respiratory tracts pass through:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dendritic cells present antigens Figure 17.12
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Helper T Cells (CD4, T H ) T H 1Activate cells related to cell-mediated immunity T H 2Activate B cells to produce eosinophils, IgM, and IgE Cytotoxic T Cells (CD8, T C ) Destroy target cells with perforin T Cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Delayed Hypersensitivity T Cells (T D ) Associated with allergic reaction, transplant rejection, and tuberculin skin test Suppressor T cells (T S ) Turn off immune response when Ag no longer present T Cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Helper T Cells Figure 17.13
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cell-mediated Cytotoxicity Figure 17.14
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Nonspecific Cells Activated macrophages: Macrophages stimulated by ingesting Ag or by cytokines Natural killer cells: Lymphocytes that destroy virus- infected cells, tumor Figure 17.15
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hypersensitivity Type 1 hypersensitivity: atopy and anaphylaxis Type II hypersensitivity: cytotoxic hypersensitivity Type III hypersensitivity: immune-complex disease Type IV hypersensitivity: delayed-type hypersensitivity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Deficiencies in the immune system Autoimmunity Immunosuppression
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Immunological techniques ELISA Latex agglutination Immunoblotting or Western blotting