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Dive into the world of monoclonal antibodies and immune system cells for targeted therapy and immunity enhancement. Learn about antibody titers, hybridomas, immunotoxins, and more. Explore how immune cells communicate through cytokines and defend against pathogens.
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Chapter 17, part B Specific Defenses of the Host: The Immune Response
The Results of Ag-Ab Binding Figure 17.9
Antibody titer: • Is the amount of Ab in serum Figure 17.10
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
Monoclonal Antibodies Figure 17.11
Immune system cells communicate via cytokines • Interleukin-1 Stimulates TH cells • Interleukin-2 Activates TH, B, TC, and NK cells • Interleukin-12 Differentiation of CD4 cells • -Interferon Increase activity of macrophages • Chemokines Cause leukocytes to move to an infection
Cell-Mediated Immunity • 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
Pathogens entering the gastrointestinal or respiratory tracts pass through: • M (microfold) cells in Peyer's patches which contains • Dendritic cells which are antigen-presenting cells and • T cells
Dendritic cells present antigens Figure 17.12
T Cells • Helper T Cells (CD4, TH) • TH1 Activate cells related to cell-mediated immunity • TH2 Activate B cells to produce eosinophils, IgM, and IgE • Cytotoxic T Cells (CD8, TC) • Destroy target cells with perforin
T Cells • Delayed Hypersensitivity T Cells (TD) • Associated with allergic reaction, transplant rejection, and tuberculin skin test • Suppressor T cells (TS) • Turn off immune response when Ag no longer present
Helper T Cells Figure 17.13
Cell-mediated Cytotoxicity Figure 17.14
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
T-independent Antigens B cell Figure 17.17
T-independent Antigens Figure 17.16
Antibody-Dependent Cell-Mediated Cytotoxicity Figure 17.18