B.E Pruitt & Jane J. Stein

Chapter 17, part BSpecific 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

• Interleukin-1Stimulates TH cells

• Interleukin-2Activates 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

Immune system cells communicate via cytokines

• 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

• M (microfold) cells in Peyer's patches which contains

• Dendritic cells which are antigen-presenting cells and

• T cells

Pathogens entering the gastrointestinal or respiratory tracts pass through:

Dendritic cells present antigens

Figure 17.12

• 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

T Cells

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

Figure 17.17

B cell

T-independent Antigens

Figure 17.16

Antibody-Dependent Cell-Mediated Cytotoxicity

Figure 17.18