TORTORA • FUNKE
• CASE
Microbiology
AN INTRODUCTION
EIGHTH EDITION
B.E Pruitt & Jane J. Stein
Chapter 17, part B
Specific Defenses of the Host:
The Immune Response
The Results of Ag-Ab Binding
Figure 17.9
• Is the amountAntibody
of Ab in serumtiter:
Figure 17.10
Another look
Ab Titer
Total
Ab
1o Ag
IgG Ab
IgM
Ab
2o Ag
Days After Immunization
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 antigenpresenting 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
Figure 17.15
T-independent Antigens
B cell
Figure 17.17
T-Dependent Antigens
Figure 17.16
Antibody-Dependent CellMediated Cytotoxicity
Figure 17.18
T-dependent and independent
antigens
•