Transcript PowerPoint Presentation to accompany Life: The Science of

Figure 18.17 Phases of the Humoral and Cellular Immune Responses
HUMORAL RESPONSE
Interleukin-1 (a cytokine)
activates a TH cell.
Class II MHC
protein
Interleukin-1
Macrophage
Cytokines
Antigen
The antigen is taken up
by phagocytosis
and degraded
in a lysosome.
Cytokines
released by the
TH cell
stimulate
it to proliferate.
T cell
receptor
A T cell receptor recognizes
processed antigen bound
to a class II MHC protein on
the macrophage.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
HUMORAL RESPONSE
TH cells
proliferate
and form
a clone.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
HUMORAL RESPONSE
Cytokines activate
B cell proliferation.
B cell
The binding of antigen to a
specific IgM receptor triggers
endocytosis, degradation, and
display of the processed antigen.
A T cell receptor recognizes
processed antigen bound to a
class II MHC protein on a B cell.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
HUMORAL RESPONSE
Plasma cell
Endoplasmic
reticulum
Antibodies
B cells proliferate
and differentiate.
The plasma cell
produces antibodies.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
CELLULAR RESPONSE
Class I MHC
protein
Infected cell
Antigen
A viral protein made in an
infected cell is degraded
into fragments and picked
up by a class I MHC protein.
Cytotoxic
T cell (TC)
A T cell receptor recognizes
processed antigen bound
to a class I MHC protein on
an infected cell.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
CELLULAR RESPONSE
TC cell
proliferates
and forms
a clone.
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
CELLULAR RESPONSE
Infected cell
Perforin
A T cell receptor again
recognizes processed antigen
bound to a class I MHC protein.
The T cell
releases perforin…
Figure 18.17 Phases of the Humoral and Cellular Immune Responses
CELLULAR RESPONSE
…which lyses
the infected cell.