Transcript Memory Cells and the Immune Response

Organization of the Animal Body
Cell and Tissue Types
Organ Systems
Organizational Hierarchy of Life
Most Complex
organism
organ system
organ
tissue
Living
cell
organelle
macromolecule
Non-living
molecule
atom
Least Complex
sub-atomic particles
Immune System
Cells, Cell
Products
and Organs
That Protect
the Body
Against Disease
Properties of the Immune
Response
A. Specificity: Unique response
against each each invader
B. Memory: Increased response at next
invasion
C. Discrimination: Ability to distinguish
“self” from “non-self”
Applying Your Knowledge
1. Specificity
2. Memory
3. Discrimination between self and non-self
Which property of the immune response:
A. keeps you from developing chicken pox a
second time? (Assume you had a severe
case at age six.)
B. helps you successfully recover from a cold?
C. causes you to reject a donated organ?
Components of the Immune System
• Cells
– Macrophages: engulf invaders
– B cells: humoral immunity
– T cells: cell-mediated immunity
• Organs
– Bone Marrow
– Spleen
– Thymus
– Tonsils
– Lymphatic vessels
– Lymph Nodes
Macrophages Engulf the Invader and
Signal Other Immune System Cells
Antigens
Viral
Invader
Macrophage
Macrophage
engulfs
invader
Macrophage
displays
“processed”
antigen
Macrophage releases
cytokines to influence
T and B cells
T Cells Become Activated, Leading to
Cell-mediated and Humoral Responses
Helper T Cell
binds to
Macrophage
Macrophage
T Cell Receptor
Macrophage
secretes
cytokines to
activate T cell
Helper T Cell
B cells
Humoral
Response
Invader binds to
B cell that carries
antibody
matching the
antigen
Antibody
Memory B cells
respond in future
invasions
Activated Helper
T cell stimulates
division of
selected B cell
Dividing B cell
gives rise to
memory B cells
and plasma cells
Plasma cells
secrete
antibodies into
bloodstream
Antibody Structure: Y-Shaped Protein
ss
BAD Antigen
Antibody has 2 heavy chains
and 2 light chains.
Variable regions bind to antigen.
Constant regions bind to cells
or other antibodies.
Three-Dimensional
Antibody Structure
Gene for
constant region
Gene
of lightfor
chain
constant region
of heavy chain
Genes for
variable region
Genes
of light for
chain
variable region
of heavy chain
Recombination during
Construction of Antibody Genes
Antibodies Mark Invaders for Destruction
Phagocytosis by
a Macrophage
Applying Your Knowledge
1.
2.
3.
4.
Light Chain
Heavy Chain
Variable Region
Constant Region
1.
2.
3.
4.
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
A. Which part of the antibody binds to the
antigen? (choices on left)
B. Which type of protein structure is seen
in a functional antibody molecule?
(choices on right)
Memory Cells and the Immune
Response
Cell-Mediated Response
Activated Helper
T cell stimulates
activity of
Cytotoxic T cells
Cytotoxic T cell
destroys infected
body cells by
forming pores in
cell membrane
Division of T cells
gives rise to
memory T cells
Memory T cell
responds in
future infections
Applying Your Knowledge
1.
2.
3.
4.
5.
Macrophage
Plasma Cell
Memory B Cell
Helper T Cell
Cytotoxic T Cell
Which immune system cell:
A. keeps you from developing chicken pox a
second time? (Assume you had a severe
case at age six.)
B. helps you successfully recover from a cold?
C. causes you to reject a donated organ?
Humoral and Cellular Immunity
Humoral
Cellular
(Antibody-mediated)
(T-cell mediated)
Hay fever
Reaction to poison ivy
Transfusion reactions Tuberculin Test
Rh disease
Reaction to bee stings
Immunization
Graft (organ) rejection
Viral and Bacterial
infections
Cancer Prevention
Cell-Mediated Immunity at Work
Cytotoxic T Cells
Cancer Cell
Diseases of the Immune System
A. Inherited Immune Deficiencies
eg. SCID: Severe Combined Immune Deficiency
B. AIDS: Acquired Immune Deficiency Syndrome
HIV infects Helper T Cells
C. Autoimmune diseases
1. Autoimmune ulcerative colitis
2. Rheumatiod arthritis
D. Allergies
Allergic Reactions
Mast Cell
Histamine vesicle
Binding site for
“allergy” antibodies
“Allergy” plasma cell releases
“allergy” antibodies
Pollen grains enter
respiratory tract
Pollen binds to
allergy antibody
Causes release
of histamine,
which causes
symptoms
Envelope
Core
(lipid bilayer) Proteins
Reverse
Transcriptase
Viral RNA in
protein coat
HIV
Glycoproteins
Protein
Coat
HIV Infection
Helper T Cell (green)
Emerging
HIV particles
Envelope acquired
from helper T cell
Recently emerged
HIV particles (red)