Transcript A Brief Overview of Immunology

A Brief Overview
of Immunology
Dennis E. Lopatin, Ph.D.
University of Michigan
What’s the bottom line?
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Immune system recognizes foreign agents
Immune response is mounted to produce
activated T cells and specific antibodies
Antibodies react with foreign agent
Activated T cells react with foreign agent
Activated T cells may influence other cells
Antibodies provide specificity to nonspecific cytotoxic systems
Immune system “remembers: what it did.
What happens upon
antigen exposure?
Virgin lymphocyte pool
B lymphocytes
T lymphocytes
PRIMARY RESPONSE
effector cells
Exposure to Antigen
(Naturally-acquired or
artificial)
memory cell pool
SECONDARY RESPONSE
effector cells
memory cell pool
Activated T lymphocytes
Plasma cells
Antibodies
Regulatory
Cytotoxic
Blood
Where is that stuff?
Serum or
Plasma
Leukocytes,
Platelets and RBC
Serum Proteins
Mononuclear
Cells
•Immunoglobulins
•Complement
•Clotting factors
•Many others
•Lymphocytes
(T cells, B cells
& NK cells)
•Monocytes
Polymorphonuclear
leukocytes (or
Granulocytes)
•Neutrophils
•Eosinophils
•Basophils
What are the effector
functions?
Antibody-Mediated
• Complement
activation
• Agglutination
• Neutralization
• Mask receptors
• Antibody-mediated
cellular cytotoxicity
(ADCC)
• Opsonization and
phagocytosis
Cell-Mediated
• Cytotoxic TLymphocyte
• Natural Killer Cells
• Antibody-mediated
cellular cytotoxicity
(ADCC)
Hypersensitivity Reactions
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Reactions that are detrimental to the host
The result of autoimmunity
An atypical immune response
An inability to eliminate a pathogen
The tissues become a carrier for a hapten
Transplanted tissues are recognized