Transcript Historical Perspectives (cont.)

An Introduction
to Immunology
Prof. Dr. Ezzat M Hassan
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 I- Historical perspective
 II- Functions of the Immune System
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I- Historical Perspectives
Smallpox

Chinese:

Egyptians:

protection provided by sniffing the powder made from crusts of
smallpox pustules.
powder from crusts of smallpox pustules or vesicle fluid applied to
skin and the surface scratched - variolation.
(Variolation is the process of taking fluid from pustules and
scratching the fluid onto skin)
Lady Montague:
introduced variolation to Europe by having her children protected
from smallpox by this process.
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I- Historical Perspectives (cont.)
Edward Jenner:
(1749-1823)

Observed that milkmaids who had suffered from cowpox did not contract
smallpox.

Protected a young boy from smallpox by deliberate immunisation with cowpox
and then challenging him with smallpox.

The term vaccination (vacca = latin for cow) was introduced to describe the
process.

In 1980 the WHO declared the world free of smallpox as a result of widespread
vaccination programs.
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I- Historical Perspectives (cont.)
Louis Pasteur:
(1822 -1895)

Studied attenuation of organisms and their subsequent use for
vaccination
eg. Chicken cholera and rabies.

Sterilisation of milk by pasteurisation.

Fermentation of wine due to action of micro-organisms.
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I- Historical Perspectives (cont.)
Elie Metchnikoff:
(1845 - 1916)

Observed the phenomenon of phagocytosis in starfish larvae.

Extended this observation to humans and described two types of phagocytic
cells circulating in the blood, noted that some fixed cells were also capable of
phagocytosis.

Called all of these cells phagocytes.

Proposed a cellular theory of immunity.
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I- Historical Perspectives (cont.)
Paul Ehrlich:
(1854 -1915)

In 1900 proposed a theoretical framework to explain the specificity of antigenantibody reactions.

Proposed the ‘side chain theory’ of antibody receptors on cells with which
antigens reacted.

From work of Ehrlich, Landsteiner and others, a humoral theory of immunity
was developed.
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I- Historical Perspectives (cont.)
Karl Landsteiner:
(1868-1943)

In 1901 defined the ABO blood group system.

Studied the chemical nature of antigens by creating chemically defined
antigens.

Coined the term hapten.

Awarded the Nobel prize in 1930 for discovery of first blood group.
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I- Historical Perspectives (cont.)
Niels Jerne:
(1944)

Clonal selection theory (specificity resides in antibodies)

Network theories of immune regulation.
Macfarlane Burnet:
(1944)

Clonal selection theory (specificity resides in lymphocytes)

Tolerance and the ‘forbidden clone’.
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I- Historical Perspectives (cont.)
Peter Medawar:
(1944)

Experimental proof for the deletion of self- reactive clones of lymphocytes
during early lymphoid maturation resulting in tolerance.

Principles of transplantation.
Charles Owen:
(1945)

Tolerance induction in twin calves (chimera).
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I- Historical Perspectives (cont.)
Astrid Fagraeus:
(1948)

Demonstrated that the plasma cell is responsible for the production of
antibodies.
Robert Porter, Gerald Edelman, Alfred Nisonoff:

In 1959, defined the structure of the immunoglobulin molecule by
using monoclonal gammopathy proteins (myeloma and macroglobulinaemia)
and protein digestion techniques.
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I- Historical Perspectives (cont.)
Jean Dausset, George Snell:
(1944)
 Identified antigens on leucocytes which determine histocompatability between
genetically different individuals.

HLA human leucocyte antigens

H2 murine (mouse, rat) leucocyte.
Paul Terasaki:

Microlymphocytotoxicity testing for HLA

These three scientists have been awarded Nobel prizes for their discoveries.
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I- Historical Perspectives (cont.)
Ralph Zinkernagel & Peter Doherty:

In 1975 demonstrated the need for self recognition in effector role of cell
mediated immunity (CMI).
Received the Nobel Prize in 1997 for this work which was carried out in the
John Curtin School for Medical Research at the Australian National University
in Canberra.
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Hi ! Take short rest!!
II-Structure and Functions of
the Immune System
1.
New Concept of immunity
2.
Functions of the immune System
1. New Concept of immunity
.Traditional
concept: Anti-infection
.New concept :The ability of the immune
system to recognize and eliminate the
antigenic non-self substances and maintain
HOMEOSTASIS
.recognize “self” from “non self”
. normally beneficial
.sometimes injurious
Immunity:
 Is derived from the Latin word immunitas
which means exemption from civic duties
and prosecution.
 Means protection from disease, especially
infectious disease.
Cells and molecules involved in such protection
constitute the immune system and the response to
introduction of a foreign agent is known as the immune
response
2. Functions of immune system
The chief function of the immune
system is to distinguish between
self and non-self.
2. Functions of immune system
1) Immune defense:
Protection from harmful environmental antigens.
2) Immune homeostasis:
Regulate and maintain the steady state of organisms.
3) Immune surveillance:
Search and destroy neoplastic cells.
Health : effective elimination or control of
health-threatening agents
(Hyporeactivity)
Immunodeficiency
(Hyperreactivity)
Health
Immunopathology
/\
Control of infectious agents and tumors is required for
healthy life.
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Hypo-reactivity (immunodeficiency):
inability to recognize and control healththreatening agents
(Hyporeactivity)
Health
Immunodeficiency
/\
Neutrophil Disorders
Antibody Deficiency
Complement Deficiency
T & B Cells Dysfunction
(Hyperreactivity)
Immunopathology
Hyper-reactivity : aberrant (exaggerated)
immune responses
(Hyporeactivity)
Immunodeficiency
Health
(Hyperreactivity)
Immunopathology
/\
Systemic Autoimmunity
Organ-Specific Autoimmunity
Allergies and Asthma
Immunopathology
The immune system consists of
two overlapping compartments:
1-the innate (inborn) immune system
and
2-the adaptive (acquired) immune system.
Nomenclature of Immune Cells and their
locations
Next Lecture :
1- Cells and Organs of the immune system
2- Innate Immunity
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