Transcript immune responses

University of Tabuk
Faculty of Applied Medical Science
Department of Medical Laboratory Technology
Basic Immunology
Dr. Nabil MTIRAOUI,
M.Sc, Ph.D
Mr.AYMAN.S.YOUSIF
M.SC
Academic Year: 1433-1434 (2012-2013)
Introduction to Immunology
Science of Immunity
Lecture 1
Mr.AYMAN.S.YOUSIF
Definition
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 Immunity : Protection from disease & especially
infectious disease or harmful substance .
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Immunology : The study of the way in which the
body
defends
itself
against
invading
environmental agents that are foreign to the body,
such as pathogenic organisms or internal invaders
(tumors).
What is the immune system?
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 Cells & molecules involved in immune protection
constitute the immune system .
 Immune system maintains the integrity of the body .
Immune response & Antigen
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
Immune response: The response to introduction
of foreign agent to the body. (antigen).
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Antigen : A substance that induces a specific
immune response i.e. is immunogenic!
Types of antigens: foreign protein, complex
carbohydrate, …etc.
Antigen-specific Receptors on lymphocytes bind
small parts of these molecules.
Fine specificity distinguishes species & subspecies of microbes.
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The Role of the Immune System
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1. Distinction between
self and non-self
antigens
2. Recognition of
challenge
3. Elimination of
challenge
Historical Development
A Short History of Immunology
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Perhaps the earliest written reference to the phenomenon
of immunity~ 430 B.C: Peloponesian War, Thucydides
describes plague – in Athens,the ones who had recovered
from the disease could nurse the sick without getting the
disease a second time
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15th centurry : Chinese and Turks use dried crusts of small pox
as ”vaccine”
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1798: Edward Jenner – smallpox vaccine
A Short History of Immunology
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Edward Jenner, “ the founder of modern immunology”
1796- Introduction of protective vaccine against small pox:
based on cow pox (in Latin - vaccinia )
A Short History of Immunology
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Noticed that milkmades that had mild disease cowpox did NOT get
smallpox.
Jenner reasoned that introducing fluid from a cowpox pustule into
people (i.e., inoculating them) might protect them from smallpox.
To test this idea, he inoculated an eight-year-old boy with fluid from a
cowpox pustule and later intentionally infected the child with
smallpox. As predicted, the child did not develop smallpox.
Vaccine was invented (latin vacca means ”cow”)
A Short History of Immunology
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A Short History of Immunology
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A Short History of Immunology
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A Short History of Immunology
Overview of the Immune System
Subjects In Immunology
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Arms of immune system.
Antigen (foreign agent) and immunogen .
Antibody related defense mechanisms.
Type of immunoresponce .
Hypersensitivity reactions ( Including Allergy )
Auto Immunity
Immunodeficiency
Transplantation
Arms of the Immune System
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Immunology is a Complex Subject
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Organs of Immune System
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P̃rimary Lymphoid Organs
Bone Marrow and Thymus
Maturation Site.
S̃econdary Lymphoid Organs
Spleen, lymph nodes,
MALT (mucosal associated lymph tissue)
GALT (gut associated lymph tissue)
Trap antigen, APC, Lymphocyte Proliferation.
Organs of Immune System
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
The immune system is
localized in several
parts of the body
 immune cells
develop in the
primary organs bone marrow and
thymus (yellow)
 immune responses
occur in the
secondary organs
(blue)
Immunology cell histology
Immunology cell histology
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Polymorphonuclear
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Mononuclear
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Does not stain to acidic or basic compounds
Acidic (red-pink)
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Many granules seen in cytoplasm
Neutral
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Non-lobed nucleus
Granulocyte
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Lobed nucleus
Stains to acidic compounds (Eosin)
Basic (blue-purple)
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Stains to basic compounds
Cells of the Immune system
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All cells of the immune
system derived from the
bone marrow.
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Hematopoietic stem cell
differentiation.
Cells of the Immune system
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Many cells of the
immune system
derived from the bone
marrow
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Hematopoietic stem
cell differentiation
Components of blood
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Serum vs. Plasma
 Serum: cell-free liquid, free from clotting factors.
 Plasma: cell-free liquid with clotting factors in solution
(must use an anticoagulant)
Components of blood
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Lymphocytes
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Many types
Mediated the adaptive
(Acquired ) immunity .
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B-cells produce antibodies
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T- cells
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 Cytotoxic
T cells(CD8)
 Helper T cells (CD4)
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The B&T–cell have a
Memory
Lymphocytes
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Plasma Cell (in tissue)
 Fully
differentiated B cells,
secretes Ab
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Natural Killer cells
 Kills
cells infected with
certain viruses
 Play role in the both innate
and adaptive immunity .
 Antigen presentation
Monocytes/Macrophage
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Phagocytosis and killing of
microorganisms
 Activation
of T cells and
initiation of immune response
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Monocytes is a young
macrophage in blood
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There are tissue-specific
macrophages
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Function as antigen presenting
cells (APC).
Dendritic Cells
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Activation of T cells and
initiate adaptive immunity
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Found mainly in lymphoid
tissue
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Function as antigen presenting
cells (APC)
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Most potent stimulator of Tcell response
Mast Cells
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Expulsion of parasites through release of
granules.
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Granules contain mediators (Histamine,
leukotrienes, chemokines, cytokines).
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Also involved in allergic responses
Neutrophil
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Granulocyte
 Cytoplasmic
granules
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Polymorphonuclear
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Phagocytosis
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Short life span (hours)
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Very important at “clearing” bacterial
infections
Innate Immunity
Eosinophils
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Kills Ab-coated parasites through de
granulation
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Involved in allergic inflammation
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A granulocyte
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Double Lobed nucleus
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Orange granules contain toxic
compounds
Basophils
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Might be “blood Mast cells’
A cell-killing cells
 Blue
granules contain toxic and
inflammatory compounds
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Important in allergic reactions
Other Blood Cells
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Megakaryocyte
 Platelet
formation
 Wound repair
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Erythrocyte
 Oxygen
transport
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