Download The Immune System

The Immune System
“What You Really Need to
Know”
Gail Lupica PhD, RN, CNE
Nurs 211
Immune System
Overview
• Non-specific Defenses (first,
second)
– Mechanical
– Chemical
– Phagocytosis
– Inflammation
• Specific Defenses (third line of
defense)
– The Immune response
Immune System
Overview
• What happens? (T & B cell
immunity)
Antigens (complex proteins) (self or
foreign) allow cells to distinguish
between self and non-self.
These cell markers destroy foreign
antigens because they are recognized
as invaders.
Immune System
Overview
• Then next time, memory cells of the
immune system recognize the same
invader and a response is developed
(B cell antibody).
• T-memory cells remember that
invader, and sets off the specific
ANTIGEN-ANTIBODY response
Immune System
Overview
Components of the Immune
System
• Immune cells (B and T cells)
•
•
•
•
Thymus (source of mat of T cells)
Lymph nodes/Lymphatic tissue
Adenoids, tonsils, spleen
Bone marrow (source of mat of B
cells)
Immune System
Overview
Let’s look at the Primary and
Secondary Immune responses…
Immune System
• Antigens: Substances that elicit the immune
response.
• All body cells have self antigens on
their surface that are unique to that person .
• The immune system tolerates self antigens just fine,
and does not recognize them as foreign.
• They are non-responsive to self.
Immune System
Antigens:
Self antigens are called cell markers
That are coded by genes:
Detected on cell membranes of leukocytes
(Provide a close match in tissues that are to be
transplanted.)
EX: Human Leukocyte Antigen (HLA)
Immune System
• Let’s look at the cells of the Immune
system…
Immune System
There are two types of lymphocytes:
• T- Lymphoctyes (cell mediated70%)
• B- lymphocytes (humoral
immunity)
Immune System
Antibodies/ Immunoglobulins
Produces by plasma cells in response
to a challenge by an antigen
Antibodies (immunoglobulins known to
have specificity for a particular
antigen)
Immune System
• Antibodies/ Immunoglobulins
• Are proteins with a unique sequence of amino acids
on a common base
• Binds to a specific matching antigen and
KILLS IT!
• They are the basis for how immunity to a
disease develops.
• Found in general circulation.
• There are five classes, each with a special
structure, and function:
Immune System
Natural vs.
Acquired Immunity
(table)
Immune System
Active
Passive
Natural
Natural contact
with antigen
through
clinical
infection---You get the
chicken pox,
mumps,
measles
Passed
through
placenta to
unborn infant or
fed to infant
through
colostrum/
breast milk—
(lots of IgA)
Artificial
Immuniza
tion with an
antigen--Immunization
with live or
killed
Injections or
infusions of
human
immune
globulin
Immune System
What are Cytokines?
Chemicals that act as messengers
to cells.
They can cause proliferation,
differentiation, secretion or
activity. There are over 100
types.
Immune System
Cytokines
Types:
Interleukins
Colony stimulating Factor (CSF)
Erythropoetin (hormone)
Tumor Necrosis Factor (TNF)
Immune System
• Hypersensitivity disorders: The
immune system overreacts against
foreign antigens
Types:
Type 1, 11, 111= humoral
(immediate)
Type 1V = cellular (delayed)
Hypersensitivity disorders
Type 1
IgE mediated response
Mast cells and Basocells release chemical
mediators when an antigen (allergen) is
bound to an Ig E antibody on a second
exposure to this allergen.
Example:???
Hypersensitivity disorders
Type 11
Antibody Mediated Cytotoxic
Disorders
What does cytotoxic mean?
Result of IgG and IgM class antibodies
interacting with tissue/cell surface antigens
• Subsequent activation or cell-mediated cytotoxicity
(the cell is doomed) occurs.
Example???
Hypersensitivity disorders
Type 111
Immune Complex Disorders
mediated by the formation of antigen-antibody
complexes (immune complexes), which cause a
release of Vasoactive mediators causing tissue damage (by
altering blood flow, and increasing vascular permeability.)
Immune complexes produce damage both in the
vascular lining itself and the organs where
they may deposit (kidney, lung, joints) causing an
inflammatory response.
Example:???
Hypersensitivity disorders
Type 1V
Cell mediated “delayed” (24-72
hours) Hypersensitivity
– It is mediated by T-cells that are Cytotoxic and release
inflammatory chemicals in the surrounding tissue.
These substances attract T or B lymphocytes. The
coagulation cascade is activated causing formation and
deposition of fibrin.
Example???
How much did you learn?
Describe the development of
antibodies to a specific antigen
How much did you learn?
Predict why a person only has chicken
pox once in a lifetime
How much did you learn?
Why is a secondary response to an
antigen faster and greater than
the primary response
How much did you learn?
Where is IgG found in the body?
How much did you learn?
Explain why a newborn infant is
protected from infection by the
measles virus immediately after
birth but later will be given measles
vaccine.
Great Job!!