Transcript 08. Concept of Inflammation and the Immune Response

Concepts of
Inflammation and
the Immune
Response
Local inflammation
Cells that contribute to the
inflammatory response
Tissue damage

Mast cells signal to
other cells
Macrophages
White blood cells
Cytokines are signaling molecules

Released by cells of the immune system
 Coordinate the immune response
Cytokines Signaling
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Autocrine
Cytokines Signaling
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2. Paracrine
Cytokines Signaling
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3. Endocrine
Immunity
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Purpose of inflammation and
immunity is to neutralize, eliminate,
or destroy organisms that invade the
internal environment.
(Continued)
Immunity (Continued)
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Immune system cells
distinguish self from
non-self proteins and
cells, which include
infected body cells,
cancer cells, and
organisms. This ability
to recognize self
versus non-self is
necessary to prevent
Human Leukocyte Antigens
Antigens are a normal
part of the person and
act as antigens if they
enter another person’s
immune system.
 These antigens specify
the tissue type of a
person.
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Inflammation
Provides immediate
protection against the
effects of tissue injury
and foreign proteins.
The capability for
inflammatory response
is critical to health and
well-being.
 Causes visible
symptoms and can rid
the body of harmful
organisms. Tissue
damage may result

CAUSES OF INFLAMMATION
(ACUTE OR CHRONIC)
1. Microbial infections.
 2. Hypersensitivity
immune reactions.
 3. Chemical
substances.
 4. Physical agents.
 5. Necrosis.

Infection
Infection is usually
accompanied by
inflammation;
however,
inflammation can
occur without
invasion by
organisms.
 Inflammation does
not always mean

Sequence of Inflammatory
Responses
Warmth
 Redness
 Swelling
 Pain
 Decreased
function

Sequence of Inflammatory
Responses

Stage I (vascular):
change in blood
vessels
– Phase I: constriction
– Phase II: hyperemia and
edema
Stage II (cellular
exudate): neutrophilia,
pus
 Stage III (tissue repair

Processes closely linked to the
inflammatatory
response:


Immune reactions
Wound healing
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1) Immune reactions:
Cell mediated immunity - T-lymphocytes
Humoral immunity
- B-lymphocytes
Concept of antigen presentation (p.173) Langerhans
cells (not to be confused with Langhans
giant cells)
Cytokines (basic principles – p. 169)
- Act as messengers between inflammatory
cells,
coordinating the inflammatory response.
2) Wound healing
 Formation of granulation
tissue and

the process of
organisation).

(Organisation 
formation of scar

tissue)
 Role of growth factors

- only basic principles

Vascular
endothelial growth
factor

(VEGF) 
stimulates
proliferation of
endothelial cells 
granulation tissue.
 Fibroblast growth
factor  stimulates
fibroblasts to
produce collagen 
fibrosis (scarring) .

Antibody Classification

All antibodies are
immunoglobulins, also
called gamma globulins.
– Globulin is a protein in a
globular shape.
– Globular proteins provide
immunity.
– Resulting term is
immunoglobulin.
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Five antibody types are
classified by size, timing,
and association.
Acquiring Antibody-Mediated
Immunity
Innate-native
immunity—natural
immunity
 Adaptive immunity
 Active immunity
 Natural active
immunity
 Artificial active
immunity
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Cell-Mediated Immunity
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Helps protect the body by
differentiating self from nonself cells; non-self cells most
easily recognized by cellmediated immunity are
cancer cells and those self
cells infected by organisms
that live within host cells.
Important in preventing the
development of cancer and
metastasis after exposure to
carcinogens.
Helper/Inducer T-cells
Most correct name is
CD4+ (cluster of
differentiation 4)
 Also called OKT4
positive or Leu-3
positive because of
specific antigens on the
membrane surface
 Helper/inducer T-cells
easily recognize self
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Helper/Inducer T-cells
(Continued)
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Helper/inducer T-cells
act as organizers in
“calling in arms“ of
various squads of
WBCs involved in
inflammatory,
antibody, and cellular
defensive actions to
destroy or neutralize
antigens.
Transplant Rejection
Hyperacute graft rejection
 Acute graft rejection
 Chronic rejection
 Treatment of transplant rejection
 Maintenance
 Rescue therapy
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TWO BASIC TYPES OF IMMUNE
RESPONSE:
- Humoral
 - Cell-mediated
 Humoral = production of antibodies
by plasma cells.
 Cell-mediated immunity =
Interaction between T-lymphocytes
and macrophages.
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Two subpopulations of T-lymphocytes:
 T-helper cells:
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“Help” B-cells to differentiate into
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plasma cells.
 T-suppressor cells:
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Regulate (suppress) antibody
production.
 (T-cytotoxic cells = subtype of Tsuppressor cells  can directly kill
“foreign” cells e.g. tumour cells, virallyinfected cells etc.)
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T-cells have receptors on
their cell surfaces that
may bind to specific
antigens (e.g. microbial
antigens)
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T-cells can only bind to
antigens which have
already been processed
by macrophages ( =
antigen-presenting
function of macrophages
Interaction between T-cells and
macrophages is regulated by cytokines.
Under certain circumstances,
or in certain specific diseases,
this interaction of T-cells and
macrophages leads to the
formation of granulomas
(“granulomatous chronic
inflammation”).
 Granulomas are small
collections of epithelioid cells
(transformed histiocytes).
 (Histiocytes are tissue
macrophages).
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