The Immune Response

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• The Immune Response
• Honors AP
• Lemon Bay High School

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• The Immune Response
• Immunity
• Free from burden
• Ability of an organism to recognize and defend
  itself against specific pathogens or antigens.
• Immune Response
• Third line of defense
• Involves production of antibodies
• generation of specialized lymphocytes against
  specific antigens.
• Antigen
• Molecules from a pathogen or foreign organism
  that provoke a specific immune response.

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The Immune System is the Third Line of Defense
Against Infection
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T - Lymphocyte activation
B - Lymphocyte activation and Production of
antibodies
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Components of Human ImmunITY
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Classification of acquired immune responses

• Natural or artificial
• How was immune response gained?
• Cell-mediated or humoral
• How is the body reacting?

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• Natural vs. artificial

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Acquired ImmunityNatural Gained in the course
of daily life

• NATURAL PASSIVE
• Antibodies pass from other to fetus (placenta) or
  mother to baby (breast milk).
• Not responding to antigens.
• Temporary 8 weeks.

• NATURAL ACTIVE
• Antigens/pathogens enter the body.
• Body generates an immune response.
• Can be lifelong (chickenpox) or temporary
  Influenza).

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Acquired Immunityartificial gained through
vaccination or immune serum.

• artificial ACTIVE
• Antigens introduced through vaccination.
• Body generates an immune response to the antigen.
• Can be lifelong (polio) or temporary (tetanus).

• artificial PASSIVE
• Preformed antibodies (antiserum) introduced by
  injection.
• Host immune system does not respond to
  antibodies.
• Temporary 3 weeks

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• Cell-mediated vs. antibody-mediated

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• Antibody-Mediated (humoral) Immunity
• Involves production of antibodies against foreign
  antigens.
• Antibodies are a class of proteins produced by
  B-cell lymphocytes.
• Antibodies are found in extracellular fluids
  (blood plasma, lymph, mucus, etc.) and on the
  surface of B cells.
• Defense against bacteria, bacterial toxins, and
  viruses that circulate freely in body fluids,
  before they enter cells.
• Also cause certain reactions against transplanted
  tissue.

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Antibodies are Proteins that Recognize Specific
Antigens
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Antibodies are Produced by B-cell Lymphocytes
t-cell Lymphocytes are produced in the thymus
gland early in life.
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• Cell Mediated Immunity
• Involves T-cells lymphocytes that recognize
  foreign antigens.
• T-cells regulate proliferation and activity of
  other cells of the immune system.
• Defense against
• Bacteria and viruses that are inside host cells
  and are inaccessible to antibodies.
• Fungi, protozoa, and worms
• Cancer cells
• Transplanted tissue

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Antigen- antibody reactions
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• Consequences of
• Antigen-Antibody Binding
• Antigen-Antibody Complex Formed when an
  antibody binds to an antigen it recognizes.
• 1. Agglutination Antibodies cause antigens
  (microbes) to clump together.
• Example Hemagglutination Agglutination of red
  blood cells.
• 2. Opsonization Antigen (microbe) is covered
  with antibodies that enhances its ingestion and
  lysis by phagocytic cells.

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Overview of the Immune Response