AP Immune System Lecture

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					Chapter 43: Immune System – Part 1


 I.      Innate – what you are born with.

1st Line Defense

             Skin and Mucous membranes
             Sweat – contains urea to kill bacteria
             Normal flora ( good bacteria)
             Tears – contains lysozyme (antibiotic)

2nd Line Defense

      Phagocytes – WBCs that eat pathogens using lysosomes
                      Or peroxisomes.

             1. Neutrophils – general eaters
             2. Monocytes (blood) or Macrophage (tissue) 
               big eaters.

             Move by positive chemotaxis
             Pseudopodial - oozing
Eosinophils – WBCs with red spots

             Attack large pathogens like protists
             Attack allergens – “red rash”
Last Line of Defense

    Natural killer cells (NK cells) – shoot protein bullets to
create holes in cells.

            -Kill virus infected cells
            - Kill damaged cells
            -Kills some cancer cells
II. Inflammatory response

                    When the body is attacked……….

Histamine is released by Mast Cells.
Chemokines – attract phagocytes
Nutriphils arrive.

Inflammation in Cells
1. Neutrophils are the first cells to respond to injury

2. Macrophages clean up debris

3. Mast cells induce swelling, warmth, and redness

4. All 3 types of cells summon more immune system cells
Mast cell attacking pollen

   A. Capillaries dilate (open) and venules constrict (close)
      to trap blood in that location.

       1. Redness, swelling (edema), heat, and pain occur
          with an inflammatory response.
Macrophages come in after the fight to clean up the debris.

Pyrogens – fire proteins secreted by WBCs

                  cause fever

Septic Shock – This term refers to infected blood traveling
through the entire body. (It can be deadly.)

Membrane Attack Complex (MAC)

        A compliment system consisting of proteins called
perforin to shoot holes in pathogens.
Cell using perforin.

Interferons – Chemicals released from damaged cells to
warn other cells that danger is coming.

            -other cells can increase defenses

  III. Acquired Immunity (A.K.A. Specific Immunity)

        Attacks specific pathogens using……
       One type cells kills one type pathogen –
                  Antigen Specific

               Antigen – surface protein on a pathogen

      Antibodies – attack and hold pathogens

                       Heavy protein chains
                       Light protein chains

       Antigen Binding site – grabs pathogen
                   Constant region – where macrophage
   grabs and disposes of antigen.

Memory Cells – hold the DNA pattern for pathogens.
       1. B (bursa) Lymphocytes –kill with antibodies

       2. T (thymus) Lymphocytes – kills with chemicals

           a. Cytotoxic T cells – Killers

           b. Helper T cells – turn on B cells and T cells

Lymphocytes have antigen receptors where they hold onto
a particular antigen.


           Unknown pathogen enters the body.

           Inflammatory response occurs.

           Antigen is read by lymphocyte.

             Lymphocyte use clonal selection to make
effectors (fighters) and memory cells
            Antibodies are created to hold pathogens until
they can be eaten.

               10-17 days to create antibodies – so we used

    Primary Immune response – 1st time exposed. Longer to
get rid of.

 Secondary Immune Response – memory cells make it easier
to make antibodies to get rid of pathogen.

Autoimmune Disorder - body attacks itself
Chapter 43: immune System – Part 2
Campbell Text 7th Ed. Pgs: 908 – 919

I. Specific Immune Responses (Fig: 43.14) (Using
     A. Humoral Immunity (refers to clearing the fluids using
antibodies) (“ Humoral” means “fluids”.)
         1. B-cells mature to become plasma cells that can
make antibodies to fight pathogens.s
         2. B-cell activation is initiated by:
             a. Interleukin 2 (IL-2) released from a T-Helper
cell. (Means “second message between WBCs”.)
             b. Plasma cells secrete about 2,000 antibodies
per second. (Polyribosomes & Alternative DNA splicing
                                    makes it possible.)
     B. Cell – mediated Immunity (refers to the use of cells in
         1. Cytotoxic T-cells mature to fight and kill infected
        2. T-helper cells initiate the two types of specific
             a. T-helper connects to the macrophage
displaying a MHC type II. It is attracted to the macrophage
                                   Interleukin -1 (IL1). This
allows the T- helper to “analyze” the antigen so it can tell the
                                   lymphocytes what to “look
for”. (Means “first message between WBCs.)
             b. Cytokines (Interleukine-2, IL-2) are then
released to relay message to B-cells and Cytotoxic T cells.
        3. Cytotoxic T- cells
             a. They are activated by an MHC class 1 or IL-2.
             b. They kill infected cells by releasing perforin.
(These are protein “bullets” similar to the compliment.)
             c. Antibodies mark the pathogen parts for
disposal by macrophages.
    C. Both types of lymphocytes will undergo Clonal
Selection to make effectors(fighters) and memory cells.

II. Antibodies (A.K.A. Immunoglobulins –Ig’s) (Means
“globular protein of the immune system”.)
     A. Structure of an antibody: (Fig:43.8)
         1. Heavy chains and light chains – These are linked
by disulfide bridges using the cysteine amino acid.
             a. This is an example of Quaternary structure of
         2. Variable region (Fig:43.11) – This area changes to
meet the pathogen’s antigen. (It acts like hands on tongs.)
              a. This area undergoes Alternative DNA splicing
to find the right combination to fight pathogen.
         3. Constant region – This area of the protein never
changes in making the “handle on the tongs”.
a. This is the part of the antibody that the macrophage can
safely grab.
     B. Types of Immunoglobulins: (Fig: 43.18)
         1. Ig M (This is the largest class.) (Think
              a. It is the first to appear in a current infection.
(Your body is playing “catch up”.)
         2. Ig G (This is the most abundant class.) (Think
         3. Ig A (This class is associated with mucous
membranes and secretions – breast milk, sweat)
         4. Ig D (This class helps with the maturation of B-
cells to plasma cells.)
         5. Ig E (This class is associated with allergic
     C. Pathogen disposal techniques: (Fig: 43.19)
         1. Neutralization (This term means “grabbing hold
of” the pathogen.)
         2. Agglutination (This term means “clumping
pathogens together”.)
         3. Opsinization (This term refers to “increased
phagocytosis ability”.)
    D. Compliment fixation (Fig: 43.19)
         1. Remember, Antibodies mark the pathogen by
attaching to the antigen’s epitope region.
         2. Complement proteins combine with the antibodies
to create a membrane attack complex (MAC).
         3. Protein bullets are released to create a hole for
    E. Immune Adherence – This is the pinning of a
pathogen against a blood vessel wall and wait for
macrophages to arrive.

III. Immunity Acquisition by individuals
     A. Active Immunity (This term refers to “putting up an
actual fight against the pathogen”.)
         1. Acquired either by direct contact with an infected
individual or Immunization (A.K.A. vaccines)
             a. Vaccines for Viruses – use disabled viruses;
for bacteria – uses weakened bacteria (little fight).
         2. Either way, the point is to make memory cells.
     B. Passive Immunity (There is no fight against a
pathogen. Antibodies are in the vaccine and thereby no
memory cells.)
         1. Natural – These antibodies are acquired by breast
milk. (Ig A)
        2. Artificial – These antibodies are received in a shot
with temporary antibodies in it. (For international travel.)

IV. Self tolerance situations:
    A. Recognition of normal body cells.
    B. ABO blood groups. (Table 43.1)
    C. Rh Factor on RBCs. (Pregnancy? – second pregnancy
can be deadly if mother is Rh - and baby is Rh +.)
        1. Antibodies could have been made because of an
Rh+ first birth. (Blood mixes during birth, antibodies made.)
    D. Tissue grafting and organ transplants. (MUST have
matching MHC’s to work.)(Suppression of immune system
is needed.)

V. Abnormal Immune System Function:
     A. Allergy (This is a false alarm.) (Mast cells are the
         1. Anaphylactic Shock (This can be deadly.)(Patient
is given epinephrine to counteract the histamine.)
     B. Autoimmune Disorders (Caused by faulty DNA.)
         1. Lupus (the wolf) – Characterized by a butterfly
rash on the nose and kidney dysfunction. (Mostly women
         2. Rheumatoid Arthritis – WBCs attack and break
down the connective tissues. (Mostly cartilage affected.)
         3. Insulin – dependent Diabetes (type 1 – Juvenile
Diabetes) – WBCs attack the pancreas cells that make
        4. Multiple Sclerosis (MS) – WBCs attack the
Schwann cells and myelin sheathes of neurons; leads to
muscle burn.
    C. Immunodeficiency Diseases (Having NO immune
        1. SCID (Infants born with no immune system.)
(A.K.A. Bubble people.)
        2. Hodgkin’s Lymphoma (This is a cancer of the
lymphocyte white blood cells.)(Lymph nodes destroyed.)
        3. Stress – This weakens the immune system.
        4. HIV/AIDS (This is caused by a retrovirus.)
            a. Host cell is the T-helper lymphocyte. (It keys
in on the CD 4 membrane marker protein.)

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