Human Immunity Objectives: Know the difference between Specific & Non- specific defenses Know how each non-specific defense works Know how the specific system works and it’s relationship with vaccine production

Human Immunity I. What is immunity?  The ability of the body to resist pathogens II. Human immune system includes two general categories against infection: A. Nonspecific defenses B. Specific defenses

III. Nonspecific Immunity A. First Line of Defense: 1.Skin – how? 2.Mucus membranes - how? B. Second Line of Defense: 1.Inflammation - how? 2.Fever - how? 3.Antimicrobial proteins 4.Phagocytes engulf foreign particles

Skin Wound Bacteria enter the wound Phagocytes move into the area and engulf the bacteria and cell debris Capillary The Inflammatory Response

IV. Specific Immunity A. When a pathogen gets past the body’s non- specific defenses….  A Specific Immune response is triggered B. Targets specific individual invaders. C. You are born with this system D. You are able to recognize millions of invaders.

IV. Specific Immunity (cont) E.Begins with a wandering macrophage engulfing the foreign invader (antigen) 1.Antigen: Any substance that triggers an immune response. 2.The HLA protein is unique to each person.

IV. Specific Immunity (cont) F. The antigen is broken down and pieces of the surface proteins of the pathogen are moved to the surface of the macrophage.

G. Only T-cells that have receptors that fit to the presented antigens bind to the macrophage. H. Binding of the T cells with the macrophage (WBC) stimulates these specific T-cells to divide many times forming many different kinds of T-cells.

V.Types of T-cells 1. Helper T cells stimulate B cells to release antibodies. a. B cells are another kind of white blood cell. b. Antibodies are proteins that bind to and inactivate or tag the foreign antigens. c. Memory B cells are also left behind for life. Antigen- binding sites AntigenAntibody

V.Types of T-cells 2.Killer T cells attack and destroy the invaders or body cells that contain viruses. 3. Memory T cells remain in the body for life.

Specific Immunity Movie

VI.Vaccines A.Take a virus or other pathogen and destroy or weaken its nucleic acid.  Why do we want to do this? 1. You can alter the DNA of the pathogen by using chemicals, radiation or growing it in a different host.  Why are you asked if you are allergic to eggs before you get a flu shot? B.Leave the protein coat undamaged.  Why?

C.Inject this mixture (the vaccine) into humans or other animals. D.Your body responds as if you had the disease and you form memory cells for this disease.  Why don’t you get this disease? E.Next time host is exposed to the pathogen, the body will recognize and destroy pathogen before the disease affects the body.  Why can you fight it off so fast?

Vaccine Movie

Immune Response Summary Movie

Cell Beach Movie