Immune System How does the immune system protect you from invaders? 1/2/2012

Immune System Non-Specific Non-Specific – kills anything Specific Specific – kills specific invaders

Non-Specific Non-Specific Immune System Skin – barrier blocking infection Mucus – sticky trap for invaders Saliva – contains lysozyme antibiotics Tears – contains lysozyme antibiotics Inflammation – causes white blood cells to come to infection site Fever – raises temperature to kill invaders

Inflammation N1cFQ0yJI&feature=related N1cFQ0yJI&feature=related Macrophages eat bacteria.

The Immune System Specific Immune System  article_set=59296&cat_id= article_set=59296&cat_id=20607

Antigens are receptor proteins on cells and parts of invaders. Antibodies bind to antigens. “self”“foreign” Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y antigen antibody Antibodies and Antigens

Specific Immune System Antigens on a bacteria or virus are discovered by antibodies on a B-Cell. B-Cells make plasma cells that create blood born antibodies, destroying the invader. B-Cells make memory cells that carry the antibody around for a long time. This enables a quicker response next time the invader attacks. (immunity)

B cell immune response tested by B cells (in blood & lymph) 10 to 17 days for full response invader (foreign antigen) B cells + antibodies Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y recognition Y Y Y Y Y Y Y Y clone 1000s of clone cells Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y plasma cells release antibodies Y Y Y Y Y Y Y Y Y Y Y Y Y memory cells “reserves” Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y YY Y Y captured invaders

What if the attacker gets past the B cells in the blood & actually infects some of your cells? You need trained assassins to kill off these infected cells! T Attack of the Killer T cells!

Specific Immune System Macrophages can eat invader cells, infected cells, or cancerous cells and then present the antigens on its surface. Infected cells present antigens on its surface. T-helper cells recognize these presented antigens and then activate killer T-Cells and B-Cells. Killer T-Cells attack and destroy any cells (foreign or not) with foreign antigens on its surface.

T cell response stimulate B cells & antibodies Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y YY Y Y killer T cell activate killer T cells or infected cell helper T cell activated macrophage activate memory T cells memory T cell

free antigens in bloodantigens on infected cells humoral responsecellular response B cellsT cells macrophages helper T cells plasma B cells memory B cells memory T cells killer T cells Y Y Y Y YY Y Y antibodies Y Y Y skin pathogen invasion antigen exposure

HIV & AIDS Human Immunodeficiency Virus  virus infects helper T cells  helper T cells don’t activate rest of immune system: T cells & B cells also destroy T cells Acquired ImmunoDeficiency Syndrome  infections by opportunistic diseases  death usually from other infections pneumonia, cancer

Origins of HIV Film Answer the Questions for a Quiz Grade!

Vaccines Vaccines are medicines that give people immunity to a virus. Vaccines have virus parts that have harmless antigens in them. The immune system responds to the antigens like a normal invasion but with out the risk. Then the body has many long term memory cells ready for the next invasion. active immunity This gives a person active immunity. passive immunity Short term passive immunity is when antibodies from another organism (pig, horse) is injected into a person. The body eventually destroys the foreign antibodies and doesn’t produce long term memory cells.