More cool info about the immune system

Have you heard about killer T cells and helper T cells?  Both killer-T and helper-T cells are white blood cells called lymphocytes.  Killer T cells can recognize body cells which are infected by virus (or other infectious agents) and cause the cell to commit suicide and kill the virus inside.  They can also punch holes in the cell’s membrane and expose the virus inside to the body’s hostile, virus-killing actions.  Killer T-cells can also attack and destroy cancer (tumor) cells. The killer T-cells are controlled by the helper T cells.  The helper T lymphocytes make decisions such as what needs to be done and which chemicals should be released to kill the foreign invader.  HIV (Human immunodeficiency virus or the AIDS virus) causes such damage because it attacks the helper T cells.  Let’s hear it for the T cells who work hard to keep us healthy.  Yeah. 

Scientists talk about innate immunity vs. acquired immunity.  Innate immunity refers to the inherited immunity each person has when he is born.  Acquired immunity happens when our bodies make “antibodies” and T-cells which target a specific germs, virus, etc.  Think of the flu shot you took last fall.  When you got your flu shot, your body recognized the flu shot as a foreign substance and began to make antibodies (also called immunoglobulins).  Within a short time (days or maybe weeks), your body has developed antibodies against the flu.  The antibodies within your body should protect you and keep you healthy if you come in contact with those strains of flu.  Vaccinations work in the same way:  our body responds to the vaccine by building antibodies which then protect us.  (Some vaccinations need booster vaccines to continue long term protection.  For example, tetanus shots are recommended every 10 years.) http://www.newworldencyclopedia.org/entry/Immune_system