The immune system is a network of cells and organs that work together
to defend the body against attacks by "foreign" invaders,
or germs. It operates by producing proteins call antibodies or specialized
white blood cells that recognize these foreign invaders as different
from us.
We all live in a sea of germs. The immune system works to keep those
germs from causing disease. When a germ does enter the body, the immune
system fights to eliminate them and help us recover.
When the immune system is malfunctioning it can cause a variety of
diseases, such as immunodeficiency, AIDS, allergy, arthritis, and maybe
even cancer.
The immune system is complex and sophisticated. It can recognize enemies
and in most cases fight off the germ before we even know it has invaded
our body.
Anything that can trigger an immune response (a bacteria, virus or
pollen), is called an antigen. Sometimes, the immune system responds
by producing a special kind of antibody called allergic antibody. That
is when allergic reactions occur. Substances that trigger the production
of allergic antibodies are called allergens.
New Research:
The major component of green tea may have a preventative effect on
HIV infection (JACI Nov 2003; William T. Shearer, MD, PhD, FAAAAI, et.
al).