Page 84 - The Miracle in the Immune System

82 THE MIRACLE OF THE IMMUNE SYSTEM

How Do The B Cells Recognise The Enemy?
In a complete state of preparedness for war, the B
cells then learn to discriminate the enemies from the
body cells before defending the body.
They do not need to expend much effort to do this,
because these cells and the antibodies they manufacture
are able to recognise the enemy directly from their
shapes without any assistance. A receptor on their sur-
face meets the antigen for which it was programmed,
and binds to several small parts on it. Thus, the antigen
is identified as a foreigner. In this way, B cells can easily
recognise antigens, such as bacteria.

What Is The Function Of B Cells?
B cells are like guards who are always on the look-
out for microbes. When they encounter an invader,
they rapidly divide and start
to produce antibodies.
These antibodies bind to
microbes like B cell recep-
tors. The enemy cells that
are marked by the antibod-
ies as foreigners are driven
out of the body at the end
of the relentless struggle of
phagocytes and T cells. By
the time the B cells inacti-
vate the enemy with the AB cell covered with bacteria.
millions of antibodies they
have produced, they have also marked it for killer cells.
Here, there is another important point, which is as im-
portant as destroying and marking foreign cells. It is