Excerpts from the Road to Immunity by Kenneth Bock, M.D. 10/23/02
Excellent book that describes how the immune system works, what happens when
it breaks down and what can be done about it. Much more concise and easier to
read than Sherry Rogers' books. Dr. Bock describes what he calls the Illness
Spiral to explain how the immune system breaks down: p, 29, "In addition
to defending us against antigens, the immune system oversees the condition of
our cells, tissues and organs. Every minute of every day, the immune
system is busy making repairs to cellular machinery. Some repairs correct
the damage caused by the immune system's fight against antigens, other repairs
are routine maintenance. Cells grow old and die. They also can be damaged,
not only by infectious agents and toxic substances but also by the by-products
of naturally occurring metabolic processes. Even when the threats to your
health are minimal, your immune system is industriously taking damaged cells out
of circulation, repairing cell membranes, cleaning up cellular debris, and helping
usher waste products out of the body. This constant activity takes place without
our awareness. ..A healthy immune system runs smoothly, dealing swiftly with
intruders or impostors, repairing any dame from minor skirmishes, and scouting
for trouble throughout the body. However, when the immune system is overburdened
and under constant attack, the body does not have the and energy to make repairs
and build up its defenses....The less energy your immune system is required to
put into defense, the more it can put into cellular repair. On the other hand,
if your immune system is constantly preoccupied with problems - and this can
mean a single serious threat or a number of moderate stresses - deficits will
build up. The less effectively it functions , the more problems develop, and the
sicker you get. I call this chain of events the Illness Spiral. When
the Illness Spiral proceeds unchecked, serious or chronic disorders can result. The
immune system is susceptible to chain reactions. Even a slight imbalance
may eventually have huge ramifications. " His analogy: "Picture
yourself in your kitchen. If you keep cooking and cooking but have not
time to do the dishes or take out the garbage, eventually an overwhelming amount
of stinking debris will pile up." P, 32, "Sometimes the immune
system makes an appropriate response to an antigen - for example, a virus - but
then when the fight should be terminated, the appropriate signals do not occur
and the reaction persists. More and more antibodies are produced, even though
they are no longer needed. It's as if the switch is turned on and ability
to turn the switch off is lost. When there is impaired host defense, the
immune system needs to be strengthened. When there is hyperactivity, the
immune system needs to be calmed down....we (must) reverse the Illness Spiral
one step at a time - like peeling off the layers of an onion. There is no
"magic bullet" that will eliminate all of the symptoms and problems
that have developed over time...the traditional one illness/one cure
approach to restoring health in these complex, chronic cases is simplistic and
shortsighted. " He closes the chapter with: " There is
a great deal we can do to help our immune system help us, including eating well,
taking supplements, minimizing our exposure to troublesome substances, and
taking advantage of natural treatments and therapies that will bring our immune
system back into balance. By providing our immune system with what it
needs and protecting it from what it doesn't , we can greatly improve our
powers of cellular self-defense." He then goes on to recommend his
"Immune System Empowerment Program" and I recommend you get the book
our of your public library or buy it for details. It is the best book on
healing the immune system I have seen.
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The
Body's First Line of Defense
The immune system is a complex of organs--highly specialized
cells and even a circulatory system separate from blood
vessels--all of which work together to clear infection from the
body.
The organs of the immune system, positioned throughout the
body, are called lymphoid organs. The word "lymph" in
Greek means a pure, clear stream--an appropriate description
considering its appearance and purpose.
| Lymphatic
vessels form a circulatory system that operates
in close partnership with blood circulation. |
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Lymphatic vessels and lymph nodes are the
parts of the special circulatory system that carries
lymph, a transparent fluid containing white blood cells,
chiefly lymphocytes. |
| Lymph bathes the tissues of
the body, and the lymphatic vessels collect and move it
eventually back into the blood circulation. Lymph nodes
dot the network of lymphatic vessels and provide meeting
grounds for the immune system cells that defend against
invaders. The spleen, at the upper left of the abdomen,
is also a staging ground and a place where immune system
cells confront foreign microbes. |
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| Organs
and tissues of the immune system dot the body in
a protective network of barriers to infection. |
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Pockets of lymphoid tissue are in many other locations
throughout the body, such as the bone marrow and thymus.
Tonsils, adenoids, Peyer's patches, and the appendix are also
lymphoid tissues.
Both immune cells and foreign molecules enter the lymph nodes
via blood vessels or lymphatic vessels. All immune cells exit
the lymphatic system and eventually return to the bloodstream.
Once in the bloodstream, lymphocytes are transported to tissues
throughout the body, where they act as sentries on the lookout
for foreign antigens.
How the Immune
System Works
Cells that will grow into the many types of more specialized
cells that circulate throughout the immune system are produced
in the bone marrow. This nutrient-rich, spongy tissue is found
in the center shafts of certain long, flat bones of the body,
such as the bones of the pelvis. The cells most relevant for
understanding vaccines are the lymphocytes, numbering close to
one trillion.
The two major classes of lymphocytes are B cells, which grow
to maturity in the bone marrow, and T cells, which mature in the
thymus, high in the chest behind the breastbone.
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B cells produce antibodies that circulate in the
blood and lymph streams and attach to foreign antigens
to mark them for destruction by other immune cells.
B cells are part of what is known as
antibody-mediated or humoral immunity, so called because
the antibodies circulate in blood and lymph, which the
ancient Greeks called, the body's "humors."
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B cells become plasma cells, which produce
antibodies when a foreign antigen triggers the
immune response. |
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Certain T cells, which also patrol the blood and lymph for
foreign invaders, can do more than mark the antigens; they
attack and destroy diseased cells they recognize as foreign. T
lymphocytes are responsible for cell-mediated immunity (or
cellular immunity). T cells also orchestrate, regulate and
coordinate the overall immune response. T cells depend on unique
cell surface molecules called the major histocompatibility
complex (MHC) to help them recognize antigen fragments.
| Antibodies
produced by cells of the immune system recognize
foreign antigens and mark them for destruction. |
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Antibodies
The antibodies that B cells produce are basic
templates with a special region that is highly specific
to target a given antigen. Much like a car coming off a
production line, the antibody's frame remains constant,
but through chemical and cellular messages, the immune
system selects a green sedan, a red convertible or a
white truck to combat this particular invader.
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However, in contrast to cars, the variety of antibodies is
very large. Different antibodies are destined for different
purposes. Some coat the foreign invaders to make them attractive
to the circulating scavenger cells, phagocytes, that will engulf
an unwelcome microbe.
When some antibodies combine with antigens, they activate a
cascade of nine proteins, known as complement, that have been
circulating in inactive form in the blood. Complement forms a
partnership with antibodies, once they have reacted with
antigen, to help destroy foreign invaders and remove them from
the body. Still other types of antibodies block viruses from
entering cells.
T Cells
T cells have two major roles in immune defense. Regulatory T
cells are essential for orchestrating the response of an
elaborate system of different types of immune cells.
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Helper T cells, for example, also known as CD4
positive T cells (CD4+ T cells), alert B cells to start
making antibodies; they also can activate other T cells
and immune system scavenger cells called macrophages and
influence which type of antibody is produced.
Certain T cells, called CD8 positive T cells (CD8+ T
cells), can become killer cells that attack and destroy
infected cells. The killer T cells are also called
cytotoxic T cells or CTLs (cytotoxic lymphocytes).
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| T
lymphocytes become CD4+ or helper T cells, or
they can become CD8+ cells, which in turn can
become killer T cells, also called cytotoxic T
cells. |
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Immune system
process
Activation of helper T
cells
After it engulfs and processes an antigen, the macrophage
displays the antigen fragments combined with a Class II MHC
protein on the macrophage cell surface. The antigen-protein
combination attracts a helper T cell, and promotes its
activation.
Activation of
cytotoxic T cells
After a macrophage engulfs and processes an antigen, the
macrophage displays the antigen fragments combined with a Class
I MHC protein on the macrophage cell surface. A receptor on a
circulating, resting cytotoxic T cell recognizes the
antigen-protein complex and binds to it. The binding process and
a helper T cell activate the cytotoxic T cell so that it can
attack and destroy the diseased cell.
Activation of B cells
to make antibody
A B cell uses one of its receptors to bind to its matching
antigen, which the B cell engulfs and processes. The B cell then
displays a piece of the antigen, bound to a Class II MHC
protein, on the cell surface. This whole complex then binds to
an activated helper T cell. This binding process stimulates the
transformation of the B cell into an antibody-secreting plasma
cell.
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Last updated July 7, 1999 (ldr)
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