HOW
YOUR IMMUNE SYSTEM WORKS AND FAILS
This article reviews the basic function of your immune
system and how it can fail. The results can be devastating. To
understand the immune system I have used an analogy of a military
defense system.
THE
TWO COMPONENTS OF THE HUMAN IMMUNE DEFENSE SYSTEM:
The human immune defense system consists of two main
components, the innate and adaptive. The innate component is so named
because it is a general defense system. It is not specialized or
specific but consists of basic defenses such as barriers, guard cells
and an alarm system. The adaptive component is also aptly named because
it develops or adapts over time as a more specialized and specific
response.
THE
INNATE IMMUNE SYSTEM AS A SECURITY SYSTEM:
The innate immune response is the automatic defense
mechanism against potential foreign invaders such as bacteria, viruses,
molds or parasites. It is analogous to defensive barriers, alarms and
guards intended to protect or defend us personally or as a society.
Such defensive barriers around our borders or sites of value to us may
include protective walls, electric fences, locked doors, security
guards and automatic alarm systems. Such systems may include automatic
motion activated lighting and alarm systems, and low level security
guards. This defense though highly effective for most threats, is not
very specific, highly trained or lethal against serious threats. It
also can be penetrated or breached easily though it may be linked to an
alarm system that can signal for help. Therefore, we need the
protection of more highly trained and specific defenses of the adaptive
immune response.
THE
INNATE IMMUNE SYSTEM CALLS FOR HELP, THE SWAT TEAM, DELTA AND GREEN
BERETS:
With the ability of the innate system to signal for help
and the adaptive systems ability to develop over time highly trained
and specialized cells and antibodies our body has a better protection
against various infections and diseases. In out culture, our adaptive
protective system includes specially trained police or military such as
SWAT teams, green berets, and the delta force. These forces are
mobilized when there is an alarm or request for highly specialized and
trained protection or defense. Though they may simply arrest or contain
a threat they have the ability to mobilize a lethal force when
necessary. However, with this amount of power or force available,
innocent bystanders can be injured or killed if there is poor
communication or identification of threats or potential invaders. This
is how the adaptive immune response works.
INNATE
IMMUNE SYSTEM COMPONENTS AND CELLS EXPLAINED:
Our innate immune defense response is then automatic and
a nonspecific system. It consists of the barriers such as the skin and
the intact intestinal wall of the digestive tract. The intact
intestinal wall is similar to a fence or wall. It is patrolled by
certain immune cells that are like security guards or rent-a-cops,
guarding the body. This includes white blood cells circulating in the
blood or present in the intestinal lining. Circulating white blood
cells typically include cells known as neutrophils, eosinophils, and
natural killer T lymphocytes. Lining the intestinal wall (skin and
respiratory tract) are other white blood cells and immune cells such as
basophils, dendritic cells, phagocytes and macrophages. In the
intestine white blood cells present in small numbers may be mobilized
to the area for specific threats. These include eosinophils, mast cells
and neutrophils.
THE
BERLIN WALL OF THE GUT:
The intestinal lining is normally an intact barrier
except when signaled to allow some bigger particles through such as
certain proteins or other nutrients. The intestinal tract lining has a
single layer of cells of the epithelial cell type. These cells are
joined tightly, shoulder to shoulder, through a scaffolding of
proteins, such as occludens. These tight junctions can open up on
signal, from proteins such as zonulin. Certain normal signals permit
the opening of the gaps between the lining cells, the paracellular
spaces, or decrease the tight junctions resulting in increase
intestinal permeability transiently. However, abnormal stimuli can
trigger opening of the tight junctions resulting in abnormally
increased intestinal permeability or leaky gut. When tight junctions
open up wall of the gut may become abnormally permeable or leaky
allowing it to be penetrated by foreign proteins including bacteria,
viruses, molds, parasites and intact food proteins or lectins.
Impairment of gut wall integrity or barrier function is an abnormal
innate immune defense. It is like an insecure border, fence or wall.
KILLER
CELLS AND THEIR WEAPONS OF IMMUNE WARFARE:
Various immune cells of the innate response can release
chemicals to contain or destroy invaders if they are near the area of
an impaired barrier or they recognize that an invader is trying to get
through just like a border patrol or roving security guard. Some of the
tissue based immune cells destroy the invaders by actually eating them
(phagocytes, eating cells and macrophages, large eating cells). They
also are able to clean up left over debris and promote healing in a
nonspecific manner.
HIGHLY
SPECIALIZED IMMUNE FIGHTER'S MISTAKES RESULTS IN DANGEROUS FRIENDLY
FIRE:
The adaptive response is one that is highly developed
and specialized (trained) in humans. It has a memory. When combined
with alarm systems from the innate immune system, a rapid, specific,
and directed immune response that is also quite powerful can be
activated or triggered. However, when such a system is activated, it
can also lead to serious collateral damage to the surrounding tissues
and cells. If the response bogs down and cannot deactivate itself an
ongoing autoimmune condition without an exit strategy can result. This
can result in chronic injury to the cells and tissues that is
characteristic of what we know as autoimmune disease.
SPECIAL
FORCES OF ANTIBODIES CAN MAKE IDENTITY MISTAKES:
The adaptive response includes the development of
specific antibodies or immunoglobulin (IgE, IgM, IgG, IgD, IgA) to
infectious agents and proteins the body recognizes as foreign
(antigens). Sometimes the body misinterprets or mistakes self-proteins
or tissues as foreign. When antibodies are made against self-proteins
they are called autoantibodies. Examples include antinuclear antibodies
(ANA) of lupus and rheumatoid factors or antibodies of rheumatoid
arthritis. The result is these classic autoimmune disorders.
SPECIAL
KILLER CELLS NECESSARY FOR DEFENSE AGAINST INVADERS:
The adaptive immune system also includes specialized
activated lymphocytes: natural killer T cells, T helper lymphocyte
cells, and gamma delta lymphocytes. The latter are also part of innate
immune system. Tiny brief lived cell called the plasma cell are also
part of the adaptive system. Because the adaptive system has a memory,
and is highly trained for future anticipated attacks it can increase
its response over time. That makes the adaptive system highly effective
in defending us against foreign invaders such as serious infections but
also highly dangerous to us if it becomes activated against our own
cells or tissues.
AUTOIMMUNE
DISEASE RESULTS FROM WELL INTENTION DEFENSES GONE AWRY:
The analogies used should help you better understand how
our immune system works and how it can fail. It also helps explain how
we can develop autoimmune diseases, new abnormal reactions to foreign
proteins such as foods resulting in food allergies or sensitivities and
how an abnormal gut barrier or leaky gut can be dangerous. Certain good
bacteria residing in our gut actually help maintain our intestinal wall
barrier function, act as antibiotics killing bad bacteria and inhibit
other bacteria and yeast from taking over our system.