The Immune System – What, Where and Why
Your First Line of Defense in the Body!
by Frank M. Jordan
What is the Immune System and Immune Response?
The immune system is our body’s incredibly complex defense network comprised of about 20 trillion white immune cells, or leukocytes, representing 1/5 of our total body cells. Leukocytes are the body’s defense cells with the purpose to defend us against foreign, disease producing substances that do not belong in our bodies and can potentially cause infection, disease, poor health and even death.
The immune system has a complex group of specialized organs, cells and tissues that are coordinated and communicate to recognize, respond and destroy health invaders (non-self) while ignoring harmless microbes (self). The immune system lymphoid organs are the thymus, spleen, bone marrow and lymph nodes in which the white blood cells are stored.
All cells of the immune system are white blood cells of five categories including (1) Lymphocytes, (2) Monocytes and Macrophages, (3) Basophils, (4) Neutrophils, and (5) Eosinophils. The Lymphocytes are then differentiated into three sub-groups: (a) T Lymphocytes; (b) B Lymphocytes and (c) Natural Killer Cells. The T Lymphocytes are of four types including: (1) Cytotoxic T cells, (2) Memory T cells, (3) Helper T cells and (4) Suppressor T cells.
The immune response is the mechanism the body uses within the immune system. When activated the body’s immune response engages to recognize, respond, resolve and then remove the agents of infection and disease. As humans, from the time of conception, we are confronted with attacks by infectious agents including viruses, bacteria, and fungus plus parasites and environmental toxins that seek to destroy our good health. Fortunately all microbes have unique antigens. What is an antigen?
Antigens are substances not made by the body described as non-self that trigger an immune response due to chemicals unique to a specific antigen. In simplified terms, antigens are molecule name tags that can be bound to by an antigen-specific antibody (AB) or a B cell antigen receptor (BCR). Every non-self microbe has a distinct and exclusive antigen name tag that enable defense by different immune system components.
This antigen binding also alerts blood components known as complements (actually 25 different proteins) to puncture holes in invader infected cells. This facilitates phagocytosis, or ingestion of the invader by phagocytes such as the macrophage. Antigens originating from our environment include viruses, chemicals, toxins, pollen and more. Harmless antigens that cause allergies are called allergens.
For a human to survive, the immune cell responses must recognize and determine the location and characteristics of pathogens immediately; then appropriately respond to neutralize or kill the health invaders by chemicals/enzymes or disrupting and breaking down the cell membrane (lysing) of a pathogen. Then phagocytosis occurs performed by phagocyte cells to ingest, break down by enzymes and kill pathogens as appropriate or present foreign antigens to cells of the Adaptive immune system.
Innate Immunity (sometimes called “non-specific”)
Innate and adaptive/acquired immunity are the two divisions of the immune system, with some immune cells participating in both. From your first breath you are in a body war to survive and your innate immune system is the first line of defense against health invaders including viruses, bacteria, parasites and toxins; in addition to sensing wounds and trauma. Macrophages, Neutrophils and mature dendritic cells are the primary cells of innate immunity, joined by the skin, tears and mucous membranes in the nose.
Innate immunity involves defense mechanisms that are non-specific and attack any antigen considered non-self without an origin from within the body. These innate cells are present before encountering non-self or sometimes described as non-anticipatory. In original form these innate immune cells go into action when and where they confront non-self cells. Innate immune cells have the greatest presence in numbers in the immune system, but have no memory. Just to be confusing, some innate cells such as macrophages also inform and are involved with the adaptive immune response as the second line of defense. Let’s next discuss complement and phagocyte cells as part of the innate immune response.
Complement in the innate immune system is a complex set of up to 25 serum proteins acting together to attempt to eliminate infectious microorganisms and other pathogens. Specifically, the complement system causes the destruction of pathogens by lysis involving piercing the outer membranes of foreign and infected cells on recognition by the immune response. Complement proteins, especially C3, make pathogens more visible to phagocytic cells such as macrophages by a process known as opsonization.
Complement activation occurs by two routes, called the classical pathway triggered by antibodies on the surface of a microorganism, or the alternative pathway activated by molecules embedded in the surface membranes of invading microorganisms; faster in response because the alternative pathway does not require the presence of antibodies. Both pathways can activate the primary protein of the complement system, C3. As a note C3 is a receptor for beta 1,3/1,6 glucan, together with Dectin-1 which can create a response to inflammation rapidly.
Lymph nodes are clusters of immune tissue that filter and detect foreign and potentially harmful substances in the lymph fluid. Lymph nodes are part of the lymphatic system which act as the body’s master drain. Cells inside the nodes examine the lymph fluid, collected from body tissues, for the presence of foreign matter. Lymph nodes are primarily clustered in the neck, armpits, chest, groin and abdomen. Lymph fluid flows in the lymphatic vessels throughout the body, helping to maintain the fluid level of cells and carrying various substances from the tissues to the blood. The human body has 1-2 quarts of lymph fluid representing 1.5-3.0% of body weight.
Macrophages are innate immune cells, but also are associated with the adaptive immune response as antigen presenting cells. Macrophages are the first line of defense that kill pathogens and remove damaged or dead cells and cellular debris through phagocytosis. In various parts of the body, the macrophages may be referred to as: Lungs – Alveolar cells; Kidneys – Mesangial cells; Brain – Microglial cells; Liver – Kupffer cells; Peyer’s Patch – Macrophages and Skin – dendritic Langerhans cells. The macrophages, as each of us, as we grow older are usually compromised by past and current diseases and poor lifestyle. As we become immuno-compromised we become less able to fight back and the cells ability to recognize pathogens becomes suspect. If our immune systems become immuno-compromised we are more susceptible to invading pathogens from colds to cancer and thus to the occurrence of illness and mortality.
A neutrophil is a mature granulocyte white blood cell formed in the bone marrow comprising released into the blood where neutrophils represents 50-70% of the total number of leukocyte white blood cells. The principal activity of the neutrophils is to ingest foreign particles, especially virulent bacteria and fungi and to fight infections and to heal injured tissues. A normal absolute neutrophil count (ANC) is between 2500 and 7500 neutrophils per cubic microliter of blood. A neutrophil level over 8,000 is considered abnormally high with high levels often due to infection or stress. Neutrophils are the first immune cells to arrive at an inflamed or injured area of the body.
Monocytes, Basophils, Eosinophils and Mast Cells
Monocytes are the largest immune cells and as part of the innate immune system can differentiate into macrophages and dendritic cells. The Monocytes circulate for about three days before entering tissues and organs to become Macrophages. Basophils are the least common type of circulating white cells and are responsible for inflammatory reactions plus allergic defenses. Eosinophils combat multicellular parasites and certain infections. Mast cells are connective cells containing granules consisting of heparin, histamine and more.
Natural Killer Cells (NK)
Natural killer cells (NK) are lymphocyte white blood cells that are nonspecific, free ranging immune cells produced in the bone marow and matured in the thymus gland. NK cells can destroy tumors and virally-infected cells without an attached antigen. The NK cells comprise about 10-15% of circulating lymphocytes as part of the innate immunity. Natural killer cells recognize antibody-coated target cells and directly attack and kill primarily cells infected with a virus or tumor cells by puncturing such cells and killing with an estimated 100 different biochemical poisons and with enzymes/cytokines by lysis or apoptosis.
Cytokines are peptides performing as cell signaling proteins, or a form of faxes, between immune cells. Cytokines are a complex category including interferons, interleukins, chemokines, lymphokines and tumour necrosis factor [TNF alpha]. Interferon is short lived when produced, but alerts cells through refractory to help promote anti-viral defenses. Immune cells including macrophages, B lymphocytes, T lymphocytes and mast cells, in addition to endothelial cells, fibroblasts and stromal cells (connective tissue cells of any organ) can all produce cytokines. Cytokines are important in the immune system acting through various cell surface receptors involved in host immune responses to infection, inflammation, trauma, sepsis, cancer and reproduction.
Several innate immune cells are also classified as Phagocytes. Phagocytosis means “big eater” while the phagocytosis process involves a cell engulfing a particle, digesting the particle, and then expelling the waste products. Phagocyte cells protect the body by phagocytosing or ingesting pathogenic or harmful non-self foreign particles, bacteria, fungi and dead or dying cells.
Phagocytes include neutrophils, monocytes, macrophages, dendritic cells and mast cells. These phagocytes all have surface receptors by which they can detect pathogens, especially bacteria, viruses, fungi and even parasites. As an example of an immune response, activated macrophages ingest a body invader such as a virus and display pieces of the virus known as antigens on the macrophage surface. The macrophage, as an antigen presenting cell (APC) presents the antigen to the Helper T-Cells. The most numerous phagocytes comprising up to 60% of your white blood cells are Neutrophils, usually found in the blood stream that respond to infection and contribute to healing damaged tissue.
Adaptive Immune Response
The adaptive, or acquired, immune response is slow to develop because it occurs after exposure to an antigen from a pathogen, usually presented by an innate immune cell, or vaccination and when the innate immune system is unable to control an infection.
Adaptive immune cells classified as Lymphocytes are 20-40% of your white blood cells that originate in the bone marrow, where one group develops into B cells that produce antibodies and alert the T lymphocytes. The two parts of the adaptive immune response are cell-mediated performed by T-cells and the humoral immune response controlled by activated B-cells and produced antibodies. When activated, the T-cells and B-cells proliferate and attack an invading pathogen. Pathogens are killed directly or by secreted antibodies that aid phagocytosis of pathogens and disrupt replication of infections.
T-cells – Cell Mediated Response
T-cells begin in the bone marrow and then travel to the thymus through the blood. Each T-cell develops a distinctive receptor (TCR) for a specific antigen. The T cell will then differentiate into an effector T cell. The T-cell can bind antigen, but it must be in the presence of a complex of proteins on the cells of the host, called the major histocompatibility complex (MHC). Note that the thymus produces fewer and fewer naive T cells as we age. This reduced T-cell presence increases our susceptibility to infections and other pathogens as we age and makes a healthy lifestyle an imperative..
The effector T-cells then join with host cells and become either a CD8 cytotoxic suppressor T-cells that suppress B-cell activity or CD4 T-helper cells. The primary function of CD8 Cytotoxic T-cells is to kill virally infected cells and also kill tumor or bacteria cells. T-helper Cells (CD4 T-cells and Th cells) have many sub types including Th1, Th2, Th 17 or regulatory T cells. CD4 helper T-cells have many functions including activating other immune cells, releasing cytokines and histamine, plus regulating the adaptive immune response.
After an infection, Memory T-cells are formed (an important part of vaccines) that if exposed again to a pathogenic antigen, can quickly activate an immune response. Memory T-cells can be CD4 or CD8. Another form of T-cell is a suppressor cell that will shut down an inflammatory response when the inflammation objective is completed.
The helper T-Cells recognize specific antigens on the macrophage surface (APC cells) and bind to the macrophages. The helper T-cells then evaluate the situation and call in the various immune system components needed to fight back effectively against a specific antigen if determined to be pathogenic.
The helper T-cells also activate the humoral side of the immune response, including the B-cells. B-lymphocytes develop and mature in the bone marrow and on presentation of a foreign antigen (non-self) on invasion of the body, begin to divide and secrete a protein known as an antibody.
These unique antibodies then bind to the antigens on the surface of the health invaders, enabling recognition by the macrophages and various T-cells classified as Cytotoxic T-cells that kill with chemicals and NK or Natural Killer T-cells that kill by lysing or ramming the pathogens.
B-cells – Humoral Immune Response
Humor in the body refers to body fluids, including blood and lymph. Humoral immunity refers to protection involving antigen-specific antibodies produced by the B-cells in the body fluids which then activate and proliferate, binding and attempting to neutralize pathogens. A challenge for the immune system is to distinguish self from non-self. All cells have proteins found on their surface. The immune cells ignore cells made by the body called “self.” All others are “non-self” and include bacteria, fungi, toxins or other foreign body. B-cells comprise about 10-15% of total Lymphocytes that release antibodies (immunoglobulins) that bind and destroy antigens of pathogenic invading cells. B-cells are of two types: (1) Memory B-cells and (2) Plasma cells.
Memory B-cells remain in the body for an extended period and when a subsequent attack occurs by the same pathogen antigen, the Memory B-cells attack immediately. When the Plasma B-cells are stimulated they produce large amounts of antibodies into the blood, where they are carried then into the tissues where millions of antibodies are secreted directed against a specific antigen.
Each B-cell makes only one specific antibody after encountering an antigen from non-self. An antigen, which is short for antibody generator, is a protein molecule containing about 20,000 atoms creates an immune response that in turn triggers a B-cell production of an antibody against that specific antigen. Antibodies are part of a group of chemicals called immunoglobulins with the most prominent being Immunoglobulin G (IgG) that marks non-self microbes so other immune cells such as NK and Killer T-cells can kill the invaders. Antibodies may be found in the blood, lymph, saliva and dthe gastrointestinal and urinary tractds, usually within 3 days after the first encounter with an antigen. The antibodies are made from amino acids by B lymphocyte cells in the lymph tissue.
As the health invader is killed and brought under control, the activated T-cells and B-cells are signaled to stop attacking by suppressor T-cells. Another type of T-cell, the Memory T-cells, remain behind to create acquired immunity and to respond quickly against the same type of invader, if the same health invader attempts to attack again. Your body contains millions of antibodies at any given time. We often translate this to mean we are building up an immunity to various viruses, bacteria, fungi or parasites.
Vaccines present a very small quantity of a specific antigen for which the B-cells produce antibodies unique to the specific antigen that are then available as memory cells to respond quickly if a future attack occurs as in influenza or polio. Unfortunately, many pathogens, especially viruses can mutate to neutralize vaccine effectiveness until a new form of antibody is developed to counter the specific mutated virus cell. This is why the four components of influenza vaccines are reviewed annually for potential effectiveness.
Microparticulate (MG) Beta Glucan Nutritional Normalization of the Immune Response
Microparticulate (MG) Beta glucan works through activation of biological response modifiers including the presence of unique receptors on the surface of the Macrophage and Dendritic immune cells that are approximate matches in size for the Beta glucan when processed to be microparticulate particles 2-4 microns in size.
This means Beta 1,3/1,6 glucan extracted from yeast cell wall and micronized, nutritionally contributes to normalization of these important huge white immune blood cells, as the first line of defense in your body. The proprietary extraction process for Beta 1,3’1,6 glucan includes attempted elimination of harmful proteins that can cause negative yeast reactions. This virtually eliminates negative allergic reactions to the micronized MG Beta 1,3/1,6 glucan. Beta glucan also nutritionally promotes the Interleukin 1 (IL1) production beneficial to insulin production in the pancreas.
Status and Future
Our immune systems are generally strong at birth but decline during life due to genetics, aging, health impact of lifestyle lacks including poor diet, lack of exercise, lack of sleep and diseases incurred over the years.
Protect and keep your immune system strong by eating a healthy diet, moderately exercising, getting adequate sleep, minimizing stress and regularly using vitamins and quality nutritional supplements. Your body is your first line of defense against all that seeks to harm you including viruses, bacteria, fungi, parasites, environmental hazards. Recognize you are constantly in a body war and your immune system is your first line of defense to provide a quality of life.
This IMMUNITION REPORTS website (www.immunitionreports.com) is designed to provide accurate and authoritative information with regard to the subject matter covered; however, this website is not intended to be a substitute for a professional consultation with a physician or a qualified health care provider or to offer medical or related professional advice. Frank Jordan is a health professional with a post-graduate degree from the University of Texas at Austin with issued and pending U.S. and Foreign Patents related to Beta glucan and the immune response, but he is not a medical doctor.
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