The Immune System

The immune system is perhaps one of the most complex and fascinating systems of the body. Although we all understand that it is the immune system's job to defend the body against foreign invaders, understanding the methods used to accomplish this is relatively new knowledge. As we move along in this series, I will attempt to provide you with definitions of the "language" used to describe the system. For you science buffs out there, I apologize for oversimplifying a complex subject in an effort to pass along some basic concepts. Bear with me while we start from the beginning and move along to modern theory and some conjecture.

By the time we are through, you will have an understanding of what vaccinations attempt to do, the role of nutritional supplements, and some speculation of how nosodes may work.

When we talk of this herb or that substance having anti-microbial properties, are we saying that it directly hunts out and kills the microbe? When we speak of "immunization" (be it vaccination or nosode) are we talking about something we put inside the body that directly attacks the offender?

NO!

In all cases we are speaking of helping the body's immune system to function at an optimum level. True health cannot be achieved unless the immune system is operating as nature intended. The magnificent design of this system is breathtaking in its concept. Consider if you will, the remarkable ability to distinguish between the body's own cells as "self" and foreign cells as "non-self". When immune defenders encounter cells or organisms carrying markers that say "foreign," they quickly swing into action to get rid of them in one way or another. Anything that can trigger this immune response is called an ANTIGEN. In other words, if you don't carry the right "passport" you're in deep doo-doo with the system.

The secret to the success of the system, is an elaborate and dynamic communications network. Millions and millions of cells, organized into sets and subsets, pass information back and forth like clouds of bees swarming around a hive. It can recognize millions of different enemies, and it can produce secretions and cells to match up with and wipe out each of them!!

Some immune cells are "general purpose" warriors and will take on all comers. Others are highly specific and will only deal with selected targets. To work effectively, most immune cells need cooperation of their fellows. Sometimes immune cells communicate by direct physical contact, sometimes by releasing chemical messengers. There is also new evidence of "electronic" communication.

When the immune system is crippled or damaged in some way, it is an invitation not only for microbial infection but also a prime setting for cancer to take hold.

In abnormal situations, the immune system can mistake "self" for "non-self" and launch an attack. The result is called "autoimmune" disease. Some forms of arthritis and diabetes are examples of this.

In other cases the immune system responds inappropriately to a seemingly harmless substance such as pollen, certain foods, etc. The result is allergy. This kind of antigen is called an ALLERGEN.

So lets get into the bits and pieces that make up the "system" and try to fit them together. As the immune system is composed of the lymphatic vessels and organs (thymus, spleen, tonsils and adenoids, and lymph nodes), white blood cells (lymphocytes, neutrophils, basophils, eosinohils, monocytes, etc.) specialized cells residing in various tissues (macrophages, mast cells, etc.) and specialized serum factors, we do have a lot of ground to cover just to get a handle on the basics.

For now lets start with a word that everybody recognizes but may not realize their limited function--- ANTIBODIES. We were all taught that antibodies wipe out specific antigens. While this is true to some extent, it needs to be emphasized that antibodies only ambush antigens in the body's fluids. They are powerless to penetrate cells.

The job of attacking target cells (either cells that have been infected by microbes or cells that have been distorted by cancer) is left primarily to T lymphocytes and other immune cells, which we will get into later.

The difference is so basic that medicine describes the immune system as having two separate branches.

1. "Humoral" immune system: Antibodies are produced to recognize and neutralize antigens. Sometimes referred to as the "specific" or "secondary" system. It is not dependent on the Thymus but rather on the "B cells" (white blood cells that originate in the bone marrow).
2. "Cell Mediated" immune system. This refers to immune mechanisms not controlled or mediated by antibodies. This involves white blood cells called T-cells (Thymus dependent) and other specialized immune cells. Sometimes referred to as the "primary" or "non specific" immune system. It is this system that provides the deeper immunity and is critical in protecting against the development of cancer and allergies.

In this section we will primarily cover some of the basics of the humoral system.

These two branches of the immune system have a reciprocal relationship. That means when the humoral branch is over stimulated (ex. vaccines, allergies), the cell-mediated branch tends to be relatively inactive. Vaccines do not stimulate the cell-mediated branch.

Normal microbial infection (what you or I would call "street infection") does stimulate the cell-mediated branch and can stimulate the humoral branch as well. In nature, the humoral system is only activated when the cell-mediated system has failed to look after the problem and needs help.

One of the fascinating aspects of the immune system is that it has a memory and the capacity to learn. Long ago physicians realized that people who had recovered from the plague would never get it again--they had acquired immunity. In order to have room for all the cells needed to match millions of possible enemies, the immune system stores just a few of each kind. When an antigen appears, those few matching cells multiply into a full-scale army. After their job is done, they fade away except that the system forever retains a "blue-print" for rapid reactivation should it ever be needed.

Within the humoral system, the prime responsibility for the immune response lies with the B cells. Each B cell is specific to the production of one type of antibody. When a B cell encounters an antigen, it gives rise to many large cells know as "plasma" cells. Every plasma cell is essentially a factory for producing antibodies. Each of the plasma cells from a given B cell manufactures millions of identical antibody molecules and pours them into the blood stream.

An antibody matches an antigen much as a key matches a lock. Some match exactly; others fit more like a skeleton key. But whenever antibody and antigen interlock, the antibody marks the antigen for destruction.

Vaccines contain microorganisms--or parts of microorganisms-- that have been treated so they will be able to provoke an antibody response but not full-blown disease. (They also contain a lot of other stuff that would be considered an "antigen" by the body--but that's a whole other subject).

The amount or concentration of a particular antibody that is in solution can be measured in a laboratory. This is called a "Titer Test". Common sense would indicate that if a Titer Test revealed that antibodies for a particular disease already exist at appropriate levels--booster shots are not required!

Here is something more to think about. Even if antibody levels do not test out as appropriate, a booster will not be necessary if the "factory" (the B cell) is healthy and fully prepared to produce them on demand! The pattern is stored in memory and providing the proper raw materials are on hand, the humoral system is capable of reacting very rapidly to a previously recognized antigen.

Actually, antibodies belong to a family of large molecules known as IMMUNOGLOBULINS. Some of you will be familiar with these from seeing lab reports with the symbols IgG, IgM, IgA, IgD, IgE. These five different types play different roles in the immune defense strategy.

For example, immunoglobulin G (IgG) works efficiently to coat microbes, speeding their uptake by other cells in the immune system. Immunoglobulin M is very effective in killing bacteria. Immunoglobulin A concentrates in body fluids--tears, saliva, the secretions of the respiratory tract and digestive tract--guarding the entrances to the body. It's believed that immunoglobulin E (whose natural job is probably to protect against parasitic infection) is one of the villains responsible for the symptoms of allergy.

One other factor plays a major role in the humoral system and that is the COMPLEMENT SYSTEM. As mentioned in previous issues, complement proteins circulate in the blood in an inactive form. The complement system is made up of about 25 body chemicals (manufactured in the liver and the spleen) that work together to "complement" the action of antibodies in destroying microbes. Complement also helps to rid the body of antibody-coated antigens (complexes).

When the first protein in the complement series is activated--typically by an antibody that has locked into an antigen protruding from a cell--it sets in motion a domino effect. Each component takes its turn in a precise chain of steps known as the "complement cascade". The end product is a cylinder inserted into, and punching a hole in, the cells' wall. With fluids and molecules flowing in and out, the cells swell and burst. Complement proteins, which cause blood vessels to become dilated and then leaky, contribute to the redness, warmth, swelling, pain, and loss of function that characterize an INFLAMMATORY RESPONSE.

The immune system has many weapons to use in its war against invaders. The two main lines of cellular defense are the T Lymphocytes and the B lymphocytes (small white blood cells). Both T cells and B cells originate in the bone marrow. B cells remain in the bone marrow until they are mature, whereas the T cells are so named because they mature and/or are instructed in their duties in the thymus gland (a small organ located under the upper breastbone).

Lymphocytes can travel throughout the body, using either the blood vessels or their own system of lymphatic vessels. Like small creeks that empty into larger and larger rivers, the lymphatic vessels feed into larger and larger channels. At the base of the neck they merge into a large duct, which discharges its contents into the blood stream. The lymphatic vessels carry LYMPH, a clear fluid that bathes the body's tissues.

They can also be found in secondary lymphoid organs such as the spleen, lymph nodes, and other lymph tissues, including tonsils, the Peyer patches of the gut, and the respiratory and urinary tracts. Lymphocytes can also accumulate in the connective and epithelial tissues throughout the body.

In the last part we provided some basic information on the B cells and their primary function (and limits). In this issue we would like to give you some basics regarding the T cells and the "Cell Mediated" immune system.

T cells contribute to the immune defenses in two major ways. Some direct and regulate the immune responses. Others are killer cells that attack cells that are infected or cancerous.

Helper-Inducer T Cells, also called helper T cells are the commanders of the immune army, and serve as the central hub of immune operations. The chief responsibility of the helper T cells is to rouse the other defender cells into motion. They interpret intelligence information and communicate with all other lymphocytes through numerous specific chemical messengers.

It is important to understand that one line of communication is directed to the B cells. As mentioned previously, the B cells do the "dirty work" of the immune system by producing antibodies. But, unlike the T cells, which are always on active duty, moving throughout the entire blood and lymphatic routes on surveillance missions, B cells do much less traveling and rest inactive in the lymph system until the T cell calls them to the site of attack. When the helper T cells recognize a virus, bacteria, etc. they stimulate B cells to make antibodies specific for that particular foreign agent. Antibodies then help to destroy the invader.

Thus much of the activity of the B cells is directly attributable to the health and activity of the T cells!

Helper T cells are long-lived and many become memory cells. Whenever they spot a future exposure to the same agent, they'll initiate an even faster and more vigorous immune response. Only a few of the B cells will become memory cells.

Suppressor T Cells keep B cells in check by inhibiting their antibody production in order to prevent over- production. Suppressor T cells also accomplish this goal by direct suppression of helper T cells.

Cytotoxic T Cells are instructed/activated by helper T cells to kill invading cells that are, for example, infected with viruses.

NK (Natural Killer) Cells are also created by helper T cells to kill tumor cells and probably microbial organisms. They perform their work by drilling holes in the membranes of enemy cells. Unlike B cells, natural killer cells do not need to be stimulated into action. They can recognize foreign agents and act independently; and thus, they are born or "natural" killers. Their activity is enormously augmented, however, by communication from a helper T cell that has been sensitized by previously recognizing the same specific foreign invader.

K Cells, like natural killer cells, kill foreign invaders. However, unlike NK cells they require the help of an antibody made by B cells specific for the enemy cell.

Both kinds of killer cells can slay on contact by means of a lethal burst of chemicals.

Although lymphocytes are the main line of defense utilized by the immune system, they are by no means the only types of white blood cells that make up the total picture.

Most of you will be familiar with the term "macrophage". I have referred to these before as the "garbage collectors" of the immune system. But let me get a little more technical and bring in a couple of other terms that you may run across that can cause confusion.

Phagocytes (or "cell eaters") are large white cells that can swallow and digest microbes and other foreign particles. Monocytes are phagocytes that circulate in the blood. When monocytes migrate into tissues, they develop into Macrophages, or "big eaters". Kuppfer cells in the liver are an example of a macrophage.

Activated by sensitized helper T cells, circulating monocytes are converted to macrophages, which are central in triggering the immune response. The macrophages engulf the foreign agent and highlight their antibodies so the helper T cell can quickly identify the invaders. Once the antibodies are marked by the macrophages as foreign invaders, helper T cells determine the immune response needed to neutralize or destroy the body's invader. Thus, the macrophage serves as a scout, providing the intelligence information with which the helper T cell determines subsequent immune response.

So our old friend the macrophage plays many roles. As scavengers, they rid the body of worn out cells and other debris. They display bits of foreign antigen in a way that draws attention of matching lymphocytes. And they churn out an amazing variety of powerful cytokines, known as monokines, which are vital to the immune response.

The battle then goes into full gear. Macrophages secrete more chemicals, or lymphokines with names like gamma-interferon, interleukin-3, Alpha-interferon, etc. and a stimulating factor for granulocytes in order to eliminate the invading threat. These substances in turn alter and strengthen the surrounding macrophages, enhancing their ability to unleash a biochemical attack to kill the microorganism.

Granulocytes are white blood cells that contain granules filled with potent chemicals that allow them to destroy the enemy. Some of these chemicals such as histamine also contribute to inflammation and allergy. One type of granulocyte, the neutrophil, is also a phagocyte; it uses its prepackaged chemicals to degrade the microbes it ingests. Neutrophiles are summoned to sites of inflammation and infection. Eosinophils and Basophils are granulocytes that "degranulate", spraying their chemicals into harmful cells or microbes nearby. Eosinophils congregate particularly at sites of allergic and parasitic reactions. They release enzymes to relieve the biochemical cause of allergy attacks. Basophils are found throughout the blood stream and at sites of inflammation.

Mast Cells are a twin of the basophil, except they are not a blood circulating cell. They are found in the lungs, skin, tongue, and linings of the nose and intestinal tract. They play an important role in the symptoms of allergy.

By now you are able to truly appreciate the complexity and intelligence of the immune system. It's not important to remember all the names you have just read, but it is important (for those that choose to think for themselves) to realize that the concept of a "strong" or "weak" immune system involves a great deal more than simply vaccinating.

Let me summarize what we have covered so far.

• The bone marrow and thymus are the main organs of the immune system.
• Helper T lymphocytes are the hub of operations, serving as both intelligence officers and battle commanders, communicating to and enabling other white cells of the immune system to perform their various combat tasks. Such communications are delivered in the form of the various chemical messengers--lymphokines--interleukin-2, gamma-interferon, colony stimulating factors, and others.
• Macrophages primarily issue the call to battle in their role as scouts; then they are promoted to elite battalions. The helper T cell commanders, armed with the intelligence information gathered by the scouts, can now recognize these foreign antigens and decide what lymphokines to secrete. This determines which branch of the immune system will be engaged and/or enhanced.
• Under helper T cell direction, cytotoxic T cells, NK cells, macrophages, and B cells all perform their various combat tasks.
• Humoral (antibody B cell mediated) immunity is generally considered a separate arm of the immune system and viewed as separate from cellular/T cell immunity. Technically, however, antibodies are not separate since B cells also depend upon communications from helper T cells to perform their task of producing antigen-specific antibodies. Another factor that diminishes their separateness is the fact that when these antibodies bind to or coat foreign agents they make it possible for some components of the cellular immunity system to function effectively.

Nothing serves as diligently in the war against disease as the skin that covers our bodies. Although our skin is not inherently part of what we consider to be the immune system organs, our outer covering plus--the epithelial linings of the mouth and gastrointestinal tract; the nostrils, sinuses, bronchials, and lungs, the respiratory tract; the genitourinary tract, and the conjunctiva of the eyes--all serve as primary barriers to infection.

In a state of health, these rapidly replicating cells of our skin and the linings of our various tracts prevent attachment and penetration by infectious agents, primarily by secreting mucus (a protective agent that lines cells), secretory IgA (which helps sequester foreign agents), and lysozymes (enzymes that actually digest foreign organisms).

As always, the "moral" of the troops can play an important role in this mans army. Keep in mind that our thoughts and emotional reactions exert an enormous influence over our immune system through the network of nerve fibers from the brain and spinal cord as well as the "neuropeptides" secreted into the bloodstream. The central and autonomic nervous systems communicate directly with the organs of the immune system. Therefore, what we think and feel and believe has a powerful ability to affect the function and size of the thymus gland, lymphocyte counts and ratios, lymphocyte function, and lymphokines and antibody secretions.

There are a multitude of studies that have clearly demonstrated that stress, personality, attitude and emotion are causative factors in many disease. Reaction to stress is entirely individual, reinforcing the fact that people and animals differ significantly in their perception and response to various events. The variations in response help account for the wide diversity of stress-induced illnesses.

Stress causes increases in the adrenal gland hormones including corticosteroids and catecholamines. Among other things, these hormones inhibit white blood cells and cause the thymus to shrink! This leads to significant suppression of the immune function, leaving the host susceptible to infections, cancer and other illnesses. The level of immune suppression is usually proportional to the level of stress.

For those of us that breed and show our animals, we must realize that we place a higher level of stress on them than the majority of pet owners. Thus we have the responsibility of ensuring that we also provide them with the means and ability to optimize their immune system.

If we are to strengthen the immune system we must consider what will bolster lymphocyte and other white cell counts, and their critical secretions, such as interferon and interleukins, and antibody levels. We must consider what will repair and maintain the integrity of the skin and mucosal epithelial linings.

We've covered a lot of technical mumbo-jumbo for you to refer to in the event that someone tries to mesmerize you with fancy terms. Granted, the immune system is complex and some kind of label has to be used to distinguish its many, many parts. For the specialist this information is vital. For the average person, it is overwhelming and can be confusing. At least you now have an awareness that mounting an immune response is not totally dependent on vaccination.

The most common reason to vaccinate is to prevent infections. Now that you have the background, lets take a simplified look at the body's natural defense system for prevention of infectious disease.

Microbes attempting to get into the body must first move past the body's external armor. The skin and the membranes lining the body's gateways not only pose a physical barrier, they are also rich in scavenger cells and IgA antibodies.

Next, invaders must escape a series of NONSPECIFIC defenses, which are ready to attack, without regard for any specific antigen markers. These include patrolling scavenger cells, natural killer (NK) cells, and complement.

Microbes that cross the nonspecific barriers must then confront specific weapons tailored just for them. Specific weapons, which include both antibodies and cells, are equipped with singular receptor structures that allow them to recognize and interact with their designated targets.

In addition, Mother Nature designed the system so that once an infectious microbe has invaded and been vanquished, the next exposure will be met with a more rapid, stronger attack of such intensity that the body is literally immune to any future infection of the same disease. When both the humoral and cell mediated systems are functioning at their optimum, infectious disease doesn't stand a chance!

The sad thing is that in today's modern world the average dog doesn't stand a chance of having an immune system that is operating at optimum levels. Starting with inherited genetic defects and adding an onslaught of nutritional imbalances or deficiencies, hormonal imbalances, exposure to toxic or noxious substances, exposure to infectious agents and drugs, etc., has markedly increased the frequency of ill health that we are seeing in our canine companions. In my opinion, the great "experiment" of this century in providing "nutrition" from a bag and "immunity" from a needle, has been a gigantic failure. Unless we are prepared to work with nature and purposely support and enhance the immune system, we have no right to expect good health for our animals.

Let's take a look at some of the components of the immune system and discuss some of the things that are important for maintaining and enhancing the system.

In considering the primary organs of the immune system it should now be obvious that first and foremost is the thymus. The thymus gland shows maximum development shortly after birth. During the aging process, the thymus gland undergoes a process of shrinkage or involution. The reason for this involution appears to be that the thymus gland is extremely susceptible to free radical and oxidative damage. Antioxidants such as vitamin C, vitamin E, selenium, zinc and beta-carotene can prevent thymic involution and enhance cell mediated immune functions.

The thymus gland also releases several hormones such as thymosin, thymopoetin and serum thymic factor, which regulate many immune functions. Low levels of the hormones in the blood are associated with depressed immunity and an increased susceptibility to infection. Many nutrients function as important cofactors in the manufacture, secretion and function of thymic hormones. Deficiencies of any one of these nutrients results in decreased thymic hormone action and impaired immune function. Zinc, vitamin B6 and vitamin C are perhaps the most critical. Supplementation with these nutrients has been shown to increase thymic hormone function and cell mediated immunity.

Next we need to consider the importance of the lymphatic system. Approximately one-sixth of the entire body consists of the space between cells. Collectively this space is referred to as the "interstitum" and the fluid within the space is referred to as the interstitial fluid. This fluid flows into the lymphatic vessels and becomes the lymph.

Lymphatic vessels usually run parallel to arteries and veins, draining waste products from tissues and transporting the lymph to lymph nodes which filter the lymph. The cells responsible for filtering the lymph are macrophages (large cells which engulf and destroy foreign particles including bacteria and cellular debris). The lymph nodes also contain B-lymphocytes (the white blood cells which are capable of initiating antibody production in response to the presence of viruses, bacteria, yeast and other organisms).

The spleen is the largest mass of lymphatic tissue in the body. In addition to producing lymphocytes, engulfing and destroying bacteria and cellular debris, the spleen is responsible for destroying worn-out blood cells and platelets. The spleen also serves as a blood reservoir. During times of demand, such as hemorrhage, the spleen can release its stored blood and prevent shock.

Although not considered a lymphatic organ, the liver produces the majority of lymph in the body. In addition, the integrity of the lymphatic system is highly dependent on special types of macrophage (Kupffer cells) that exist in the liver. Kupffer cells are responsible for filtering bacteria, yeast (like Candida albicans) and toxic foreign compounds that are absorbed by the gastrointestinal tract. These cells, when functioning properly, are extremely effective in filtering the blood. Healthy Kupffer cells have been shown to engulf and destroy a single bacteria in less than 1/100 of a second.

Clumps of lymphoid tissue are found in many other parts of the body, especially in the linings of the digestive tract and the airways and lungs that serve as gateways to the body. These tissues include the tonsils, the adenoids, and the appendix.

Thus we can see that the "immune system" is nothing more (or less) than an integral part of natures design of the body and the dynamic interaction of all of its parts.

Obviously, a broad range of nutrients are required for immune function. There are many books, review articles and primary research papers that discuss the relationship between nutrition and the immune system.

Wholesome nutrition is a key component of maintaining a healthy immune system. You're probably tired of hearing me say this but a raw diet is unsurpassed in providing the best nutrition for both dogs and cats. Proper digestion is a requirement for optimum health, and incomplete or disordered digestion can be a major contributor to the development of many diseases. The problem is not only that ingestion of foods and nutritional substances are of little benefit when breakdown and assimilation are inadequate, but also that incompletely digested food molecules can be inappropriately absorbed into the blood stream. This can lead to various diseases and the development of food allergies. Dogs and cats were designed to digest RAW FOODS! Cooking and processing is totally a "man made" concept and is foreign to nature's digestive design for these animals.

The basic premise of natural rearing is to provide an animal with the best chance of having an immune system that functions at an optimal level. THE HEART AND SOUL OF ANY NATURAL REARING PROGRAM IS AND ALWAYS WILL BE A RAW FOOD DIET!

Thousands of years of traditional usage and more recent scientific research has shown that certain substances and approaches (generally not in the realm of conventional medicine) can be incorporated into an immune enhancing program. In past issues of our newsletter we have provided information on many of these and will continue to do so in future issues.

For example:

• Herbal supplements and medicines such as garlic, ginsing, licorice root, echinacea, astragalus, etc. have been show to impart numerous benefits to immune function (particularly the cell-mediated branch). Now that you have the background it is more meaningful when you understand that these benefits include macrophage stimulation, increased phagocytosis, increased NK (natural killer) cell counts, increased interferon, and enhancement of delayed hypersensitivity response. A number of herbs also have direct antiviral and anti-tumor activity.
• Medicinal mushrooms such as shiitake and ganoderma, also stimulate the production of interferon and other well defined immune parameters.
• Glandular extracts, particularly thymus and spleen, have been considered potentiators of immune function by many naturopathic physicians and veterinarians and are frequently prescribed.
• Acupuncture has been found to enhance many immune parameters. It can increase the number of T cells, lymphocytes in general, T cell ratios, NK cell activity, B cells and phagocytic activity.
• Homeopathy has been used effectively to treat infections and immune deficiencies. One of the theories behind the use of "Nosodes" is that this homeopathic form of immunization provides the system with the "pattern" of a particular disease. The pattern will be stored in "memory" cells, thus preparing for a rapid immune response to that infection in the future.

In a full natural rearing program, of equal importance to immune system enhancement, is the avoidance of chemical toxins, drugs, vaccinations, flea collars, pills, chemical wormers, antibiotics, steroids, etc. to the greatest extent possible. Each of these has a detrimental effect on the immune system and can trigger an overload that is difficult and sometimes impossible for the body to handle.

To quote Dr. Jean Dodds, D.V.M. "Viral disease and recent vaccination with single or modified-live virus vaccines, ...are increasingly recognized contributors to immune-mediated blood disease, bone marrow failure and organ dysfunction."

Lets put a little perspective into the relative importance of the cell mediated system with a quick summary along with some percentages.

The "workers" of the immune system are various white blood cells. A lymphocyte is a specialized form of white blood cell, representing 25-40% of the total blood count, whose numbers increase during viral infection and when fighting cancer.

Lymphocytes are produced in the bone marrow and come in two basic forms. B cells mature in the bone marrow and produce antibodies to neutralize foreign cells (this is know as the humoral system). B cells account for 10-15% of all lymphocytes.

T cells mature in the thymus gland and react to and destroy specific invading antigens (this is known as cell-mediated immunity). 75-80% of lymphocytes are T cells. T cells are predisposed to respond to specific foreign substances (antigens) or infections.

Natural Killer (NK) cells are a type of nonspecific, free-ranging lymphocyte that is neither a B nor T cell. Unlike other lymphocytes, NK cells are not activated by a specific antigen. They can recognize and quickly destroy any antigen on first contact. They have a potent cell-killing activity, being armed with an estimated 100 different biochemical poisons for destroying foreign cells. Their role is surveillance, to rid the body of aberrant or foreign cells before they can grow and produce cancer or infection. NK cells account for 5-10% of all lymphocytes.

Main Types of T-cells:

Helper T cells (also known as T-4 or CD-4 cells) secrete immune proteins (particularly the interleukins and interferon) to stimulate B cells, macrophages, and activate Killer T cells. They account for 60-75% of all the T cells.

Killer T cells (T-8 or CD-8) cells bind to the specific invader and secrete enzymes to destroy it. They account for 25-30% of all T cells.

Suppressor T cells prevent excessive immune reactions by suppressing antibody activity.

If you pay close attention to the aforementioned percentages you will note that conventional vaccination attempts to stimulate B cell recognition only, or about 10% of the total lymphocytes. It ignores 90% of the overall immune system. With all the additional risks involved, does it really make any sense to subject an animal to this kind of questionable immune "enhancement"??? Repeatedly???

Or does it make more sense to work on the other 90% with good nutrition and natural, non-harmful methods of enhancement?

When I adopted the natural rearing method for my animals, I had very little of this information available. I just knew that there had to be something better than what I had been doing in the past. After many years of experience and research, I have found nothing to make me regret my decision. On the contrary, the more I learn the more convinced I become that I am truly providing my dogs with the opportunity to be "the best that they can be."

The choice is yours. I hope I have given you enough basic information to really "think for yourself" about the care and maintenance of the immune system in your animals.