Relationship Between Stress and the Immune System Term Paper

Immune System and Stress

How quickly a deceased human (or animal) body breaks down is testament to how well the immune system works. While a body is alive, the immune system protects the body at every living moment from bacteria and other foreign invaders. The immune system is a complex system of cells -- which have varying functions -- and generated at discreet regions of the body, a circulatory system -- the lymphatic system -- that feeds of and into the blood circulatory system and lymph nodes that act as effective filters and stores of foreign bodies marked for destruction by antibody action. Most of the time, the immune system protects the body. But on rare occasions we might need outside help: this is when he system does not "figure out" the invasion and the body has to be coaxed into producing antibodies by inoculation with weaker forms of the pathogen. In the case of HIV and AIDS, the body has not been able to create an effective defense, thus these immune deficiency disorders have become the scourge of the last few decades. This essay will not only describe key component of the immune system and how a body uses this system, but will also explore the cause and effect relationship between stress, the immune system and certain diseases.

Key Components of the Immune System

While elaborating on the immune lymph system, one often fails to recognize the role of the skin and openings on the face as the first line of defense. The outer epidermis protects the entire body. The epidermis contains Langerhans cells mixed with melanocytes. These cells warn the immune system of impending attacks. The skin also has antibacterial properties. Nasal passages contain tiny hair that trigger sneezing mechanism to expel germs. The mucus also serves to trap bacteria. The eyes are also exposed. Tears and mucus contains lysozyme, which digests the cell walls of certain bacteria. The basic internal defense mechanism is associated with the lymphatic system. Lymph is a plasma component of the blood that flows (without heart pressure) through the body. Lymph receives nutrients from the blood and carries it to the cells. This fluid also detects the presence of pathogens and signals the defense mechanism. This plasma is filtered through the lymph nodes back into the blood stream. Lymph nodes are found at strategic regions in the body: in the adenoids, tonsils, armpits, groin and in the Peyer patches in the lower abdominal region. These nodes contain cells and tissue. They trap bacteria and other foreign objects. Swollen lymph nodes are a sign of infection. (Brain, 2003)

Three organs are important in the immune system. The thymus, which is situated between the breastbone and the heart, the spleen and the bone marrow are responsible for producing the different types of cells that are responsible for defense. Specific immune cells produce antibodies (antibody mechanism discussed in the next section) by the immune cells in response to an antigenic (foreign body) attack. These are often called immunoglobulins (Igs) and gammaglobulins. Antibodies are proteins that bind to toxins and antigens disabling the function of these invaders or signal action from other cells. Antibodies work in collusion with Complement proteins, a set of free-floating proteins in the system. The liver produces this set of nine proteins. The immune system also contains several hormones called lymphokines. For instance, tymosine signals the production of lymphocytes. Interleukins (IL) are produced by white blood cells. IL-2 suppression in AIDS patients has come under a lot of scrutiny in developing treatment modalities for that disease. (Yarchoan, Mitsuya and Broder, 1993) TNF or tumor necrosis factor kills tumor cells. Interferon targets viruses.

The cells primarily implicated in a body's defense mechanism are white blood cells. Depending on their function, WBCs or leukocytes are of different types, all produced in the bone marrow. The different types are Granulocytes (further subdivided into neutrophils, eosinophils and basophils), lymphocytes and monocytes. The last and the largest enter the tissues and are then called macrophages. These cells "swallow" up the detritus of infections such as whole bacteria, dead cells and tissues. Lymphocytes are further divided into B cells and T cells -- these are critical to the immune system. B cells produce antibodies that create marks on antigens. This signals that these entities should be destroyed. B cells circulate in the blood and the lymph. T cells coordinate and regulate the overall immune response. They not only mark the antigens (helper T cells), but they can also destroy diseased cells.There are certain cell molecules called MHCs (major histocompatibility complex). These are beacons to cells that might be antigenic. Helper T cells are known as CD4 positive T cells. They alert B cells to make antibodies, alert other killer T cells called CD8 positive T cells and also macrophages. (Brain, 2003)

Antibody response

Antibody response is about specificity. Specific antibodies are produced to specific antigens. The helper T cells first recognize the antigen through MHCs; they help the B cells produced antibodies. Occasionally, there are certain markers on antigens trigger B cell response without the helper T cells. Though the basic function is the same, the mechanisms are often different. The basic structure of an antibody protein is its Y-shape. The tips of the Y are sensitive to specific antigens. In some cases, the antibody might coat an antigen such that it becomes a target for macrophage. In other cases, an antibody-antigen complex is formed. This complex renders the toxicity of the antigen chemically inert. The formation of this complex signals a cascade event that ends up in the activation of the Complement proteins. These proteins go to work, disabling the antigen by lysing its cells wall. Or, the cascade may proceed further with a signal that directs the macrophages to destroy the antigen. Sometimes, the mere binding of the antigen renders the complex into a size and shape that does not allow the antigen to infiltrate the cell wall. The mechanism of antibody response is in two stages: primary and secondary. Initially, when an antigen first infiltrates, there is no antibody production. This is probably the time it takes for recognition of antigen in order to determine specificity of the antibody. Then antibody production rises logarithmically, plateaus and then decreases when the antigen has been removed. (Glaser, Kiecolt-Glaser, Bonneau, Malarkey, Kennedy and Hughes, 1992)

Stress and the Immune System

Stress plays an important role in the depression of the immune system -- whether chronic or everyday stress. Though specific origins of the causative factors are not known, there is ample evidence to indicate this. Asthma for instance is affected by stress. Histamines, which block air passages due to the formation of antigen-IL complexes, are often created due to stress. Stress makes the body more susceptible to antigen attack. In several cases, family therapy was more helpful in helping asthmatic children. This was important because they complained about allergies to substances that were found to be harmless. Diabetes is also caused by stress, because stress affects insulin metabolism. Overweight and stressed out adults suffered from Diabetes II. Juvenile diabetes was found to be caused in children who had lost loved ones. (Miller, Cohen and Ritchey, 2002) The stress levels were high among those who cared for family members with dementia. Studies showed that their IL-6 (Interleukin hormone) was higher. This made them more susceptible to illnesses.

From understanding how the immune system basically works and how stress might come to affect it, one might surmise that social interactions that reduced stress will have a salutary effect on the person, the immune system making a person less susceptible to diseases. Less stress would mean that catecholamine and hormonal levels would be well regulated thus enhancing the immune system. Since stress results from people who are traumatized, support groups constructs, group therapy or individual psychiatric care would certainly indirectly improve the immune system-response. Other interactions and interventions would include one or more of the following: Care would be taken that the patient or some one susceptible to stress would take his or her medications as properly; rest is an important consideration, as is proper exercise; healthy regimen of diets would also be important; relaxation techniques, time management and expression of thoughts and feelings are key. Stress is often coincidental with the feeling of a loss of control. Any intervention that allows the patient to perceive control is important in reducing stress.

Diseases and their Relation to Stress

There is no cure for herpes. The manifestation of symptoms does not occur for a several years after the onset of the diseases. While, stress does not cause the disease, symptoms that are dormant will flare up in cases of stress. There have been studies on herpes spread in dogs, especially puppies. When herpes spread through the air infected the *****, it would not whelp at all or deliver a stillborn or smaller than normal litter. In 80% of the cases, the ***** was known to be infected. However, if stress.....