Without a properly functioning immune system, we wouldn't live past birth. The secret of looking younger and living a longer and more fulfilled life lies in keeping the immune system operating as efficiently and effectively as possible. Our immune system, however, is one of the first bodily systems to deteriorate with advancing age.
Most classic 'diseases of aging', such as heart disease, arthritis, cancer and pneumonia, occur only after our immune system begins to lose potency.
Scientists consider that the immune system is controlled by the same genes that guide the aging process.
The immune system begins to attack itself (autoimmune diseases such as arthritis) upon aging.
When the aging immune system loses its efficiency in cleansing the body of defective and dead normal cells, the build up of cellular garbage facilitates the aging of other organs.
||COMPONENTS OF THE IMMUNE SYSTEM
Two groups of cells constitute our immune system. White blood cells (leukocytes) are examples of this first group. The main activity of these phagocytes (scavenger cells) is to engulf and eat foreign invaders to the body.
Lymphocytes make up the second group of cells in our immune system. This is a far more important group, having the capability to recognize and respond to individual enemies to the body. T-cells and B-cells are lymphocytes. These scavengers are made in the lymph glands and function in lymph (a suspension of the cells in a clear yellowish fluid resembling blood plasma) through the lymphatic vessels to the blood stream. The lymphocytes seem to be the most important of the phagocyte cells in the battle against cancer and other diseases. A malignant disease is often observed to be infiltrated with lymphocytes, and a high degree of lymphocyte infiltration is now accepted as a reliable indicator of favorable outcome of the disease.
B-cells function as foot soldiers in the immune system army. They produce substances called antibodies (immunoglobins) that stimulate a sequence of other chemical reactions. The result of this biochemistry is the destruction of a specific invader, without harming the body itself.
A more interesting characteristic of a B-cell is its ability to 'remember' an invading cell. Should an invader return, the B-cell quickly dispenses its antibodies and the invading cell now meets a quicker death, as compared to its predecessor. This, for example, accounts for our permanent immunity to childhood diseases, once we have had the illness.
Vaccines contain weakened or dead strains of dangerous viruses or bacteria. By assembling this false attack, our B-cells mobilize and are now prepared to fight off a real attack, such as cold viruses during the influenza season.
Continuing with our army analogy, the T-cells represent the sergeants and lieutenants. They direct the fighting and participate in it themselves. Various subgroups of T-cells work together to control the immune army through a complex system of chemical commands. T-cells help stimulate the immune system when danger is imminent and slow down the immune response when it gets too strong. Whereas B-cells conduct their fighting from a distance, T-cells combat at close range. These T-cells are our prime defense against cancer cells.
More recently discovered components of the immune system are the interferon’s. These agents are produced by cells infected by a virus. Some scientists feel that malignant cells may manufacture this substance. In any event, interferon’s are proteins that kill viruses. They assist other cells in the body to resist infection. There is some evidence that interferon’s help in the effort by the human body to control a developing cold or some other infection or cancer. We make twenty different kinds of interferon molecules, each kind engaging in somewhat different activities in different cells in the body. This is important because most drugs are ineffective against cancer and other viral infections (AIDS, for example).
Prostaglandins are small molecules that play an important role in our immune system. These lipids (fats) function as hormones and aid in the regulation of the heartbeat and the responses of the immune system. Whenever any tissue is disturbed or damaged, it releases prostaglandins. The prostaglandins are involved with other substances in producing inflammation of the tissues — redness, swelling, pain, tenderness, and heat which results from increased flow of blood and the movement of leukocytes and other cells and substances to the region in response to the hormones.
The master gland of the immune system is the thymus. It functions as a command centre for T-cells and as an officer's training school. Immature white blood cells, the raw recruits, travel from the bone marrow, to the thymus to be turned into mature, functioning T-cells. The thymus also makes hormones that circulate throughout the body and help T-cells and B-cells interact effectively.
While each component of the immune system is important on its own, no single part can work effectively without the help of others. We still have much to learn about our immune system.