The Miracle Of The Immune System

Antibody Classes

We earlier stated that antibodies are a type of protein. These proteins, functioning in the defence of the body within the immune operation, are called "immune globulin" (a type of protein) and designated as "Ig". 

The most characteristic proteins of the defence system, the immune globulin molecules bind to the antigens to inform other immune cells of the existence of the antigen or to start the destructive chain reactions of the war. 

IgG (Immune Globulin G): IgG is the most common antibody. Its development takes only a few days, while its life span ranges from a few weeks to several years. IgGs circulate in the body and are mainly present in the blood, lymphatic system, and intestine. They circulate in the bloodstream, directly target the invader, and latch on to it as soon as they detect it. They have a strong antibacterial and antigen-destroying effect. They protect the body against bacteria and viruses, and neutralize the acidic property of toxins (poisons). 

Additionally, the IgG may squeeze itself between cells, and eliminate the bacteria and micro-organic invaders that have infiltrated to the cells and the skin. Due their above-mentioned ability and small size, they can enter the placenta of a pregnant woman and protect an undefended foetus against possible infections. 

If antibodies were not created with this characteristic which permits them to penetrate the placenta, the unborn child in the mother's womb would be unprotected against microbes. It would be under the threat of death even before it was born. For this reason, the antibodies of the mother protect the embryo against the enemies until the time of birth. 

IgA (Immune Globulin A): These antibodies are present in sensitive regions where the body fights with antigens such as in tears, saliva, mother's milk, blood, air sacs, mucus, gastric and intestinal secretions. The sensitivity of those regions relates directly to the tendency of bacteria and viruses to prefer such damp mediums. 

IgAs, which are structurally quite similar to each other, settle in those regions of the body where microbes are most likely to enter, and they keep this area under control. This is like placing reliable soldiers on guard at strategically critical points. 

The antibodies, which protect the foetus from various diseases in the mother's womb, do not abandon the newborn following their birth, but continue to guard them. All newborn babies do need ongoing assistance from the mother, because there are no IgAs in the organism of a newborn baby. During this period, the IgAs present in the milk the baby sucks from its mother protect the baby's digestive system from the effect of many microbes. Just like IgGs, this antibody class also disappears after they have fulfilled their term of service, when the baby is a few weeks old. 

Have you ever wondered who sends you these antibodies that try to protect you from microbes, when you are in the form of an embryo and unaware of anything? Is it your mother or your father? Or is it that they have taken a common decision and sent you these antibodies together? Certainly, the help in question is out of the control of both parents. The mother is not even aware that she has been endowed with such an aid plan. The father is just as unaware of all that is going on. 

Then why do the cells present in the mother's breast and productive of these antibodies function in such a way? Which power has told these cells that the newborn needs antibodies? It is by no means a coincidence that the cells engaging in antibody production for the baby are located in the place where the newborns suckle. 

Here, there is another very important miracle. Antibodies are protein-structured organisms. Proteins, on the other hand, are digested in the human stomach. Therefore, normally, the baby suckling milk from its mother would digest these antibodies in its stomach, and would become unprotected against microbes. The stomach of the newborn baby, however, is created in such a way that it does not digest and destroy these antibodies. The production of protein-digesting enzymes is very little at this stage. Therefore, antibodies vital for life are not digested and they protect the newborn baby from its enemies. 

The miracle does not end here. The antibodies, which are not broken down by the stomach, can, however, be absorbed by the intestine as a whole. The intestinal cells of the newborn are created in such a way as to do so. 

Unquestionably, it is no coincidence that these miraculous events are arranged in such a sequence. The human body, a meticulously planned example of creation, passes from the embryonic stage to having a fully functional immune system in a perfectly phased manner. This is because the events that are supposed to take place in the body every day, every hour and every minute, are computed in an extremely finely-tuned manner. Certainly, the author of this precise calculation is God, Who creates everything according to a very intricate plan. 

IgM (Immune globulin M): These antibodies are present in the blood, lymph and on the surface of the B cells. When the human organism encounters an antigen, IgM is the first antibody that is produced in the body in response to this enemy. 

An unborn child can produce IgMs in the sixth month of gestation. If an enemy ever attacks the baby in the mother's womb, for example, if it infects it with a microbial disease, the baby's IgM production will increase. In order to determine whether the foetus has been infected with a disease or not, the IgM level in its blood is measured. 

IgD (Immune globulin D): IgDs are also present in the blood, lymph, and on the surface of B cells. They are not capable of acting independently. By attaching themselves to the surfaces of T cells, they help them capture antigens. 

IgE (Immune globulin E): IgEs are antibodies circulating in the bloodstream. These antibodies, which are responsible for calling fighter and some other blood cells to war, also cause some allergic reactions in the body. For this reason, the level of IgE is high in allergic bodies.