The Miracle Of The Immune System

Cells On Duty in the System

If an enemy overcomes all barriers and succeeds in entering our body, this does not mean that the defence army has been defeated. On the contrary, the real war has just begun, and the main soldiers come into play at this stage. The first soldiers to meet the foe are the eater cells, that is, phagocytes, which continuously travel in our body and keep control of what is going on.

These are "special cleaning cells", which ingest the unwanted microbes that have penetrated the inner surfaces of the body, and alert the defence system when necessary. 

Certain cells in the defence system capture, break down, digest, and eliminate the miniscule particles and liquid foreign matter that have entered our body. This event is called "phagocytosis". (cell engulfing)

Phagocytosis is one of the most important elements of the immune system. It provides an immediate and effective protection against infections. 

Phagocytes, considered the "police forces of the body," can be examined under two separate headings. 

1. Mobile police forces: These roam in the blood and shuttle forwards and backwards between the tissues when required. These cell units, which circulate throughout the body, also serve as scavengers. 

2. Immobile police forces: These are immobile macrophages, which are situated in the gaps in various tissues. They perform phagocytosis on the micro-organisms from where they are, without moving. 

If the invader antigens (foreign micro-organisms) are few enough for the present eater cells to deal with, they are destroyed with no extra alarm being given. But if the invader microbes are too great in number, the eater cells may fail to get them under control. Unable to digest all of them, they expand in size. When distended by the antigens, the cells burst, causing a liquid substance (pus) to overflow. This does not mean that the war is lost. So far, the eater cells have just met the microbes, which have still many tougher barriers to pass. The formation of pus activates the lymphocytes, which have been delivered from the bone marrow, the lymph nodes, and above all, the thymus. In a second wave of defence, the newly arriving defence cells attack everything they find around, including cell debris, available antigens, and even old white blood cells. These defence cells are the real eater cells, - the macrophages, a type of phagocyte. 

The First Aid Forces: The Macrophages

When the war becomes intense, the macrophages swing into action. Macrophages operate in a specific manner exclusive to themselves. They do not become involved in a one-to-one combat like the antibodies. Unlike the antibodies, they do not work with a system similar to a bomb aimed at a single target. Just like a gun firing lead shot, or a bomb that can be aimed at many targets together, the macrophages can destroy a great number of enemies together, all at the same time. 

Like all other defence cells, the macrophages are also derived from the bone marrow. The macrophages, which have a very long life span, can live for months, and even years. Despite their small size (10-15 micrometers), they are highly crucial for human life. They possess the ability to absorb and digest big molecules in the cell through phagocytosis (ingestion). 

Their characteristic of ingestion makes them the scavengers of the defence system. They remove all materials that need to be cleaned up, such as micro-organisms, antigen-antibody complexes, and other substances similar in structure to an antigen. At the end of these processes, substances that would be qualified as antigens are digested, and thus pose no further threat to the organism. 

General Alarm

When a country is involved in war, a general mobilization is declared. Most of the natural resources and the budget are expended on military requirements. The economy is re-arranged to meet the needs of this extraordinary situation and the country is involved in an all-out war effort. Similarly, the defence system would also announce mass mobilization, recruiting all of its elements to fight the enemy. Do you wonder how this happens? 

If enemy members are more than the currently fighting macrophages can handle, a special substance is secreted. The name of this substance is "pyrogen" and it is a kind of alarm call. 

After traveling a long way, "pyrogen" reaches the brain where it stimulates the fever-increasing centre of the brain. Once alerted, the brain sets off alarms in the body and the person develops a high fever. The patient with a high fever naturally feels the need to rest. Thus, the energy needed by the defence army is not spent elsewhere. The pyrogen produced by the macrophages is perfectly designed to trigger the fever-raising mechanism of the brain. Therefore, the macrophage, and the pyrogen, and the temperature-raising centre of the brain, and the brain have all to be created at the same time. 

As is evident, there is a perfect plan at work. Every requirement is created flawlessly for this plan to succeed; the macrophages, the pyrogen substance and other similar substances, the fever-raising centre of the brain and the fever-raising mechanisms of the body…

In the absence of even one of these, the system would simply not work. Therefore, it can by no means be claimed that such a system could have originated step by step through evolution. 

Who, then, has made this plan? 

Who knows that the body's fever must rise, and that only that way the energy needed by the defence army will not be spent elsewhere?

Is it the macrophages?

Macrophages are merely tiny cells invisible to the naked eye. They do not have the capacity to think. They are living organisms that only obey an established superior order; they merely carry out their duties. 

Is it the brain?

Definitely no. Nor does the brain possess any power to create or produce something. Just as in all other systems, in this system, too, it is in a position not to give orders, but to obey orders and submit to them. 

Is it man?

Certainly not. This system protects man from certain death, although he is not even aware that such a perfect system is at work in his own body. Even if man were ever ordered to develop an army in his own body to fight the enemy and cause his fever to rise, and provide this army to work round the clock in his entire body, he would simply have no idea what to do. 

Today, mankind is not even able to understand the details of the present order in the defence system, despite all the technology at its disposal - much less imitate it. 

It is an obvious fact that man was created with all of his features in place. Willingly or unwillingly, he submits to his Creator and the systems He established. Just as everything else does…

…No, everything in the heavens and earth belongs to Him. Everything is obedient to Him. (Surat al-Baqara: 116)

Information Transfer

Another incredible function of the macrophages is supplying the lymphocytes, i.e., the B and T cells, which are the real heroes of the defence system, with information about the enemy. After phagocytosing the antigen, the antigen-presenting cells go to the lymph nodes (lymphatic tissue) through the lymphatic channels. 

This is a very important detail. Only if a cell possesses consciousness and reason can it be capable of supplying and forwarding the information pertaining to an enemy to the relevant centres. For the macrophage cell to know that this information will be processed by the lymphocytes, it has to be perfectly informed about the general strategy of the defence system. It is very clear that the macrophage, just like all the other cells, is the obedient element of a totally integrated system.