Immune system, protection, immune defense ,virus, bacteria

We are only aware of the world around us.  Often some of us wonder at the world within i.e. The micro biological universe or the sub atomic worlds of matter. Biology and medical science explore the first and  Physics and Atomic Sciences the next. Both amazing and fascinating aspects of creation which are at the root of the visible macro world with which we are familiar and in which we lead our lives oblivious of the other world deep within.

Here let us explore the biological universe within us which makes us keep alive and defends us beyond our imagination. Any species survives because of its inbuilt defenses called the immune system. Microbes, bacteria, virus, parasites, fungus protozoa called pathogens are perpetually seeking to invade our organism, multiplying within and consuming it till its demise and transferring to other organisms through techniques of infection.

So too our decaying cells infected cells and dead cells that create the debris in our system  which like in any municipal system requires to be cleaned or eliminated. This also includes rebellious cancer cells which have a plan of their own. A rogue created often by our addictions and harmful activities. These rogues in our own organism require to be eliminated no less than the invading pathogen.

I suppose Pathogens have a right of survival in creation as much as we do. Nature allows survival of the fittest, If a pathogen has superior ability to survive, then it will overcome the organism it  infiltrates and be the survivor. If the organism has evolved to withstand this onslaught then it will overcome the pathogens invasion and be the survivor. The human race as also many species of animals and living beings are the organisms that have survived to the present day despite the  war with the micro world of pathogens. If they had not survived we wouldn’t be here like the Dianasores  who became extinct. Extinction is allowed by nature when the victim is weak and has failed to evolve adequate defenses at the level at which pathogens exist in the micro universe.

It is not enough to have strength and muscles to deal with adversaries at the macro level – one organism against the other, though that too is vital, but the ability to deal with micro biological threats is equally important. Else, while you may become supreme as intelligence has made Homo Sapiens it cannot ensure supremacy at the micro level where another form of intelligence comes into play in the game of survival. Survival requires ability to procreate and multiply because organisms are mortal, ensuring survival over millennia. The same yard stick applies to other competitors, this time not at the macro level but at a micro level. Nature (God?) is ambitious but not sparing for the weak whether at macro or micro levels.  Having provided the best with evolution of the cerebral cortex it does not have unquestioned favorites. Its cardinal axiom is SURVIVAL OF THE FITTEST not survival of the most worthy, the most beautiful, the most desirable, the most creative or even the most intelligent.

.  Nature is God’s handmaiden to protect and maintain His creation in the form He conceived, and there is no guarantee that He cannot change his mind as with the Gigantic beings of his earlier creations of life forms like the dinosaurs or the early stages of human evolution- The Neanderthal gives way to Homo Sapiens, Who knows whats next. In the process He is possibly not  opposed to his micro level creations and allows them free play in their own evolution. Quite like the mutations that have produced the present level of Homo Sapiens so also mutations at all levels for arriving at the most deserving. Thus His finest product yet, us, are allowed to mutate in like manner to overcome threats to survival of a prize creation, MAN. Lets have a glimpse at how that has become possible for deserving candidates.

Firstly I am no scientist or micro biologist and can claim no expertise other than imagination and free thought as to what may be going on, based on what i have read from eminent findings and research into the biological world of the micro cosmos. All i can do is give a perspective based on my readings and mystical inspiration, for whatever that may be worth. And yes the capability to wonder at this exquisite creation of which i am a part not just at the obvious visible macro world of our lives, but equally at the micro world which possibly holds the real secrets of His intentions both at the Biological level and the atomic or sub atomic levels. His intentions  at the micro level possibly resemble roots of grand trees that produce leaves to feed and flowers to procreate and fruit to  survive to the next generation. So too our roots in the micro level be they threat, defense or survival. His intentions appear to be not merely survival but diversification. The idea of male and female is precisely that – no two fingerprints should be alike. species should be varied, beautiful to behold and more numerous than you can ever imagine. After all that is the wonder of creation whether biological, atomic or the universe of planets, black holes, suns and life forms. Hats off to Him for such a thought about diversification in creation. There is no great achievement in a creation of clones, no great achievement in like rather than dissimilar beings. He is the master creator with imagination beyond our perceptions.

So, with these esoteric and mystical thoughts let us try and understand as an example, what He did to help us evolve our own defense system at the micro level so that our survival as His favorite element in creation would be justified. Here let us ponder over the Covid revolution at the micro level with numerous mutations to see whether it is a challenge to His choice of Homo Sapiens being His single grandest  element in creation. Let us explore the nature of our amazing inbuilt defenses in the game of survival of the fittest.

After reading a range of literature on the subject I feel overwhelmed at the thoroughness and intricacy of the designed or evolved defenses we possess within making us at least for now the fittest survivor on this planet.

That amazing defense is what goes by the name of THE IMMUNE SYSTEM. It is not unlike an army with the latest technology to defeat any invader. There are soldiers, spies and intelligence agencies always on the alert, fortresses where those with special skills congregate, alarm systems to inform  about an invasion, systems and forces to take care of rebellion from within, the ability to detect among millions of inhabitants and workers what constitutes the nation and what is alien, also who has been compromised and has  been forced to collude with the enemy,  what agencies exist to clear the dead and any debris on account of warfare, how to identify the sick and diseased to quarantine or remove them from the state, how to train and coordinate different forces of defense, where to begin recruitment of fresh forces when a threat is perceived,( the bone marrow is not unlike a military Academy training and forming soldiers of different specializations as required by the perceived threat) )how to mark and identify a known enemy, how to register and remember  a former enemy, how to keep meticulous records of sources of threat and be available to identify them when they attack, how to engage in repair of damaged resources after the war and elimination of the enemy, how to utilize  chemical resources available for warfare, how to have different agencies for specific defense needs, Where to train forces to handle every situation that may arise, ad infinitum, to ensure the survival of the state (our organism against all odds).

Rather picturesque in presentation but necessary analogies for laymen to get the full picture of this wonder within us.

The Immune system has two categories. First what is termed the Innate Immune system and next the Adaptive Immune System. The first was what we have always been blessed with for survival against the microbiological enemies. the second is a product of evolution when the innate defenses were rendered stronger and more effective. Together these two aspects of the immune system have made us survive to the present day. Not all living beings have both. some have a modified form of the first but only mammals with jaws have both. Let us now plunge into the facts of what are these defenses.


The cellular inhabitants of this state which is our living organism, have two types, the RBC or red blood corpuscles and the WBC or white blood corpuscles (among other cells like skin heart and brain cells). The first is a kind of worker cell that performs a crucial activity. Transferring vital oxygen from our lungs to the rest of the body.

the workers keeping us alive by transferring oxygen

The latter, white blood cells are different.

Cells of immunity :Leukocyte, lymphocyte, eosinophil, neutrophil, monocyte, basophil dendritic cell Vector illustration on isolated background

They have a range of obligations and duties which include defense from invading pathogens like bacteria, virus, fungus, parasites, protozoa, and internal enemies like aberrant cells that have forgotten their duties are disobedient and wish to do as they please, multiplying at the expense of the host or State. These White Knights as I would like to call them defend against external as well as internal threats to the organism. Something to remember – not all cells can divide. The brain cells and the red cells do not reproduce themselves or divide. Cells die at an appropriate time which is fixed – call it cell suicide while more cells as required are then produced in the bone marrow, what i call the training academy. – all this is highly organised and programmed (except of course the cancer cell which has turned into an alien like the Pathogen who does not have to listen to the body’s dictates and never commits suicide.)


 At the Innate Immune system stage of defense the following warriors are available:

White blood cells called Leucocytes

A subdivision called Phagocytes which include Monocytes or Macrophages, Neutrophils and Dendritic white cells meaning cells that attack engulf and dissolve or consume the invading Pathogen. This process of killing the Pathogen through engulfing and consuming is called Phagocytosis, thus their description as  PHAGOCYTES.

Macrophage engulfing bacteria

Neutrophil engulfing bacteria.  infections. Neutrophils are part of the body’s immune response. . They extrude extracellular traps to catch and engulf (phagocytose) and destroy pathogens such as bacteria and viruses, and foreign material that has entered the body.

This defense belongs to our Innate Immune System. The three white warriors of this initial immune system , are not very advanced but very effective in warding off an initial attack.    Monocytes and the most numerous Neutrophils are the white warriors that travel perpetually in the blood stream in pursuit of invading Pathogens while the Dentritic white warriors  explore the external environment to detect presence of invaders at the location of the skin, nose , lungs and stomach and intestines the first barriers which Pathogens have to cross. Neutrophils are the first to arrive at the site of infection where acute inflamation occurs. Monocytes enter damaged tissues and become Macrophages which are the most numerous residents in tissues  and act as scavengers ridding the body of worn out cells and other cell debris not unlike municipal workers.

Neutrophils are the leukocytes found in the largest numbers in the bloodstream and they primarily fight bacterial infections.

Eosinophils are white warriors that specialize in targeting parasitic infections. Eosinophils and Basophils are involved in creating allergic reactions. Both release histamine and other proinflammatory compounds from their granules upon stimulation.




  • Natural killer (NK) cells are lymphocytes that recognize and kill abnormal or infected cells by releasing proteins that trigger apoptosis or cell suicide, vital for elimination of defective, worn out and infected cells..


  • Monocytes are large, mononuclear leukocytes that circulate in the bloodstream. They may leave the bloodstream and take up residence in body tissues, where they differentiate and become tissue-specific macrophages and dendritic cells.

  • All the above warriors are leucocytes and belong to the first army or the innate immune system.

Before proceeding further let us learn what are Antigens and Antibodies.  Every pathogen has a unique molecule which marks it called an Antigen.  An Antibody is a y shaped protein used by the Immune system to identify and mark the pathogen for destruction. The antibody recognizes the unique molecule and binds to it whether it be a Pathogen or an infected cell and thereby tags it for destruction by relevant elements of the Immune system.

antibodies latching on to pathogen’s molecule to identify for destruction

The Innate Immune system ( I I S) and the Adaptive Immune system (A I S) are like two armies that need to coordinate their activity depending on the severity of the threat. The IIS has limited capability in facing the threat despite Phagocyte warriors plus above mentioned other specialists and is the first line of defense. It is able to prevent a menace that has appeared from overrunning the organism on a first onslaught. But this does not eliminate the growing threat from a persistent pathogen only limits its progress.. it then uses its messenger warrior the dentritic phagocite to carry the  antigen from the pathogen to the advanced army of the AIS .

DENDRITIC  WHITE CELLS the third category of Phagocyte warriors   present antigens to our T cells.

Dendritic cells

antigen presenting cell

These white warriors, the T cells play a key role in our ADAPTIVE IMMUNE SYSTEM  and are the most important  white warriors of this evolved immune system. Their origin  are the stem cells in our bone marrow. the T cell warriors  play a central role in eliminating virus infections and Cancer. when about their job they recruit other Leukocytes to the battlefield and help the soldiers to distinguish invaders from  self cells that belong to the host organism.  This  regulatory ability to distinguish alien from host cells to prevent their destruction are  however used by the cunning cancer cells to defend themselves from destruction by T cells. Dendritic warriors of the first army are to be found in the vicinity of the Lymphocytes the more advanced warriors of the modern army because they are always in the process of conveying antigen clues to the advanced warriors the T cells. They also can raise an alarm when a threat is detected in the external environment and are located on the skin, nose, lungs, stomach and intestines. They are the messengers that link the two Immune systems helping to coordinate their defense mechanisms as a joint effort against the enemy. The Lymphocytes belong exclusively to the  Adaptive Immune system.

Natural killer (NK) cells belong to the innate immune system. They generally serve as a first line of defense against foreign pathogens. This includes bacterial or virus particles or virus infected cells. NK cells are not specific in their immune response. In the sense that they recognize a wide variety of bacteria so any bacteria will activate them. This is good because when you spot an enemy, you must immediately engage and kill.  NK cells also have the ability to sense stressed cells i.e. cells that are infected with a virus or are turning cancerous. They will seek them out and destroy them before they do any harm. Therefore, they serve  as the sentinels of the body. They also induce damaged infected and worn out cells to commit suicide.


The adaptive Immune system on the other hand relies on soldiers with a specific target producing a stronger and more particular immune response aided by superior immunological memory, each Pathogen is remembered by its signature antigen. The Adaptive Immune system is antigen specific, able to memorize and identify a Pathogen or its infected cell. thus the adaptive system is able to marshall its lymphocite white cells to destroy the particular invading Pathogen at a higher level than the inniate imuune system’s abilities. But the difference between the two warriors is that the former attacks all invaders at random while the more specialised T cell warrior targets only 1 ignoring the rest.

Then the Adaptive Immune system has another warrior called the B cell.  The B cell produces specific antibodies for specific pathogens. The antibodies lock on to the pathogen and mark them for destruction by other elements of the immune system. On the other hand the B cells may also inhibit the destruction of a cell, like tumor cells. Cancer cells take advantage of B cells to protect them from destruction by T cells. B and T cells are the armory of the adaptive immune system and come into the war when the White cell warriors of the innate immune system are unable to produce an effective defense because they have little or no immunological memory. Generally  the white warriors of the Innate immune system are efficient and able to ward off the threat. The T and B cells are called Lymphocytes because they are to be found in the lymph organs and are 18 to 42 % of all leukocytes. T cells are of two types -the helper and the killer. helpers activate the B cells to produce antibodies to mark the pathogen in question while T killer cells destroy  infected cells  and cancer cells.  Adaptive immune cells remember foreign invaders after their first encounter and fight them off the next time they enter the body.  The Innate immune warriors are unable to do so without antigen memory. Vaccines seek to do precisely that to create immunological memory where it may not exist.


tHE LYMPH FORTRESSES are located in several parts of the body. Lymph nodes are classified as “secondary” lymphoid organs, with the primary lymph organs being the thymus gland, tonsils, spleen, and bone marrow. The white warriors of the innate immune system and adaptive immune system congregate at these sites, like soldiers in  a fortress. they release into the blood stream when a threat is signaled. There are hundreds of Lymph nodes inside the body. they are located mainly in the neck, between the lungs , armpits and groin. The lymph fluids from lymph vessels enter these filters where Pathogens and cancerous cells are eliminated by the immune warriors. Those that escape into the blood stream are then dealt with by the warriors of the first and specialized armies there.


Apart from the external shell defense, skin, nose, lung, guts, intestines, stomach and internal immune defenses both innate and adaptive, the invading pathogen is subjected to what we can call chemical defenses and warfare.The complement system is a biochemical storm that attacks the surfaces of foreign cells. It contains over 20 different proteins and is named for its ability to “complement” the killing of pathogens by antibodies.. Complement is the major humoral component of the innate immune response.The cascade results in the production of peptides that attract immune cells, and coat the surface of a pathogen, marking it for destruction. This deposition of complement can also kill cells directly. 

This vast network of cells and tissues is constantly on the lookout for invaders, and once an enemy is spotted, a complex attack is mounted.

The immune system is spread throughout the body and involves many types of cells, organs, proteins, and tissues. Crucially, it can distinguish our tissue from foreign tissue — self from non-self. Dead and faulty cells are also recognized and cleared away by the immune system.

If the immune system encounters a pathogen, for instance, a bacterium, virus, or parasite, it mounts a  immune response.

Apart from the two immune systems and their cellular forces there are also mucus membranes that help trap or destroy pathogens. Mucus in the throat, bronchi. hair like structures called cilia in the nose, saliva with killer enzymes, stomach acids, even tears. and beneficial bacteria in the guts together support the immune systems.

All blood cells are produced in the bone marrow some like lymphocytes are created or mature and are stored in the spleen, thymus , lymph nodes, tonsils – called lymphoid organs.

The bowel plays a central role in defending the body against germs: More than half of all the body’s cells that produce antibodies are found in the bowel wall These cells detect foreign substances, and then mark and destroy them. They also save information about the substances in order to be able to react more quickly the next time.

In a nutshell,this then is the amazing defenses that we have been provided with,  for our survival at the microbiological level, to ward off dangers from pathogens that exist at that level and to enable us to destroy the damaged and dead cells and the malignant cancer cells to maintain our supremacy as Homo sapiens on our planet.

I suppose it goes without saying that no medicine or vaccine can compete with the body’s ability to defend and repair itself.  All they can do is to assist the inbuilt system to improve or aid in the recognition of its foes. That ability also flows from the cerebral cortex which too is based within not in some lab. The vaccines and medical science can be termed an evolution beyond that of the Adaptive immune system. But in the final analysis it is the body’s system that gives us clues about vaccine defense as too the fight against cancer can be borrowed from our immune system which daily engages in removing aberrant failed or faulty  cells, else we all would have cancer in our very youth. The T cells the B cells and their antibodies, the marker cells like dendrite cells, and macrophages ,  the leukocytes in their variety of specializations, the chemicals and protein defenses we generate from within, , the helper cells and natural killer cells that induce cell suicide and detect  tumors and cancers when cells fail or rebel, even before we undertake a cat scan the amazing alerts that the immune system are capable of to diligently protect the organism, no medical ability could duplicate, like fevers  and inflamations arising from our immune reactions to kill pathogens and the repair mechanisms there after to help us recover, are all the gifts of the Master Biologist. We learn to fly after studying avian abilities, make mobile engines after studying the bodies processes, nature is a library from which we have learnt so many lessons, antibiotics are already readily available in nature for us to copy or derive from and our own brains the perfect study to make mechanical brains in computer technology. Nature of which we are an integral part is the source of all advancements by simple emulation from the Great Guide. Yes we have been enabled and with that gift we shall overcome and evolve. Our gratitude and applause to the Universal Essence.