Natural Killer Cell
A natural killer cell refers to a cell that is able to respond to and obliterates another cell without any previous stimulus. A natural killer cell, often referred to as NK cell, is basically a white blood cell that functions as our body’s immune or resistance system’s first line of guard against alien attackers such as viruses, bacteria and tumors. These cells are called ‘natural killers’ as they do not require to act in response to particular antigens (antibody generators). These cells simply need to identify that a cell is alien and it is not a part of our system. Since these cells are very potent, our body has several steps in position that are intended to thwart the natural killer cells from acting unbridled and attacking their host by mistake.
Basically, natural killer (NK) cells are small lymphocytes (a type of white blood cells involved in the human body’s immune system) that are created in the bone marrow and grow completely in the absence of the thymus (an organ located in the upper anterior part of the chest cavity just at the back of the sternum). In fact, the natural killer cells search for a ‘banner’ or sign emerging from the normal cells and the NK cells forbear the normal cells when they identify the ‘banner’. In the event any such ‘banner’ is non-existent, the natural killer cells connect to the marked cell and discharge a gush of chemicals that break through the walls of the target cells breaking them up.
The natural killer (NK) cells are a form of white blood cells that have pouches known as granules containing chemicals that have the capability to destroy any foreign cell in the body. Thus, when the natural killer cells come into contact with any tumor cell or any cell that is contaminated by a pathogen (disease bearing microorganisms), they encircle these diseased cells and obliterate them by releasing the chemicals enclosed in the granules. These chemicals split the cell walls of the contaminated cells causing them to eventually disintegrate.
The researchers made use of high speed microscopy imaging techniques to observe the manner in which the natural killer cells differentiate any healthy cell from a contaminated or ailing cell in the body. They found that receptors on the exterior of the natural killer cells work together with proteins on any cell that they come in contact with. In case the new cell sets off more of the activator receptors of the natural killer cells, the NK cells switch on their killing device. On the other hand, if the new cells activate more deterrent receptors of the natural killer cells, then the NK cells spare consider them to be healthy cells and leave them undisturbed.
It is essential to undertake a brief journey into biology to facilitate one’s comprehension regarding the manner in which the natural killer (NK) cells function. These cells search for proteins found in the human body and called Human Leukocyte Antigens (HLAs) that are found on the exterior of other cells. The natural killer cells ignore a cell when they are able to identify the HLA proteins as being a part of the ‘self’ assuming that it fits in. In contrast, if the HLAs appear to be alien materials to the natural killer cells, the latter discharge chemical toxins to obliterate such foreign cells.
It may be noted that HLAs are articulated by means of the Major Histocompatibility Complex, a cluster of genes present in the sixth chromosome. The Major Histocompatibility Complex is considered ‘major’ as it performs a decisive function in the approval or elimination of transplanted or relocated tissues. When the HLAs on a particular organ do not go with or match, the body will immediately reject it by means of the natural killer cells drawing near to save the body from any harm from an identified invader.
Each natural killer cell possesses several receptors that are made use of by the NK cells to collect information regarding the cells it gets in touch with. Usually, a minimum of one particular receptor ought to be triggered for a natural killer cell to initiate any action. Additional cells in the immune system may also get occupied in the response by way of the immune system becoming active to tackle the new health problems that come into sight. It may be mentioned here that the natural killer cells function by attaching them to the dubious or ailing cells and necessarily infusing them with cytotoxins – substances that are intended to obliterate diseased cells.
Of course, there are occasions when the things go wrong with the natural killer (NK) cells too. For instance, every so often a woman carries a baby having compatible HLAs, but the natural killer cells presume that the fetus is harmful or dangerous for the body. In such cases, an assortment of medical treatments is used with the aim of enabling the baby to grow so that the woman is able to carry the child to term or give it a normal birth. Sometimes, the natural killer cells may also become malignant by developing lymphoma – a type of cancer that begins in immune system cells. What is worse is that treatment of natural killer (NK) cell lymphoma is exceedingly complicated.
Enhance natural killer cells to avoid swine flu
It is common knowledge that a vigorous immune system helps in safeguarding from viruses and that includes the deadly H1N1 swine flu. However, very few people are aware of the fact that herbal and dietary enhancements are able to remarkably enhance the level of fortification from swine flu by means of increasing the intensity or number of natural killer (NK) cells in our body. It may be mentioned here that the natural killer cells have the capability to obliterate viruses without damaging the healthy cells in our body.
The panic of swine flu has gripped us to such an extent that people across the world have been adopting extreme steps such as closing academic institutions, calling off graduation ceremonials and even airline flights to retard the spread of the H1N1 swine flu virus. Even the government authorities in different countries have been counseling more hand washing and keeping away from handshakes. However, despite such sweeping measures little could be done so far to prevent earlier influenza pandemics that have claimed millions of lives in 1918.
On the other hand, researchers have been advocating escalating the intensity or number of natural killer (NK) cell white blood cells in the blood with a view to prevent contagion with pandemic swine flu and other viruses. It has been established that natural killer cells fortify us from viruses when we are infected and the other white blood cells endeavor to generate antibodies to combat the new viruses. Studies have confirmed that even herbal and dietary supplements sold over the counter are able to enhance the levels of natural killer cells. AHCC or Active Hexose Correlated Compound boosts up our immune system. According to published research findings, AHCC is extorted from mushrooms and they are able to increase the natural killer cell levels in our system by anything between 200 per cent and 300 per cent.
It may be noted here that with age, the levels of natural killer (NK) cells are likely to decline in our system. Patients suffering from conditions such as chronic fatigue syndrome, Lymes disease, fibromyalgia, HIV or babesia are expected to have lesser numbers or intensity of the natural killer (NK) cells. In addition to this, human herpes, Herpes Simplex, Cytomegalus and Epstein Barr viruses too restrain immunity or affect the resistance power of our body.
According to researchers, reduction in sugar intake also helps in enhancing the immunity or resistance power of our body. Several researches have shown that consumption of 100 grams of sugar diminished immunity for more than five hours. Researchers have gauged the action of neutrophils present in white blood cells that swallow up and eradicate bacteria and other microorganisms that are detrimental for our health. During the period of researches, it was found that the action of neutrophil was diminished by over 45 per cent, i.e. approximately for two hours, after consumption of sugar.
Intake of too much of sugar results in chronic immune repression among numerous Americans. On an average, all Americans consume approximately 125 grams of sucrose sugar every day. On top of this, every day average Americans ingest around 50 grams of refined sugar. A normal 12 ounce cola drink encloses around 10 teaspoons or 41 grams of sugar, while a Milky Way candy bar has 35 grams of sugar. Even several herbal teas and energy drinks are made sweeter by adding great amounts of fructose corn syrup that again is basically a refined sugar. According to estimates, approximately 20 per cent of Americans ingest more than 75 grams of an overwhelming amount of fructose corn syrup every day. As various parts of our immune system function in concert by means of chemical messenger arrangements, escalating the actions of neutrophil is able to augment the actions of natural killer (NK) cells too.
Natural killer (NK) cell deficiency
Deficiency of natural killer (NK) cell in one’s system is considered to be a hereditary immune system malady where the patient suffers from very low or non-existent intensity of a specific form of white blood cells natural killer (NK) cells. These NK cells assist the immune system to combat various ailments and contagions.
The natural killer (NK) cells have the capability to identify as well as obliterate the cells in the body that have been infected with viruses or even cancer. These cells have pocket or pouches, known as granules, and they are full with chemicals or compounds that annihilate the contaminated cells on coming into contact.
People who are hale and hearty usually experience the rise and fall in the number of natural killer (NK) cells in their blood. These cells follow a particular pattern and quickly swell in number when there is an infection in the body and subsequently decline for around five to seven days after the infection has been cured.
Patients suffering from deficiency of NK cells are usually born with very small levels or absence of the natural killer cells. Therefore, compared to healthy people, these patients are more susceptible to infections and diseases. It may be noted here that the expectancy of life of an individual often depends on the severity of the NK cell deficiency in him or her. In fact, deficiency of natural killer (NK) cells may also result in incurable infections and latest researches on the subject have hinted that patients enduring this syndrome are faced with an enhanced degree of risk of developing cancer.
What is, however, unfortunate is that the scientists are yet to ascertain the precise reason for the occurrence of natural killer (NK) cell deficiency in an individual.