The immune system is an extremely important, but complex system. The immune system fights off various pathogens and keeps patients alive. One piece of the immune system is a group of cells called natural killer cells. No, natural killer cells are not as deadly as they sound. They actually play an important role in the immune system and help keep you alive.
Immunity is more important than ever in the modern world, with the emergence of COVID-19. Understanding how immunity works and all of the factors that could affect immunity is of key importance. Natural killer cells can help patients fight off potential diseases and improve their overall health.
Due to the fact that natural killer cells are so important, patients may be interested in increasing their natural killer cell levels. This can improve a patient’s ability to fight off infections. Let’s discuss natural killer cells and how they play such an important role in the immune system.
What Are Natural Killer Cells?
The immune system can be broken down into two separate parts. The innate immune system or cell mediated immune system is the part of the immune system that attacks any foreign invader that enters the body. The other part is the acquired immune system. This part of the immune system remembers the hostile foreign invaders and is ready to attack the same foreign invaders if they return again.
Natural killer cells are part of the innate immune system. The research community believes that natural killer cells either bind to foreign invaders in the body causing them to die or encourage the production of cytokines, which can help fight the foreign invader. Natural killer cells are a type of white blood cell. Natural killer cells can be classified in two different ways.
Types Of Natural Killer Cells
There are a variety of natural killer cells depending on the location of the body. These slight variations can have a drastic impact on how they act in the body.
Dim Natural Killer Cells
Also known as peripheral natural killer cells, these cells are found in the bloodstream. Identifying foreign invaders in the bloodstream is the primary goal of this natural killer cell. This type of natural killer cells generally cause cells to explode when a natural killer cell binds to it.
Bright Natural Killer Cells
There are also natural killer cells present in the uterus, bone marrow, secondary lymphoid tissue, liver, and skin. Researchers believe that this subset of natural killer cells is not as deadly as the natural killer cells found in the bloodstream.
Patients with COVID-19 were found to have depleted levels of bright natural killer cells. Patients who had severe cases of COVID-19 had depleted levels of dim natural killer cells. This is interesting that natural killer cells were involved heavily in the immune system’s response to
COVID-19. It appears that natural killer cells may have been the first line of defense against COVID-19. If the bright natural killer cells did not fight off the virus, then the dim natural killer cells were brought in to continue to fight the virus.
How Do Natural Killer Cells Work?
Natural killer cells play a role in defense against various pathogens and tumor formation. Researchers are still beginning to understand exactly how natural killer cells work, but it is understood that they play a vital role in the immune system. There is some level of understanding of natural killer cells and how they work in the body. Natural killer cells act around three days after an infection enters the body.
Normally, the immune system works by releasing cytokines when the body detects an infected cell. The cytokines will then kill the infected cell by either destroying the cell wall and/or membrane or programming the cell to die. Natural killer cells do not work in this way; they are extremely unique. Natural killer cells do not wait for the immune system to tell it to attack and kill an infected cell. This allows the body to respond to a pathogen much more quickly, as the body does not have to wait for an immune response.
Natural killer cells have another advantage to complement the immune system’s response as well. Some infected cells and pathogens do not have the markers, which set off the immune system’s response to release cytokines. In these cases, natural killer cells are vital. The natural killer cells can kill the cells that are missing the activation markers that are typically present.
Natural killer cells may also play a part in adaptive immune response. These cells have the ability to immediately adjust to the environment that they are subjected to. They can create antigen-specific immune system memories, which can prevent another infection from the same pathogen. Natural killer cells ability in both the innate and adaptive immune systems showcases the therapeutic potential of these cells.
Natural killer cells may be able to help patients who develop cancer. A treatment that involves natural killer cells could improve the outcome for patients with cancer. If a certain cell has unique surface markers, then natural killer cells can target those cells. The natural killer cells can then destroy the cancerous cells and eliminate the tumor without harming the rest of the body. There have been a few promising studies that showcase the power of natural killer cells.
Natural killer cells also play a role in not only the immune system response, but potentially pregnancy as well.
Role In Pregnancy
The research community believes that natural killer cells play an important role in pregnancy, as they are found in the placenta. The research is still relatively new and researchers are attempting to understand how natural killer cells affect pregnancy.
Natural killer cell levels are higher in women that have miscarried, but that does not necessarily mean that the natural killer cells are causing the miscarriage. Some studies have shown that natural killer cells may be responsible for causing a third of miscarriages. The natural killer cells may be attacking the pregnancy believing that the fetus is a foreign agent.
However, there is another school of thought on why natural killer cells are elevated in women who typically miscarry. Miscarriages are extremely stressful situations and natural killer cell levels are elevated when a patient is stressed. Some researchers believe that some patients have immune systems that react more significantly to stress, which is why these patients have higher levels of natural killer cells.
Natural Killer Cells & Autoimmune Diseases
Rheumatoid arthritis is a long-term chronic condition where a patient’s joints are constantly inflamed. Natural killer cells may play a role in the development of the disease. Natural killer cells have the ability to damage normal cells and potentially cause autoimmune diseases. Researchers were able to isolate natural killer cells from patients with rheumatoid arthritis.
Patients with rheumatoid arthritis have depleted levels of natural killer cells present in their bloodstream. The natural killer cells were also less capable of fighting off pathogens and the development of cancer. Interestingly, the percentage of lymphocytes in the fluid of swollen joints was composed of a high number of natural killer cells. These cells may be causing the additional inflammation that a patient feels when they have arthritis.
Natural killer cells are incredibly important and it may be helpful to understand exactly where they come from.
Where Do Natural Killer Cells Come From?
Researchers are not entirely sure how natural killer cells develop in the body. Natural killer cells were once thought to develop exclusively in bone marrow. Current research suggests that natural killer cells may develop in both the thymus and the liver. Wherever the natural killer cells develop, researchers understand how natural killer cells develop.
Natural killer cells start as many other cell types do in the body, as stem cells. There are five stages of development of natural killer cells. Hematopoietic stem cells will first differentiate into lymphoid progenitor cells in the bone marrow. The lymphoid progenitor cells will then differentiate into pre-NK precursors that can be identified by certain factors.
At this point the premature natural killer cells will begin to develop activating and inhibitory receptors that work to eliminate pathogens in the body. The natural killer cells then go through a few more stages of development until they become mature natural killer cells. Once a natural killer cell has high cytolytic activity, they are considered mature and fully developed. Natural killer cells can then perform their duties and defend the body from various pathogens and cancer tumor formation.
How Can I Increase My Natural Killer Cell Count?
Because natural killer cells are so valuable, most patients would want to find a way to increase the number of natural killer cells that are present in their body. It only makes sense that the more natural killer cells that are present would result in an increase in immunity and overall health. Researchers are looking into ways that patients can increase their natural killer cell levels. Researchers believe that as we age our natural killer cells become less effective.
Probiotics
One interesting way that patients may be able to increase their natural killer cell count is through the use of probiotics. These supplements have been lauded for their therapeutic benefits for many years, although their mechanism of action is not widely understood. Probiotics may be able to help natural killer cells improve their immune response. These supplements may be able to elicit a reaction from natural killer cells on the microlevel.
One study looked at six trials involving 364 healthy elderly subjects, where the patients were given various doses of probiotics. In one trial, the patients were given a probiotic called Bacillus coagulans. When patients were given this probiotic, their natural killer cell activity level increased significantly.
Lifestyle Changes
There are some lifestyle changes that a patient can make that hypothetically should increase their natural killer cell count. Regular cardiovascular exercise, strength training, eating more antioxidants, massage therapy, and more could all potentially increase the natural killer cell levels. These lifestyle changes may be able to stimulate natural killer cell activity and encourage the body to produce more natural killer cells. There is little research on the effectiveness of these lifestyle changes, however.
Enzymatically Modified Rice Bran
A modified rice bran enables the digestive system to digest arabinoxylan, a hard fiber. Researchers believe that this fiber enables the body to produce more natural killer cells and activate them. This modified rice bran was shown to increase natural killer cell activity by 84% in one study. Some research has shown that the rice bran worked in just two days. This supplement can be used during flu season when patients are more susceptible to pathogens.
Stem Cells
Stem cell therapy may be able to help patients increase the number of natural killer cells that are present in their immune system. Natural killer cells start off as stem cells, so supplying the body additional stem cells could result in the production of additional natural killer cells. The research into this area is relatively scarce, as natural killer cells are still not fully understood.
Stem cells have also shown the ability to regulate the immune system’s response. Natural killer cells that are causing autoimmune diseases could be prevented from eliciting that response from the immune system through the use of stem cell therapy. The future is bright for the development of stem cell based therapies for a variety of conditions, including potentially increasing a patient’s natural killer cell count.
The development of natural killer cell research is an incredibly interesting development in science’s understanding of the immune system. New exciting therapies and treatments could be developed from developing a further understanding of natural killer cells. Researchers may be able to treat conditions and diseases that have no effective treatments.
Increasing a patient’s natural killer cell count may improve the immune system’s ability to respond to cancer development and pathogens. BioXcellerator is looking forward to continuing to research natural killer cells. Our team is dedicated to continuing to develop innovative therapies that will improve our patient’s quality of life.