Immune Cells
Immune cells act as soldiers to defend our bodies from invaders such as viruses and foreign bodies. Different immune cells play different roles in a human’s immune system.
The immune system is the foundation of a healthy body, for it helps to fight off diseases and remove cells that fail to function normally. The ability of the immune system to protect the body against new threats, by generating and activating new immune cells, declines rapidly with age. The immune system is typically categorized into two systems; innate and adaptive. Both systems work closely together and take on different tasks.
How Your Immune System May Be Weakened?
When invaders get inside your body, the immune system sends outlines of defense. At other times, it weakens, fails and becomes ineffective. This can happen due to poor nutrition, lack of exercise and sleep, consumption of alcohol, smoking habits, etc. Your immune system can also be weakened by certain medicines and other drugs used to treat cancer.
Immune System
Innate Immune System
The innate immune system is the FIRST LINE of defense to attack or destroy any invaders such as viruses, bacteria, parasites and toxins. Natural Killer (NK) cells and Dendritic Cells (DC) are one of the primary components of this system. Other cells that are present in the innate immune system are macrophages, mast cells, neutrophils, basophils and eosinophils. Each of these cells has its own functions which collectively form the total defense of our highly complex immune system.
Adaptive Immune System
Adaptive immune cells are the second and specific line of defense, and they are called to action by the innate immune system. Adaptive immune system gets its name because it adapts and changes when you are exposed to specific microbes that your innate immune system can’t fight. Cells of the adaptive immune system are B cells and T cells.
Types & Functions of Immune Cells
Natural Killer (NK) Cells
Natural Killer (NK) Cells are just what they sound like, tough and assassin-type cells. It can recognize infected cells, create holes in the bad cells and program cell death. It removes infected cells without further immune response.
Dendritic Cells
(DC)
(DC)
Dendritic Cells (DC) are known as professional antigen-presenting cells. Antigen refers to any substance that prompts an immune response. Other cells can present antigens but none do as efficiently as dendritic cells. It also acts as the bridge between the innate immune system and the adaptive immune system.
Macrophage
Macrophage is a large white blood cell that is an important part of our immune system. It is known as “big eater” as it destroys bacteria by
phagocytosis which resembles the action of engulfing, ingesting and killing
bacteria or viruses with enzymes.
T Cells
T Cells hunt down and destroy cells that are infected with germs or that have become cancerous. It facilitates and also directly attack cells infected with viruses, and they are vital in host immune response against pathogens.
B Cells
B Cells differentiate into plasma cells and produce antibodies against antigens. These antibodies then recognize and bind to specific pathogen.
Interaction of Immune Cells
The Importance of NK Cells
- NK cells are the “first responders” to the cancerous cells before T cells are summoned [1]. NK cells are important in controlling infections before the adaptive immune system take response.
- Low NK activity group has higher cancer incidence rates compared with medium and high NK activity groups. (11-year follow up study, 92 men, 62 women)[2].
- Cancers or viral infections developed evasion tactics to avoid T cell recognition [3], but NK cells are able to kill the cancer cells by recognizing the differences between cancerous cells and normal cells [4]. Hence, by increasing the number of NK cells may enhance its function and treat cancer more effectively.
- NK cells have shorter life span of only 2 weeks therefore the likelihood of dangerous side effects is low. Also, NK cells seldom cause side effects like chemotherapy and radiotherapy as NK cells do not attack healthy cells [5].
Did You Know?
Cancer Cells vs Tumour
Cancer cells are mutated cells but NOT all mutated cells are cancerous cells. Non-engineered NK Cells have the ability to remove mutated cells but not tumour. A tumour is a group of cancerous cells lumped together. Within a tumour there may be different cancerous cells. Tumours are normally treated with surgery, radiotherapy, chemotherapy and immunotherapy.
Immunotherapy
Immunotherapy is a treatment method for cancer that activates immune response in your body, as well as to teach your immune system how to identify and destroy cancerous cells. Immunotherapy can be divided into (1) drug based and (2) cell-based.
- Drug-based immunotherapy such as checkpoint inhibitor releases a natural brake on your immune system so that immune cells such as T cells recognize and begin to attack tumours.
- Cell-based immunotherapy such as CAR-T therapy where a patient’s T cells are engineered in the laboratory so that they will bind to specific cancerous cancer cells and kill them. Other cell-based immunotherapy include DC, NK cells and others.
Why Should Your Store Your Immune Cells?
- Ex vivo (outside the body) expansion of own immune cells can be performed to obtain large amount of cells that could be infused back to the body without any rejection.
- Cells in our body get old and exhausted as we age or fall sick.
- Immune cells helps rebuild and strengthen the body’s immunity to guard against mutated cells at all time.
Who Should Store Immune Cells?
At the age of 20, the immune system reaches its maximum functional level. As the age increases, the functionality decreases. This
also causes the risk of being diagnosed with diseases, increase much higher. Therefore, every young and healthy adult should store
their immune cell as early as possible.
NK Cells For Covid-19
NK Cells
FDA has approved clinical trials on Covid-19 treatment using NK cells.
The FDA clearance allowed to begin phase I/II clinical trials on 86 critically ill
Covid-19 patients.
Studies showed that there is robust activation of natural killer cells during viral
infection regardless of the virus class. It demonstrated a range of biological activities
that would allow to recognize and kill infected cells. [6]
References
- O’Connor, G. M., Hart, O. M., & Gardiner, C. M. (2006). Putting the natural killer cell in its place. Immunology, 117(1), 1-10.
- Imai, K., Matsuyama, S., Miyake, S., Suga, K., & Nakachi, K. (2000). Natural cytotoxic activity of peripheral-blood lymphocytes and cancer incidence: an 11 year follow-u study of a general population. The lancet, 356(9244), 1795-1799.
- Garrido, F., Aptsiauri, N., Doordujin, E. M., Lora, A. M. G., & van Hall, T. (2016). The urgent need to recover MHC class I in cancers for effective immunotherapy. Current Opinion in Immunology, 39, 44-51.
- Lynda, AK. (2017). NK Cells in Cancer Immunotherapy, Natural Killer Cells, Mourad Aribi, IntechOpen, DOI: 10.5772/intechopen.71217. Available from: https:// www.intechopen.com/books/natural-killer-cells/nk-cells-in-cancer-immunotherapy
- University of Central Florida. (2018). Natural killer cells may open lifesaving cancer treatments to more patients. Science Daily. Available from www.sciencedaily.com/releases/ 2018/10/181002114010.htm IMC
- FDA clears IND application for natural killer cell-based COVID-19 therapy (April 2, 2020). Retrieved from https://www.healio.com/hematology-oncology/cell-therapy/news/online/%7B90e365e2-5579-4643-976c- cbb17ff5ff16%7D/fda-clears-ind-application-for-natural-killer-cell-based-covid-19-therapy