Written by Thiti Samutharat, MD. Verita Life Thailand.
The Role of the Immune System
The immune system plays a pivotal role in the protection of the human body against various kinds of diseases, infection or the defective immune system itself. Since defective cells are the body’s very own cells, conditions that are associated with mutated cells may not be completely detected and destructed by the immune system. Cancer cells and other variants of cell mutations also have the ability to evade or undermine an immunologic response. Thus, the recent emergence of immunotherapy has paved a new road to the treatment of these chronic diseases and malignancies.
Immunotherapy is designed to enhance the immune system to more effectively detect and combat abnormal cells. It has also shown enhanced-effects when applied together with medical, radiotherapeutic, chemotherapeutical as well as surgical treatments. Like other forms of treatment, it consists of many types, but mainly divided into two major constituents: those that act directly against the mutated or defective cells, and; those that act directly to enhance the immune system. One of the most widely-discussed subtypes of immunotherapy is none other than the “Natural Killer” Cell (NK Cell) or NK Cell Therapy. The discovery of Natural Killer cells was first addressed in the early 1970s by Dr. Ronald Herberman and his team.
What are Natural Killer cells?
Natural Killer cells are known to be the first line of defence against foreign, damaged, infected or malignant cells. As their name implies, Natural Killer cells eliminate cells that are prone to pose dangers upon the host’s immune system; hence, are deemed to be the key regulators in immunosurveillance, transplantation rejection reaction, and early immune response against viruses. Natural Killer cells are able to differentiate between healthy and mutated cells mainly via their surface receptors. Additionally, they typically kill the foreign or mutated cells through the secretion of special enzymes (i.e. Granzyme B and perforin), as well as induction of specific cellular pathways directly leading to the death of their targeted cells. They can also release specific immunologic substances, medically-referred to as the “pro-inflammatory cytokines”, that exhibit direct anti-tumoural response, along with activation of specific immunologic reaction within the host. Hence, these cells do not exhibit their functions only through direct elimination of malignant or virally-transformed cells, but also through their positive or negative immunomodulation (change in body’s immune system) on T cells, a subtype of a white blood cell.