This article will talk about the natural killer or NK cells. But first, we will introduce you to the essential immune system in the body and things that we should know about before proceeding to NK cells. Starting from the 2 primary categories of our immune system.

How many types of NK cells are there?

1. The innate or nonspecific immune systems comprised white blood cells that act as the first defence in attacking any bacteria or uncommon pathogen entering the body. The white blood cells type Macrophages, Neutrophils, and Dendritic would destroy bacterias and pathogens through phagocytosis. There are also innate lymphoid cells (ILCs), which are very important. These leukocytes are developed from tissues that produce white blood cells, Common Lymphoid Progenitors  (CLPs). These cells secrete Cytokine and create 2 groups of white blood cells, Innate and Adaptive, which further develop essential immunity cells of NK cells, ILC_1s, ILC_2s, ILC_3s and Lymphoid Tissue inducer (LTi) cells. The primary roles of these cells are maintaining body balance, regulating cells to grow normally, maintaining metabolism level, including repairment. If the functions of these cells are abrupt, it could cause allergy or autoimmune diseases.
2. The adaptive immune system is an immune system acquired after an infection. Then, the body recognizes it afterwards, enabling the immune system to fight germs promptly before the infection can cause diseases. The process uses lymphocyte types T- lymphocyte and B- lymphocyte.

NK Cells and Their Crucial Role in the COVID Situation

The question would be, what roles do NK cells play in the COVID situation, and why is it receiving more attention. It is due to the primary function of NK cells, which are:

1. To destroy cells infected with bacteria and viruses because NK cells contain small vesicles comprising proteins called perforin, α-defensins, antimicrobial molecules, and protein-digesting enzymes that cause the infected cells to die
2. To detect and determine which cells are infected with a virus when other immune systems are not functioning properly. For example, the decreased signalling of MHC class I would reduce the lymphocyte detection capacity. As a result, the disinfection process becomes less effective, where the NK cells come in. Its role is to detect which cells are infected, then destroy and transmit the signal to lymphocytes to enter an immune system at a specific level to eliminate the virus effectively
3. To destroy tumour cells because NK cells recognize normal cells in the body. If there are abnormal cells, it will eliminate such cells, even if it’s just a non-fatal tumour.
4. To destroy cancer cells because they are abnormal cells and grow faster than normal cells. NK cells will eliminate cancer cells through their recognition capacity and immediately destroy them.

Now that you have read everything, you would probably see the importance of our immune system, especially our brilliant killer NK cells. It is definitely a peace of mind to have our immune system active, especially during these 2-3 years with the covid virus that came out of nowhere. It definitely harmed the world economy.

We will discuss more in details about NK cells in this article, including its effects on our body. We will start with different tests for NK cells, which can be divided into 2 categories:

• NK cells count focusing on the amount of NK cells in our body
• NK cells activity focusing on NK cells’ capacity to function       

The current COVID-19 situation requires vaccination to prevent severe symptoms. However, it is not recommended for a young child/toddler to get vaccinated, and parents might not be resigned to get their children vaccinated as well. The tests for NK cells are useful in this situation because:

1. As natural immunity is the best defense, getting tests for NK cells Is one of the best measures in this situation. Parents would be able to tell the health condition of their child, which allow them to plan for their child’s nutritions and diets accordingly for better immunity.
2. In addition to decreasing the chances of getting infected by viruses, it is also a great kickstart for the children to start building a healthy habit and maintain their health. As NK cells’ functions include detecting tumors and cancers, which are considered as a silent threat that either passed through genetically or arose from surrounding environments, it is highly beneficial to know whether the amount and functionality of NK cells are at an appropriate level. It is recommended to take the tests every year to ensure children’s continuous strong health.

Whether you are a child or an adult living among millions germs and viruses everyday, having a strong immunity is one of the best ways to guarantee you’ll live a long life with less chances of getting diseases.