NK Cells Can Resist Viruses, Fight Solid Tumors, Eliminate “Zombie” Cells, and Extend Life by 20-30%

In the past two years, a new cancer cell therapy has gradually attracted attention. Researchers have discovered that natural killer (NK) cells have greater potential as a cellular anti-cancer therapy that is safer, cheaper and faster.

As the scientific community explores immune cells more deeply, the anti-tumor properties of NK cells are gradually being discovered. Professor Carl June, the inventor of CAR-T and known as the "Father of CAR-T", also supports NK cell therapy. Professor Carl June is very excited about the future of NK cell therapy. He said that NK cell therapy will significantly advance the field of tumor immunology, and he believes that the NK cell and T cell fields have great synergy, and this combination can help patients with serious diseases.

What  are NK cells?

NK cells (Natural Killer Cells) are the core cells of human innate immune cells. They have dual functions of cytotoxicity and immune regulation. They are the first line of defense to protect human health all year round. They do not need to be activated to Go straight into battle and kill the enemy. It combines the three major functions of immune surveillance, immune response, and immune memory. Because of its alert response and broad-spectrum killing of enemies, NK immunity is often called the "special police" unit of the immune army and the "first line of defense" for human health.

Compared with other anti-cancer immune cells, NK cells are stronger and more effective in killing tumors and virus-infected cells. Its activation does not depend on tumor cell surface antigens, nor does it require the immune system's antigen recognition reaction to determine its "attack" target, like T cells. NK cells swim in blood vessels throughout the body and perform immune surveillance functions. They can detect and activate immune defense functions at the first time, and quickly kill diseased and cancerous cells. Therefore, they are recognized by the medical community as the first line of defense against cancer.

Normal people metabolize millions of cells every day, hundreds of which can become cancerous. The immune function of NK cells in healthy people is strong enough to clean up cancerous cells in a timely manner. But for cancer patients, on the one hand, the growth of tumors hinders the differentiation and maturation of NK cells in the bone marrow; on the other hand, due to the invasion of cancer cells, the remaining NK cells in the body have extremely weak combat effectiveness, resulting in low immune function, Inability to effectively identify and kill cancer cells. Therefore, NK cells in health are more active and lethal than those in disease.

Advantages of NK cells

Immunotherapy expert Katy Rezvani said that NK cells are an ideal cell therapy that combines efficacy, safety and relative ease of use for the following three reasons:

• NK cells do not require antigen presentation and have a faster onset of action
• NK cells have broader anti-tumor effects
• no serious side effects

Many of the above characteristics are evident, and NK cells have more advantages in fighting solid tumors.

Clinical application of NK cell immunotherapy

Remove zombie cells and extend life by 20%-30%

We all know that human aging is caused by the aging of cells that constitute the basic units of the human body. As we age, cells that have stopped growing accumulate in the body, forming useless "zombie cells", which over time can cause aging-related diseases. , such as age-related degenerative diseases, cardiovascular diseases, malignant tumors, tissue/organ fibrosis, diabetes, osteoporosis, autoimmune diseases, etc. These diseases have very high morbidity and mortality rates and are important factors in human death.

Aging is the result of the accumulation of "zombie cells" in the body. As the core cells of innate immune cells, NK cells are the absolute main force in eliminating senescent cells.

On February 4, 2016, Nature magazine published an article on the latest results of Baker, a molecular biologist at the Mayo Clinic in the United States: immune cells, mainly NK cells, that eliminate senescent cells can extend the life span of animals by 20% to 30%.

These results also confirm that eliminating these zombie cells could delay tumor formation, preserve tissue and organ function, and even be an attractive way to extend healthy lifespan without significant side effects.

NK cell immunotherapy is highly lethal against liver cancer

At present, the main treatment for liver cancer is surgical resection. Since most patients are already in the middle and late stages when diagnosed, and the prognosis is poor, radiotherapy and interventional therapy are sometimes used. For some patients who are not suitable for surgery, only conservative treatment can be used, and the effect is not ideal.

Recent research by scientists has found that in primary liver cancer tissues, the number of NK cells is significantly lower than in other normal tissues, and the activity of NK cells is weaker. NK cells cultured in vitro show obvious killing effects on liver cancer cells. This means that NK cell immunotherapy has great application value in the treatment of liver cancer.

In a recent research report published in the "Journal of Modern Oncology", medical scientists from the Oncology Institute of Fuda Cancer Hospital, Jinan University, analyzed 17 liver cancer patients treated from February 2016 to September 2017. NK cell immunotherapy was carried out, and highly active NK cells that proliferated in vitro were injected into the patient, and the patient's condition was followed, observed and detected. The results showed that after NK cell immunotherapy, the objective response rate of all patients was 14.3%, and the disease control rate was 71.4%. From the perspective of short-term clinical efficacy, the efficacy of patients who received more courses of treatment was slightly better than that of patients who received fewer courses of treatment. , and there were no adverse reactions in the patients before and after treatment, which fully demonstrates the safety and effectiveness of NK cell immunotherapy.

NK cell immunotherapy can be used for advanced lung cancer

A clinical study published in the journal "Onco Targets Ther" aims to explore the efficacy of highly activated NK cell immunotherapy in patients with advanced lung cancer. Researchers recruited 13 patients with stage III to IV lung cancer, isolated donor peripheral blood mononuclear cells from the patients, and expanded NK cells. After 12 days of culture, the cells were collected and intravenously infused on days 13 to 15. Note. Patients enrolled in the group must receive at least 1 course of treatment (each course includes 3 infusions. Each infusion time is within 30 minutes), and they must receive no more than 3 treatment courses per month. Each course of 3 infusions should be within 3 days. Continuously within days.

The results of the study are satisfactory: after 3 months of follow-up, not only no side effects were observed in all patients, but according to RECIST guidelines, 11 patients (84.6%) had stable disease and 2 patients (15.4%) had disease progression. In addition, IFN-γ (gamma interferon) levels significantly increased and CEA (carcinoembryonic antigen) levels significantly decreased after treatment. The overall immune function of patients receiving NK cell therapy remained stable. This study is the first to describe the efficacy of NK cells in the treatment of advanced lung cancer. These clinical observations indicate that NK cells are safe and effective in the treatment of advanced lung cancer.

Resist viruses: influenza, hepatitis B, COVID-19

In recent years, immune cell therapy is developing rapidly. In addition to being effective in the field of cancer treatment, NK cells are also effective against viruses that produce immune escape. They have been clinically proven to be effective against such viruses, such as influenza A virus, hepatitis B virus, and HIV. , hepatitis C virus, it is also effective against the new coronavirus that is raging around the world.

The new coronavirus is a virus that interferes with immunity. Patients with the new coronavirus have a decrease in lymphocytes in blood reports, which has the characteristics of a special virus that affects immunity. Therefore, it can cause large-scale infection and spread, and the disease may worsen and lead to certain critical cases.

NK cells kill infected cells to prevent these cells from becoming virus culture bases and prevent the replication of more viruses.

As innate totipotent immune cells, how do NK cells resist viral invasion?

First, NK cells play an indirect immune mediating role, interacting with various other immune cells in the body to enhance the immune system's immune response to viruses.

Secondly, NK cells are the body’s first line of defense against cancer cells and viral infections. They can directly kill tumor cells non-specifically. This natural killing activity does not require the mediation of a series of immune responses such as antigen recognition to work. Requires antibodies and is not MHC-restrictive (a common way for specific viruses to defeat the immune system).

` Those who have strong immunity and successfully evaded the new coronavirus were spared precisely because of the effectiveness of the immune cells in their bodies that resist the virus. Its number and vitality determine the strength of its effectiveness.