Do you get the flu? The answer may be in your genome

From the end of last year to March and April this year, the flu pandemic around the world, and even many people have died. Have you ever worried that you will be infected with this terrible virus? According to Genomic Medicine, there is now a way to predict if you are susceptible to the flu.

Do you get the flu? The answer may be in your genome

In this study, researchers at Stanford University School of Medicine found a sign in human blood that predicts whether or not they will be infected with the flu virus. Specifically, the researchers found that people infected with influenza had lower levels of natural killer cells (NK cells) in their immune cells. If the levels of these cells in the blood are above a certain threshold, people will not get the flu.

NK cells are cytotoxic lymphocytes that are essential for the innate immune system and function similarly to cytotoxic T cells in adaptive immune responses in vertebrates. NK cells provide a rapid response to virus-infected cells, function about 3 days after infection, and respond to tumor formation. Typically, immune cells detect the major histocompatibility complex (MHC) present on the surface of infected cells, triggering the release of cytokines, causing lysis or apoptosis. However, NK cells are unique in that they are able to recognize stress cells without antibodies and MHC, allowing for a faster immune response.


They were named "natural killers" because the original idea was that they did not need to activate to kill cells that lacked the MHC class 1 "self" marker. This effect is particularly important because harmful cells lacking MHC I markers cannot be detected and destroyed by other immune cells such as T lymphocytes.

The cytoplasmic small particles of NK cells contain proteins such as perforin and protease, called granzymes. During the action with microorganisms, perforin forms pores on the cell membrane of the target cell after release from the cells destined for killing, producing a water channel through which the granzyme and related molecules can enter, inducing apoptosis or osmotic cells. Lysis. The difference between apoptosis and cell lysis is immunologically important: cells infected with the lytic virus may only release viral particles, and apoptosis leads to internal destruction of the virus. The antimicrobial molecule alpha-defensin is also secreted by NK cells, destroying bacterial cell walls in a manner similar to neutrophils, killing bacteria directly.

In this study, the researchers discovered a gene called KLRD1 that determines the level of NK cells in a human. KLRD1 is a receptor gene found on the surface of NK cells. The study found that the expression level of KLRD1 in the blood before the infection of the human can predict who will be infected with the flu virus, with an accuracy rate of 86%.

The researchers analyzed blood samples from 52 people who had previously participated in the Influenza Challenge Study. In these early studies, volunteers were exposed to influenza virus (H1N1 or H3N2) and the researchers will monitor whether they are ill. The researchers used an algorithm to calculate the proportion of different types of immune cells in the blood before exposure to the virus.

The researchers found that the level of NK cells in people who eventually contracted the flu was very low. If more than 10% of the subject's immune cells are made up of NK cells, he will not get sick; if the NK cells are less than 10%, they will eventually get the flu. The researchers then positioned KLRD1 as a gene that represents NK cell levels and predicts flu susceptibility.

This discovery can be used to develop better flu vaccines

Researchers hope that their findings will one day help doctors determine who is at the highest risk of getting the flu, and then determine who is most likely to benefit from the flu treatment; it can also be used to develop better flu shots.

“Understanding the protective effects of NK cells is essential, so we can potentially use this to design better flu vaccines,” we see, Dr. Pvskadi, associate professor of medical and biomedical data science at Stanford University School of Medicine. NK cells are protective between different strains, and perhaps this will be a universal flu vaccine."

NK cells can also eliminate malignant cells

According to Health Innovation, a study published in the European Journal of Immunology pointed out that the body can produce immunity against tumor cells, just like against pathogens (viruses). NK cells express various types of immune receptors, which are designed to sense pathological changes in their own cells. The balance of inhibition and activation of NK cells determines their activation status, and the use of NK cell strength by inhibiting the receptor/ligand system using this polymorphism has become an integral part of clinical treatment.

Lymph node tumors, called lymphomas, are malignant tumors that originate in B lymphocytes or T cells of the lymphatic system. NK cells have the potential to attack B lymphoma cells and are therefore considered to be possible pathways for new therapeutic strategies.

In previous studies, it was found that NK cells near the tumor showed dysfunction. The data shows that when NK cells are placed in a normal environment, their function can be restored within a few hours. These results indicate that the factors that cause NK cell inactivation come from the tumor itself.

The researchers identified two important tumor-specific factors associated with impaired NK cell function. First, specific inflammatory cytokines (IL-10) are indirectly involved in the inactivation of NK cells. Second, tumor cells produce a protective mechanism for NK cells. The specific surface molecules of tumor cells (NK g2d ligand) to which NK cells can bind are down-regulated. They explained that NK cells lack an important activation mechanism and are no longer able to carry out cytotoxic activity.

However, despite the tumor cell suppression strategy, NK cells produce the cytokine interferon-gamma (IFN-γ) at an early stage, and IFN-γ is essential for further activation of an anti-tumor immune response.

The researchers speculate that metastatic NK cells are a possible strategic option for the treatment of B-cell lymphoma. According to the results of the study, this treatment can be optimized when the transferred NK cells have been activated in vitro prior to injection, bypassing the missing activation potential in the tumor microenvironment. They then concluded that additional injections of IFN-γ or anti-IL-10 antibodies could further support immunological activity.