Researchers at the Virology Center at the Medical University of Vienna, Austria, have found a relationship between the absence of natural killer cell receptors, NK cells, and the occurrence of serious cases of Covid-19. The research was published in the scientific journal Genetics in Medicine.

The results indicate that those who were hospitalized with Covid-19, in general, are more likely to have a genetic variation that causes the lack of NKG2C receptors, which help to fight viral infections. NKG2Cs communicate with cells infected with HLA-E, one of its surface structures. This interaction results in the destruction of infected cells.


However, some people have a natural deficiency in these receptors. This failure is due to a genetic variation that is found in about 4% of the population, who do not have the receptors, and another 30% who have only a small portion of them.

Study leader Elisabeth Puchhammer-Stöckl explains that the absence of the receptor was particularly prevalent in Covid-19 patients undergoing treatment in intensive care units. “And that regardless of age or sex. Genetic variations in the HLA-E of the infected cell were also associated with the severity of the disease, although to a lesser extent ”, he says.

Exterminating cells are important in fighting viral infections. Credit: Arquivo / UFRGS

What are NK cells?

The name of the NK cells comes from the acronym in English for Natural Killers (or natural exterminators, in free translation). They are the lymphocytes necessary for the innate immune system to function satisfactorily.

These cells are important in combating viral infections and also in fighting various cancer cell lines. This is because NK have a cytotoxic activity that allows to fight cancer cells without knowing them previously, unlike T lymphocytes.


The discovery of Elisabeth's team is important because it demonstrates the importance of NK cells in the fight against Covid-19. In addition, they can be useful for drug research that are effective to prevent serious cases of the disease.

Street: Medical Xpress

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