Researchers at the laboratory of the University of Colorado at Boulder (USA) have found that a specific protein variant of IFNAR2, which plays the role of regulating the immune response, may be an important factor that affects the severity of COVID-19. The findings of their study were published in the journal Cell.

During the research, the team of scientists studied the hitherto unknown versions of proteins that play an important role in immune function. One of them, the IFNAR2, is capable of regulating the intensity of interferon signals, an important component of the immune response.

According to biologist Ed Chuong, one of the authors of the paper, understanding the work of the IFNAR2 will open up opportunities for targeted strengthening or weakening of the immune response, which could become the basis for new methods of treating infections, autoimmune diseases, and cancer.

The research looked also at transposons, bits of DNA that infiltrated primate genomes during evolution. Some of them are of viral origin and may play a role in the spread of cancer cells, while others are caused by mutations in the genome itself. Previously considered "junk DNA", transposons affect cell functions.

One of the important findings was the study of the interferon 2 receptor. The researchers identified its shortened version, which interacts with interferon, but does not transmit signals. This "short" version of the receptor acts as a "bait" to prevent the immune system from overreacting. Experiments have shown that removing this variant from the genome of cells increases their sensitivity to interferon and enhances antiviral responses, including protection against SARS-CoV-2 and dengue fever virus.

But as the researchers note, the excess of this receptor can increase susceptibility to infections, and its deficiency is associated with autoimmune diseases and chronic inflammatory disorders. Differences in levels of this protein in different people may explain individual characteristics of immune responses, including susceptibility to severe infections and inflammation.