posted on 06/15/2022 16:16 / updated on 06/15/2022 16:17
The research was published in the scientific journal Cell systems on Tuesday (14/6) and showed that the thousand genes identified are responsible for 77% of the drivers of serious cases of covid-19 – (credit: Pixabay)
A joint study by the Universities of Sheffield, in the United Kingdom, and Stanford University, in the United States, identified more than a thousand genes linked to the development of severe cases of covid-19. This is a significant finding, the researchers say, to begin to understand why some people experience more severe symptoms of the coronavirus — and others don’t.
The research was published in the scientific journal cell systems on Tuesday (14/6) — you can read it in full at this link — and showed that the thousand genes identified are responsible for 77% of the drivers of serious cases of covid-19.
First, the researchers analyzed the genetic data of lung tissue cells from a healthy human. The data helped identify gene expression in 19 different types of lung cells, including epithelial cells that line the respiratory tract and are the first defense against infections.
Next, they observed data collected by the COVID-19 Host Genetics Initiative — a health database — looking for genetic clues (such as DNA mutations, called single nucleotide polymorphisms) that could indicate whether someone is more likely to have severe Covid-19.
Searches for answers
Based on the findings, the researchers needed to verify whether the mutations found could increase the chances of serious infection by covid-19. So they performed a genome-wide search of lung tissue for mutations from patients with the disease and from healthy patients.
While it was clear to them which mutations were most likely to carry disease risk, the researchers still did not know which genes were affected by such mutations. To have the final list of genes, they used molecular clues to decipher the region of the genome where the mutation occurred and, ultimately, narrow the region down to specific genes.
“When you are studying the genetic basis of the disease, you are trying to identify the regions of the genome that are responsible. If you know where to fish – all the hot spots, in this case, the active genomic regions in the lungs – you have a much better chance of catching more fish than if you were looking across the ocean,” explains Michael Snyder, one of the authors of the study. study.
The researchers were also interested in knowing which cell types harbored faulty gene expression. Thus, the study also determines that severe cases of covid-19 are associated with a weakened response of two immune cells – NK cells (Natural Killer) and T cells.
“NK cells, which humans are born with and are the body’s first line of defense against infections, are known for their ability to destroy viruses and cancer cells. They are like generals directing the war. They mobilize other immune cells, telling them where to go and what to do. We found that in people with severe coronavirus infection, critical genes in NK cells are less expressed, so there is a less robust immune response. The cell is not doing what it should be doing,” explains Dr Johnathan Cooper-Knock, another author of the study.
“Our findings lay the groundwork for a genetic test that can predict who is born with an increased risk of severe covid-19,” he said. “Imagine there are 1,000 DNA changes linked to severe Covid-19. If you have 585 of these changes, it can make you quite susceptible, and you should take all the necessary precautions,” adds Snyder.