Researchers infected 36 people with the virus that causes COVID-19 to understand why some people seem to evade the virus. The answer was in his immune system.
New research has analyzed why some people don’t get sick of COVID-19 deliberately infecting a small number of healthy individuals in highly controlled environments.
The researchers administered the virus nasally to 36 healthy adult volunteers with no history of COVID-19. They analyzed cells from the nose and blood of study participants and published their results.
They examined cells from the nose and blood of study participants and published their findings in the journal Nature.
They then used a technology called single cell sequencing to examine the genetic information (DNA and RNA) of individual cells.
“This is a unique opportunity to see what the immune response to a new pathogenin adults without a history of COVID-19 and in a context in which factors such as time of infection and comorbidities can be controlled,” says Dr. Rik Lindeboom, co-author of the study from the Netherlands Cancer Institute, in a statement.
A gene that can prevent prolonged infection
Individuals who rapidly cleared the virus did not show a typical generalized immune response. Instead, they showed subtle immune responses.
According to the researchers, the high levels of activity of a gene called HLA-DQA2 before exposure could have helped these participants prevent prolonged infection.
In contrast, six individuals who developed a prolonged infection had a rapid immune response in the blood but slower in the nosewhich allowed the virus to establish itself there.
“These findings shed new light on the crucial initial events that allow the virus to take hold or eliminate it quickly before symptoms develop,” said Dr. Marko Nikolić, another of the study’s authors, from University College London.
The researchers also found common patterns in T cell receptors (TCR), the protein on the surface of T cells designed to recognize specific antigens.
When a TCR binds to a pathogen presented by an infected or abnormal cell, it triggers T cell activation. T cells can directly kill infected cellsactivating other immune cells and helping long-term immunity by remembering the pathogen.
Study conclusions and preparation for future infections
This study has allowed us to better understand how immune cells communicate and could help develop therapies targeting T cells not only against COVID-19, but also against other diseases.
“We now have a much better understanding of the full range of immune responses, which could lay the groundwork for develop potential treatments and vaccines that mimic these natural protective responses“said Nikolić.
This study is part of the Human Cell Atlasan international collaborative group created in 2016 with the goal of mapping all human cells.
