There are still many unresolved questions regarding the coronavirus responsible for Covid-19. For example, what is the immune response of the human body against the pathogen during infection with or without symptoms, severe or not? Researchers conducted a study, published on April 21 in the journal Cell Reports Medicine.
“Antibodies capable of killing infected cells”
Scientists from the Institut Pasteur, the Vaccine Research Institute and the CNRS, National Center for Scientific Research, used epidemiological studies carried out by Inserm, the National Institute for Health and Medical Research. Using the data collected, the researchers analyzed the antibodies induced in patients with symptomatic or non-symptomatic Covid-19. It turns out that the antibodies made are ” polyfunctional “. They have several abilities: one that neutralizes the virus and one that kills cells infected with the coronavirus. Indeed, defensive substances make it possible to activate certain other defense mechanisms, such as “ NK killer cells (Natural Killer) », Indicates the press release.
The good news is that the results of this study show the presence of polyfunctional antibodies in all participants who contracted Covid-19, ” regardless of the severity of the disease “. However, the amount is a little less in people who do not have symptoms, which is almost half of those infected with the coronavirus.
New tests to measure antibody levels
The antiviral functions induced by the coronavirus are still poorly understood by the scientific world. This is why the teams have developed tests, using video microscopy, to precisely analyze the multiple functions of antibodies, in this context. They find that in the first place, a phenomenon of recognition of the infected cells is set up by the antibodies. Secondly, the NK cells (natural killer) intervene to destroy these cells. Plasma proteins take part in this process. Thanks to them, the cells identified by the antibodies are destroyed. This experiment therefore demonstrates “ new antiviral activity of antibodies. “Timothée Bruel, co-author and researcher, concludes that” This study has shown that individuals infected with SARS-CoV-2 have antibodies capable of attacking the virus in different ways, by preventing it from entering cells (neutralization) or by killing infected cells through activation of NK cells “.
