New clues show how the immune system fights against COVID-19


When the immune system detects an invasive virus such as COVID-19, it sends swarms of antibodies to block it, blocking its ability to adhere to cells and marking it for destruction by ‘other cells. Ara, new research shows in astonishing detail how this process works in people who have successfully recovered from COVID-19 and offer new insights to help others.

So far, scientists have focused on a part of the coronavirus ear, the receptor-binding domain, that the virus uses to connect and access human cells. This part of the coronavirus attaches directly to a person’s cells to infect it and is the part that researchers have established as a priority for the development of vaccines and drugs. Monoclonal therapies with antibodies approved last year for emergency use by the U.S. Food and Drug Administration use this same goal.

Now, a team led by immunologists Gregory Ippolito and Jason Lavinder of the University of Texas at Austin has examined more closely the blood samples from four people who recovered from COVID-19 and found that most of the antibodies that made their bodies to fight the disease actually went to other parts of the coronavirus rise.

In fact, up to 80% of their antibodies are directed to other parts of the ear protein. These antibodies were targeted at another area of ​​the umbrella-shaped protein crown, Ippolito explains. And it is that this part of the ear protein, called the N-terminal domain, mutates more frequently. Changes in this region are responsible for many of the variants of concern. These variants can prevent the detection of some of the most common antibodies in our defensive arsenal, bypassing the immune system.

More protection

But another large group of antibodies goes to the spike stem, called the S2 subunit. Scientists report that this is reassuring, as it is a region that does not change often, so if antibodies that recognize the virus are able to neutralize it, they should offer a layer of protection against any variant.

No antibodies that bind to S2 have yet been found to be strongly protective, but Lavinder says that if some can be found, they could play a role in the next generation of vaccines and booster vaccines developed to deal with them. to variants. It could even point the way to a vaccine that provides protection against all coronaviruses, not just COVID-19.

“The idea is that because this region is significantly conserved in all coronaviruses, a good coronavirus vaccine could be produced,” says Ippolito. “It could be important for strategic vaccine design in the future.”

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