Be optimistic.. the discovery of antibodies against Omicron and the subsequent mutations

0
3


International scientific team identified antibodies that neutralize Omicron strain and other variants of the novel coronavirus; These antibodies target areas of the virus’s spike protein (spike) that remain essentially unchanged as the viruses mutate.

By targeting these “broadly neutralizing” antibodies to the spike protein, it may be possible to design vaccines and antibody therapies that will be effective; not only against omicron variable But also against other variables that may emerge in the future, explains David Weissler, a researcher at the Howard Hughes Medical Institute and associate professor of biochemistry at the University of Washington School of Medicine in Seattle.

 expressive

expressive

This discovery tells us that “by focusing on antibodies that target these highly conserved sites on the barbed protein, there is a way to overcome the ongoing evolution of the virus,” Wessler says, in a report published on the University of Washington website.

Wessler led the research project that found these antibodies, in cooperation with a team of researchers from Switzerland, and published the results of their work in the latest issue of the journal Nature.

A statistic for “Reuters” showed that more than 283.23 million people were infected with the emerging coronavirus worldwide, while the total number of deaths resulting from the virus reached 5 million and 716,761 .

Infections with the virus have been recorded in more than 210 countries and regions since the first cases were discovered in China in December 2019.

expressive

expressive

The omicron mutant contains 37 mutations in the thistle protein The virus uses it to attach to and invade human cellsThis is an unusually large number of mutations, and these changes are thought to explain in part why the variant is able to spread so quickly, infecting vaccinated people, and reinfecting those who were previously infected.

“The main questions we were trying to answer were: ‘How did this set of mutations in the omicron’s barbed protein affect its ability to bind to cells and evade immune system antibody responses?'” says Weissler.

Wessler and colleagues speculate that a large number of omicron mutations may have accumulated during a long-term infection, in a person with a weakened immune system, or because the virus jumped from humans to an animal species and back again.

To assess the effect of these mutations, the researchers engineered a virus called a “pseudovirus” to produce spiky proteins on its surface, as coronaviruses do, and then created pseudoviruses containing spiky proteins with omicron mutations and those in the first variants identified in the epidemic.
The researchers first looked to see how different versions of the barbed protein were able to bind to a protein on the surface of cells that the virus uses to attach to and enter the cell, a protein called the angiotensin-converting enzyme receptor (ACE2).

The researchers found that the spiny protein from Omicron was able to bind 2.4 times better than the barbed protein found in the virus isolated at the beginning of the epidemic, and they also found that the Omicron version was able to bind to the “ACE2” receptors in mice efficiently, indicating that Omicron may be Able to pass between humans and other mammals.

The researchers then looked at how well the antibodies generated against previous versions of the virus protected against the omicron variant, and did so using antibodies from patients who had previously had previous versions of the virus, had been vaccinated against previous strains of the virus, or were infected and then vaccinated. . They found that antibodies from people who had been infected with previous strains, and from those who received one of the six most widely used vaccines currently available, reduced the ability to prevent infection.

Antibodies from people who became infected, recovered, and then received two doses of the vaccine also reduced their activity; But the decrease was less, about 5 times, which clearly indicates that vaccination after infection is beneficial.

expressive

expressive

In a group of dialysis patients who received a booster dose, the subjects’ antibodies showed a 4-fold decrease in neutralization activity. “This shows that a third dose is really helpful against Omicron,” says Weissler.

The researchers found that all but one of the antibody treatments currently allowed, or approved for use in patients exposed to the virus, had no activity, or significantly reduced the activity of Omicron in the laboratory, and the exception was the antibody called “Sotrovimab”, which was It has 2 to 3 times the neutralizing activity.

But when they tested a larger group of antibodies created against previous versions of the virus, the researchers identified 4 classes of antibodies that retained their ability to neutralize the omicron, and members of each of these classes target one of 4 specific regions of the thorny protein found not only in variants of the emerging “Corona” virus, but also in a group of related coronaviruses, called “sarbic” viruses, and these sites may persist on the protein; Because they perform an essential function that the protein loses if it mutates, these regions are called “conserved.”

The discovery that antibodies are able to neutralize, by recognizing protected areas in many different variants of the virus, suggests that the design of vaccines and antibody therapies that target these regions can be effective against a wide range of variants that appear through mutations.





Source link
https://www.alarabiya.net/coronavirus/2021/12/30/%D8%AA%D9%81%D8%A7%D8%A1%D9%84%D9%88%D8%A7-%D8%A3%D8%AC%D8%B3%D8%A7%D9%85-%D9%85%D8%B6%D8%A7%D8%AF%D8%A9-%D9%8A%D9%85%D9%83%D9%86%D9%87%D8%A7-%D8%AA%D8%AD%D9%8A%D9%8A%D8%AF-%D8%A3%D9%88%D9%85%D9%8A%D9%83%D8%B1%D9%88%D9%86-%D9%88%D9%85%D8%A7-%D9%8A%D8%AA%D8%A8%D8%B9%D9%87-%D9%85%D9%86-%D8%AA%D8%AD%D9%88%D8%B1%D8%A7%D8%AA

LEAVE A REPLY

Please enter your comment!
Please enter your name here