An antibody has been identified that can neutralize all known variants of the SARS-CoV-2 coronavirus

An antibody has been identified that can neutralize all known variants of the SARS-CoV-2 coronavirus
An antibody has been identified that can neutralize all known variants of the SARS-CoV-2 coronavirus
Anonim

The monoclonal antibody SARS2-38 targets that part of the S-protein of the virus that is little changed due to mutations. Therefore, it can work against the most common variants of the Covid-19 pathogen today.

Antibodies to coronavirus

In addition to vaccines against Covid-19, experts are studying monoclonal antibodies - proteins obtained in laboratories that mimic the ability of the immune system to fight against an antigen. Many such drugs have previously been shown to be effective in animals, and some have been approved for the treatment of patients in emergency departments. According to scientists, therapy with monoclonal antibodies is useful for patients at risk and will help vaccines to resist a pandemic.

Most antibodies to SARS-CoV-2 have neutralizing properties and prevent the virus from binding to human cells, that is, they act against the receptor binding domain (RBD) of the S-protein of the causative agent of Covid-19. At the same time, the researchers discovered inhibitory antibodies: they target the N-terminal domain (NTD) of the spike and the S2 domain (it is already responsible for fusion with the cell membrane and penetration into the cell). But, as we know, the problem is that the virus is changing. And its new variants acquire mutations in the S-protein, thereby gaining resistance to monoclonal or polyclonal antibodies. Therefore, to treat patients, additional drugs are required that will be effective against SARS-CoV-2 strains.

Employees of the University of Washington School of Medicine in St. Louis have identified an antibody to the receptor-binding domain of SARS-CoV-2, which is able to overcome all variants of the virus known to date. A preprint of the work was published in the journal Immunity. The researchers began by experimenting with mice, injecting them with a key part of the spike protein - the receptor-binding domain. Then the antibody-producing cells were removed and 43 antibodies were obtained, nine of which were tested in rodents.

While some proteins have shown a limited ability to protect against infection with the "classic," Wuhan strain, others have been effective when administered prophylactically or therapeutically. And two antibodies - SARS2-02 and SARS2-38 - were able to neutralize the virus strains of concern. The first binds an epitope that includes residues E484 and L452, but shows reduced potency against variants B.1.351 ("beta"), B.1.617.2 ("delta"), B.1.429 ("epsilon"), B.1.1. 28 / P.1 ("gamma"), B.1.526 80 ("iota") and B. 1.617.1 ("kappa"), encoding these mutations. The second antibody, on the other hand, binds the epitope centered on residues K444 and G446 - and neutralized all the strains mentioned above.

“Analysis of the structure of SARS2-38 showed that this antibody binds to a conserved epitope on RBD (that is, common to different strains. - Ed.). Thus, targeting this conserved domain region can provide protection against all emerging variants of the virus,”write the biologists. At the same time, SARS2-38 has a high neutralizing ability, which means it works well even at low concentrations. “This is an unusual combination for an antibody. Plus, it binds to a unique region of the S-spike protein that other antibodies do not target. It would be possible to consider the option of combining SARS2-38 with other similar proteins to create a combination therapy, "- summed up the authors of the work.

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