New research has revealed that polyethic nanoantibodies can block SARS-CoV-2 infections and inhibit mutation escape

Picture from Science, 2021, doi:10.1126/science.abe6230.
antibodies are an important weapon for the immune system against infection.
they bind to the surface structure of bacteria or viruses, preventing them from replicating.
, one of the strategies to fight the disease is to mass produce effective antibodies and inject them into the patient.
president- and outgoing U.S. President Donald Trump's rapid recovery from the virus infection is likely to be due to this approach.
, however, the antibody used to treat him is complex in structure and cannot penetrate deeply into the tissue, which can lead to unnecessary complications.
addition, the production of antibodies is difficult and time-consuming.
, they may not be suitable for widespread use.
We focus on another group of molecules, nanoantibodies," explains Dr. Florian Schmidt of the Institute of Innational Immunology at the University of Bonn and co-author of the paper, which produces large quantities of yeast or bacteria.
antibody is an antibody fragment that is very simple and can be produced by bacteria or yeast at a lower cost.
, however, the number of different antibodies produced by the immune system is almost endless, and they can identify different target structures.
, for example, only a handful of antibodies can beat SARS-CoV-2.
these antibodies is like looking for a grain of sand on Germany's Baltic coast.
S. Schmidt explained, "We first injected the surface protein of this coronavirus into an alpaca and a llama.
their immune systems produce antibodies that primarily target the virus.
addition to complex normal antibodies, alpacas and llamas produce a simpler antibody variant that can serve as the basis for nanoantibodies.
weeks later, the researchers took blood samples from the animals, extracting genetic information that produced antibodies.
this "library" also contains millions of different construction diagrams.
in a complex process, they extracted antibodies that identified important structures on the surface of the coronavirus--- the tingling --- proteins.
"We got dozens of nanoantibodies in total, and then we analyzed them further," explained Dr. Paul-Albert König, co-author of the paper and head of the nanoantibodies core facility at the University of Bonn School of Medicine.
" found four of the millions of molecules in cell cultures, four nanoantibod molecules have actually been shown to be effective against the pathogen.
X-ray structures and electron microscope analysis, we were able to further demonstrate how they interact with the virus's prickly proteins," explains König.
the study was led by Martin Hällberg of the Karolinska Institute of Medicine in Sweden, Nicholas Wu of the University of Illinois at Urbana-Champaign, and Ian Wilson of the Scripps Institute in the United States.
SARS-CoV-2 prickly protein is essential for infection.
it functions like a magic patch, through which the pathogen adheres to the attacked cell.
next, the prickly protein changes its structure.
it discards ingredients that are important to the virus's attachment and mediates the fusion of the virus's envelope with the cell membrane.
antibodies also seem to trigger this structural change before the virus hits its target cells--- which is an unexpectedly novel pattern of action," said König, a research group.
the change is likely irreversible;
also take advantage of another advantage of nanoantibodies over antibodies: they are simple in structure, allowing direct combinations to form molecules that are hundreds of times more effective.
have fused two nanoantibodies that target different parts of this prickly protein," explains König.
this fusion is very effective in cell cultures.
, we can confirm that this greatly reduces the probability that the virus will develop resistance to active preparations through escape mutations.
"they believe these molecules could be developed into a novel and promising treatment.
, a spin-off at the University of Bonn, will test these nanoantibodies in clinical studies.
: 1.Paul-Albert Koenig et al. Structure-guided multivalent nanobodies block SARS-CoV-2 infection and suppress mutational escape. Science, 2021, doi:10.1126/science.abe6230. 2.Promising new antibodies against SARS-CoV-2 found