A group of researchers from the Higher Council for Scientific Research (CSIC) have managed to produce effective antibodies against the most aggressive variants of COVID-19. Antibodies can also be used to detect the virus and their use could be extended to be applied in antigenic tests, as well as as therapy in infected patients.
Researchers from the National Center for Biotechnology (CNB-CSIC) led by Luis Ángel Fernández and José María Casasnovas have published the results of the study in Frontiers in Immunology and have managed to develop antibodies by cell cultures in the laboratory. The CSIC has patented this technology and is now looking for companies interested in bringing these antibodies to market.
The scientists selected the nanoantibodies that best bound to the region of the viral protein S (spike) of SARS-CoV-2 and that blocked the entry of the virus into the cell, in short.a, those with higher virus-neutralizing activity. Administration of a single dose of these antibodies protected from death caused by COVID-19 to between 85 and 100 percent of infected animals, They fully recovered within two weeks. The CNB-CSIC research groups have developed these antibodies starting from segments generated by camel immunization in collaboration with Juan Alberto Corbera, from the University of Las Palmas de Gran Canaria.
Why has it been investigated in dromedaries?
Camelids (dromedaries, llamas, alpacas, etc.) produce a type of antibody capable of recognizing the antigen with a single protein chain, instead of two as in the rest of the animal species. Thus, the antigen recognition zone in these antibodies is smaller, and they can reach regions on the surface of viruses and bacteria that are otherwise inaccessible”, explains Luis Ángel Fernández, who heads the CNB’s bacterial engineering group.
“In the laboratory we isolate the binding zone of these antibodies, small fragments known as nanoantibodies with great ability to block viruses and bacteria. As they have sequences very similar to those of human antibodies, they can be used directly in therapy without generating rejection”, concludes Fernández.
The CSIC he already explained almost two years ago, in May 2020, that he was studying how to produce nanoantibodies specific against COVID-19 from samples of immunized camels. Why this animal?
“Human and animal antibodies are made up of two different protein chains that associate to create the binding zone for the antigen (virus or bacteria) and thus be able to block it and prevent its entry into the cells”, Fernández pointed out before developing the nanoantibodies. “However, there is an exception to this rule. Camelids (dromedaries, llamas, alpacas, etc.) produce a special type of antibodies capable of recognize antigen with a single protein chain. Thus, the antigen recognition zone in these antibodies is smaller, which allows them to reach otherwise inaccessible regions on the surface of viruses and bacteria”, explained the expert.
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