Scientists are working on developing an arsenal of nano-sized weapons in the war against COVID-19. These molecules, called nanobodies, have been in the spotlight due to the characteristic properties that make them particularly well suited as potential countermeasures against viral infections. In a boost to the field, scientists at the University of Zurich have created a platform for generating large nanobody libraries and selecting those with the highest virus-neutralizing potential at unprecedented speeds. Together with industry partners Absolute Antibody, the researchers are racing to bring their selection of potentially life-saving molecules to the global community.
Nanobodies, also known as single-domain antibodies, are small protein fragments that have the ability to bind selectively to a target, such as a viral protein. At just a tenth of the size of whole antibodies, nanobodies have distinct advantages for clinical applications: they can penetrate previously inaccessible parts of the body and are easier to manufacture at mass scales. Nanobodies were inspired by a type of antibody produced by the immune system of camels, llamas, and alpacas called VHH fragments. They are now being tested for their possible use in treating diseases like cancer and Alzheimer’s.
Researchers are especially interested in exploring how nanobodies can be used to fight COVID-19 because nanobodies could be administered as an inhalable drug. An inhalable spray would deliver nanobodies to the lungs of infected patients much faster than “traditional” antibody therapeutics, which are often infused into the bloodstream. Researchers from the laboratory of Markus Seeger have created a research tool for mining for synthetic nanobodies that attach to the receptor-binding domain (RBD) of SARS-CoV-2. Previous studies have shown that blocking this RBD site on the virus arrested its ability to enter lung cells and cause or worsen COVID-19 disease. In just two short weeks, the Seeger lab identified over 60 unique RBD-blocking nanobodies using their platform.
The team is collaborating with Absolute Antibody, who bring their expertise in engineering and manufacturing antibodies for clinical use. “By partnering with Absolute Antibody, we have extended the reach and applications of our new synthetic nanobodies, furthering their potential in the race to develop urgently required therapeutics,” said Seeger. Additionally, nanobodies could play a big role in lessening the devastating effects of the pandemic not just as therapeutics, but also in COVID-19 diagnostics.