It is called AeroNabs and helps block the action of the coronavirus SARS-CoV-2, responsible for COVID-19, before it infects respiratory cells. Better yet, it can be dispensed as a nasal spray or an inhaler.
This molecule could alter the second wave of contamination currently raging during this period of pandemic of COVID-19. Her name is AeroNabs and was developed by two pharmaceutical chemistry researchers at the University of California, San Francisco (UCSF). “If AeroNabs is as effective as we anticipate it could change the course of this pandemic around the world”, proclaims Aashish Manglik, one of the co-inventors of the medical device in a press release relayed by Science Daily. With his colleague Peter Walter and other researchers, he details their discovery in a study still in pre-publication on bioRxiv. AeroNabs consists of a single domain antibody (not to be confused with anti-COVID-19 monoclonal antibodies currently studied) or ” nanobody. This is a molecular fragment of an antibody, ten times smaller in size than the entire original molecule. In certain species of camelids (llamas, camels and dromedaries) or of cartilaginous fish, this fragment – which, in general, should not have any immune power – is able to recognize an antigen, a foreign molecule, and to act like a normal antibody . Smaller and more stable than the complete molecule, the single domain antibody can thus be easily synthesized.
AeroNabs was discovered after triage of more than two billion ” nanobodies »Synthetic collected by the laboratory of two American researchers. One of them, Nb6, turned out to be a perfect blocker of the Spike protein of the SARS-CoV-2 coronavirus. As a reminder, this surface protein (shown in red in the photo above) shows a “crown” to the target respiratory cells. It then fits like a key into the receptor-binding (RBD) domains of their surface proteins called ACE2. Once the connection is made, the virus enters the cell and uses it to reproduce itself en masse and start the infection. Nb6 binds to the Spike protein before it comes into contact with ACE2, and thus prevents a SARS-CoV-2 virion from infecting a target cell. To strengthen the efficiency of the system, the Californian researchers have even succeeded in tripling their molecule: mNb6-tri can thus completely block the three crown segments of the Spike protein. According to tests carried out on copies of the virus kept at the Institut Pasteur in Paris, this triple molecule would thus be 200,000 times more effective than ” nanobody Alone, even at low doses. “Its effectiveness is such that it surpassed our ability to measure it”, welcomes Peter Walter. Inserted into the DNA of a harmless bacterium or a yeast capable of making it, the AeroNabs molecule can be deployed in the human body easily. In addition, the AeroNabs-microbe combination can be delivered through a simple inhaler or nasal spray. If it passes clinical trials in human patients, it could constitute the first preventive treatment against COVID-19.
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