April 5-11 2021
Lipopeptides: a new weapon against COVID-19?
Entry of SARS-CoV-2 into cells requires the fusion of viral and cellular membranes. This fusion is mediated by the spike (S) surface viral protein. We already knew that peptides (small proteins) that bind to one end of the S protein inhibit membrane fusion. Dutch and American researchers recently tested this type of peptide, coupled with lipides, as a prophylactic and therapeutic treatment against viral infections. They developed a specific dimeric lipopeptide from the SARS-CoV-2 S protein and demonstrated that it prevented transmission of the virus in ferrets.
The researchers firstly compared the in vitro effectiveness of monomeric and dimeric lipopeptides from the SARS-CoV-2 S protein. They showed that a dimeric lipopeptide was more effective and also non-toxic for cells, even in very high doses. In addition, it seems that this lipopeptide is effective against viral variants that are currently spreading.
They then tested the effectiveness of this molecule in vivo, through an animal model often used for the study of the transmission of respiratory viruses: the ferret. Mustelids (from the ferret family) can be naturally infected with SARS-CoV-2, as the outbreaks in mink farms proves (see News-COVID-19.info letter Novembre 16-22 2020). During this test, the ferrets were treated preventively with lipopeptide administered intranasally, before being put in contact with infected ferrets over 24 hours. Non-infected ferrets were used as a control group to measure the effectiveness of the treatment. The result was that none of the treated ferrets were infected with the virus, whereas all the non-treated ferrets were.
The prophylactic intranasal administration of lipopeptide, developed by researchers, does seem to prevent transmission of SARS-CoV-2 between ferrets. These results need to be confirmed in humans. Lipopeptides, unlike antibodies, are inexpensive to make and are easily stored. They could therefore prove to be a safe and effective supplementary tool to hold back the COVID-19 pandemic.