Banana protein may have the potential to work against SARS-CoV-2

A paper in Cell Reports Medicine details the efficacy of H84T-BanLec against all known human-infecting coronaviruses, including MERS, the original SARS, and SARS-CoV2, including the omicron variant.

"When COVID-19 occurred, we of course wanted to study the therapy's potential and discovered it was effective against every type of coronavirus, in vitro and in vivo," study author said "Whether delivered systemically or through the nose in animal models, or prophylactically or therapeutically early on in the illness, it worked."

H84T-BanLec is derived from a lectin (a carbohydrate-binding protein) isolated from banana fruit. It accomplishes its remarkable viral-blocking abilities by binding to high-mannose glycans, polysaccharides that are present on the surface of the viruses, but only very rarely on normal healthy human cells. After binding, the virus cannot enter cells to infect them.

Using atomic force microscopy and related methods, the team confirmed that H84T develops multiple strong bonds with the spike protein, which, the authors said, probably explains why it's hard for a coronavirus to be resistant to the lectin.

Despite their anti-viral potential, lectins have traditionally been avoided as possible therapies because they are proteins that can stimulate the immune system in a potentially harmful way, explains Markovitz. However, H84T-BanLec has been modified to remove this effect and showed no detrimental effects in the animal models.

While several treatments for COVID-19 currently exist, including remdesivir, nirmatrelvir/ritonavir and monoclonal antibodies, they have varied levels of effectiveness, side effects and ease of use and many have proven less effective as SARS-CoV2 continues to evolve.

H84T-BanLec holds unique promise, according to the team, because it is effective against all coronavirus variants as well as influenza viruses.

Reference:

David Markovitz et al,Cell Reports Medicine,DOI 10.1016/j.xcrm.2022.100774