Capture and neutralization of SARS‐CoV‐2 and influenza virus by algae‐derived lectins with high‐mannose and core fucose specificities

Abstract

AbstractWe first investigated the interactions between several algae‐derived lectins and severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). We created lectin columns using high‐mannose (HM)–type glycan‐specific lectins OAA and KAA‐1 or core fucose–specific lectin hypninA‐2 and conducted binding experiments with SARS‐CoV‐2. The results showed that these lectins were capable of binding to the virus. Furthermore, when examining the neutralization ability of nine different lectins, it was found that KAA‐1, ESA‐2, and hypninA‐2 were effective in neutralizing SARS‐CoV‐2. In competitive inhibition experiments with glycoproteins, neutralization was confirmed to occur through HM‐type or core fucose–type glycans. However, neutralization was not observed with other lectins, such as OAA. This trend of KAA‐1 and ESA‐2 having the neutralizing ability and OAA not having it was also similar to influenza viruses. Electron microscopy observations revealed that KAA‐1 and hypninA‐2 strongly aggregated SARS‐CoV‐2 particles, while OAA showed a low degree of aggregation. It is believed that the neutralization of SARS‐CoV‐2 involves multiple factors, such as glycan attachment sites on the S protein, the size of lectins, and their propensity to aggregate, which cause inhibition of receptor binding or aggregation of virus particles. This study demonstrated that several algae‐derived lectins could neutralize SARS‐CoV‐2 and that lectin columns can effectively recover and concentrate the virus.