The specific core fucose-binding lectin Pholiota squarrosa lectin (PhoSL) inhibits hepatitis B virus infection in vitro.

Glycosylation of proteins and lipids in viruses and their host cells is important for viral infection and is a target for antiviral therapy. Hepatitis B virus (HBV) is a major pathogen that causes acute and chronic hepatitis; it cannot be cured because of the persistence of its covalently closed circular DNA (cccDNA) in hepatocytes. Here we found that Pholiota squarrosa lectin (PhoSL), a lectin that specifically binds core fucose, bound to HBV particles and inhibited HBV infection of a modified human HepG2 cell line, HepG2-hNTCP-C4, that expresses an HBV receptor, sodium taurocholate cotransporting polypeptide. Knockout of fucosyltransferase 8, the enzyme responsible for core fucosylation and that aids receptor endocytosis, in HepG2-hNTCP-C4 cells reduced HBV infectivity, and PhoSL facilitated that reduction. PhoSL also blocked the activity of epidermal growth factor receptor, which usually enhances HBV infection. HBV particles bound to fluorescently labeled PhoSL internalized into HepG2-hNTCP-C4 cells, suggesting that PhoSL might inhibit HBV infection after internalization. As PhoSL reduced the formation of HBV cccDNA, a marker of chronic HBV infection, we suggest that PhoSL could impair processes from internalization to cccDNA formation. Our finding could lead to the development of new anti-HBV agents.