N-acetylgalactosamine (GalNAc)-specific lectins mediate enhancement of Hantaan virus infection

N-acetylgalactosamine (GalNAc)-specific lectins, Dolichos biflorus agglutin in (DBA), and soybean agglutinin (SBA), enhanced Hantaan (HTN) virus infect ions in Vero E6 and P388D1 cells. Treatment of Vero E6 cells with the lecti ns either before or during, but not after, virus inoculation resulted in le ctin-mediated enhancement of infection (LME), indicating that GalNAc-specif ic lectin affects an early stage of the infection. Lectin blot and FAGS ana lysis showed that the ability of HTN virus envelope glycoproteins and cell surface molecules to bind DBA and SEA was essential for LME. GalNAc clearly inhibited LME, indicating that the lectins bind with their specific carboh ydrate-binding site. These results suggest that a lectin cross-link between the virus and the cell surface is the most plausible mechanism for inducin g infection enhancement.