Hepatitis B surface antigen on subviral particles reduces the neutralizing effect of anti-HBs antibodies on hepatitis B viral particles in vitro

•Hepatitis B viral particles (VP) and subviral particles (SVP) were fractionated.•SVP were efficient in protecting VP by adsorbing neutralizing anti-HBs antibodies.•SVP were less efficient in blocking viral entry by binding to target cells.•Thus, SVP may facilitate cell-to-cell spread in presence of neutralizing antibodies.

During hepatitis B virus (HBV) infections subviral particles (SVP) consisting mainly of hepatitis B surface antigen are present at much higher concentration than viral particles (VP) in serum. To investigate reasons for this excess of SVP production, SVP and VP were fractionated on a Nycodenz gradient and analyzed for HBV infection of HepG2-NTCP cells with and without anti-HBs antibodies. Our findings showed that SVP significantly reduced the neutralization of VP by anti-HBs, while SVP had little effect on viral entry, supporting the assumption that SVP serve as decoy facilitating cell-to-cell spread of HBV in the presence of neutralizing antibodies.

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