Fig. 1

Hepatocyte maintenance medium (HMM) enhances HBV infection in HepG2-NTCP cells. A HepG2-NTCP cells were inoculated with HBV at 100 or 500 genome equivalents (GE)/cell diluted in 4% PEG8000-containing DMEM or HMM in the presence or absence of 10 μM cyclosporin A (CsA). After 16 hours (h), the inoculum was removed, and cells were washed and refed with either DMEM supplemented with 10%FBS and 2%DMSO (D10/2%DMSO) or HMM. At 10 days (d) post-inoculation, cells were fixed and subjected to immunofluorescence assays using an anti-HBc antibody. Nuclei were stained with DAPI. B, C HMM was added to the HepG2-NTCP cell culture before, during, or after HBV inoculation (100 GE/cell). At 10 d (B) or 8 d (C) post-inoculation, cells were fixed and stained with an anti-HBc antibody. Scale bar  =  50 μm. HBV-infected areas were quantified using the ImageJ software (NIH), and data were normalized to values in culture infected with 100 GE/cell of HBV in the regular medium (D10/2% DMSO) and presented as mean  ±  SEM from two independent experiments