In vitro infection of human peripheral blood mononuclear cells by a defective hepatitis B virus with a deletion in the PreS1 region of the viral genome

summary . Previously, we identified a defective hepatitis B virus (HBV) which contains a 183 nucleotide deletion in the PreS1 region of the viral genome affecting the S gene promoter in sera from hepatitis B surface antigen (HBsAg)‐negative patients with serum HBV‐DNA. The aim of this study was to analyse the infectivity of this mutant. Peripheral blood mononuclear cells (PBMC) from a healthy donor were incubated with serum samples from 2 HBsAg‐negative patients with serum HBV‐DNA (infected with wild‐type and deletion mutant HBV), from an HBsAg carrier (infected with wild‐type HBV) and from a healthy donor. After 1 week, HBV‐DNA was detected by polymerase chain reaction (PCR) in all supernatants and cells incubated with the HBV‐DNA‐positive inocula. DNase and trypsin pretreatment confirmed intracellular localization of HBV‐DNA in cells. HBV‐RNA and covalently closed circular HBV‐DNA were also detected in PBMC, indicating that the viral DNA infecting these cells was transcriptionally active. Deletion mutant and wild‐type HBV were detected in the supernatants and cells infected with the two HBsAg‐negative sera, while only wild‐type HBV was detected in the supernatant and cells incubated with the serum from the HBsAg‐carrier. In conclusion, this HBV deletion mutant can infect, replicate and release viral particles in in vitro infected PBMC.