ULTRASTRUCTURAL ANALYSIS OF HEPATITIS-B VIRUS IN HEPG2-TRANSFECTED CELLS WITH SPECIAL EMPHASIS ON SUBVIRAL FILAMENT MORPHOGENESIS

The intracellular accumulation of empty hepatitis B virus (HBV) partic les of filamentous shape leads to a direct cytopathic effect in so-cal led ground-glass hepatocytes. The aim of this study was to investigate how these filaments can be structurally formed at the cellular level. By electron microscopy, we reexamined the HBV-producer HepG2T-14 cell s, which have been described as producing a substantial amount of empt y HBV filaments compared with the other forms of HBV particles. Examin ation of ultrathin sections of HepG2T14 cells revealed the presence of HBV virions and filaments at the periphery of extremely large intrace llular cisternae, probably related to a pre-Golgi compartment, Very lo ng filaments appeared to be formed by a tubular budding of a long port ion of the cisterna membrane. This phenomenon may be identical to that observed in the hepatocytes of HBV chronic carriers, in which the ina bility of the infected cell to export long HBV filamentous particles t hrough the cellular secretion pathway seems to be at the origin of a d irect cytopathic effect.