ABSTRACT
Objective To investigate whether cell lines expressing apolipoprotein E-enhanced green fluorescence protein (apoE-EGFP) can support assembly of infectious hepatitis C virus particles. Methods apoE stably down-regulated Huh7. 5. 1 cell lines (sh-apoE cell lines) were established by shRNA gene silencing technique, and cell lines expressing apoE-EGFP fusion protein (apoE-EGFP cell lines) were established. The culture supernatants of wild-type Huh7. 5. 1 cells, control cells (sh-NT cells), sh-spoE cells and apoE-EGFP cells transfected with HCV RNA were collected and the HCV titer of supernatants was determined by TCID50. The interaction of apoE with HCV structure protein E2 was examined by immunofluorescence and confocal microscopy, and the expression of apoE-EGFP on the surface of HCV particles purified by FLAG-specific affinity gll was analyzed by Western blotting analysis. Results The apoE-EGFP fusion protein was highly expressed in sh-apoE cell lines. The infectivity of HCV from apoE-EGFP cell culture supernatant was not significantly different with those of HCV from Huh7. 5. 1 and sh-NT cells. apoE-EGFP infused protein had fluorescent co-location with HCV structural protein E2, and was detected on the surface of HCV particles purified by FLAG-specific affinity gll. Conclusion The apoE-EGFP fusion protein is an important component of HCV particles and apoE-EGFP cell lines can support the assembly of HCV particles.