J Korean Surg Soc.  2007 Feb;72(2):117-127.

Study on HBV Gene Replication and Expression of Experimental Hepatitis B Model Using Baculovirus Gene Delivery System

• Lee WJ
• Yang YI
• Jang WH
• Lee SJ
• Kim WW
• Choi CS
• Choi YK

Abstract

PURPOSE: The lack of reliable in vitro infection systems or convenient animal models has hindered the progress of hepatitis B virus (HBV) research and the development of new treatment options. We established an in vitro model of hepatitis B, using recombinant HBV encoding baculovirus, which provided HBV replication and antigens expression in HepG2 cells. The objectives of this study were to characterize the magnitude of HBV expression and the level of replication obtainable in HepG2 cells, to establish the optimum infection and culture conditions of HBV expression and replication.
METHODS
Replication of a competent HBV genome encoding the baculovirus, RC-HBV-Bac, was generated for delivering the HBV genome to HepG2 cells. HBV replication and antigens expression were determined in relation to the infection and culture conditions.
RESULTS
In RC-HBV-Bac infected HepG2 cells, HBsAg, HBeAg and HBcAg were expressed in the cytoplasm and nuclei, and secreted into the medium. HBV replication was evidenced by the presence of a replication complex and covalently closed circular (ccc) DNA in the cytoplasmic fraction of infected cells. The level of HBV expression was directly proportional to the multiplication of RC-HBV-Bac infection. Polyethylene glycol was able to enhance the infection efficiency of the baculovirus to HepG2 cells. High levels of HBV replication were achieved under culture conditions supplemented with dimethyl sulfoxide and a low serum concentration.
CONCLUSION
This in vitro model of hepatitis B, generated by baculovirus gene delivery, represents a simple and flexible system for the study of HBV replication and drug testing.

Keyword

Hepatitis B virus; Recombinant baculovirus; HBV replication; HBV-associated antigens expression; In vitro model

MeSH Terms

Baculoviridae*
Cytoplasm
Dimethyl Sulfoxide
DNA
Gene Transfer Techniques*
Genome
Hep G2 Cells
Hepatitis B Core Antigens
Hepatitis B e Antigens
Hepatitis B Surface Antigens
Hepatitis B virus
Hepatitis B*
Hepatitis*
Models, Animal
Polyethylene Glycols
DNA
Dimethyl Sulfoxide
Hepatitis B Core Antigens
Hepatitis B Surface Antigens
Hepatitis B e Antigens
Polyethylene Glycols