Viral Hepatitis
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 14, 2006; 12(10): 1551-1557
Published online Mar 14, 2006. doi: 10.3748/wjg.v12.i10.1551
Efficient expression of histidine-tagged large hepatitis delta antigen in baculovirus-transduced baby hamster kidney cells
Ying-Wei Chiang, Jaw-Chin Wu, Kuei-Chun Wang, Chia-Wei Lai, Yao-Chi Chung, Yu-Chen Hu
Ying-Wei Chiang, Kuei-Chun Wang, Chia-Wei Lai, Yao-Chi Chung, Yu-Chen Hu, Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, China
Jaw-Chin Wu, Institute of Clinical Medicine, National Yang Ming University and Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan, China
Author contributions: All authors contributed equally to the work.
Supported by National Health Research Institutes (NHRI-EX94-9412EI) and VTY Joint Research Program, Tsou's Foundation (VGHUST94-P6-32)
Correspondence to: Dr. Yu-Chen Hu, Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, China.
Telephone: +886-3-5718245 Fax: +886-3-5715408
Received: June 10, 2005
Revised: October 1, 2005
Accepted: November 18, 2005
Published online: March 14, 2006

AIM: To study the baculovirus/mammalian cell system for efficient expression of functional large hepatitis delta antigen (L-HDAg).

METHODS: A recombinant baculovirus expressing histidine-tagged L-HDAg (L-HDAgH) was constructed to transduce baby hamster kidney (BHK) cells by a simplified transduction protocol.

RESULTS: The recombinant baculovirus transduced BHK cells with efficiencies higher than 90% as determined by flow cytometry. The expression level was significantly higher than that obtained by plasmid transfection and was further enhanced 3-fold to around 19 pg/cell by the addition of 10 mmol/L sodium butyrate. Importantly, the expressed L-HDAgH was localized to the cell nucleus and correctly isoprenylated as determined by immunofluorescence labeling and confocal microscopy. Moreover, L-HDAgH interacted with hepatitis B surface antigen to form virus-like particles.

CONCLUSION: The fusion with histidine tags as well as overexpression of L-HDAgH in the baculovirus-transduced BHK cells does not impair the biological functions. Taken together, the baculovirus/mammalian cell system offers an attractive alternative for high level expression of L-HDAgH or other proteins that require extensive post-translational modifications.

Keywords: Baculovirus, Hepatitis delta virus, L-HDAg, Mammalian cell, Protein expression, Transduction