Viral Hepatitis
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 14, 2006; 12(30): 4836-4842
Published online Aug 14, 2006. doi: 10.3748/wjg.v12.i30.4836
HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro
Mostafa K El-Awady, Ashraf A Tabll, Yasmine S El-Abd, Mahmoud M Bahgat, Hussein A Shoeb, Samar S Youssef, Noha G Bader El Din, El-Rashdy M Redwan, Maha El-Demellawy, Moataza H Omran, Wael T El-Garf, Said A Goueli
Mostafa K El-Awady, Yasmine S El-Abd, Samar S Youssef, Noha G Bader El Din, Moataza H Omran, Wael T El-Garf, Ashraf ATabll, Department of Biomedical Technology, National Research Center, Tahrir Street, PO 12622, Dokki, Cairo, Egypt
Mahmoud M Bahgat, Department of Medicinal Chemistry, National Research Center, Tahrir Street, PO 12622, Dokki, Cairo, Egypt
Hussein A Shoeb, Department of Microbiology and Immunology Faculty of Pharmacy Cairo University, Cairo, Egypt
El-Rashdy M Redwan, Maha El-Demellawy, Genetic Engineering and Biotechnology Research Institute , New Borg El-Arab City, Alexandria, Egypt
Said A Goueli, Department of Pathology School of Medicine, University of Wisconsin Madison WI, United States
Author contributions: All authors contributed equally to the work.
Supported by the Ministry of Scientific Research, Academy of Scientific Research and Technology, Medical Research Council Code: P5-MED-030-01 and US-Egypt joint project BIO7-002-011
Correspondence to: Dr. Mostafa K El-Awady, Department of Biomedical Technology, National Research Center, Tahrir Street, PO 12622, Dokki, Cairo, Egypt. mkawady@yahoo.com
Telephone: +20-12-3132640 Fax: +20-2-3370931
Received: October 18, 2005
Revised: December 23, 2005
Accepted: January 24, 2006
Published online: August 14, 2006
Abstract

AIM: To establish a cell culture system with long-term replication of hepatitis C virus (HCV) genome and expression of viral antigens in vitro.

METHODS: HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect naïve cells. The presence of minus (antisense) RNA strand, and the detection of core and E1 antigens in cells were examined by RT-PCR and immunological techniques (flow cytometry and Western blot) respectively.

RESULTS: The intracellular HCV RNA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies (anti-core, and anti-E1). Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells.

CONCLUSION: HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.

Keywords: Hepatitis C virus; In vitro propagation; Genomic replication; Gene expression; HepG2 cells