Viral Hepatitis
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Apr 28, 2006; 12(16): 2530-2535
Published online Apr 28, 2006. doi: 10.3748/wjg.v12.i16.2530
Antibody to E1 peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro
Mostafa K EL-Awady, Ashraf A Tabll, Khaled Atef, Samar S Yousef, Moataza H Omran, Yasmin El-Abd, Noha G Bader-Eldin, Ahmad M Salem, Samir F Zohny, Wael T El-Garf
Mostafa K EL-Awady, Ashraf A Tabll, Khaled Atef, Samar S Yousef, Moataza H Omran, Yasmin El-Abd, Noha G Bader-Eldin, Wael T El-Garf, Department of Biomedical Technology, National Research Center, Cairo, Egypt
Ahmad M Salem, Samir F Zohny, Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
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: +2-2-3362609 Fax: +2-2-3370931
Received: November 2, 2005
Revised: December 26, 2005
Accepted: January 14, 2006
Published online: April 28, 2006
Abstract

AIM: To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus (HCV). Specific polyclonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes.

METHODS: Hyper-immune HCV E1 antibodies were incubated over night at 4 °C with serum samples positive for HCV RNA, with viral loads ranging from 615 to 3.2 million IU/ mL. Treated sera were incubated with HepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RT-PCR and flow cytometry.

RESULTS: Direct immunostaining using FITC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera (72%) showed complete inhibition of infectivity as detected by RT-PCR.

CONCLUSION: In house produced E1 antibody, blocks binding and entry of HCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents.

Keywords: Flow cytometry; Hepatitis C virus; E1 envelope; Therapeutic antibodies; Direct immuno-fluorescence; HepG2 cells