Immune Netw.  2001 Apr;1(1):77-86. 10.4110/in.2001.1.1.77.

Definition of the peptide mimotope of cellular receptor for hepatitis C virus E2 protein using random peptide library

• Lee IH
• Paik JE
• Seol SY
• Seog DH
• Park SG
• choi IH

• KMID: 2150560
• DOI: http://doi.org/10.4110/in.2001.1.1.77

Abstract

BACKGROUND: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell .
METHODS
In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides.
RESULTS
Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patient s captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides.
CONCLUSION
Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.

Keyword

Hepatitis C virus; E2 protein; Phage peptide library; Peptide mimotope; Cellular receptor

MeSH Terms

Antibodies
Antigen-Antibody Complex
Bacteriophages
Carcinoma, Hepatocellular
Conserved Sequence
Databases, Nucleic Acid
Enzyme-Linked Immunosorbent Assay
Flaviviridae
Gene Library
Genome
Hepacivirus*
Hepatitis C*
Hepatitis*
Hepatitis, Chronic
Hepatocytes
Humans
Immunoglobulin G
Immunoprecipitation
Liver Cirrhosis
Mass Screening
Peptide Library*
Peptides
RNA
Antibodies
Antigen-Antibody Complex
Immunoglobulin G
Peptide Library
Peptides
RNA