Isolation and Epitope Characterization of Human Monoclonal Antibodies to Hepatitis C Virus Core Antigen

Abstract

In this study we describe the establishment of two hybridoma cell lines secreting human monoclonal antibodies to the 22-kD nucleocapsid protein (core, p22) of the hepatitis C virus (HCV). For this purpose we isolated B lymphocytes from an anti-HCV positive blood donor and infected them with Epstein-Barr (EBV). We obtained several lymphoblastoid cell clones secreting antibodies to the recombinant HCV core protein. The B-cell cultures were oligoclonally expanded and two of them were fused with the (mouse:human) heteromyeloma cell line K6H6/B5. The resulting stable hybridomas produce antibodies of the IgG1/kappa (U1/F10) and the IgM/kappa (Ul/F11) isotype reacting specifically with the recombinant core protein p22. To identify the epitopes recognized by these antibodies we synthesized overlapping peptides (13-mer and 6-mer) from the amino terminus of the core amino acid sequence. Antibody reactivity to these peptides was analyzed in an immunoblot assay. Finally, we were able to define a linear epitope recognized by the Ul/F10 antibody on the nucleocapsid protein. The antibody shows specificity to the sequence N-VYLLPR-C, which corresponds to the amino acids 34-39 of the core sequence.

Characterization of monoclonal antibodies against hepatitis C virus nonstructural protein 3: Different antigenic determinants from human B cells

“…Several studies concerning B-cell epitope analysis of HCV core antigens have been documented; however, only few studies concerning B-cell antigenic determinants in NS-3 region have been reported [Nasoff et al, 1991;Koskinas et al, 1994;Siemoneit et al, 1994;Moradpour et al, 1996]. A previous study has suggested multiple B-cell antigenic regions (NS3-e, NS3-a, NS3-a/b, NS3-b/c) identified by human B cells [Hwang et al, 1996].…”

Preclinical Evaluation of Two Neutralizing Human Monoclonal Antibodies against Hepatitis C Virus (HCV): a Potential Treatment To Prevent HCV Reinfection in Liver Transplant Patients

“…The HCV genotype of this donor is unknown. B cells from this donor were transformed with Epstein-Barr virus (42). The supernatants of the resulting lymphoblastoid clones were screened by ELISA with an extract of cells infected with a recombinant vaccinia virus, RMPA95, expressing the envelope proteins E1 and E2 of an HCV genotype 1a (H) strain.…”

Crystal Structure of a Hydrophobic Immunodominant Antigenic Site on Hepatitis C Virus Core Protein Complexed to Monoclonal Antibody 19D9D6

“…Among the different anticore mAbs obtained, mAb 19D9D6 appeared to be specific for an epitope encompassed by residues 29 -33 within the main antigenic domain (9), a property shared by the major human epitope of core (10,11). Furthermore, mAb 19D9D6 is of special interest, since it detects, with a good sensitivity, viral core Ag in sera of patients with chronic HCV infection.…”