title: Characterization of Anti-HCV Antibodies in IL-10-Treated Patients.
abstract: There is limited information on the direct role of the neutralizing antibody responses against hepatitis C virus (HCV) infection or methodologies to study them. Previously we have demonstrated that interleukin-10 (IL-10) administered to chronic hepatitis patients led to a decrease in disease activity, but an increase in HCV viral burden. The mechanism behind this is unknown. The objective of this study was to examine the antibody response in IL-10-treated patients. To establish a neutralization antibody assay, HCV-positive and HCV-negative sera were collected and incubated with HCV strain JFH-1 particles before culture with Huh 7.5 cells. Viral replication was measured a week later by either indirect immunofluorescence assay (iIFA) or real-time reverse transcriptase polymerase chain reaction (RT-PCR). After validation of the methodology, the sera from 30 previously-described subjects of a group previously treated with IL-10 were tested for the neutralization capacity of their antibodies. The amount of total anti-HCV antibody in the sera was also measured by direct staining of HCV full-length replicon cells. With this validated neutralization assay for anti-HCV antibodies we found that HCV-neutralizing antibodies are universally present, but with significantly different titers. In patients who were treated with IL-10, the total anti-HCV antibody titers appear to be constant, but with significantly decreased antibody neutralization activity. Our study validates an assay to quantitatively determine the presence and strength of HCV-specific neutralizing antibodies. We have found that IL-10-treated patients have significantly lower HCV antibodies, but maintain the total anti-HCV antibody titer, suggesting a novel mechanism by which IL-10 treatment increases viral load in patients.
authors: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida, USA.
authors: Erika A
authors: EA
authors: Eksioglu
authors: Jennifer
authors: J
authors: Bess
authors: Graham
authors: G
authors: Jones
authors: Jennifer
authors: J
authors: Dettloff
authors: Parinda
authors: P
authors: Dangmeon
authors: Hui-Jia
authors: HJ
authors: Dong
authors: Haizhen
authors: H
authors: Zhu
authors: Roberto
authors: R
authors: Firpi
authors: Yiling
authors: Y
authors: Xu
authors: David R
authors: DR
authors: Nelson
authors: Chen
authors: C
authors: Liu
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood*; D002460:Cell Line; D005260:Female; D005455:Fluorescent Antibody Technique; D018937:Hepatitis C Antibodies / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000097:blood* / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D016753:Interleukin-10 / Q000627:therapeutic use*; D008297:Male; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000627:therapeutic use*
chemical_list: D057134:Antibodies, Neutralizing; D018937:Hepatitis C Antibodies; D011994:Recombinant Proteins; D016753:Interleukin-10