Neutralizing Antibodies in Patients with Chronic Hepatitis C, Genotype 1, against a Panel of Genotype 1 Culture Viruses: Lack of Correlation to Treatment Outcome

Abstract

The correlation of neutralizing antibodies to treatment outcome in patients with chronic hepatitis C virus (HCV) infection has not been established. The aim of this study was to determine whether neutralizing antibodies could be used as an outcome predictor in patients with chronic HCV, genotype 1, infection treated with pegylated interferon-α and ribavirin. Thirty-nine patients with chronic hepatitis C, genotype 1a or 1b, with either sustained virologic response (n = 23) or non-sustained virologic response (n = 16) were enrolled. Samples taken prior to treatment were tested for their ability to neutralize 6 different HCV genotype 1 cell culture recombinants (1a: H77/JFH1, TN/JFH1, DH6/JFH1; 1b: J4/JFH1, DH1/JFH1, DH5/JFH1). The results were expressed as the highest dilution yielding 50% neutralization (NAb50-titer). We observed no genotype or subtype specific differences in NAb50-titers between patients with chronic HCV infection with and without sustained virologic response when tested against any of the included culture viruses. However, NAb50-titers varied significantly with a mean reciprocal NAb50-titer of 800 (range: 100–6400) against DH6/JFH1 compared to a mean NAb50-titer of 50 (range: <50–400) against all other included isolates. Subsequent studies demonstrated that the efficient neutralization of DH6/JFH1 could be linked to engineered adaptive mutations in the envelope-2 protein. In analysis of envelope 1 and 2 sequences of HCV, recovered from a subset of patients, we observed no apparent link between relatedness of patient sequences with culture viruses used and the corresponding neutralization results. In conclusion, pre-treatment levels of neutralizing antibodies against HCV genotype 1 isolates could not predict treatment outcome in patients with chronic HCV infection. High neutralization susceptibility of DH6/JFH1 could be correlated with adaptive envelope mutations previously highlighted as important for neutralization. Our study emphasizes the importance of using multiple culture viruses for neutralization studies and contributes to the current knowledge about neutralizing epitopes, important for future therapeutic- and vaccine-studies.

Patterns of longitudinal change in hepatitis C virus neutralization titers correlate with the outcome of peginterferon and ribavirin combination therapy

“…C and B). Similar findings have been reported in studies using HCVpp or JFH1‐based chimeric viruses [Morishima et al, ; Pedersen et al, ]. The current study extends these observations onto the level of autologous HCV isolates.…”

Adaptive Mutations Enhance Assembly and Cell-to-Cell Transmission of a High-Titer Hepatitis C Virus Genotype 5a Core-NS2 JFH1-Based Recombinant

“…The influence of envelope mutations on the sensitivity of extracellular HCV to neutralizing antibodies has previously been described (33,34,(45)(46)(47)(48)(49)(50)(51)(52). Thus, we investigated if the adaptive amino acid changes present in SA13/JFH1 Core-NS5B influenced virus sensitivity to neutralization compared to SA13/ JFH1 orig .…”

“…Typically, our fittest recombinant, SA13/JFH1 orig , yields infectivity titers of approximately 5.0 log 10 FFU/ml (Fig. 2); however, other Core-NS2 recombinants typically produce lower infectivity titers in the range of 3.5 to 4.5 log 10 FFU/ml or 50% tissue culture infective doses (TCID 50 )/ml (18,21,23,25,45,(67)(68)(69). While it is important to note that direct comparisons of infectivity titers between laboratories are difficult due to differences in methodologies used for titer determination, as well as variation between Huh7.5 cell cultures in different laboratories, titers of Ͼ6.0 log 10 TCID 50 /ml or FFU/ml have been reported in only a few studies for genotype 2a HCVcc JFH1 (30,37) and J6/JFH1 (35,38).…”

“…For example, amino acid changes in the viral envelope glycoproteins, especially E2, have previously been associated with altered sensitivity to neutralizing antibodies (33,34,(45)(46)(47)(48)(49)(50)(51)(52). The role of changes to the envelope glycoproteins in respect to HCV immunogenicity remains to be fully elucidated.…”

“…Several studies have shown that alterations to E2 especially can cause changes in neutralization sensitivity. This includes deletion of the hypervariable region 1 (HVR1) (43,44) and specific amino acid changes (33,34,(45)(46)(47)(48)(49)(50)(51)(52). Furthermore, changes to the envelope glycoproteins can also cause changes in the biophysical properties of HCV (43,44,53).…”