We confirmed that two hypervariable regions (HVR1 and HVR2) were present in this amplified region, as described in our previous report (Hijikata et al., 1991a) and we found that the HVR1 regions of HCV-J and HCV-US were 27 and 21 amino acids in length, respectively, and began from the N-terminal amino acid of gp70.
The nt sequence of a cDNA fragment of E2/NS1 region of HCV, from six different serum samples, which comprises the hypervariable regions-1 (HVR-1) and -2 (HVR-2), revealed sequence heterogeneity with type II HCV (75.4 to 80.7% nt homology and 75.5 to 79.7% amino acid homology).
We further investigated the sequence variability of the HCV genomic region that entirely encodes the envelope proteins (gp35 and gp70); these sequences were derived from virus isolated during the acute and chronic phases of hepatitis in one patient, and we found that HVR1 was a major site for genetic mutations in HCV after the onset of hepatitis.
Sequence analysis of the HCV hypervariable region 1 (HVR1) in both cases indicated that HVR1 populations from the cells at 8 days p.i. were apparently different from those of the original inocula.
The anti-HVR1 antiserum induced protection against homologous HCV infection in chimpanzees, but not against the emergence of neutralization escape mutants that were found to be already present in the complex viral quasispecies of the inoculum.
To determine how interferon-alpha (IFN-alpha) treatment changes the heterogeneity of the hepatitis C virus (HCV) population, the hypervariable region 1 (HVR1) was directly sequenced, and the virus load was quantified in 15 patients who had received IFN-alpha for 15 months.
The complexity of hypervariable region 1 (HVR1) quasispecies of hepatitis C virus (HCV) in serum and peripheral blood mononuclear cells (PBMCs) was assessed at several time points in 11 patients with chronic hepatitis C. Polymerase chain reaction and single-strand conformation polymorphism analysis revealed that four patients (36%) showed serial changes in the complexity of HVR1 quasispecies, which were identical in both serum and PBMCs; two patients (18%) showed both serial changes in quasispecies and differences in quasispecies between serum and PBMCs; and five patients (45%) showed neither serial changes in nor quasispecies differences between serum and PBMCs.
Genetic variability of HCV was assessed by determining the nucleotide sequence corresponding to the hypervariable regions (HVR1 and HVR2) of the putative envelope protein (E2/NS1) in positive- and negative-stranded HCV RNA from the cancerous and surrounding non-cancerous liver tissue, peripheral blood mononuclear cells and serum of a patient with HCC.
In conclusion, there was a high degree of genetic variation in HVR1 of HCV specimens isolated from hemophiliacs compared with posttransfusion patients.
Further characterization of the HVR1-specific antibodies in patient sera by attachment studies of HCV to the human fibroblasts suggested that HVR1-specific antibodies in sera obtained early p.i. can neutralize virus of the anti-D IgG preparation.
HCV quasispecies heterogeneity was determined by single-strand conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1).
The aims of the study were to optimize a genotype-independent primer set for amplification of HVR-1 and to establish a sensitive SSCP analysis for rapid and non-isotopic detection of predominant serum HCV quasispecies.
To study the effects of the immunosuppression caused by the reduction of CD4 activity on the composition of hepatitis C virus (HCV) populations, we analyzed the number of HCV quasispecies clones and the nucleotide diversity of the hypervariable region 1 (HVR1) of HCV in 37 patients with hemophilia with persistent HCV infection, with or without human immunodeficiency virus (HIV).
At 16 mo, the HVR1 amino acid sequences of HCV observed in the infant's sera were very similar to those from the donor (his maternal grandfather) on the day of transfusion.
Quasispecies heterogeneity was quantitated by analysis of 490 hypervariable region 1 (HVR1) clones using gel shift analysis (GSA), which allowed determination of two components of HCV quasispecies heterogeneity: genetic complexity (number of variants) and genetic diversity (mean genetic distance between variants).
Phages were identified which react very frequently with patients' sera and bind serum antibodies that cross-react with a large panel of HVR1 peptides derived from natural HCV variants.
These findings suggest that phylogenetic and serological analyses of HVR1 sensitively detect unrecognized and multiple transmission of HCV occurring within the same room in hemodialysis centers.
These findings suggest that anti-E2 and anti-HVR1 antibodies induced in mice have the ability to bind with HCV particles in an isolate cross-reactive manner and highlight the possible application of combining several sequences of HVR1 to generate broadly reactive anti-HVR1 antibodies.
Our findings indicate that HVR1 variation has an adaptive significance and is associated with favorable features of liver disease and suggest that prospective, rather than static, observations are required to model the process of HCV variation.