N. Kato et al., VIRUS ISOLATE-SPECIFIC ANTIBODIES AGAINST HYPERVARIABLE REGION-1 OF THE HEPATITIS-C VIRUS 2ND-ENVELOPE PROTEIN, GP70, Japanese journal of cancer research, 85(10), 1994, pp. 987-991
Hypervariable region 1 (HVR1), located in the N-terminal region of a p
utative second envelope glycoprotein (gp70) of hepatitis C virus (HCV)
, contains immunological B-cell epitopes which might be neutralizing e
pitopes. To clarify whether B-cell epitopes within HVR1 are common amo
ng virus isolates or specific for the homologous virus isolate, we exa
mined the reactivities of sera from 53 patients with chronic hepatitis
or hepatocellular carcinoma/liver cirrhosis against two different HVR
1 peptides (HVR1 I-1 and HVR1 Y-1) derived from patient I with sporadi
c acute hepatitis and an asymptomatic carrier Y, respectively, using o
ur original assay system for the detection of anti-HVR1 antibody. All
patients examined had a history of blood transfusion. Most sera showed
no reactivity with either HVR1 I-1 or HVR1 Y-1 peptide. Only seven an
d fourteen serum samples reacted significantly, although weakly, with
HVR1 I-1 and HVR1 Y-1 peptides, respectively, compared with the serum
from patient I or asymptomatic carrier Y. The blood transfusions of mo
st reactive cases had occurred more than thirty years earlier. Six cas
es reacted with both HVR1 I-1 and HVR1 Y-1 peptides, but further analy
sis revealed that only three cases reacted weakly with the peptide for
either epitope I or II, identified within HVR1 I-1. These results ind
icate that the B-cell epitopes within HVR1 are fairly specific for the
homologous virus isolate, and this may represent a serious difficulty
in the development of a vaccine against HCV.