Persistent infection mechanism of GB virus C/hepatitis G virus differs from that of hepatitis C virus.
OBJECTIVE
Changes in the deduced amino acid sequence of the envelope 2 (E2) region of the GB virus C/hepatitis G virus (GBV-C/HGV) were analyzed to investigate whether or not the region contributes to persistent infection with the virus.


METHODS
Eight patients with acute hepatitis C and 1 patient with acute hepatitis of unknown etiology were included in the study. GBV-C/HGV RNA was detected in 6 patients, including the patient with hepatitis of unknown origin. The nucleotide sequence of the E2 region of hepatitis C virus (HCV) and GBV-C/HGV was determined by direct sequencing of polymerase chain reaction products in 5 patients with HCV infection and in 6 patients with GBV-C/HGV infection twice during the period of early infection and several months or years later in each patient.


RESULTS
The mean substitution rate of the deduced amino acid sequence in the E2 region was over 100 times lower (p < 0.001) in GBV-C/HGV (0.01 +/- 0.04/month/100 sites) than in HCV (2.4 +/- 1.7/month/100 sites). The amino acid sequence of the loop domain of GBV-C/HGV-E2 did not change in any of the 6 patients. On the other hand, the sequence of the hypervariable region of HCV-E2 changed remarkably (5.9 +/- 4.3/month/100 sites). No amino acid substitution in the loop domain was observed in 7 additional patients who showed persistent GBV-C/HGV viremia for more than 2 years.


CONCLUSIONS
These results indicate that changes in the amino acid sequence of the E2 region are not involved in the mechanism of persistent GBV-C/HGV infection.
Orii
K
K
Second Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
Tanaka
E
E
Rokuhara
A
A
Maruyama
A
A
Ichijo
T
T
Yoshizawa
K
K
Kiyosawa
K
K
D000208:Acute Disease; D000328:Adult; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D005260:Female; D018067:Flaviviridae / Q000235:genetics* / Q000472:pathogenicity; D016174:Hepacivirus / Q000235:genetics* / Q000472:pathogenicity; D006526:Hepatitis C / Q000821:virology*; D006525:Hepatitis, Viral, Human / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014759:Viral Envelope Proteins / Q000032:analysis / Q000235:genetics
D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus