Inoue J, Ueno Y, Wakui Y, Fukushima K, Kondo Y, Kakazu E, Ninomiya M, Niitsuma H, Shimosegawa T. Enhanced replication of hepatitis B virus with frameshift in the precore region found in fulminant hepatitis patients.
J Infect Dis 2011;
204:1017-25. [PMID:
21881116 DOI:
10.1093/infdis/jir485]
[Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND
The genotype B of hepatitis B virus (HBV) was reported to associate with fulminant hepatitis (FH). We aimed to clarify the characteristics of HBV obtained from FH patients in an area of Japan where genotype B HBV is prevalent.
METHODS
Using serum samples of 16 HBV-associated FH patients, partial HBV sequences were determined. The effects of HBV mutation/insertion/deletion were evaluated using an in vitro HBV replication system.
RESULTS
Of the 16 HBV isolates, 31% belonged to subgenotype B1/Bj, 38% were subgenotype B2/Ba, and 31% were subgenotype C2/Ce. Notably, the single nucleotide insertion/deletion that resulted in a frameshift of the precore protein was found exclusively in 60% of B1/Bj strains. An in vitro study showed that all of the frameshift mutants had significantly higher amounts of HBV DNA than did the wild type. One of the isolates had a novel insertion of A between nucleotides 1900 and 1901, which resulted in a 3-nucleotide change within the Kozak sequence of the core protein and enhanced the core protein expression in vitro.
CONCLUSIONS
The frameshift insertion/deletion in the precore region enhanced HBV replication and might be associated with the development of FH by the subgenotype B1/Bj HBV.
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