Amino Acid Polymorphism in Hepatitis B Virus Associated With Functional Cure

Abstract

The amino acid substitution I97L in the HBc region is associated with stable hepatitis achieving a functional cure with the sustained loss of HBsAg. This substitution leads to low level of cccDNA via the production of an immature virion with a single-stranded genome. BACKGROUND & AIMS:To provide an adequate treatment strategy for chronic hepatitis B, it is essential to know which patients are expected to have a good prognosis and which patients do not require therapeutic intervention. Previously, we identified the substitution of isoleucine to leucine at amino acid 97 (I97L) in the hepatitis B core region as a key predictor among patients with stable hepatitis. In this study, we attempted to identify the point at which I97L affects the hepatitis B virus (HBV) life cycle and to elucidate the underlying mechanisms governing the stabilization of hepatitis. METHODS:To confirm the clinical features of I97L, we used a cohort of hepatitis B e antigen-negative patients with chronic hepatitis B infected with HBV-I97 wild-type (wt) or HBV-I97L. The effects of I97L on viral characteristics were evaluated by in vitro HBV production and infection systems with the HBV reporter virus and cell culture-generated HBV. RESULTS:The ratios of reduction in hepatitis B surface antigen and HBV DNA were higher in patients with HBV-I97L than in those with HBV-I97wt. HBV-I97L exhibited lower infectivity than HBV-I97wt in both infection systems with reporter HBV and cell culture-generated HBV. HBV-I97L virions exhibiting low infectivity primarily contained a single-stranded HBV genome. The lower efficiency of cccDNA synthesis was demonstrated after infection of HBV-I97L or transfection of the molecular clone of HBV-I97L. CONCLUSIONS:The I97L substitution reduces the level of cccDNA through the generation of immature virions with single-stranded genomes. This I97L-associated low efficiency of

Production and Purification of Cell Culture–generated Hepatitis B Virus by Transient Transfection and Density Gradient

“…Measure the HBV DNA levels by real-time PCR targeting the HBs region by using the plasmid containing the PCR fragment amplified by primers for the real-time PCR as the standard (Tables 4 and 5) ( Figure 4 ) ( Honda et al, 2021 ).…”

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen

“…To assess the efficacy and safety of the L-HBsAg vaccine, we combined it with two kinds of effective adjuvants for immunization in rhesus macaques and evaluated the induction of antibody to various regions of HBsAg. To investigate the neutralizing ability of induced antibodies, we exploited the infection system of cell culture-generated HBV (HBVcc) and HBV reporter viruses 21 – 23 . The HBV reporter virus infection system can be used to evaluate neutralization by vaccine-induced antibodies against HBV variants with VEM or HBV clones of various genotypes in cell culture.…”

Hepatitis B Virus Reactivation After Switch to Cabotegravir/Rilpivirine in Patient with Low Hepatitis B Surface Antibody

“…The primary goal in managing chronic hepatitis B is to achieve an undetectable hepatitis B surface antigen (HBsAg) level. Cases where seroconversion from HBsAg to anti-HBs occurs is considered a functional cure, although, the risk for de novo reactivation persists and is not eliminated ( 2 ).…”