Persistent Loss of Hepatitis B Virus Markers in Serum without Cellular Immunity by Combination of Peginterferon and Entecavir Therapy in Humanized Mice

Abstract

Nucleot(s)ide analogues and peginterferon (PEG-IFN) treatment are the only approved therapies for chronic hepatitis B virus (HBV) infection. However, complete eradication of the virus, as indicated by persistent loss of hepatitis B surface antigen (HBsAg), is rare among treated patients. This is due to long-term persistence of the HBV genome in infected hepatocytes in the form of covalently closed circular DNA (cccDNA). In this study, we investigated whether administration of a large dose of a nucleoside analogue in combination with PEG-IFN can achieve long-term loss of HBsAg in human hepatocyte chimeric mice. Mice were treated with a high dose of entecavir and/or PEG-IFN for 6 weeks. High-dose combination therapy with both drugs resulted in persistently negative HBV DNA in serum. Although small amounts of HBV DNA and cccDNA (0.1 and 0.01 copy/cell, respectively) remained in the mouse livers, some of the mice remained persistently negative for serum HBV DNA at 13 weeks after cessation of the therapy. Serum HBsAg and hepatitis B corerelated antigen (HBcrAg) continued to decrease and eventually became negative at 12 weeks after cessation of the therapy. Analysis of the HBV genome in treated mice showed accumulation of G-to-A hypermutation and CpG III island methylation. Persistent loss of serum HBV DNA and loss of HBV markers by high-dose entecavir and PEG-IFN combination treatment in chimeric mice suggests that control of HBV can be achieved even in the absence of a cellular immune response.

When Hepatitis B Virus Meets Interferons

“…And peg-IFN monotherapy showed greater advantages in HBeAg seroconversion compared to peg-IFN-LMV combination or LMV monotherapy (32 and 27% vs. 19%) ( Lau et al, 2005 ). The combination of high-dose peg-IFN and NAs resulted in sustained loss of serum HBV DNA and other HBV markers in an immunodeficient mouse model ( Uchida et al, 2017 ), suggesting that HBV replication can be effectively inhibited by antivirals in the absence of a cellular immune response. A recombinant human serum albumin (rHSA)-IFN-α2a fusion protein is under development and aims to extend the in vivo half-life of IFN-α.…”

Regulation of the Hepatitis B virus replication and gene expression by the multi-functional protein TARDBP

“…The following primer sets were used for mRNA quantification: TARDBP, 5′-CCCCAGATATTGCCAATATC-3′ and 5′-AAGTTTCCAATATGCTCAATTAAG-3′; Precore, 5′-GGTCTGTTCACCAGCACCAT-3′ and 5′-GGAAAGAAGTCAGAAGGCAA-3′; Core, 5′-CCGGAAAGCTTGAGCTCTTCTT-3′ and 5′-CACAGAATAGCTTGCCTGAGTG-3′; APOA2 5′-CAACTGTGCTACTCCTCACCAT-3′ and 5′-TGGAAGTACTGAGAAACCAGG C-3′; Total HBV RNA, 5′-GAGTGCTGTATGGTGAGGTG-3′ and 5′-TTTGGGGCATGGACATTGAC-3′. Quantification of HBV mRNAs (precore and pregenomic) was performed as we described recently 62 . Gene expression was normalized to that of GAPDH.…”

Understanding the antiviral effects of RNAi-based therapy in HBeAg-positive chronic hepatitis B infection

“…We model this (see model ( 5 )) as a constant reduction of the HBV DNA synthesis rate to , where is the ETV efficacy. Experimental studies in humanized mice have shown that serum HBV DNA declines in biphasic manner while HBV-infected cell are not lost in the first months following NA treatment initiation 46 , 47 . To account for the biphasic HBV DNA decay in the absence of infected cell killing, we assume that ETV has additional time-dependent inhibitory effects on intracellular HBV DNA synthesis and model it by decreasing further to , where is a constant and t is the time in days post ETV initiation.…”