scholar 引用：3
页数：11
发表时间：13 December 2017
发表刊物：Journal of Hepatology
作者：Congrong Niu, Li Li, ...,Simon P. Fletcher
Highlights:
- GS-9620 has no direct antiviral activity against HBV.
- Type I IFN induced by GS-9620 durably suppresses HBV without reducing cccDNA levels.
- GS-9620-induced cytokines enhance HBV antigen presentation.
- Established HBV infection does not modulate innate immune sensing or signaling.
Lay summary
GS-9620 is a drug currently being tested in clinical trials for the treatment of chronic hepatitis B virus (HBV) infection. GS-9620 has previously been shown to suppress HBV in various animal models, but the underlying antiviral mechanisms were not completely understood. In this study, we determined that GS-9620 does not directly activate antiviral pathways in human liver cells, but can induce pro- longed suppression of HBV via induction of an antiviral cytokine called interferon. However, interferon did not destroy the HBV genome, suggesting that other parts of the immune response (e.g. activation of immune cells that kill infected cells) also play an important role in the antiviral response to GS-9620.
摘要：
Background & Aims
GS-9620, an oral agonist of toll-like receptor 7 (TLR7), is in clinical development for the treatment of chronic hepatitis B (CHB). GS-9620 was previously shown to induce prolonged suppression of serum viral DNA and antigens in the woodchuck(土拨鼠) and chimpanzee(黑猩猩) models of CHB. Herein, we investigated the molecular mechanisms that contribute to the antiviral response to GS-9620 using in vitro models of hepatitis B virus (HBV) infection.
Methods
Cryopreserved(冷冻保存) primary human hepatocytes (PHH) and differentiated HepaRG (dHepaRG) cells were infected with HBV and treated with GS-9620, conditioned media from human peripheral blood mononuclear cells treated with GS-9620 (GS-9620 conditioned media [GS-9620-CM]), or other innate immune stimuli. The antiviral and transcriptional response to these agents was determined.
Results
GS-9620 had no antiviral activity in HBV-infected PHH, consistent with low level TLR7 mRNA expression in human hepatocytes. In contrast, GS-9620-CM induced prolonged reduction of HBV DNA, RNA, and antigen levels in PHH and dHepaRG cells via a type I interferon (IFN)-dependent mechanism. GS-9620-CM did not reduce covalently closed circular DNA (cccDNA) levels in either cell type. Transcriptional profiling demonstrated that GS-9620-CM strongly induced various HBV restriction factors – although not APOBEC3A or the Smc5/6 complex – and indicated that established HBV infection does not modulate innate immune sensing or signaling in cryopreserved PHH. GS-9620-CM also induced expression of immunoproteasome subunits and enhanced presentation of an immunodominant viral peptide in HBV-infected PHH.
Conclusions
Type I IFN induced by GS-9620 durably suppressed HBV in human hepatocytes without reducing cccDNA levels. Moreover, HBV antigen presentation was enhanced, suggesting additional components of the TLR7-induced immune response played a role in the antiviral response to GS-9620 in animal models of CHB.
Discussion：
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In summary, our data provide important insights into the mechanisms underlying the antiviral response to GS-9620 in animal models of CHB. In addition, this study suggests that established HBV infection does not actively inhibit innate immunity in our cell culture model. This has important implications for how HBV establishes chronicity, as well as for the therapeutic response to innate immune agonists such as GS- 9620.
Introduction：
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In the current study we investigated the molecular mecha- nisms responsible for the antiviral response to GS-9620 using in vitro models of HBV infection in cryopreserved primary human hepatocytes (PHH), as well as differentiated HepaRG (dHepaRG) cells.
正文组织架构：
1. Introduction
2. Materials and methods
2.1 Ethics statement
2.2 Additional materials and methods
2.3 Statistical analysis
3. Results
3.1 Cytokines induced by GS-9620 reduce HBV DNA, RNA and antigens, but do not alter cccDNA levels
3.2 GS-9620-induced cytokines inhibit HBV via a type I IFN- dependent mechanism
3.3 Established HBV infection does not significantly modulate the transcriptional response to GS-9620-induced cytokines
3.4 Established HBV infection does not significantly modulate the transcriptional response to various innate immune stimuli
3.5 GS-9620-induced cytokines strongly increase the expression of various HBV restriction factors, but not APOBEC3A or the Smc5/6 complex
3.6 Cytokines induced by GS-9620 enhance presentation of an immunodominant HBV peptide
4. Discussion
正文部分内容摘录：
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Data is expressed as mean ± standard error of the mean (SEM). Statistical significance was tested using a two-tailed t test (for two sample comparisons) or either one-way or two-way ANOVA with multiple comparison correction (for multiple compar- isons). A value of p <0.05 was considered significant.这篇paper没有涉及到RNAseq？有的
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RNA sequencing (RNA-Seq) are provided in the supplementary information.
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这一篇的机制和discussion中的分析都值得借鉴？
