CRISPR-Cas13b-mediated suppression of HBV replication and protein expression.

BACKGROUND & AIMS: New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression. METHODS: Cas13b CRISPR RNAs (crRNAs) were designed to target multiple regions of HBV pregenomic RNA. Mammalian cells transfected with replication competent wild-type HBV DNA of different genotypes, a HBV-expressing stable cell line, a HBV infection model and a hepatitis B surface antigen (HBsAg)-expressing stable cell line were transfected with PspCas13b-BFP (blue fluorescent protein) and crRNA plasmids, and the impact on HBV replication and protein expression was measured. Wild-type HBV DNA, PspCas13b-BFP and crRNA plasmids were simultaneously hydrodynamically injected into mice, and serum HBsAg was measured. PspCas13b mRNA and crRNA were also delivered to a HBsAg-expressing stable cell line via lipid nanoparticles and the impact on secreted HBsAg determined. RESULTS: Our HBV-targeting crRNAs strongly suppressed HBV replication and protein expression in mammalian cells by up to 96% (p <0.0001). HBV protein expression was also reduced in a HBV-expressing stable cell line and in the HBV infection model. CRISPR-Cas13b crRNAs reduced HBsAg expression by 50% (p <0.0001) in vivo. Lipid nanoparticle-encapsulated PspCas13b mRNA reduced secreted HBsAg by 87% (p = 0.0168) in a HBsAg-expressing stable cell line. CONCLUSIONS: Together, these results show that CRISPR-Cas13b can be programmed to specifically target and degrade HBV RNAs to reduce HBV replication and protein expression, demonstrating its potential as a novel therapeutic option for chronic HBV infection. IMPACT AND IMPLICATIONS: Owing to the limitations of current antiviral therapies for hepatitis B, there is an urgent need for new treatments that target multiple aspects of the HBV replication cycle to improve rates of functional cure. Here, we present CRISPR-Cas13b as a novel strategy to target HBV replication and protein expression, paving the way for its development as a potential new treatment option for patients living with chronic hepatitis B.

Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.

BACKGROUND & AIMS: Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system. METHODS: To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types. RESULTS: We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment. CONCLUSIONS: This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights. CLINICAL TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT02476617). IMPACT AND IMPLICATIONS: Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.

High end-of-treatment hepatitis B core-related antigen levels predict hepatitis flare after stopping nucleot(s)ide analogue therapy.

BACKGROUND AND AIMS: Accurate biomarkers to predict outcomes following discontinuation of nucleos(t)ide analogue (NA) therapy are needed. We evaluated serum hepatitis B core-related antigen (HBcrAg) level as a biomarker for predicting outcomes after NA discontinuation. METHODS: Patients with HBeAg-negative chronic hepatitis B (CHB) without cirrhosis were enrolled in a prospective trial evaluating clinical outcomes until 96 weeks after NA discontinuation. End of treatment (EOT) and off-treatment levels of serum HBcrAg, HBsAg, HBV RNA and HBV DNA were used to predict key clinical outcomes including hepatitis flare (ALT ≥5 × ULN and HBV DNA > 2000 IU/mL). The SCALE-B score was calculated for the purposes of model validation. RESULTS: HBcrAg was tested amongst 65 participants. The median age was 54 years, 54% were male and 83% were Asian. HBcrAg was detectable in 86% patients. HBcrAg level ≥4 log U/mL at EOT was predictive of hepatitis flare [8/10 (80%) vs. 17/55 (31%), p = .001]. The presence of either HBcrAg ≥4 log U/mL or detectable HBV RNA at EOT predicted for both biochemical relapse and hepatitis flare. The SCALE-B model at EOT predicted for virological relapse, biochemical relapse, hepatitis flare and HBsAg loss in this cohort. An increase in the serum HBcrAg level off-treatment was also associated with hepatitis flare. No participant with EOT HBcrAg level ≥4 log U/mL achieved HBsAg loss. CONCLUSIONS: High levels of serum HBcrAg predict for hepatitis flare after stopping NA therapy and low likelihood of HBsAg loss at week 96. People with high levels of serum HBcrAg are not suitable candidates for NA discontinuation.

Hepatitis B and Hepatitis C Virus Infection Promote Liver Fibrogenesis through a TGF-ß1-Induced OCT4/Nanog Pathway.

Hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection accelerates liver fibrosis progression compared with HBV or HCV monoinfection. Octamer binding transcription factor 4 (OCT4) and Nanog are direct targets of the profibrogenic TGF-ß1 signaling cascade. We leveraged a coculture model to monitor the effects of HBV and HCV coinfection on fibrogenesis in both sodium taurocholate cotransporting polypeptide-transfected Huh7.5.1 hepatoma cells and LX2 hepatic stellate cells (HSCs). We used CRISPR-Cas9 to knock out OCT4 and Nanog to evaluate their effects on HBV-, HCV-, or TGF-ß1-induced liver fibrogenesis. HBV/HCV coinfection and HBx, HBV preS2, HCV Core, and HCV NS2/3 overexpression increased TGF-ß1 mRNA levels in sodium taurocholate cotransporting polypeptide-Huh7.5.1 cells compared with controls. HBV/HCV coinfection further enhanced profibrogenic gene expression relative to HBV or HCV monoinfection. Coculture of HBV and HCV monoinfected or HBV/HCV coinfected hepatocytes with LX2 cells significantly increased profibrotic gene expression and LX2 cell invasion and migration. OCT4 and Nanog guide RNA independently suppressed HBV-, HCV-, HBV/HCV-, and TGF-ß1-induced α-SMA, TIMP-1, and Col1A1 expression and reduced Huh7.5.1, LX2, primary hepatocyte, and primary human HSC migratory capacity. OCT4/Nanog protein expression also correlated positively with fibrosis stage in liver biopsies from patients with chronic HBV or HCV infection. In conclusion, HBV and HCV independently and cooperatively promote liver fibrogenesis through a TGF-ß1-induced OCT4/Nanog-dependent pathway.

Eliminating hepatitis C in Australia: a novel model of hepatitis C testing and treatment for people who inject drugs at a medically supervised injecting facility.

OBJECTIVE: To evaluate the feasibility of testing and treating people who inject drugs at a supervised injecting facility for hepatitis C virus (HCV) infection. DESIGN: Retrospective cohort study. SETTING, PARTICIPANTS: People who inject drugs who attended the Melbourne supervised injecting facility, 30 June 2018 - 30 June 2020. MAIN OUTCOME MEASURES: Proportion of people tested for hepatitis C; proportions of people positive for anti-HCV antibody and HCV RNA, and of eligible people prescribed direct-acting antiviral (DAA) treatment; sustained virological response twelve weeks or more after treatment completion. RESULTS: Of 4649 people who attended the supervised injecting facility during 2018-20, 321 were tested for hepatitis C (7%); 279 were anti-HCV antibody-positive (87%), of whom 143 (51%) were also HCV RNA-positive. Sixty-four of 321 had previously been treated for hepatitis C (20%), 21 had clinically identified cirrhosis (7%), eight had hepatitis B infections (2%), and four had human immunodeficiency virus infections (1%). In multivariate analyses, people tested for hepatitis C were more likely than untested clients to report psychiatric illness (adjusted odds ratio [aOR], 9.65; 95% confidence interval [CI], 7.26-12.8), not have a fixed address (aOR, 1.59; 95% CI, 1.18-2.14), and to report significant alcohol use (aOR, 1.57; 95% CI, 1.06-2.32). The median number of injecting facility visits was larger for those tested for hepatitis C (101; interquartile range [IQR], 31-236) than for those not tested (20; IQR, 3-90). DAA treatment was prescribed for 126 of 143 HCV RNA-positive clients (88%); 41 of 54 with complete follow-up data were cured (76%). CONCLUSIONS: People who attend supervised injecting facilities can be tested and treated for hepatitis C on site. Models that provide streamlined, convenient hepatitis C care promote engagement with treatment in a group in which the prevalence of hepatitis C is high.

Australian consensus recommendations for the management of hepatitis B.

INTRODUCTION: The prevalence of hepatitis B virus (HBV) infection in Australia is nearly 1%. In certain well defined groups the prevalence is far greater, yet an estimated 27% of people living with HBV infection remain undiagnosed. Appropriate screening improves detection, increases opportunity for treatment, and ultimately reduces the significant morbidity and mortality associated with the development of liver fibrosis and hepatocellular carcinoma (HCC). MAIN RECOMMENDATIONS: This statement highlights important aspects of HBV infection management in Australia. There have been recent changes in nomenclature and understanding of natural history, as well as a newly defined upper limit of normal for liver tests that determine phase classification and threshold for antiviral treatment. As the main burden of hepatitis B in Australia is within migrant and Indigenous communities, early identification and management of people living with hepatitis B is essential to prevent adverse outcomes including liver cancer and cirrhosis. CHANGE IN MANAGEMENT AS A RESULT OF THIS GUIDELINE: These recommendations aim to raise awareness of the current management of hepatitis B in Australia. Critically, the timely identification of individuals living with hepatitis B, and where appropriate, commencement of antiviral therapy, can prevent the development of cirrhosis, HCC and mother-to-child transmission as well as hepatitis B reactivation in immunocompromised individuals. Recognising patient and viral factors that predispose to the development of cirrhosis and HCC will enable clinicians to risk-stratify and appropriately implement surveillance strategies to prevent these complications of hepatitis B.

Hepatitis B and pregnancy: understanding the experiences of care among pregnant women and recent mothers in metropolitan Melbourne.

BACKGROUND: Pregnant women are a priority group for hepatitis B testing. Guideline-based care during antenatal and post-partum periods aims to prevent mother-to-child transmission of hepatitis B virus and lower the risk of liver complications in mothers. This qualitative study explored knowledge of hepatitis B and experiences of hepatitis B related care among pregnant women and mothers. METHODS: Semi-structured interviews were conducted with thirteen women with hepatitis B who were attending antenatal or post-partum hepatitis B care. The interviews were thematically analysed to assess knowledge and understanding of hepatitis B. Participants were recruited from specialist clinics in metropolitan Melbourne between August 2019 and May 2020. RESULTS: Four major themes were identified from interviews: (1) knowledge and understanding of hepatitis B, (2) treatment pathways, (3) accessing hepatitis B related care, and (4) disclosing status to friends. Most participants displayed an understanding of hepatitis B transmission, including mother to child transmission. The main motivator of post-partum attendance was reassurance gained concerning their child's health. Sources of hepatitis B information included doctors, online information and family. Participants identified parents and siblings as sources of support and reported an unwillingness to disclose hepatitis B status to friends. CONCLUSIONS: Women attending antenatal or post-partum care reported having overall positive experiences, particularly regarding reassurance of their child's health, but displayed misconceptions around horizontal transmission. Knowledge gained from these results can contribute to the development of targeted models of care for pregnant women and mothers with young children to ensure their successful linkage to care.

Hepatitis C virus leaves an epigenetic signature post cure of infection by direct-acting antivirals.

The increasing worldwide prevalence of Hepatocellular carcinoma (HCC), characterized by resistance to conventional chemotherapy, poor prognosis and eventually mortality, place it as a prime target for new modes of prevention and treatment. Hepatitis C Virus (HCV) is the predominant risk factor for HCC in the US and Europe. Multiple epidemiological studies showed that sustained virological responses (SVR) following treatment with the powerful direct acting antivirals (DAAs), which have replaced interferon-based regimes, do not eliminate tumor development. We aimed to identify an HCV-specific pathogenic mechanism that persists post SVR following DAAs treatment. We demonstrate that HCV infection induces genome-wide epigenetic changes by performing chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) for histone post-translational modifications that are epigenetic markers for active and repressed chromatin. The changes in histone modifications correlate with reprogramed host gene expression and alter signaling pathways known to be associated with HCV life cycle and HCC. These epigenetic alterations require the presence of HCV RNA or/and expression of the viral proteins in the cells. Importantly, the epigenetic changes induced following infection persist as an "epigenetic signature" after virus eradication by DAAs treatment, as detected using in vitro HCV infection models. These observations led to the identification of an 8 gene signature that is associated with HCC development and demonstrate persistent epigenetic alterations in HCV infected and post SVR liver biopsy samples. The epigenetic signature was reverted in vitro by drugs that inhibit epigenetic modifying enzyme and by the EGFR inhibitor, Erlotinib. This epigenetic "scarring" of the genome, persisting following HCV eradication, suggest a novel mechanism for the persistent pathogenesis of HCV after its eradication by DAAs. Our study offers new avenues for prevention of the persistent oncogenic effects of chronic hepatitis infections using specific drugs to revert the epigenetic changes to the genome.

A qualitative exploration of enablers for hepatitis B clinical management among ethnic Chinese in Australia.

An estimated 18% of people living with chronic hepatitis B (CHB) in Australia were born in China. While guideline-based care, including regular clinical monitoring and timely treatment, prevent CHB-related cirrhosis, cancer and deaths, over three-quarters of people with CHB do not receive guideline-based care in Australia. This qualitative study aimed to identify enablers to engagement in CHB clinical management among ethnic Chinese people attending specialist care. Participants self-identified as of Chinese ethnicity and who attended specialist care for CHB clinical management were interviewed in Melbourne in 2019 (n = 30). Semi-structured interviews covered experiences of diagnosis and engagement in clinical management services, and advice for people living with CHB. Interviews were recorded with consent; data were transcribed verbatim and thematically analysed. Receiving clear information about the availability of treatment and/or the necessity of long-term clinical management were the main enablers for participants to engage in CHB clinical management. Additional enablers identified to maintain regular clinical monitoring included understanding CHB increases risks of cirrhosis and liver cancer, using viral load indicators to visualize disease status in patient-doctor communication; expectations from family, peer group and medical professionals; use of a patient recall system; availability of interpreters or multilingual doctors; and largely subsidized healthcare services. In conclusion, to support people attending clinical management for CHB, a holistic response from community, healthcare providers and the public health sector is required. There are needs for public health programmes directed to communicate (i) CHB-related complications; (ii) availability of effective and cheap treatment; and that (iii) long-term engagement with clinical management and its benefits.

The risk of hepatitis C virus recurrence in hepatitis C virus-infected patients treated with direct-acting antivirals after achieving a sustained virological response: A comprehensive analysis.

BACKGROUND & AIMS: The risk for hepatitis C virus (HCV) recurrence persists after HCV eradication with direct-acting antivirals (DAAs), particularly in patients with ongoing high-risk behaviours. Our aim was to assess the risk of HCV recurrence (late relapse and/or reinfection) post-sustained virological response (SVR). METHODS: We searched the literature for studies reporting HCV recurrence rates post-SVR in PubMed, Web of Science and the Cochrane Library. Identified publications were divided into groups based on patient risk for HCV reinfection: low-risk HCV mono-infection, high-risk HCV mono-infection and a human immunodeficiency virus (HIV)/HCV coinfection. The HCV recurrence rate for each study was calculated by using events divided by the person-years of follow-up (PYFU). HCV recurrence was defined as confirmed, detectable HCV RNA post-SVR. RESULTS: In the 16 studies of low-risk patients, the pooled recurrence rate was 0.89/1000 PYFU (95% confidence interval [CI], 0.16-2.03). For the 19 studies of high-risk patients, the pooled recurrence rate was 29.37/1000 PYFU (95% CI, 15.54-46.91). For the eight studies of HIV/HCV-coinfected patients, the pooled recurrence rate was 23.25/1000 PYFU (95% CI, 4.24-53.39). The higher pooled estimates of recurrence in the high-risk and HIV/HCV-coinfected populations were predominantly driven by an increase in reinfection rather than late relapse. CONCLUSIONS: The HCV recurrence risk after achieving SVR with all-oral DAAs therapy is low, and the risk of HCV recurrence in high-risk and HIV/HCV-coinfected populations was driven by an increase in reinfection rather than late relapse.

Helicobacter pylori antimicrobial resistance in Melbourne, Australia. Time to review therapeutic guidelines?

BACKGROUND: Antimicrobial resistance (AMR) in Helicobacter pylori is a global concern. The AMR data to inform the Australian Therapeutic Guidelines are based on data over 20 years old. AIMS: To evaluate the frequency of AMR in H. pylori isolates from gastric biopsy specimens received in our laboratory in Melbourne, Australia. To review the literature on resistance rates in Australia and compare historic data. METHODS: A retrospective, observational study summarising AMR rates in all H. pylori isolates from our laboratory from 2015 to June 2020. Microbiology laboratory in metropolitan Melbourne, Australia, receiving referrals from private hospitals, gastroenterology clinics and endoscopy suites. Population minimum inhibitory concentration distributions and frequency of resistance to clarithromycin, amoxicillin, metronidazole and tetracycline in H. pylori isolates. RESULTS: Three hundred and eighty-six H. pylori isolates with susceptibility testing data were identified. The frequency of resistance in this cohort was: clarithromycin 89.9%, amoxicillin 23.5%, metronidazole 66.1% and tetracycline 4.4%. Comparison with historical data may suggest increasing AMR rates in Australia. The main limitation is the lack of treatment history to correlate AMR results. CONCLUSIONS: Definitive conclusions from this cohort cannot be made, but trends suggest rising levels of primary H. pylori AMR rates in Australia. This has important implications for empirical treatment decision making and treatment outcomes. Primary H. pylori AMR requires dedicated studies and current Australian therapeutic guideline recommendations may require re-evaluation. We propose considerations for improving the management of H. pylori in Australia. A centralised public health approach to H. pylori AMR surveillance should be established.

Telehealth model of care for outpatient inflammatory bowel disease care in the setting of the COVID-19 pandemic.

BACKGROUND: Advances in inflammatory bowel disease (IBD) monitoring, greater number of available treatments and a shift towards tight disease control, IBD care has become more dynamic with regular follow ups. AIMS: We assessed the impacts of the COVID-19 pandemic on outpatient IBD patient care at a tertiary centre in Melbourne. More specifically, we assessed patient satisfaction with a telehealth model of care, failure to attend rates at IBD clinics and work absenteeism prior to and during the pandemic. METHODS: We conducted a retrospective, qualitative analysis to assess our aims through an online survey. We invited patients who attended an IBD outpatient clinic from April to June 2020 to participate. This study was conducted at a single, tertiary referral hospital in Melbourne. The key data points that we analysed were patient satisfaction with a telehealth model of care and the effect of telehealth clinics on work absenteeism. RESULTS: One hundred and nineteen (88.1%) patients were 'satisfied' or 'very satisfied' with the care received in the telehealth clinic. Eighty-four (60.4%) patients reported needing to take time off work to attend a face-to-face appointment, compared to 29 (20.9%) patients who needed to take time off work to attend telehealth appointments (P < 0.001). Clinic non-attendance rates were similar prior to and during the pandemic with rates of 11.4% and 10.4% respectively (P = 0.840). CONCLUSIONS: Patients report high levels of satisfaction with a telehealth model of care during the COVID-19 pandemic, with clinic attendance rates not being affected. Telehealth appointments significantly reduced work absenteeism when compared to traditional face-to-face clinics.

Hepatitis B-related outcomes following direct-acting antiviral therapy in Taiwanese patients with chronic HBV/HCV co-infection.

BACKGROUND & AIMS: The outcome of HBV infection, including the dynamics of HBsAg and HBV virological reactivation, among patients coinfected with HCV receiving direct-acting antivirals (DAAs) remains unclear. Thus, we aimed to analyze HBV-related outcomes in these patients. METHODS: Serial HBsAg and HBV DNA levels were measured in 79 HBV/HCV-coinfected patients receiving DAAs (13 receiving anti-HBV nucleot(s)ide analog [NUC] therapy simultaneously). The endpoints included HBsAg dynamics and seroclearance, HBV reactivation (HBV DNA >1 log increase or >100 IU/ml if undetectable at baseline) and HBV-related clinical reactivation. RESULTS: HBsAg levels declined from a median of 73.3 IU/ml at baseline to 16.2 IU/ml at the end-of-DAA treatment and increased to 94.1 IU/ml at 12 months post-treatment. During a mean 11.1-months of follow-up, 8 (10.1%) patients experienced HBsAg seroclearance and 30 (38.0%) HBV reactivation (12-month cumulative incidence, 10.3% and 40.4%, respectively). Patients with pre-treatment HBsAg ≤10 IU/ml had a significantly higher rate of HBsAg seroclearance (hazard ratio [HR] 8.52; 95% CI 1.048-69.312) and lower risk of HBV reactivation than those with pre-treatment HBsAg >10 IU/ml (HR 2.88; 95% CI 1.057-7.844) in multivariate analyses. Six patients (4 cirrhotics) not receiving NUC therapy experienced HBV-related clinical reactivation; 3 of the 4 cirrhotics developed liver failure and 2 died despite immediate NUC therapy. Compared to untreated HBV-monoinfected patients, HBV/HCV-coinfected patients without NUC prophylaxis had a similar rate of HBsAg seroclearance, but a significantly higher risk of HBV reactivation following DAA therapy (HR 6.59; 95% CI 2.488-17.432). CONCLUSIONS: DAA-treated HBV/HCV-coinfected patients had significantly higher rates of HBV seroclearance, particularly among those with low pre-treatment HBsAg titer, but were at higher risk of HBV reactivation, particularly among those with higher pre-treatment HBsAg titer. Prophylactic anti-HBV therapy is essential for cirrhotic patients, irrespective of baseline HBV DNA levels. LAY SUMMARY: We studied outcomes relating to hepatitis B virus (HBV) in patients coinfected with both hepatitis B and C. Patients receiving direct-acting antiviral treatment for hepatitis C were more likely to experience seroclearance (or functional cure of HBV), but were also more likely to experience HBV reactivation, which can lead to hepatitis, liver failure and death. In coinfected cirrhotic patients being treated for HCV, prophylactic treatment for HBV is mandatory.

A Long Noncoding RNA Regulates Hepatitis C Virus Infection Through Interferon Alpha-Inducible Protein 6.

Long noncoding RNAs (lncRNAs) play a critical role in the regulation of many important cellular processes. However, the mechanisms by which lncRNAs regulate viral infection and host immune responses are not well understood. We sought to explore lncRNA regulation of hepatitis C virus (HCV) infection and interferon response. We performed RNA sequencing (RNAseq) in Huh7.5.1 cells with or without interferon alpha (IFNα) treatment. Clustered regularly interspaced short palindromic repeats/Cas9 guide RNA (gRNA) was used to knock out selected genes. The promoter clones were constructed, and the activity of related interferon-stimulated genes (ISGs) were detected by the secrete-pair dual luminescence assay. We constructed the full-length and four deletion mutants of an interferon-induced lncRNA RP11-288L9.4 (lncRNA-IFI6) based on predicted secondary structure. Selected gene mRNAs and their proteins, together with HCV infection, in Huh7.5.1 cells and primary human hepatocytes (PHHs) were monitored by quantitative real-time PCR (qRT-PCR) and western blot. We obtained 7,901 lncRNAs from RNAseq. A total of 1,062 host-encoded lncRNAs were significantly differentially regulated by IFNα treatment. We found that lncRNA-IFI6 gRNA significantly inhibited HCV infection compared with negative gRNA control. The expression of the antiviral ISG IFI6 was significantly increased following lncRNA-IFI6 gRNA editing compared with negative gRNA control in Japanese fulminant hepatitis 1 (JFH1)-infected Huh7.5.1 cells and PHHs. We observed that lncRNA-IFI6 regulation of HCV was independent of Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling. lncRNA-IFI6 negatively regulated IFI6 promoter function through histone modification. Overexpression of the truncated spatial domain or full-length lncRNA-IFI6 inhibited IFI6 expression and increased HCV replication. Conclusion: A lncRNA, lncRNA-IFI6, regulates antiviral innate immunity in the JFH1 HCV infection model. lncRNA-IFI6 regulates HCV infection independently of the JAK-STAT pathway. lncRNA-IFI6 exerts its regulatory function via promoter activation and histone modification of IFI6 through its spatial domain.

Hepatitis C Virus Infection in Pregnancy: An Update.

Parenteral transmission is the major route of hepatitis C virus transmission in adults; however, vertical transmission is most common in children. There are several factors that have been shown to be associated with vertical transmission of hepatitis C virus, including hepatitis C virus RNA, human immunodeficiency virus coinfection, and peripheral blood mononuclear cell infection. As there is no effective vaccine to prevent hepatitis C virus infection, and there are no human data describing the safety of the new direct acting antiviral agents in pregnancy, the only preventive strategy for vertical transmission is to treat the hepatitis C virus infection before becoming pregnant. Direct acting antiviral agents are interferon-free, and many are also ribavirin-free. Based on animal studies, sofosbuvir plus ledipasvir may be the best safety profile during pregnancy for now; however, it is too early to recommend treating hepatitis C virus-infected pregnant women with these direct acting antiviral agents currently.

MicroRNA 130a Regulates both Hepatitis C Virus and Hepatitis B Virus Replication through a Central Metabolic Pathway.

Hepatitis C virus (HCV) infection has been shown to regulate microRNA 130a (miR-130a) in patient biopsy specimens and in cultured cells. We sought to identify miR-130a target genes and to explore the mechanisms by which miR-130a regulates HCV and hepatitis B virus (HBV) replication. We used bioinformatics software, including miRanda, TargetScan, PITA, and RNAhybrid, to predict potential miR-130a target genes. miR-130a and its target genes were overexpressed or were knocked down by use of small interfering RNA (siRNA) or clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 guide RNA (gRNA). Selected gene mRNAs and their proteins, together with HCV replication in OR6 cells, HCV JFH1-infected Huh7.5.1 cells, and HCV JFH1-infected primary human hepatocytes (PHHs) and HBV replication in HepAD38 cells, HBV-infected NTCP-Huh7.5.1 cells, and HBV-infected PHHs, were measured by quantitative reverse transcription-PCR (qRT-PCR) and Western blotting, respectively. We selected 116 predicted target genes whose expression was related to viral pathogenesis or immunity for qPCR validation. Of these, the gene encoding pyruvate kinase in liver and red blood cell (PKLR) was confirmed to be regulated by miR-130a overexpression. miR-130a overexpression (via a mimic) knocked down PKLR mRNA and protein levels. A miR-130a inhibitor and gRNA increased PKLR expression, HCV replication, and HBV replication, while miR-130a gRNA and PKLR overexpression increased HCV and HBV replication. Supplemental pyruvate increased HCV and HBV replication and rescued the inhibition of HCV and HBV replication by the miR-130a mimic and PKLR knockdown. We concluded that miR-130a regulates HCV and HBV replication through its targeting of PKLR and subsequent pyruvate production. Our data provide novel insights into key metabolic enzymatic pathway steps regulated by miR-130a, including the steps involving PKLR and pyruvate, which are subverted by HCV and HBV replication.IMPORTANCE We identified that miR-130a regulates the target gene PKLR and its subsequent effect on pyruvate production. Pyruvate is a key intermediate in several metabolic pathways, and we identified that pyruvate plays a key role in regulation of HCV and HBV replication. This previously unrecognized, miRNA-regulated antiviral mechanism has implications for the development of host-directed strategies to interrupt the viral life cycle and prevent establishment of persistent infection for HCV, HBV, and potentially other viral infections.

Dynamic changes in innate immune responses during direct-acting antiviral therapy for HCV infection.

The role of the endogenous interferon (IFN) system has been well characterized during IFN-based therapy for chronic hepatitis C virus (HCV) infection; less is known for direct-acting antivirals (DAAs). In this phase 3b open-label study, we assessed changes in IFN-stimulated genes (ISGs) in non-cirrhotic treatment-naïve or pegIFN/RBV-experienced HCV-GT1a-infected patients receiving paritaprevir/ritonavir/ombitasvir + dasabuvir + ribavirin (PrOD + R) for 12 weeks. ISG expression was quantified from peripheral blood mononuclear cells at baseline, treatment weeks (TW)2, TW4, TW8, end of treatment (EOT) and at post-treatment week 12. Paired sera were used to assess IFN-α/IFN-related chemokines/cytokines. Twenty-five patients were enrolled. Overall sustained virologic response (SVR)12 was 92% (no virologic failure [VF]) and 100% for those completing the study protocol. Two patients were excluded from the ISG analysis due to lack of post-treatment samples. The majority of ISGs were downregulated at TW2-TW4 (nadir TW4); however, a relative increase was observed at TW8-EOT, although levels were lower than baseline. This downregulation was accompanied by increases in IFN-α/IFN-related chemokines, a finding not observed with TH 1/2-related cytokines. Following SVR, ISG expression returned to TW2 levels. In conclusion, PrOD + R for 12 weeks was well-tolerated with no VF. Our data demonstrate dynamic alterations in innate immune profiles during highly potent IFN-free DAA therapy. The downregulation of ISG post-therapy suggests reversal of the "exhausted" ISG phenotype following SVR, and the rise in ISGs and IFN-α/IFN-responsive chemokines late during therapy suggests resetting of IFN responsiveness that may be relevant in determining duration of or immunological sequelae from DAA therapy, including HBV reactivation.

Tyrosine kinase SYK is a potential therapeutic target for liver fibrosis.

Spleen tyrosine kinase (SYK) plays a critical role in immune cell signaling pathways and has been reported as a biomarker for human hepatocellular carcinoma (HCC). We sought to investigate the mechanism by which SYK promotes liver fibrosis and to evaluate SYK as a therapeutic target for liver fibrosis. We evaluated the cellular localization of SYK and the association between SYK expression and liver fibrogenesis in normal, hepatitis B virus (HBV)-infected, hepatitis C virus (HCV)-infected and non-alcoholic steatohepatitis (NASH) liver tissue (n=36, 127, 22 and 30, respectively). A polymerase chain reaction (PCR) array was used to detect the changes in transcription factor (TF) expression in hepatic stellate cells (HSCs) with SYK knockdown. The effects of SYK antagonism on liver fibrogenesis were studied in LX-2 cells, TWNT-4 cells, primary human HSCs, and three progressive fibrosis/cirrhosis animal models, including a CCL4 mouse model, and diethylnitrosamine (DEN) and bile duct ligation (BDL) rat models. We found that SYK protein in HSCs and hepatocytes correlated positively with liver fibrosis stage in human liver tissue. HBV or HCV infection significantly increased SYK and cytokine expression in hepatocytes. Increasing cytokine production further induced SYK expression and fibrosis-related gene transcription in HSCs. Up-regulated SYK in HSCs promoted HSC activation by increasing the expression of specific TFs related to activation of HSCs. SYK antagonism effectively suppressed liver fibrosis via inhibition of HSC activation, and decreased obstructive jaundice and reduced HCC development in animal models. Conclusion: SYK promotes liver fibrosis via activation of HSCs and is an attractive potential therapeutic target for liver fibrosis and prevention of HCC development. (Hepatology 2018).

Macrophage Activation Marker Soluble CD163 Is a Dynamic Marker of Liver Fibrogenesis in Human Immunodeficiency Virus/Hepatitis C Virus Coinfection.

Background: Coinfection with human immunodeficiency virus (HIV) accelerates hepatitis C virus (HCV)-related liver fibrosis. Macrophages are triggered during both viral infections and are critical in liver inflammation/fibrogenesis. Liver fibrosis strongly associates with serum soluble CD163 (sCD163, a macrophage activation marker); comprehensive evaluation in HIV/HCV coinfection is lacking. Methods: We retrospectively analyzed sCD163 (enzyme-linked immunosorbent assay) and hepatic CD163 (immunofluorescent CD163/CD68 costaining) in patients infected with HIV/HCV, HCV, or HIV, pre- and post-antiviral therapy. Results: sCD163 was significantly higher in HIV/HCV compared to either monoinfection, and decreased following successful antiviral therapy, although did not fully normalize. In HIV/HCV, sCD163 was associated with necroinflammation, Ishak fibrosis scores, and noninvasive fibrosis scores. We observed a novel trend whereby sCD163 levels progressively increase with increasing Ishak fibrosis score, peaking at stage 4, above which levels plateaued. Periportal CD163+ macrophage frequency was also higher with increasing fibrosis score. When stratified by fibrosis stage, sCD163 levels were higher in HIV/HCV than HCV but only in individuals with mild to moderate fibrosis. Conclusions: In HIV/HCV, increasing sCD163 levels accompanied periportal CD163+ macrophage enrichment in mild to moderate fibrosis, but not in established cirrhosis, suggesting that sCD163 is a dynamic biomarker of fibrogenesis rather than accumulated fibrosis. Our findings implicate HIV-related macrophage activation in accelerated fibrosis progression in HIV/HCV coinfection.