The interferon-stimulated gene viperin has been shown to have antiviral activity against hepatitis C virus (HCV) in the context of the HCV replicon, although the molecular mechanisms responsible are not well understood. Here we demonstrate that viperin plays an integral part in the ability of interferon to limit replication of cell culture derived HCV (JFH-1) that accurately reflects the complete viral life cycle. Using confocal microscopy and Fluorescence Resonance Energy Transfer (FRET) analysis we demonstrate that viperin localizes and interacts with HCV NS5A at the lipid droplet interface. In addition viperin also associates with NS5A and the pro-viral cellular factor, VAP-A at the HCV replication complex. The ability of viperin to limit HCV replication was dependent on residues within the C-terminus as well as an N-terminal amphipathic helix. Removal of the amphipathic helix redirected viperin from the cytosolic face of the ER and the lipid droplet to a homogenous cytoplasmic distribution, coinciding with a loss of antiviral effect. C-terminal viperin mutants still localized to the lipid droplet interface and replication complexes but did not interact with NS5A proteins as determined by FRET analysis. In conclusion we propose that viperin interacts with NS5A and the host factor VAP-A to limit HCV replication at the replication complex. This highlights the complexity of host control of viral replication by interferon stimulated gene expression.

The host protein viperin is an interferon stimulated gene (ISG) that is up-regulated during a number of viral infections. In this study we have shown that dengue virus type-2 (DENV-2) infection significantly induced viperin, co-incident with production of viral RNA and via a mechanism requiring retinoic acid-inducible gene I (RIG-I). Viperin did not inhibit DENV-2 entry but DENV-2 RNA and infectious virus release was inhibited in viperin expressing cells. Conversely, DENV-2 replicated to higher tires earlier in viperin shRNA expressing cells. The anti-DENV effect of viperin was mediated by residues within the C-terminal 17 amino acids of viperin and did not require the N-terminal residues, including the helix domain, leucine zipper and S-adenosylmethionine (SAM) motifs known to be involved in viperin intracellular membrane association. Viperin showed co-localisation with lipid droplet markers, and was co-localised and interacted with DENV-2 capsid (CA), NS3 and viral RNA. The ability of viperin to interact with DENV-2 NS3 was associated with its anti-viral activity, while co-localisation of viperin with lipid droplets was not. Thus, DENV-2 infection induces viperin which has anti-viral properties residing in the C-terminal region of the protein that act to restrict early DENV-2 RNA production/accumulation, potentially via interaction of viperin with DENV-2 NS3 and replication complexes. These anti-DENV-2 actions of viperin show both contrasts and similarities with other described anti-viral mechanisms of viperin action and highlight the diverse nature of this unique anti-viral host protein.

Background: Interferon-induced transmembrane (IFITM) proteins limit a broad range of RNA viruses. Results: Tyrosine phosphorylation of IFITM2 and IFITM3, and S-palmitoylation of the IFITM proteins, are crucial for antihepatitis C virus (HCV) activity. Conclusion: IFITM2 and IFITM3 are able to limit HCV infection by targeting the late entry stages of the virus. Significance: IFITM proteins inhibit HCV at early and late stages of entry.

Host factors play an important role in all facets of the hepatitis C virus (HCV) life cycle and one such host factor is signal transducer and activator of transcription 3 (STAT3). The HCV core protein has been shown to directly interact with and activate STAT3, while oxidative stress generated during HCV replication in a replicon-based model also induced STAT3 activation. However, despite these findings the precise role of STAT3 in the HCV life cycle remains unknown. We have established that STAT3 is actively phosphorylated in the presence of replicating HCV. Furthermore, expression of a constitutively active form of STAT3 leads to marked increases in HCV replication, whereas, conversely, chemical inhibition and small interfering RNA (siRNA) knockdown of STAT3 leads to significant decreases in HCV RNA levels. This strongly implicates STAT3 as a proviral host factor. As STAT3 is a transcription factor, up-regulation of a distinct set of STAT3-dependent genes may create an environment that is favorable for HCV replication. However, STAT3 has recently been demonstrated to positively regulate microtubule (MT) dynamics, by way of a direct sequestration of the MT depolymerizing protein Stathmin 1 (STMN1), and we provide evidence that STAT3 may exert its effect on the HCV life cycle by way of positive regulation of MT dynamics. Conclusion: We have demonstrated that STAT3 plays a role in the life cycle of HCV and have clarified the role of STAT3 as a proviral host factor. (HEPATOLOGY 2013;58:1558-1568

Background: Liver disease and hepatocellular carcinoma (HCC) are important contributors to the mortality gap between Indigenous and non-Indigenous Australians. However, there is a lack of population based high quality data assessing the differences in HCC epidemiology and outcomes according to Indigenous status. The aim of this study was therefore to perform a large epidemiological study of HCC investigating differences between Indigenous and non-Indigenous Australians with HCC.Methods: Study design was a retrospective cohort study. Data linkage methodology was used to link data from cancer registries with hospital separation summaries across three Australian jurisdictions during 20 0 0-2017. Cumulative survival (Kaplan-Meier) and the differences in survival (Multivariable Coxregression) by Indigenous status were assessed.Findings: A total of 229 Indigenous and 3587 non-Indigenous HCC cases were included in the analyses. Significant epidemiological differences identified for Indigenous HCC cases included younger age at onset, higher proportion of females, higher rurality, lower socioeconomic status, and higher comorbidity burden (all p < 0.001). The distribution of cofactors was also significantly different for Indigenous Australians including higher prevalence of alcohol misuse, hepatitis B, and diabetes and more frequent presence of multiple HCC cofactors (all p < 0.001). Indigenous Australians received curative HCC therapies less frequently (6.6% vs. 14.5%, p < 0.001) and had poorer 5-year survival (10.0% vs. 17.3%, p < 0.001; unadjusted hazard ratio (HR) = 1.42 96%CI 1.21-1.65) compared to non-Indigenous Australians. The strength of the association between indigenous status and survival was weaker and statistically non-significant after adjusting for rurality, comorbidity burden and lack of curative therapy (adjusted-HR = 1.20 95%CI 0.97-1.47) Interpretation: Such data provide a call to action to help design and implement health literacy, liver management and HCC surveillance programs for Indigenous people to help close the liver cancer mortality gap.

Background and aims Screening for latent tuberculosis infection (LTBI) is recommended prior to solid organ transplantation. Interferon‐gamma release assays (IGRAs) are the most widely used test for LTBI screening; however, assessment of IGRA performance in patients with end‐stage liver disease is limited. The purpose of this study was to evaluate the prevalence and predictors of indeterminate (INDT) IGRA results in liver transplantation candidates. Methods Between March 2011 and May 2018, we retrospectively analyzed 155 patients undergoing liver transplantation assessment, who underwent IGRA testing (Quantiferon‐TB Gold, QFT‐G) to exclude LTBI. Characteristics of patients, including age, gender, etiology of liver disease, MELD score, and absolute lymphocyte counts, were compared by QFT‐G result (determinate vs INDT). Results Of the 155 patients screened, the rate of positive, negative, and INDT results were 5.2%, 69.8%, and 25%, respectively. The only variable independently associated with an indeterminate test on multivariate analysis was MELD score (odds ratio = 1.07, 95% CI = 1.01‐1.14 per unit increase; P = 0.014). In 95% of INDT tests, both TB antigen tube and the positive control tube were negative and repeat testing gave the same indeterminate result, suggestive of anergy rather than laboratory error. Conclusions Our study suggests a high rate of INDT IGRA results during screening of liver transplant candidates for LTBI, associated with severity of liver disease and anergy. Because of the high rate of INDT QFT‐G testing in this setting, individualized risk assessment is required including a thorough assessment of clinical risk factors and knowledge of local TB prevalence.

Patients with cirrhosis have increased morbidity from hepatitis A virus (HAV) and hepatitis B virus (HBV) infections, and vaccination against these infections is an important standard of care. However, vaccination in patients with cirrhosis is hindered by immune dysfunction and there is limited high-quality literature available. The aim of this work therefore was to compare immune responses of standard dose (SD) with high-dose accelerated (HDA) vaccination in cirrhotic patients.

Cirrhosis of the liver is increasing, with growing patient numbers in hospital outpatient departments, as well as increasing admissions due to decompensated liver disease. Decompensated cirrhosis of the liver is a common and debilitating illness causing disability, readmissions to hospital, and decreased quality of life, and can lead to liver cancer. The advent of the chronic liver disease nurse (CLDN) position in our hospital in 2009 was the first role in Australia dedicated to providing care to patients with cirrhosis. The role incorporates the care of patients with stable compensated disease, case management of patients with complications of decompensated disease, and hepatocellular carcinoma coordination. After a pilot randomized controlled trial and almost 10 years of service, this article describes the role of the CLDN and presents key performance indicators that will assist other centers considering introducing the role or elements of it into their service.