How Hepatitis C Virus Research Articles

Hepatitis C virus eradication decreases the risks of liver cirrhosis and cirrhosis-related complications (Taiwanese chronic hepatitis C cohort).

It is currently unknown how hepatitis C virus (HCV) eradication with pegylated interferon and ribavirin (PR) therapy affects the incidence of new-onset liver cirrhosis (LC) in patients without cirrhosis and the incidence of decompensated liver disease (DLD) or hepatocellular carcinoma (HCC) in patients with cirrhosis. Taiwanese chronic hepatitis C cohort (T-COACH) is a nationwide HCV registry cohort from 23 hospitals in Taiwan recruited between 2003 and 2015. This study enrolled 10693 patients with chronic hepatitis C (CHC), linked to the Taiwan National Health Insurance Research Database, receiving PR therapy for at least 4weeks for new-onset LC and liver-related complications (DLD or HCC). Of the 10693 patients, 1372 (12.8%) patients had LC, and the mean age was 54.0±11.4years. The mean follow-up duration was 4.38±2.79years, with overall 46798 person-years. The 10-year cumulative incidence rates of new-onset LC were 5.0% (95% confidence interval [CI]: 3.2-7.7) in patients without cirrhosis with a sustained virologic response (SVR) and 21.9% (95% CI: 13.4-32.4) in those without SVR (hazard ratio [HR]: 0.22, P<0.001). The 10-year cumulative incidence rates of liver-related complications were 21.4% (95% CI: 11.1-37.2) in patients with cirrhosis with SVR and 47.0% (95% CI: 11.1-86.0) in those without SVR after adjustment for age, sex, and competing mortality (HR: 0.52, P<0.001). Hepatitis C virus eradication with PR therapy decreased the incidence of new-onset LC in noncirrhotic patients and the incidence of liver-related complications in cirrhotic patients with CHC.

Interactive Impacts from Hepatitis C Virus Infection and Mixed Cryoglobulinemia on Complement Levels.

How hepatitis C virus (HCV) infection and mixed cryoglobulinemia interactively affect complement levels remains elusive, and we aimed to elucidate it. A prospective cohort study of 678 consecutive chronic HCV-infected (CHC) patients was conducted. Of 678, 438 had completed a course of anti-HCV therapy and 362 had achieved a sustained virological response (SVR). The baseline and 24-week post-therapy variables including complement levels and mixed cryoglobulinemia status were surveyed. At baseline, lower complement component 3 (C3) and component 4 (C4) levels were noted in patients with than those without mixed cryoglobulinemia. The differences between pre-therapy (in 678 CHC patients) and 24-week post-therapy (in 362 SVR patients) factors associated with C3 levels were interferon λ3 (IFNL3) genotype, triglycerides, cirrhosis, and estimated glomerular filtration rate; the different associations with C4 levels were cirrhosis, sex and high sensitivity C-reactive protein. Compared with baseline, SVR patients without pre- and post-therapy mixed cryoglobulinemia had increased C3 levels, and SVR patients with pre-therapy mixed cryoglobulinemia had increased C4 levels. Lower C3 levels were noted in SVR patients with than those without post-therapy mixed cryoglobulinemia. HCV might affect C3 levels through IFNL3 genotype, triglycerides, cirrhosis, and renal function; and affect C4 with a link to sex, inflammation, and cirrhosis. That C3 levels decreased in CHC patients without mixed cryoglobulinemia or in SVR patients with post-therapy mixed cryoglobulinemia, and C4 levels decreased in CHC patients with mixed cryoglobulinemia, suggested that mixed cryoglobulinemia and HCV infection antagonistically and synergistically decrease C3 and C4 levels, respectively.

Liver steatosis and dyslipidemia after HCV eradication by direct acting antiviral agents are synergistic risks of atherosclerosis

AimWe comprehensively analyzed how hepatitis C virus (HCV) eradication by interferon (IFN)-free direct-acting-antiviral-agents (DAAs) affects liver steatosis and atherogenic risk.MethodsPatients treated with IFN-free-DAAs who underwent transient elastography before and at 24-weeks post-treatment, including controlled attenuation parameter (CAP), and achieved sustained viral response (SVR) were enrolled. The association between changes in liver steatosis, lipid-metabolism, and genetic and clinical factors was analyzed.ResultsA total of 117 patients were included. The mean CAP and low-density lipoprotein cholesterol (LDL-C) levels were significantly elevated at SVR24. However, baseline LDL-C and CAP values were significantly negatively correlated with changes in these values after HCV eradication, indicating that in patients with high baseline values, the values generally decreased after HCV eradication. Mean small-dense LDL-C (sdLDL-C), which has greater atherogenic potential, was significantly elevated only in patients with both dyslipidemia (LDL-C >140 mg/dL) and liver steatosis (CAP >248 dB/m) at SVR24. Those patients had significant higher baseline BMI, LDL-C, and total-cholesterol levels.ConclusionsGenerally, successful HCV eradication by IFN-free-DAAs decreases CAP and LDL-C in patients with high baseline values. However, elevated LDL-C was accompanied with elevated sdLDL-C only in patients with liver steatosis and dyslipidemia at SVR24; therefore, those patients may require closer monitoring.

Correction: Hepatitis C virus NS4B induces the degradation of TRIF to inhibit TLR3-mediated interferon signaling pathway.

[This corrects the article DOI: 10.1371/journal.ppat.1007075.].

Hepatitis C virus NS4B induces the degradation of TRIF to inhibit TLR3-mediated interferon signaling pathway.

Toll-like receptor 3 (TLR3) senses dsRNA intermediates produced during RNA virus replication to activate innate immune signaling pathways through adaptor protein TRIF. Many viruses have evolved strategies to block TLR3-mediated interferon signaling via targeting TRIF. Here we studied how hepatitis C virus (HCV) antagonizes the TLR3-mediated interferon signaling. We found that HCV-encoded NS4B protein inhibited TLR3-mediated interferon signaling by down-regulating TRIF protein level. Mechanism studies indicated that the downregulation of TRIF by NS4B was dependent on caspase8. NS4B transfection or HCV infection can activate caspase8 to promote TRIF degradation, leading to suppression of TLR3-mediated interferon signaling. Knockout of caspase8 can prevent TRIF degradation triggered by NS4B, thereby enhancing the TLR3-mediated interferon signaling activation in response to HCV infection. In conclusion, our work revealed a new mechanism for HCV to evade innate immune response by blocking the TLR3-mediated interferon signaling via NS4B-induced TRIF degradation.

Recovery of lipid metabolic alterations in hepatitis C patients after viral clearance: Incomplete restoration with accelerated ω-oxidation

How hepatitis C virus (HCV)-associated lipid metabolic alterations recover after sustained virological response (SVR) remains elusive. The aforementioned recovery pattern was investigated. In a prospective cohort study of 438 chronic hepatitis C (CHC) patients with SVR after anti-HCV therapy, 164 sex- and age-matched genotype I (G1) and G2 patients underwent paired-serum liquid chromatography-tandem mass spectrometry analyses before and 24 weeks after therapy. Subjects without CHC served as controls (n=100). CHC patients had lower baseline lipid levels than controls. Among CHC patients, pre-therapy total cholesterol levels were positively associated with HCV RNA levels; G1 patients had higher pre-therapy HCV RNA levels than G2 patients. Repeated measures analysis of variance of CHC patients showed that lathosterol, lanosterol, total hydroxysphingomyelin, and total phosphatidylcholines levels, and total dicarboxyacylcarnitine/total acylcarnitine (indicators of ω-oxidation) and pre-β-lipoprotein ratios elevated 24 weeks after therapy compared with the levels before therapy. Levels of total lysophosphatidylcholines and α- and β-lipoprotein ratios decreased. Subgroup analyses showed elevated 7-dehydrocholesterol and lanosterol levels, particularly in G2 and male patients, who had broader spectra of altered phosphatidylcholines and acylcarnitines than G1 and female patients, respectively. Compared with controls, CHC patients had higher post-therapy levels of total lysophosphatidylcholines and hydroxysphingomyelins and ratios of total dicarboxyacylcarnitines/total acylcarnitines but lower cholesterol levels. At 24weeks after therapy, accelerated cholesterol biosynthesis, hepatic lipid export, ω-oxidation, and decreased systemic inflammation were noted in CHC patients with SVR, with greater efficiency in G2 and male patients. Regardless, HCV-associated lipid metabolic alterations required >24weeks for restoration or were incompletely reversible after SVR.

Postural characterization in subjects with Parkinson's disease using a synthetic index based on the Gait Profile Score

How hepatitis C virus (HCV)–associated lipid metabolic alterations recover after sustained virological response (SVR) remains elusive.The aforementioned recovery pattern was investigated.In a prospective cohort study of 438 chronic hepatitis C (CHC) patients with SVR after anti-HCV therapy, 164 sex- and age-matched genotype I (G1) and G2 patients underwent paired-serum liquid chromatography-tandem mass spectrometry analyses before and 24 weeks after therapy. Subjects without CHC served as controls (n = 100).CHC patients had lower baseline lipid levels than controls. Among CHC patients, pre-therapy total cholesterol levels were positively associated with HCV RNA levels; G1 patients had higher pre-therapy HCV RNA levels than G2 patients. Repeated measures analysis of variance of CHC patients showed that lathosterol, lanosterol, total hydroxysphingomyelin, and total phosphatidylcholines levels, and total dicarboxyacylcarnitine/total acylcarnitine (indicators of ω-oxidation) and pre-β-lipoprotein ratios elevated 24 weeks after therapy compared with the levels before therapy. Levels of total lysophosphatidylcholines and α- and β-lipoprotein ratios decreased. Subgroup analyses showed elevated 7-dehydrocholesterol and lanosterol levels, particularly in G2 and male patients, who had broader spectra of altered phosphatidylcholines and acylcarnitines than G1 and female patients, respectively. Compared with controls, CHC patients had higher post-therapy levels of total lysophosphatidylcholines and hydroxysphingomyelins and ratios of total dicarboxyacylcarnitines/total acylcarnitines but lower cholesterol levels.At 24 weeks after therapy, accelerated cholesterol biosynthesis, hepatic lipid export, ω-oxidation, and decreased systemic inflammation were noted in CHC patients with SVR, with greater efficiency in G2 and male patients. Regardless, HCV-associated lipid metabolic alterations required >24 weeks for restoration or were incompletely reversible after SVR.

Hepatitis C virus G1b infection decreases the number of small low-density lipoprotein particles.

To investigate how hepatitis C virus (HCV) G1b infection influences the particle number of lipoproteins. The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV G1b infection (active HCV group) and 91 with cleared HCV infection (SVR group), were examined. Serum lipoprotein was fractionated by high-performance liquid chromatography into twenty fractions. The cholesterol and triglyceride concentrations in each fraction were measured using LipoSEARCH. The number of lipoprotein particles in each fraction was calculated using a newly developed algorithm, and the relationship between chronic HCV G1b infection and the lipoprotein particle number was determined by multiple linear regression analysis. The median number of low-density lipoprotein (LDL) particles was significantly lower in the active HCV group [1182 nmol/L, interquartile range (IQR): 444 nmol/L] than in the SVR group (1363 nmol/L, IQR: 472 nmol/L, P < 0.001), as was that of high-density lipoprotein (HDL) particles (14168 nmol/L vs 15054 nmol/L, IQR: 4114 nmol/L vs 3385 nmol/L, P = 0.042). The number of very low-density lipoprotein (VLDL) particles was similar between the two groups. Among the four LDL sub-fractions, the number of large LDL particles was similar between the two groups. However, the numbers of medium (median: 533.0 nmol/L, IQR: 214.7 nmol/L vs median: 633.5 nmol/L, IQR: 229.6 nmol/L, P < 0.001), small (median: 190.9 nmol/L, IQR: 152.4 nmol/L vs median: 263.2 nmol/L, IQR: 159.9 nmol/L; P < 0.001), and very small LDL particles (median: 103.5 nmol/L, IQR: 66.8 nmol/L vs median: 139.3 nmol/L, IQR: 67.3 nmol/L, P < 0.001) were significantly lower in the active HCV group than in the SVR group, respectively. Multiple linear regression analysis indicated an association between HCV G1b infection and the decreased numbers of medium, small, and very small LDL particles. However, active HCV infection did not affect the number of large LDL particles or any sub-fractions of VLDL and HDL particles. HCV G1b infection decreases the numbers of medium, small, and very small LDL particles.

Induction of C/EBPb-Thr266 Phosphorylation by HCV Infection is Indispensable for the Zone-3 Phenotype and Proliferation in Cultured Human Hepatocytes

Liver acinar zonation allows for diverse functions to be performed on demand by specialized hepatocytes. Therefore, understanding how hepatitis C virus (HCV) infection may modulate the acinar zone phenotypes should provide insights into the pathophysiology of HCV infection. We assessed the effects HCV infection in the highlydifferentiated primary human hepatocyte culture that we have developed for the efficient replication of intact HCV virions. We found that HCV genotype 1 infection stimulated the zone-3 phenotype after 72 hr since the cultured hepatocytes expressed GS, β-Catenin and HIF-1α , markers of zone-3 hepatocytes. HCV infection also induced phosphorylated-C/EBPβ-Thr266 and proliferation in these cultured hepatocytes. A peptide designed to selectively inhibit phosphorylation of C/EBPβ-Thr266 blocked this phosphorylation, the zone-3 phenotype and hepatocyte proliferation induced by HCV infection in these cultured human hepatocytes. In addition, we found that in normal, uninfected human hepatocytes, unphosphorylated-C/EBPβ-Thr266 was associated with protein von Hippel Lindau (pVHL) and Axin (inhibitors of HIF-1α and β-catenin activation, respectively). These associations were blocked by the HCV infection since phosphorylated C/EBPβ-Thr266 was not associated with either pVHL or Axin. The inhibition of C/EBPβ-Thr266 phosphorylation normalized the association of unphosphorylatable C/EBPβ-Thr266 with pVHL and Axin, which is expected to inhibit the activation of HIF-1α and β−catenin. Collectively, these results strongly suggest that C/EBPβ-Thr266 phosphorylation is indispensable for the activation of GS, HIF-1α and β-catenin, and the induction of zone-3 phenotype in HCV-infected human hepatocytes.

Active RNA Replication of Hepatitis C Virus Downregulates CD81 Expression

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81.

Three-dimensional Huh7 cell culture system for the study of Hepatitis C virus infection

BackgroundIn order to elucidate how Hepatitis C Virus (HCV) interacts with polarized hepatocytes in vivo and how HCV-induced alterations in cellular function contribute to HCV-associated liver disease, a more physiologically relevant hepatocyte culture model is needed. As such, NASA-engineered three-dimensional (3-D) rotating wall vessel (RWV) bioreactors were used in effort to promote differentiation of HCV-permissive Huh7 hepatoma cells.ResultsWhen cultured in the RWV, Huh7 cells became morphologically and transcriptionally distinct from more standard Huh7 two-dimensional (2-D) monolayers. Specifically, RWV-cultured Huh7 cells formed complex, multilayered 3-D aggregates in which Phase I and Phase II xenobiotic drug metabolism genes, as well as hepatocyte-specific transcripts (HNF4α, Albumin, TTR and α1AT), were upregulated compared to 2-D cultured Huh7 cells. Immunofluorescence analysis revealed that these HCV-permissive 3-D cultured Huh7 cells were more polarized than their 2D counterparts with the expression of HCV receptors, cell adhesion and tight junction markers (CD81, scavenger receptor class B member 1, claudin-1, occludin, ZO-1, β-Catenin and E-Cadherin) significantly increased and exhibiting apical, lateral and/or basolateral localization.ConclusionThese findings show that when cultured in 3-D, Huh7 cells acquire a more differentiated hepatocyte-like phenotype. Importantly, we show that these 3D cultures are highly permissive for HCV infection, thus providing an opportunity to study HCV entry and the effects of HCV infection on host cell function in a more physiologically relevant cell culture system.

Future directions for investigation of fatigue in chronic hepatitis C viral infection

Fatigue is a common and often debilitating symptom for people living with chronic hepatitis C viral infection. Numerous published reports in the past decade have attempted to address the nature and aetiology of fatigue in chronic hepatitis C; however, this field is plagued with lack of clarity about how hepatitis C virus (HCV)-related fatigue occurs and when it is experienced by the infected person. Consequently, both patients and clinicians alike are unclear about how to mediate or prevent the negative consequences of HCV-related fatigue. In the following article, the authors identify areas of ambiguity and incongruity that have evolved primarily from the underlying assumptions and methodological decisions of researchers in the field of HCV-related fatigue. Research related to fatigue in chronic illness is drawn upon to suggest future directions for investigations and interventions in the field of HCV-related fatigue. Future research needs to move beyond the subjective symptomatology of HCV-related fatigue and begin to account for the multidimensional and contextualised nature of the fatigue experience.

Association of Hepatitis C Virus Seropositivity With Inflammatory Markers and Heart Failure in Persons With Coronary Heart Disease: Data From the Heart and Soul Study

Background How hepatitis C virus (HCV) affects coronary heart disease (CHD) risk factors and outcomes is largely unknown. Methods and Results Among a cohort of patients with stable CHD, we examined the association between HCV seropositivity and levels of inflammatory markers (C-reactive protein [CRP], fibrinogen, interleukin-6, and tumor necrosis factor [TNF]-α) and risk for the following outcomes: death, cardiovascular (CV) events, and heart failure events. A total of 84 (8.6%) participants were found to be seropositive for HCV. HCV-seropositive patients were found to have significantly lower adjusted mean levels of CRP (2.6 vs. 4.4; P < .01) and fibrinogen (340 vs. 398; P < .01), but higher levels of TNF-α (7.1 vs. 4.8; P < .01). Age-adjusted rates for HCV seropositive vs. seronegative were as follows: death 93 vs. 42/1,000 p-y ( P < .01), CV events 62 vs. 40 ( P = .13), and heart failure 76 vs. 29 ( P < .01). After adjustment for demographic and clinical factors, HCV remained significantly associated with an increased risk for heart failure events (HR = 2.13; 95% CI: 1.19–3.80). Conclusions In this cohort with CHD, HCV seropositive participants had higher rates of death, CV events, and heart failure hospitalizations during follow-up. After adjustment for CV risk factors, HCV seropositivity remained independently associated with risk for heart failure events.

Tagging of NS5A expressed from a functional hepatitis C virus replicon

Knowledge of how hepatitis C virus (HCV) proteins associate with components of the host cell to form a functional replication complex is still limited. To address this issue, HCV replicon constructs were generated where either green fluorescent protein (GFP) or the Propionibacterium shermanii transcarboxylase domain (PSTCD) was introduced into the NS5A coding region. Insertion of both GFP and PSTCD was tolerated well, allowing formation of stable replicon-containing cell lines that contained viral protein and transcript levels that were comparable to those of an unmodified parental replicon. Cell lines generated from the GFP-tagged NS5A replicon allowed live-cell visualization of the location of NS5A. Cell lines generated from the PSTCD-tagged replicons allowed rapid and efficient precipitation of the PSTCD-tagged NS5A, as well as other HCV non-structural proteins, using streptavidin-coated magnetic beads. Both replicons represent useful tools that offer different but complementary ways of examining replication-complex formation in cells.

Transmission of hepatitis C virus quasispecies between human adults

To elucidate how hepatitis C virus (HCV) with multiple variants (quasispecies) is transmitted and adapts to the host during infection, we compared nucleotide and deduced amino acid sequences from hypervariable region1 (HVR1) of the E2 gene of HCV between a donor and a recipient who developed hepatitis after a needlestick accident. Thirty clones from each subject were sequenced after PCR amplification, cloning, and purification of plasmid DNA from single colonies of transformed bacteria. Genetic analysis revealed that the recipient's viral sequences were much less diverse than the donor's. We found a single predominant HCV HVR1 clone of the recipient in 22/30 isolates with the same amino acid sequence, and mimic clones in 8/30 isolates with only one amino acid substitution. These were all absent in the donor, who had 21 highly diverse sequences. Phylogenetic analysis of virus E1/E2 gene sequences showed that the recipient's unique sequences were related to the population of variants from the donor, in whom one isolate had 96% similarity to the recipient's predominant amino acid sequence. These results suggest that a minor subset of the donor's HCV variants is selectively transmitted to the recipient, and that the selection determines the predominant variant in the new host.