Pathophysiology of hepatitis C virus infection and related liver disease

THG-1/TSC22D4 Promotes IL-1 Signaling through Stabilization of TRAF6 in Squamous Cell Carcinoma

Malignant neoplasms arise within a region of chronic inflammation, which is a key factor in all aspects of tumorigenesis including initiation, proliferation, invasion, angiogenesis, and metastasis. IL-1 plays critical functions in tumor development by influencing the tumor microenvironment and promoting cancer progression. However, the mechanism of continuous activation of the IL-1-mediated inflammatory pathway in tumors has not been fully elucidated. This study provides a novel mechanism of the autocrine activation of IL-1 signaling in squamous cell carcinoma (SCC) through a novel oncoprotein, TSC-22 homologous gene-1 (THG-1, also known as TSC22D4). The RNA sequencing analysis revealed that THG-1 overexpression enhances the transcription of NF-κB targets including IL1A, IL1B, TNFA, and IL8. Furthermore, THG-1 knockdown reduced the responsiveness to IL-1 through the suppression of NF-κB nuclear translocation. To elucidate the mechanism, we focused on a THG-1 interacting protein, NRBP1. We found that NRBP1 facilitates the degradation of TNF receptor-associated factor 6 (TRAF6) through its E3 ubiquitin ligase activity. THG-1 bound to NRBP1 and suppressed the degradation of TRAF6. Furthermore, THG-1 knockdown reduced TRAF6 abundance and NF-κB activity in SCC cells. Public database analyses of head and neck SCC revealed that high expression of THG-1 is associated with the activation of the IL-1 and TNF pathways, which share TRAF6 in the signal transductions. Finally, THG-1 abundance in laryngeal SCC specimens is elevated in patients with recurrence. These results indicated that THG-1 drives the self-sufficiency of IL-1-mediated inflammatory pathway, which could contribute to the future diagnosis and immunotherapy of SCCs. Implications: An oncoprotein, THG-1/TSC22D4 activates the IL-1-mediated inflammatory pathway through the suppression of TRAF6 degradation, which mediates the continuous inflammation in tumors.

Extrahepatic Cancer Risk in Patients with Hepatitis C Virus Infection Treated with Direct-Acting Antivirals

Chronic hepatitis C virus (HCV) infection is associated with an increased risk of extrahepatic cancers, particularly non-Hodgkin lymphoma. The introduction of direct-acting antivirals (DAAs) has revolutionized HCV therapy, resulting in high cure rates. However, concerns have been raised about potential effects on cancer risk. This review summarizes the current evidence on extrahepatic cancer risk in HCV-infected patients treated with DAAs. We examined epidemiologic data on HCV-associated extrahepatic cancers and explored potential mechanisms linking HCV to carcinogenesis outside the liver. Studies evaluating cancer outcomes after DAA therapy were critically reviewed while considering methodological challenges. While some studies suggested a reduced risk of extrahepatic cancers after DAA therapy, others showed no significant change. Limitations included short follow-up periods and confounding variables. Immunological changes following rapid HCV clearance may have complex effects on cancer risk. Long-term prospective studies and mechanistic investigations are needed to fully elucidate the relationship between DAA therapy and extrahepatic cancer risk in HCV patients. Clinicians should remain vigilant for extrahepatic malignancies in this population.

Global trends in hepatitis C-related hepatocellular carcinoma mortality: A public database analysis (1999-2019)

BACKGROUND

Hepatitis C is the leading cause of chronic liver disease worldwide and it significantly contributes to the burden of hepatocellular carcinoma (HCC). However, there are marked variations in the incidence and mortality rates of HCC across different geographical regions. With the advent of new widely available treatment modalities, such as direct-acting antivirals, it is becoming increasingly imperative to understand the temporal and geographical trends in HCC mortality associated with Hepatitis C. Furthermore, gender disparities in HCC mortality related to Hepatitis C are a crucial, yet underexplored aspect that adds to the disease's global impact. While some studies shed light on gender-specific trends, there is a lack of comprehensive data on global and regional mortality rates, particularly those highlighting gender disparities. This gap in knowledge hinders the development of targeted interventions and resource allocation strategies.

AIM

To understand the global and regional trends in Hepatitis C-related HCC mortality rates from 1990 to 2019, along with gender disparities.

METHODS

We utilized the Global Burden of Disease database, a comprehensive repository for global health metrics to age-standardized mortality rates due to Hepatitis C-related HCC from 1999 to 2019. Rates were evaluated per 100000 population and assessed by World Bank-defined regions. Temporal trends were determined using Joinpoint software and the Average Annual Percent Change (AAPC) method, and results were reported with 95% confidence intervals (CI).

RESULTS

From 1990 to 2019, overall, there was a significant decline in HCC-related mortality rates with an AAPC of -0.80% (95%CI: -0.83 to -0.77). Females demonstrated a marked decrease in mortality with an AAPC of -1.06% (95%CI: -1.09 to -1.03), whereas the male cohort had a lower AAPC of -0.52% (95%CI: -0.55 to -0.48). Regionally, East Asia and the Pacific demonstrated a significant decline with an AAPC of -2.05% (95%CI: -2.10 to -2.00), whereas Europe and Central Asia observed an uptrend with an AAPC of 0.72% (95%CI: 0.69 to 0.74). Latin America and the Caribbean also showed an uptrend with an AAPC of 0.06% (95%CI: 0.02 to 0.11). In the Middle East and North Africa, the AAPC was non-significant at 0.02% (95%CI: -0.09 to 0.12). North America, in contrast, displayed a significant upward trend with an AAPC of 2.63% (95%CI: 2.57 to 2.67). South Asia (AAPC -0.22%, 95%CI: -0.26 to -0.16) and Sub-Saharan Africa (AAPC -0.14%, 95%CI: -0.15 to -0.12) trends significantly declined over the study period.

CONCLUSION

Our study reports disparities in Hepatitis C-related HCC mortality between 1999 to 2019, both regionally and between genders. While East Asia and the Pacific regions showed a promising decline in mortality, North America has experienced a concerning rise in mortality. These regional variations highlight the need for healthcare policymakers and practitioners to tailor public health strategies and interventions. The data serves as a call to action, particularly for regions where mortality rates are not improving, emphasizing the necessity for a nuanced, region-specific approach to combat the global challenge of HCC secondary to Hepatitis C.

Medicinal Plants against Viral Infections: A Review of Metabolomics Evidence for the Antiviral Properties and Potentials in Plant Sources

Most plants have developed unique mechanisms to cope with harsh environmental conditions to compensate for their lack of mobility. A key part of their coping mechanisms is the synthesis of secondary metabolites. In addition to their role in plants' defense against pathogens, they also possess therapeutic properties against diseases, and their use by humans predates written history. Viruses are a unique class of submicroscopic agents, incapable of independent existence outside a living host. Pathogenic viruses continue to pose a significant threat to global health, leading to innumerable fatalities on a yearly basis. The use of medicinal plants as a natural source of antiviral agents has been widely reported in literature in the past decades. Metabolomics is a powerful research tool for the identification of plant metabolites with antiviral potentials. It can be used to isolate compounds with antiviral capacities in plants and study the biosynthetic pathways involved in viral disease progression. This review discusses the use of medicinal plants as antiviral agents, with a special focus on the metabolomics evidence supporting their efficacy. Suggestions are made for the optimization of various metabolomics methods of characterizing the bioactive compounds in plants and subsequently understanding the mechanisms of their operation.

Role of Immunological Cells in Hepatocellular Carcinoma Disease and Associated Pathways

Hepatocellular carcinoma (HCC) remains one of the predominant causes of cancer-related mortality across the globe. It is attributed to obesity, excessive alcohol consumption, smoking, and infection by the hepatitis virus. Early diagnosis of HCC is essential, and local treatments such as surgical excision and percutaneous ablation are effective. Palliative systemic therapy, primarily with the tyrosine kinase inhibitor Sorafenib, is used in advanced cases. However, the prognosis for advanced HCC remains poor. This Review additionally describes the pathophysiological mechanisms of HCC, which include aberrant molecular signaling, genomic instability, persistent inflammation, and the paradoxical position of the immune system in promoting and suppressing HCC. The paper concludes by discussing the growing body of research on the relationship between mitochondria and HCC, suggesting that mitochondrial dysfunction may contribute to the progression of HCC. This Review focuses on immunological interactions between different mechanisms of HCC progression, including obesity, viral infection, and alcohol consumption.

The trends in death of primary liver cancer caused by specific etiologies worldwide: results from the Global Burden of Disease Study 2019 and implications for liver cancer management

BACKGROUND

Over past decades, epidemiological patterns of liver cancer (LC) have changed dramatically. The Global Burden of Disease (GBD) study provides an opportunity for tracking the progress in cancer control with its annual updated reports at national, regional and global level, which can facilitate the health decision-making and the allocation of health resources. Therefore, we aim to estimate the global, regional and national trends of death caused by liver cancer due to specific etiologies and attributable risks from 1990 to 2019.

MATERIALS AND METHODS

Data was collected from the GBD study 2019. Estimated annual percentage changes (EAPC) were used to quantify the trends of age-standardized death rate (ASDR). We applied a linear regression for the calculation of estimated annual percentage change in ASDR.

RESULTS

From 1990 to 2019, the ASDR of liver cancer decreased globally (EAPC =  - 2.23, 95% confidence interval [CI]: - 2.61 to - 1.84). Meanwhile, declining trends were observed in both sexes, socio-demographic index (SDI) areas, and geographies, particularly East Asia (EAPC =  - 4.98, 95% CI: - 5.73 to - 4.22). The ASDR for each of the four major etiologies fell globally, while liver cancer caused by hepatitis B had the largest drop (EPAC =  - 3.46, 95% CI: - 4.01 to - 2.89). China has had dramatic decreases in death rates on a national scale, particularly when it comes to the hepatitis B etiology (EAPC =  - 5.17, 95% CI: - 5.96 to - 4.37). However, certain nations, such as Armenia and Uzbekistan, saw a rise in liver cancer mortality. Controlling smoking, alcohol, and drug use contributed to a drop in LC-related mortality in the majority of socio-demographic index areas. Nevertheless, the excessive body mass index (BMI) was portrayed as the underlying cause for LC fatalities.

CONCLUSION

From 1990 to 2019, there was a worldwide decrease in deaths caused by liver cancer and its underlying causes. However, rising tendencies have been observed in low-resource regions and countries. The trends in drug use- and high BMI-related death from liver cancer and its underlying etiologies were concerning. The findings indicated that efforts should be increased to prevent liver cancer deaths through improved etiology control and risk management.

Successes in antiviral drug discovery: a tribute to Nick Meanwell

Drug discovery is a difficult task, and is even more challenging when the target evolves during therapy. Antiviral drug therapy is an excellent example, exemplified by the evolution of therapeutic approaches for treatment of hepatitis C and HIV-1. Nick Meanwell and his colleagues made important contributions leading to molecules for treatment of hepatitis C and HIV-1, each with distinct mechanisms of action. This review summarizes the discovery and impact of these drugs, and will highlight, where applicable, the broader contributions of these discoveries to medicinal chemistry and drug discovery.

Proteolysis-targeting chimeras in biotherapeutics: Current trends and future applications

The success of inhibitor-based therapeutics is largely constrained by the acquisition of therapeutic resistance, which is partially driven by the undruggable proteome. The emergence of proteolysis targeting chimera (PROTAC) technology, designed for degrading proteins involved in specific biological processes, might provide a novel framework for solving the above constraint. A heterobifunctional PROTAC molecule could structurally connect an E3 ubiquitin ligase ligand with a protein of interest (POI)-binding ligand by chemical linkers. Such technology would result in the degradation of the targeted protein via the ubiquitin-proteasome system (UPS), opening up a novel way of selectively inhibiting undruggable proteins. Herein, we will highlight the advantages of PROTAC technology and summarize the current understanding of the potential mechanisms involved in biotherapeutics, with a particular focus on its application and development where therapeutic benefits over classical small-molecule inhibitors have been achieved. Finally, we discuss how this technology can contribute to developing biotherapeutic drugs, such as antivirals against infectious diseases, for use in clinical practices.

Design and cytotoxic evaluation via apoptotic and antiproliferative activity for novel 11(4-aminophenylamino)neocryptolepine on hepatocellular and colorectal cancer cells

The current study evaluated the cytotoxic activity of 11(4-Aminophenylamino)neocryptolepine (APAN), a novel derivative of neocryptolepine, on hepatocellular (HepG2) and colon (HCT-116) carcinoma cell lines as well as, the possible molecular mechanism through which it exerts its cytotoxic activity. The APAN was synthesized and characterized based on their spectral analyses. Scanning for anticancer target of APAN by Swiss software indicated that APAN had highest affinity for protein tyrosine kinase 6 enzyme. Furthermore, Super pred software indicated that APAN can be indicated in hepatic and colorectal cells with 92%. Molecular docking studies indicated that the binding affinity scores of APAN for protein PDB code: 6CZ4 of tyrosine kinase 6 recorded of - 6.6084 and RMSD value of 0.8891°A, while that for protein PDB: 7JL7 of caspase 3 was - 6.1712 and RMSD of 0.8490°A. Treatment of HepG2 and HCT-116 cells with APAN induced cytotoxicity with IC₅₀ of 2.6 and 1.82 μg/mL respectively. In addition, it induced injury and serious morphological changes in cells including, disappearance of microvilli, membrane blebbing, cytoplasmic condensation, and shrunken nucleus with more condensed chromatin. Moreover, APAN significantly increased protein expression of annexin V (apoptotic marker). Furthermore, APAN significantly increased protein expression of caspase 3 and P53. However, it significantly reduced secretion of VEGF protein into the medium and decreased protein expression of PCNA and Ki67 in HepG2 and HCT-116 cells. This study indicated that APAN had cytotoxic activity against HepG2 and HCT-116 cells via increasing the expression of apoptotic proteins and reducing the expression of proliferative proteins.

Non-coding ribonucleic acid-mediated CAMSAP1 upregulation leads to poor prognosis with suppressed immune infiltration in liver hepatocellular carcinoma

Liver hepatocellular carcinoma (LIHC) is well-known for its unfavorable prognosis due to the lack of reliable diagnostic and prognostic biomarkers. Calmodulin-regulated spectrin-associated protein 1 (CAMSAP1) is a non-centrosomal microtubule minus-end binding protein that regulates microtubule dynamics. This study aims to investigate the specific role and mechanisms of CAMSAP1 in LIHC. We performed systematical analyses of CAMSAP1 and demonstrated that differential expression of CAMSAP1 is associated with genetic alteration and DNA methylation, and serves as a potential diagnostic and prognostic biomarker in some cancers, especially LIHC. Further evidence suggested that CAMSAP1 overexpression leads to adverse clinical outcomes in advanced LIHC. Moreover, the AC145207.5/LINC01748-miR-101–3p axis is specifically responsible for CAMSAP1 overexpression in LIHC. In addition to the previously reported functions in the cell cycle and regulation of actin cytoskeleton, CAMSAP1-related genes are enriched in cancer- and immune-associated pathways. As expected, CAMSAP1-associated LIHC is infiltrated in the suppressed immune microenvironment. Specifically, except for immune cell infiltration, it is significantly positively correlated with immune checkpoint genes, especially CD274 (PD-L1), and cancer-associated fibroblasts. Prediction of immune checkpoint blockade therapy suggests that these patients may benefit from therapy. Our study is the first to demonstrate that besides genetic alteration and DNA methylation, AC145207.5/LINC01748-miR-101-3p-mediated CAMSAP1 upregulation in advanced LIHC leads to poor prognosis with suppressed immune infiltration, representing a potential diagnostic and prognostic biomarker as well as a promising immunotherapy target for LIHC.

Hepatitis C mortality trends in San Francisco: can we reach elimination targets?

PURPOSE

Hepatitis C virus (HCV) is the most common blood-borne infection in the United States, and a leading cause of liver disease, transplant, and mortality. CDC HCV elimination goals include reducing HCV-related mortality by 65% (from 2015) by 2030.

METHODS

We used vital registry data (CDC WONDER) to estimate overall and demographic-specific HCV-related mortality from 1999 to 2019 in San Francisco and then used an exponential model to project progress toward HCV elimination. Local trends were compared to state and national trends.

RESULTS

Between 1999 and 2019, there were 1819 HCV-related deaths in San Francisco, representing an overall age-adjusted mortality rate of 9.4 (95% CI 9.0, 9.9) per 100,000 population. The age-adjusted HCV-related mortality rates were significantly higher among males (13.7), persons aged 55 years and older (28.0), Black and/or African Americans (32.2) compared to other racial groups, and Hispanic/Latinos (11.6) compared to non-Hispanic and/or Latinos. Overall and in most subgroups, mortality rates were lowest between 2015 and 2019. Since 2015, San Francisco observed a significantly larger reduction in agbe-adjusted HCV-related mortality than California or the U.S. Projected age-adjusted HCV-related mortality rates for San Francisco for 2020 and 2030 were 4.7 (95% CI 3.5, 6.2) and 1.1 (95% CI 0.7, 1.8), respectively.

CONCLUSIONS

Based on trends between 2015 and 2019, San Francisco, California, and the U.S. are projected to achieve 65% reduction in HCV-mortality at or before 2030. Based on current trends, San Francisco is projected to achieve this goal earlier.

Environmental exposure as a risk-modifying factor in liver diseases: Knowns and unknowns

Liver diseases are considered to predominantly possess an inherited or xenobiotic etiology. However, inheritance drives the ability to appropriately adapt to environmental stressors, and disease is the culmination of a maladaptive response. Thus “pure” genetic and “pure” xenobiotic liver diseases are modified by each other and other factors, identified or unknown. The purpose of this review is to highlight the knowledgebase of environmental exposure as a potential risk modifying agent for the development of liver disease by other causes. This exercise is not to argue that all liver diseases have an environmental component, but to challenge the assumption that the current state of our knowledge is sufficient in all cases to conclusively dismiss this as a possibility. This review also discusses key new tools and approaches that will likely be critical to address this question in the future. Taken together, identifying the key gaps in our understanding is critical for the field to move forward, or at the very least to “know what we don't know.”

Biomarkers in Hepatobiliary Cancers: What is Useful in Clinical Practice?

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) exhibit a poor prognosis with 5-year overall survival rates around 15%, all stages combined. Most of these primary liver malignancies are metastatic at diagnostic, with only limited therapeutic options, relying mainly on systemic therapies. Treatment modalities are different yet partially overlapping between HCC and BTC. The complex molecular profile of BTC yields to several actionable therapeutic targets, contrary to HCC that remains the field of antiangiogenic drugs in non-molecularly selected patients. Immunotherapy is now validated in the first line in HCC in combination with bevacizumab, while clinical activity of single agent immunotherapy appears limited to a subset of patients in BTC, still poorly characterized, and combinations are currently under investigation. In this review, we provide a critical evaluation and grading of clinical relevance on (i) the main prognostic biomarkers in HCC and BTC, (ii) the main theragnostic biomarkers in both tumors, and lastly (iii) what is recommended in clinical practice.

Protective effect of aminoguanidine against lipopolysaccharide-induced hepatotoxicity and liver dysfunction in rat

Lipopolysaccharide (LPS) as the major component of the outer membrane of Gram-negative bacteria activates macrophages to produce a high level of pro-inflammatory cytokines which is considered as a cause of liver dysfunction. Overproduction of nitric oxide (NO) has been suggested to have a role in hepatic injury. The aim of the present study was to explore the protective effects of aminoguanidine (AG) as inducible nitric oxide synthase (iNOS) inhibitor against LPS -induced liver dysfunction in rat. The animals were divided into five groups: (1) control (2) LPS (3) LPS-AG50, (4) LPS-AG100 and (5) LPS-AG150. LPS (1 mg/kg) was injected for 5 weeks and AG (50, 100 and 150 mg/kg) was administered 30 min before LPS. Drugs were injected intraperitoneally. LPS induced liver dysfunction presented by increasing the serum level of alkaline phosphatase (ALK-P), alanine aminotransferase (ALT), aspartate aminotransferase (AST). Pretreatment with AG restored harmful effects of LPS on liver function. In addition, LPS resulted in hepatotoxicity, accompanied by enhancing the level of interleukin (IL)-6, malondialdehyde (MDA) and nitric oxide (NO) metabolites and decreasing the content of total thiol groups and superoxide dismutase (SOD) and catalase (CAT) activity. Injection of AG before LPS attenuated LPS-induced hepatotoxicity through decreasing the level of IL-6, MDA and NO metabolites and increasing total thiols and SOD and CAT activity. Considering the protective effect of AG which was seen in the present study, it seems that increased levels of NO due to activation of iNOS has a role in LPS-induced hepatic injury.

Immunobiology and immunotherapy of HCC: spotlight on innate and innate-like immune cells

Immune-based therapies such as immune checkpoint inhibitors have revolutionized the systemic treatment of various cancer types. The therapeutic application of monoclonal antibodies targeting inhibitory pathways such as programmed cell death-1(PD-1)/programmed cell death ligand 1 (PD-L1) and CTLA-4 to cells of the adaptive immune system has recently been shown to generate meaningful improvement in the clinical outcome of hepatocellular carcinoma (HCC). Nevertheless, current immunotherapeutic approaches induce durable responses in only a subset of HCC patients. Since immunologic mechanisms such as chronic inflammation due to chronic viral hepatitis or alcoholic and nonalcoholic fatty liver disease play a crucial role in the initiation, development, and progression of HCC, it is important to understand the underlying mechanisms shaping the unique tumor microenvironment of liver cancer. The liver is an immunologic organ with large populations of innate and innate-like immune cells and is exposed to bacterial, viral, and fungal antigens through the gut-liver axis. Here, we summarize and highlight the role of these cells in liver cancer and propose strategies to therapeutically target them. We also discuss current immunotherapeutic strategies in HCC and outline recent advances in our understanding of how the therapeutic potential of these agents might be enhanced.

Accelerating the elimination of hepatitis C in Kuwait: An expert opinion

The hepatitis C virus (HCV) is estimated to affect 71 million people worldwide. In 2016, the World Health Organization adopted the first global health sector strategy to eliminate viral hepatitis as a public health threat by 2030. In December 2018, the European Association for the Study of the Liver, International Liver Foundation convened an expert panel to address the elimination of HCV in Kuwait. Several steps have already been taken to eliminate HCV in Kuwait, including free HCV treatment for Kuwait's citizens, high blood safety standards, and the implementation of screening and awareness programs. The expert panel made several recommendations aimed at accelerating the elimination of HCV in Kuwait: The development of a national strategy and action plan to guide all HCV elimination activities; the formation of a coordination mechanism to support collaboration between hepatitis working committees; the prioritization of micro-elimination at primary, secondary or tertiary facilities, in prisons and rehabilitation centers; and ensuring the involvement of multiple stakeholders - including relevant civil society groups - in all activities. Enhanced screening and linkage to care should be prioritized in Kuwait, with the expansion of the prescriber base to primary healthcare providers and nurse practitioners to be considered. Raising awareness and educating people about HCV infection also remain essential to achieve the goal of HCV elimination. Lastly, a national HCV registry should be developed to help monitor the implementation of viral hepatitis plans and progress towards achieving national and international targets.

Hepatitis C virus infection impacts work productivity and fatigue: An epidemiologic real-life study

INTRODUCTION AND OBJECTIVE

Hepatitis C virus (HCV) infection and treatment impact the patient's daily life and work productivity. Until recently, treatments were associated with side effects and insufficient virologic and hepatic results. This study evaluated fatigue, work productivity, and treatment modalities in patients with HCV infection.

MATERIALS AND METHODS

This cross-sectional, non-interventional, multicenter study was conducted in real-life settings between March and December 2015 at 109 sites in France.

RESULTS

Data from 1269 patients were evaluable. The mean patient age was 55.8±12.5 years; 53.3% (676) patients were male. A total of 80.1% (1015) of patients were Caucasian and 62.3% (791) had a genotype 1 infection, 34.2% (433) had at least one comorbidity and 15.6% (198) had ≥1 clinical sign/symptom. Illicit drug use was the main route of HCV transmission and accounted for 36.8% (466) of all infections. Fibrosis stage F0/F1 was reported in 41.4% (525) of patients. A majority of patients (60.4%, 764) had never been treated. In patients previously treated, 85.8% (430) received ribavirin and pegylated interferon and only 13.4% (67) direct-acting antivirals. The mean percent of global impairment due to health was highest (34.8±30.9%) in patients 18-45 years of age. The prevalence of active employed patients with a total fatigue score≥its median value (45/160) was 38.6%. The mean percent work time missed due to health was 9.6±23.6% for working patients of 18-45 years of age and 7.3±21.8% for working patients of 45-65 years of age. The mean overall prevalence of employed patients with impairment due to health issues was 21.8±26.8%. The prevalence of patients with a reduced work activity of ≥50% due to their health status was 32.1%.

CONCLUSION

These data reinforce the request for improved disease management in France, allowing patients with HCV infection to increase work productivity, reduce fatigue, and, hopefully, cure their disease.

Pharmacology Update for the Treatment of Hepatitis C Virus

Hepatitis C virus (HCV) is a common infectious disease affecting people worldwide. In the past 10 years, the incidence of HCV has steadily increased in the United States. With the advent of new direct-acting antiviral medications, the treatment of HCV has become important and can cure the infection.

Junctional and somatic hypermutation-induced CX4C motif is critical for the recognition of a highly conserved epitope on HCV E2 by a human broadly neutralizing antibody

Induction of broadly neutralizing monoclonal antibodies (bNAbs) that bind to the viral envelope glycoproteins is a major goal of hepatitis C virus (HCV) vaccine research. The study of bNAbs arising in natural infection is essential in this endeavor. We generated a human antibody, 8D6, recognizing the E2 protein of HCV isolated from a chronic hepatitis C patient. This antibody shows broadly neutralizing activity, which covers a pan-genotypic panel of cell culture-derived HCV virions (HCVcc). Functional and epitope analyses demonstrated that 8D6 can block the interaction between E2 and CD81 by targeting a highly conserved epitope on E2. We describe how the 8D6 lineage evolved via somatic hypermutation to achieve broad neutralization. We found that the V(D)J recombination-generated junctional and somatic hypermutation-induced disulfide bridge (C-C) motif in the CDRH3 is critical for the broad neutralization and binding activity of 8D6. This motif is conserved among a series of broadly neutralizing HCV antibodies, indicating a common binding model. Next, the 8D6 inferred germline (iGL) was reconstructed and tested for its binding affinity and neutralization activity. Interestingly, 8D6 iGL-mediated relatively strong inhibition of the 1b genotype PR79L9 strain, suggesting that PR79L9 may serve as a potential natural viral strain that provides E2 sequences that induce bNAbs. Overall, our detailed epitope mapping and genetic studies of the HCV E2-specific mAb 8D6 have allowed for further refinement of antigenic sites on E2 and reveal a new mechanism to generate a functional CDRH3, while its iGL can serve as a probe to identify potential HCV vaccine strains.

Immune Therapy for Liver Cancers

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) display a poor prognosis with 5-year overall survival rates around 15%, all stages taken together. These primary liver malignancies are often diagnosed at advanced stages where therapeutic options are limited. Recently, immune therapy has opened new opportunities in oncology. Based on their high programmed death-ligand 1 expression and tumor-infiltrating lymphocytes, HCC and BTC are theoretically good candidates for immune checkpoint blockade. However, clinical activity of single agent immunotherapy appears limited to a subset of patients, which is still ill-defined, and combinations are under investigation. In this review, we provide an overview of (i) the biological rationale for immunotherapies in HCC and BTC, (ii) the current state of their clinical development, and (iii) the predictive value of immune signatures for both clinical outcome and response to these therapies.

Angiogenesis and immune checkpoint inhibitors as therapies for hepatocellular carcinoma: current knowledge and future research directions

Hepatocellular carcinoma (HCC) is the second deadliest cancer worldwide, due to its high incidence and poor prognosis. Frequent initial presentation at advanced stages along with impaired liver function limit the use of a broad therapeutic arsenal in patients with HCC. Although main HCC oncogenic drivers have been deciphered in recent years (TERT, TP53, CTNNB1 mutations, miR122 and CDKN2A silencing), therapeutic applications derived from this molecular knowledge are still limited. Given its high vascularization and immunogenicity, antiangiogenics and immune checkpoint inhibitors (ICI), respectively, are two therapeutic approaches that have shown efficacy in HCC. Depending on HCC immune profile, combinations of these therapies aim to modify the protumoral/antitumoral immune balance, and to reactivate and favor the intratumoral trafficking of cytotoxic T cells. Combination therapies involving antiangiogenics and ICI may be synergistic, because vascular endothelial growth factor A inhibition increases intratumoral infiltration and survival of cytotoxic T lymphocytes and decreases regulatory T lymphocyte recruitment, resulting in a more favorable immune microenvironment for ICI antitumoral activity. First results from clinical trials evaluating combinations of these therapies are encouraging with response rates never observed before in patients with HCC. A better understanding of the balance and interactions between protumoral and antitumoral immune cells will help to ensure the success of future therapeutic trials. Here, we present an overview of the current state of clinical development of antitumoral therapies in HCC and the biological rationale for their use. Moreover, translational studies on tumor tissue and blood, prior to and during treatment, will help to identify biomarkers and immune signatures with predictive value for both clinical outcome and response to combination therapies.

Persistent gamma delta T-cell dysfunction in chronic HCV infection despite direct-acting antiviral therapy induced cure

Immune dysfunction is a hallmark of chronic HCV infection and viral clearance with direct antivirals recover some of these immune defects. TCRVγ9Vδ2 T-cell dysfunction in treated HCV patients however is not well studied and was the subject of this investigation. Peripheral blood cells from patients who had achieved sustained virologic response (SVR) or those who had relapsed after interferon-free therapy were phenotyped using flow cytometry. Functional potential of Vγ9Vδ2 T cells was tested by measuring proliferation in response to aminobisphosphonate zoledronic acid, and cytotoxicity against HepG2 hepatoma cell line. TCR sequencing was performed to analyse impact of HCV infection on Vδ2 T-cell repertoire. Vγ9Vδ2 cells from patients were activated and therapy resulted in reduction of CD38 expression on these cells in SVR group. Relapsed patients had Vδ2 cells with persistently activated and terminally differentiated cytotoxic phenotype (CD38⁺ CD45RA⁺ CD27^- CD107a⁺ ). Irrespective of outcome with therapy, majority of patients had persistently poor Vδ2 T-cell proliferative response to zoledronate along with lower expression of CD56, which identifies anti-tumour cytotoxic subset, relative to healthy controls. There was no association between the number of antigen reactive Vγ2-Jγ1.2 TCR rearrangements at baseline and levels of proliferation indicating nonresponse to zoledronate is not due to depletion of phosphoantigen responding chains. Thus, HCV infection results in circulating Vγ9Vδ2 T cells with a phenotype equipped for immediate effector function but poor cytokine response and expansion in response to antigen, a functional defect that may have implications for susceptibility for carcinogenesis despite HCV cure.

Early high levels of regulatory T cells and T helper 1 may predict the progression of recurrent hepatitis C after liver transplantation

BACKGROUND

Immune response failure against hepatitis C virus (HCV) has been associated with an increased regulatory T cell (Treg) activity. After liver transplantation (LT), 80% of patients experience an accelerated progression of hepatitis C recurrence. The aim of this work was to assess the involvement of Tregs, T helper (Th) 1, 2 and 17 cells in recurrent hepatitis C.

METHODS

Peripheral blood cells obtained before and one month after LT from 22 recipients were analysed. Forty-four key molecules related to Treg, Th1, 2 and 17 responses, were evaluated using qRT-PCR. Liver recipients were classified in two groups according to graft fibrosis evaluated by the METAVIR score on the biopsy performed one year after LT (mild: F ≤ 1, n = 13; severe: F > 1, n = 9). Patients developing a severe recurrence were compared with patients with a mild recurrence.

RESULTS

mRNA levels of Treg markers obtained one month after LT were significantly increased in patients with a severe disease course when compared to patients with a mild recurrence. Markers of the Th1 response were elevated in the same group. No differences in the markers determined before LT were observed.

CONCLUSION

These findings suggest that Treg, induced by a multifactorial process, which could include a strong Th1 response itself, may play a role in suppressing the early antiviral response, leading to a severe recurrence of hepatitis C.

Metabolomic-Based Methods in Diagnosis and Monitoring Infection Progression

A robust biomarker screening and validation is crucial for overcoming the current limits in the clinical management of infectious diseases. In this chapter, a general workflow for metabolomics is summarized. Subsequently, an overview of the major contributions of this omics science to the field of biomarkers of infectious diseases is discussed. Different approaches using a variety of analytical platforms can be distinguished to unveil the key metabolites for the diagnosis, prognosis, response to treatment and susceptibility for infectious diseases. To allow the implementation of such biomarkers into the clinics, the performance of large-scale studies employing solid validation criteria becomes essential. Focusing on the etiological agents and after an extensive review of the field, we present a comprehensive revision of the main metabolic biomarkers of viral, bacterial, fungal, and parasitic diseases. Finally, we discussed several articles which show the strongest validation criteria. Following these research avenues, precious clinical resources will be revealed, allowing for reduced misdiagnosis, more efficient therapies, and affordable costs, ultimately leading to a better patient management.

Mitochondrial damage and iron metabolic dysregulation in hepatitis C virus infection

Hepatitis C virus (HCV) infection often leads to chronic hepatitis that can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Although HCV infection is expected to decrease due to the high rate of HCV eradication via the rapid dissemination and use of directly acting antivirals, HCV infection remains a leading cause of HCC. Although the mechanisms underlying the HCC development are not fully understood, oxidative stress is present to a greater degree in HCV infection than in other inflammatory liver diseases and has been proposed as a major mechanism of liver injury in patients with chronic hepatitis C. Hepatocellular mitochondrial alterations and iron accumulation are well-known characteristics in patients with chronic hepatitis C and are closely related to oxidative stress, since the mitochondria are the main site of reactive oxygen species generation, and iron produces hydroxy radicals via the Fenton reaction. In addition, phlebotomy is an iron reduction approach that aims to lower serum transaminase levels in patients with chronic hepatitis C. Here, we review and discuss the mechanisms by which HCV induces mitochondrial damage and iron accumulation in the liver and offer new insights concerning how mitochondrial damage and iron accumulation are linked to the development of HCC.

Impact of Alcohol and Coffee Intake on the Risk of Advanced Liver Fibrosis: A Longitudinal Analysis in HIV-HCV Coinfected Patients (ANRS HEPAVIH CO-13 Cohort)

Background: Coffee intake has been shown to modulate both the effect of ethanol on serum GGT activities in some alcohol consumers and the risk of alcoholic cirrhosis in some patients with chronic diseases. This study aimed to analyze the impact of coffee intake and alcohol consumption on advanced liver fibrosis (ALF) in HIV-HCV co-infected patients. Methods: ANRS CO13-HEPAVIH is a French, nationwide, multicenter cohort of HIV-HCV-co-infected patients. Sociodemographic, behavioral, and clinical data including alcohol and coffee consumption were prospectively collected using annual self-administered questionnaires during five years of follow-up. Mixed logistic regression models were performed, relating coffee intake and alcohol consumption to ALF. Results: 1019 patients were included. At the last available visit, 5.8% reported high-risk alcohol consumption, 27.4% reported high coffee intake and 14.5% had ALF. Compared with patients with low coffee intake and high-risk alcohol consumption, patients with low coffee intake and low-risk alcohol consumption had a lower risk of ALF (aOR (95% CI) 0.24 (0.12–0.50)). In addition, patients with high coffee intake had a lower risk of ALF than the reference group (0.14 (0.03–0.64) in high-risk alcohol drinkers and 0.11 (0.05–0.25) in low-risk alcohol drinkers). Conclusions: High coffee intake was associated with a low risk of liver fibrosis even in HIV-HCV co-infected patients with high-risk alcohol consumption.

Lower levels of dehydroepiandrosterone sulfate are associated with more advanced liver fibrosis in chronic hepatitis C

Chronic infection with the hepatitis C virus induces liver fibrosis, but it is unknown why some patients progress to advanced fibrosis while others remain with mild disease. Recently, an inverse association between serum levels of dehydroepiandrosterone sulphate (DHEA-S) and liver fibrosis in patients with nonalcoholic fatty liver disease was described, and it was postulated that dehydroepiandrosterone (DHEA) has antifibrotic effects. Our aim was to compare serum DHEA-S levels with liver fibrosis in hepatitis C patients. We collected serum samples from hepatitis C patients at the same day they underwent a liver biopsy. S-DHEA was compared to different stages of fibrosis. Binary logistic regression models were applied to evaluate independent variables associated to fibrosis. We included 287 patients (43.9% male). According to fibrosis stages 0, 1, 2, 3 and 4, median serum DHEA-S levels were 103 (26-462), 73 (5-391), 46 (4-425), 35 (6-292) and 28 (2-115) μg/dL, respectively (P < .001). Median serum DHEA-S levels were 74 (5-462) vs 36 (2-425) μg/dL for mild (F0-1) vs significant (F2-4) fibrosis, respectively (P < .001). Median serum DHEA-S levels were 64 (4-462) vs 31 (2-292) μg/dL for non advanced (F0-2) vs advanced fibrosis (F3-4), respectively (P < .001). The same association was found when the subgroup of HCV patients with and without steatosis or steatohepatitis was analysed. The association between lower DHEA-S levels and advanced fibrosis was independent of age, gender, diabetes mellitus, obesity and steatosis. Lower circulating DHEA-S levels are associated with more advanced stages of liver fibrosis in hepatitis C patients.

Inflammatory responses and inflammation-associated diseases in organs

Inflammation is a biological response of the immune system that can be triggered by a variety of factors, including pathogens, damaged cells and toxic compounds. These factors may induce acute and/or chronic inflammatory responses in the heart, pancreas, liver, kidney, lung, brain, intestinal tract and reproductive system, potentially leading to tissue damage or disease. Both infectious and non-infectious agents and cell damage activate inflammatory cells and trigger inflammatory signaling pathways, most commonly the NF-κB, MAPK, and JAK-STAT pathways. Here, we review inflammatory responses within organs, focusing on the etiology of inflammation, inflammatory response mechanisms, resolution of inflammation, and organ-specific inflammatory responses.

Clinical Pharmacokinetics and Pharmacodynamics of Ledipasvir/Sofosbuvir, a Fixed-Dose Combination Tablet for the Treatment of Hepatitis C

Ledipasvir/sofosbuvir (Harvoni^®), a fixed-dose combination tablet of an NS5A inhibitor ledipasvir and an NS5B polymerase inhibitor sofosbuvir, is approved in the US, European Union, Canada, and other regions for the treatment of chronic hepatitis C virus infection in adults. Following absorption, ledipasvir reaches maximum plasma concentrations (T _max) 4-4.5 h post-dose and is eliminated with a terminal half-life (t _1/2) of 47 h. Sofosbuvir undergoes intracellular activation to an active triphosphate GS-461203 (not detected in plasma) and ultimately to GS-331007, a predominant circulating metabolite, which is the primary analyte of interest in clinical pharmacology studies. Sofosbuvir is rapidly absorbed and eliminated from plasma (T _max: 0.8-1 h; t _1/2: 0.5 h). The peak plasma concentrations for GS-331007 are achieved between 3.5 and 4 h post-dose; the elimination t _1/2 for GS-331007 is 27 h. Ledipasvir/sofosbuvir exhibits a favorable clinical pharmacology profile; it can be administered once daily without regard to food and does not require dose modification in hepatitis C virus-infected patients with any degree of hepatic impairment or mild to moderate renal impairment. The pharmacokinetic profiles of ledipasvir, sofosbuvir, and GS-331007 (predominant circulating metabolite of sofosbuvir) are not significantly affected by demographic variables; pharmacokinetic/pharmacodynamic analyses reveal no exposure-response relationships for efficacy or safety. The review summarizes the clinical pharmacokinetics, pharmacodynamics, and pharmacokinetic/pharmacodynamic analyses for ledipasvir/sofosbuvir.

Patch-Clamp Study of Hepatitis C p7 Channels Reveals Genotype-Specific Sensitivity to Inhibitors

Hepatitis C is a major worldwide disease and health hazard, affecting ∼3% of the world population. The p7 protein of hepatitis C virus (HCV) is an intracellular ion channel and pH regulator that is involved in the viral replication cycle. It is targeted by various classical ion channel blockers. Here, we generated p7 constructs corresponding to HCV genotypes 1a, 2a, 3a, and 4a for recombinant expression in HEK293 cells, and studied p7 channels using patch-clamp recording techniques. The pH50 values for recombinant p7 channels were between 6.0 and 6.5, as expected for proton-activated channels, and current-voltage dependence did not show any differences between genotypes. Inhibition of p7-mediated currents by amantadine, however, exhibited significant, genotype-specific variation. The IC50 values of p7-1a and p7-4a were 0.7 ± 0.1 nM and 3.2 ± 1.2 nM, whereas p7-2a and p7-3a had 50- to 1000-fold lower sensitivity, with IC50 values of 2402 ± 334 nM and 344 ± 64 nM, respectively. The IC50 values for rimantadine were low across all genotypes, ranging from 0.7 ± 0.1 nM, 1.6 ± 0.6 nM, and 3.0 ± 0.8 nM for p7-1a, p7-3a, and p7-4a, respectively, to 24 ± 4 nM for p7-2a. Results from patch-clamp recordings agreed well with cellular assays of p7 activity, namely, measurements of intracellular pH and hemadsorption assays, which confirmed the much reduced amantadine sensitivity of genotypes 2a and 3a. Thus, our results establish patch-clamp studies of recombinant viroporins as a valid analytical tool that can provide quantitative information about viroporin channel properties, complementing established techniques.

Hepatitis C virus NS5A protein interacts with lysine methyltransferase SET and MYND domain-containing 3 and induces activator protein 1 activation

Hepatitis C virus (HCV) non-structural protein 5A (NS5A) is a multifunctional protein that is involved in the HCV life cycle and pathogenesis. In this study, a host protein(s) interacting with NS5A by tandem affinity purification were searched for with the aim of elucidating the role of NS5A. An NS5A-interacting protein, SET and MYND domain-containing 3 (SMYD3), a lysine methyltransferase reportedly involved in the development of cancer, was identified. The interaction between NS5A and SMYD3 was confirmed in ectopically expressing, HCV RNA replicon-harboring and HCV-infected cells. The other HCV proteins did not bind to SMYD3. SMYD3 bound to NS5A of HCV genotypes 1b and 2a. Deletion mutational analysis revealed that domains II and III of NS5A (amino acids [aa] 250 to 447) and the MYND and N-SET domains of SMYD3 (aa 1 to 87) are involved in the full extent of NS5A-SMYD3 interaction. NS5A co-localized with SMYD3 exclusively in the cytoplasm, thereby inhibiting nuclear localization of SMYD3. Moreover, NS5A formed a complex with SMYD3 and heat shock protein 90 (HSP90), which is a positive regulator of SMYD3. The intensity of binding between SMYD3 and HSP90 was enhanced by NS5A. Luciferase reporter assay demonstrated that NS5A significantly induces activator protein 1 (AP-1) activity, this being potentiated by co-expression of SMYD3 with NS5A. Taken together, the present results suggest that NS5A interacts with SMYD3 and induces AP-1 activation, possibly by facilitating binding between HSP90 and SMYD3. This may be a novel mechanism of AP-1 activation in HCV-infected cells.

The effect of the hepatitis C virus (HCV) NS3 protein on the expression of miR-150, miR-199a, miR-335, miR-194 and miR-27a

Hepatitis C virus (HCV) infection is considered one of the most important causes of chronic liver diseases. Many reports have shown that the proteins of the HCV via interactions with gene expression regulatory networks such as cellular pathways and microRNAs can contribute to the development of chronic liver diseases. The present study aimed to investigate the effects of the HCV NS3 protein on the expression of miR-150 miR-199a, miR-335, miR-194, miR-27a in a cell culture model. Plasmids expressing the full length of the HCV NS3 protein were transfected into the LX-2 cell line, while at the same time a plasmid expressing empty GFP (green fluorescent protein) was used as a negative control group. Subsequently, total RNA was extracted and real-time PCR was performed to measure microRNA expression levels. Additionally, the trypan blue exclusion test was performed to examine the effect of the expressing NS3 protein plasmid on cellular viability. The analysis of microRNA gene expression in LX-2 cells indicated that the NS3 protein, which is endogenous to HCV, can significantly upregulate the expression of miR-27a and downregulate the expression of miR-335 and miR-150 in comparison with the control plasmid expressing GFP and normal cells (p < 0.01). These results suggest that the HCV NS3 protein may play a role in the pathogenesis of chronic hepatic diseases such as liver fibrosis via interaction with cellular microRNAs and modulation of microRNA gene expressions.

Nanoparticles in Antiviral Therapy

In addition to general unavailability of specific antiviral therapeutics for a variety of viral diseases, usage of most antiviral drugs is linked to their limited solubility in aqueous media, short half-life time, and inadequate penetration to specified anatomic compartments. Accordingly, there is continuous effort to improve physicochemical characteristics of existing antiviral drugs. Since nanomaterials display remarkable physical and chemical properties, high surface area to volume ratio, and increased reactivity, new approaches for antiviral therapies include combinations of nanomaterials and current antiviral agents. Multivalent nanostructures, polymers, dendrimers, and liposomes can establish multivalent binding interactions with many biological systems and thus can target pathogenic interactions. There are reports about anitiviral activities of different metal nanoparticles, especially silver nanoparticles and their potential for treatment, prophylaxis, and control of viral infections. Integration of classic antiviral drugs, in the form of multiple ligands, onto nanostructures provides the advantages by creating a high local concentration of active molecules. This article will summarize the antiviral activity of different nanoparticle-based approaches currently available for the treatment of viral infections, and it will discuss metal nanoparticles as possible future antiviral drugs.

Discovery of a Potent Acyclic, Tripeptidic, Acyl Sulfonamide Inhibitor of Hepatitis C Virus NS3 Protease as a Back-up to Asunaprevir with the Potential for Once-Daily Dosing

The discovery of a back-up to the hepatitis C virus NS3 protease inhibitor asunaprevir (2) is described. The objective of this work was the identification of a drug with antiviral properties and toxicology parameters similar to 2, but with a preclinical pharmacokinetic (PK) profile that was predictive of once-daily dosing. Critical to this discovery process was the employment of an ex vivo cardiovascular (CV) model which served to identify compounds that, like 2, were free of the CV liabilities that resulted in the discontinuation of BMS-605339 (1) from clinical trials. Structure-activity relationships (SARs) at each of the structural subsites in 2 were explored with substantial improvement in PK through modifications at the P1 site, while potency gains were found with small, but rationally designed structural changes to P4. Additional modifications at P3 were required to optimize the CV profile, and these combined SARs led to the discovery of BMS-890068 (29).

2015 Philip S. Portoghese Medicinal Chemistry Lectureship. Curing Hepatitis C Virus Infection with Direct-Acting Antiviral Agents: The Arc of a Medicinal Chemistry Triumph

The development of direct-acting antiviral agents that can cure a chronic hepatitis C virus (HCV) infection after 8-12 weeks of daily, well-tolerated therapy has revolutionized the treatment of this insidious disease. In this article, three of Bristol-Myers Squibb's HCV programs are summarized, each of which produced a clinical candidate: the NS3 protease inhibitor asunaprevir (64), marketed as Sunvepra, the NS5A replication complex inhibitor daclatasvir (117), marketed as Daklinza, and the allosteric NS5B polymerase inhibitor beclabuvir (142), which is in late stage clinical studies. A clinical study with 64 and 117 established for the first time that a chronic HCV infection could be cured by treatment with direct-acting antiviral agents alone in the absence of interferon. The development of small molecule HCV therapeutics, designed by medicinal chemists, has been hailed as "the arc of a medical triumph" but may equally well be described as "the arc of a medicinal chemistry triumph".

Metabolism and Disposition of Pan-Genotypic Inhibitor of Hepatitis C Virus NS5A Ombitasvir in Humans

Ombitasvir (also known as ABT-267) is a potent inhibitor of hepatitis C virus (HCV) nonstructural protein 5A (NS5A), which has been developed in combination with paritaprevir/ritonavir and dasabuvir in a three direct-acting antiviral oral regimens for the treatment of patients infected with HCV genotype 1. This article describes the mass balance, metabolism, and disposition of ombitasvir in humans without coadministration of paritaprevir/ritonavir and dasabuvir. Following the administration of a single 25-mg oral dose of [(14)C]ombitasvir to four healthy male volunteers, the mean total percentage of the administered radioactive dose recovered was 92.1% over the 192-hour sample collection in the study. The recovery from the individual subjects ranged from 91.4 to 93.1%. Ombitasvir and corresponding metabolites were primarily eliminated in feces (90.2% of dose), mainly as unchanged parent drug (87.8% of dose), but minimally through renal excretion (1.9% of dose). Biotransformation of ombitasvir in human involves enzymatic amide hydrolysis to form M23 (dianiline), which is further metabolized through cytochrome P450-mediated oxidative metabolism (primarily by CYP2C8) at the tert-butyl group to generate oxidative and/or C-desmethyl metabolites. [(14)C]Ombitasvir, M23, M29, M36, and M37 are the main components in plasma, representing about 93% of total plasma radioactivity. The steady-state concentration measurement of ombitasvir metabolites by liquid chromatography-mass spectrometry analysis in human plasma following multiple doses of ombitasvir, in combination with paritaprevir/ritonavir and dasabuvir, confirmed that ombitasvir is the main component (51.9% of all measured drug-related components), whereas M29 (19.9%) and M36 (13.1%) are the major circulating metabolites. In summary, the study characterized ombitasvir metabolites in circulation, the metabolic pathways, and the elimination routes of the drug.

TCR gene-modified T cells can efficiently treat established hepatitis C-associated hepatocellular carcinoma tumors

The success in recent clinical trials using T cell receptor (TCR)-genetically engineered T cells to treat melanoma has encouraged the use of this approach toward other malignancies and viral infections. Although hepatitis C virus (HCV) infection is being treated with a new set of successful direct anti-viral agents, potential for virologic breakthrough or relapse by immune escape variants remains. Additionally, many HCV+ patients have HCV-associated disease, including hepatocellular carcinoma (HCC), which does not respond to these novel drugs. Further exploration of other approaches to address HCV infection and its associated disease are highly warranted. Here, we demonstrate the therapeutic potential of PBL-derived T cells genetically engineered with a high-affinity, HLA-A2-restricted, HCV NS3:1406-1415-reactive TCR. HCV1406 TCR-transduced T cells can recognize naturally processed antigen and elicit CD8-independent recognition of both peptide-loaded targets and HCV+ human HCC cell lines. Furthermore, these cells can mediate regression of established HCV+ HCC in vivo. Our results suggest that HCV TCR-engineered antigen-reactive T cells may be a plausible immunotherapy option to treat HCV-associated malignancies, such as HCC.

Liver and blood cytokine microenvironment in HCV patients is associated to liver fibrosis score: a proinflammatory cytokine ensemble orchestrated by TNF and tuned by IL-10

BACKGROUND

In this study, we have evaluated the immunological status of hepatitis C virus (HCV)-infected patients aiming at identifying putative biomarkers associated with distinct degrees of liver fibrosis. Peripheral blood and tissue T-cells as well as cytokine levels were quantified by flow cytometry.

RESULTS

Data analysis demonstrated higher frequency of circulating CD8(+) T-cells and Tregs along with a mixed proinflammatory/IL-10-modulated cytokine pattern in HCV patients. Patients with severe liver fibrosis presented lower frequency of circulating CD8(+) T-cells, higher levels of proinflammatory cytokines, but lower levels of IL-10, in addition to the higher viral load. Despite the lower frequency of intrahepatic T-cells and scarce frequency of Tregs, patients with severe liver fibrosis showed higher levels of proinflammatory cytokines (TNF and IFN-γ). The tissue proinflammatory cytokine pattern supported further studies of serum cytokines as relevant biomarkers associated with different liver fibrosis scores. Serum cytokine signature showed that mild liver fibrosis is associated with higher IL-10 serum levels as compared to severe liver disease. There was a clear positive connection of IL-10 with the TNF node in patients with mild liver fibrosis, whereas there is an evident inverse correlation between IL-10 with all other cytokine nodes.

CONCLUSIONS

These results suggest the absence of modulatory events in patients with severe liver damage as opposed to mild fibrosis. Machine-learning data mining pointed out TNF and IL-10 as major attributes to differentiate HCV patients from non-infected individuals with highest performance. In conclusion, our findings demonstrated that HCV infection triggers a local and systemic cytokine ensemble orchestrated by TNF and tuned by IL-10 in such a manner that mirrors the liver fibrosis score, which highly suggests the relevance of these set of biomarkers for clinical investigations.

Genetic, metabolic and environmental factors involved in the development of liver cirrhosis in Mexico

Liver cirrhosis (LC) is a chronic illness caused by inflammatory responses and progressive fibrosis. Globally, the most common causes of chronic liver disease include persistent alcohol abuse, followed by viral hepatitis infections and nonalcoholic fatty liver disease. However, regardless of the etiological factors, the susceptibility and degree of liver damage may be influenced by genetic polymorphisms that are associated with distinct ethnic and cultural backgrounds. Consequently, metabolic genes are influenced by variable environmental lifestyle factors, such as diet, physical inactivity, and emotional stress, which are associated with regional differences among populations. This Topic Highlight will focus on the genetic and environmental factors that may influence the metabolism of alcohol and nutrients in the setting of distinct etiologies of liver disease. The interaction between genes and environment in the current-day admixed population, Mestizo and Native Mexican, will be described. Additionally, genes involved in immune regulation, insulin sensitivity, oxidative stress and extracellular matrix deposition may modulate the degree of severity. In conclusion, LC is a complex disease. The onset, progression, and clinical outcome of LC among the Mexican population are influenced by specific genetic and environmental factors. Among these are an admixed genome with a heterogenic distribution of European, Amerindian and African ancestry; a high score of alcohol consumption; viral infections; a hepatopathogenic diet; and a high prevalence of obesity. The variance in risk factors among populations suggests that intervention strategies directed towards the prevention and management of LC should be tailored according to such population-based features.

Pathogen-Associated Molecular Pattern Recognition of Hepatitis C Virus Transmitted/Founder Variants by RIG-I Is Dependent on U-Core Length

Despite the introduction of direct-acting antiviral (DAA) drugs against hepatitis C virus (HCV), infection remains a major public health concern because DAA therapeutics do not prevent reinfection and patients can still progress to chronic liver disease. Chronic HCV infection is supported by a variety of viral immune evasion strategies, but, remarkably, 20% to 30% of acute infections spontaneously clear prior to development of adaptive immune responses, thus implicating innate immunity in resolving acute HCV infection. However, the virus-host interactions regulating acute infection are unknown. Transmission of HCV involves one or a few transmitted/founder (T/F) variants. In infected hepatocytes, the retinoic acid-inducible gene I (RIG-I) protein recognizes 5' triphosphate (5'ppp) of the HCV RNA and a pathogen-associated molecular pattern (PAMP) motif located within the 3' untranslated region consisting of poly-U/UC. PAMP binding activates RIG-I to induce innate immune signaling and type 1 interferon antiviral defenses. HCV poly-U/UC sequences can differ in length and complexity, suggesting that PAMP diversity in T/F genomes could regulate innate immune control of acute HCV infection. Using 14 unique poly-U/UC sequences from HCV T/F genomes recovered from acute-infection patients, we tested whether RIG-I recognition and innate immune activation correlate with PAMP sequence characteristics. We show that T/F variants are recognized by RIG-I in a manner dependent on length of the U-core motif of the poly-U/UC PAMP and are recognized by RIG-I to induce innate immune responses that restrict acute infection. PAMP recognition of T/F HCV variants by RIG-I may therefore impart innate immune signaling and HCV restriction to impact acute-phase-to-chronic-phase transition.

IMPORTANCE

Recognition of nonself molecular patterns such as those seen with viral nucleic acids is an essential step in triggering the immune response to virus infection. Innate immunity is induced by hepatitis C virus infection through the recognition of viral RNA by the cellular RIG-I protein, where RIG-I recognizes a poly-uridine/cytosine motif in the viral genome. Variation within this motif may provide an immune evasion strategy for transmitted/founder viruses during acute infection. Using 14 unique poly-U/UC sequences from HCV T/F genomes recovered from acutely infected HCV patients, we demonstrate that RIG-I binding and activation of innate immunity depend primarily on the length of the uridine core within this motif. T/F variants found in acute infection contained longer U cores within the motif and could activate RIG-I and induce innate immune signaling sufficient to restrict viral infection. Thus, recognition of T/F variants by RIG-I could significantly impact the transition from acute to chronic infection.

Pharmacokinetics and safety of co-administered paritaprevir plus ritonavir, ombitasvir, and dasabuvir in hepatic impairment

BACKGROUND & AIMS

Paritaprevir, ombitasvir, and dasabuvir are direct-acting antivirals for treatment of chronic hepatitis C virus (HCV) infection. The aim of this study was to characterize the effects of mild, moderate, and severe hepatic impairment on the pharmacokinetics of these drugs.

METHODS

HCV-negative subjects with normal hepatic function (n=7) or mild (Child-Pugh A, n=6), moderate (Child-Pugh B, n=6), or severe (Child-Pugh C, n=5) hepatic impairment received a single-dose of the combination of paritaprevir plus ritonavir (paritaprevir/r, 200/100 mg), ombitasvir (25 mg), and dasabuvir (400 mg). Plasma samples were collected through 144 hours after administration for pharmacokinetic assessments.

RESULTS

Paritaprevir, ombitasvir, dasabuvir, and ritonavir exposures (maximal plasma concentration, C(max), and area under the concentration-time curve, AUC) were minimally affected in subjects with mild or moderate hepatic impairment. Differences in exposures between healthy controls and subjects with mild or moderate hepatic impairment were less than 35%, except for 62% higher paritaprevir AUC in subjects with moderate hepatic impairment. Paritaprevir and dasabuvir AUC were significantly higher in subjects with severe hepatic impairment (950% and 325%, respectively). However, ombitasvir AUC was 54% lower and ritonavir AUC was comparable. Adverse events included eye stye, insomnia, and pain from an infiltrated intravenous line.

CONCLUSIONS

The changes observed in paritaprevir, ritonavir, ombitasvir, and dasabuvir exposures in subjects with mild or moderate hepatic impairment do not necessitate dose adjustment. Subjects with severe hepatic impairment had substantially higher paritaprevir and dasabuvir exposures.

Nanostructures for the Inhibition of Viral Infections

Multivalent interactions are omnipresent in biology and confer biological systems with dramatically enhanced affinities towards different receptors. Such multivalent binding interactions have lately been considered for the development of new therapeutic strategies against bacterial and viral infections. Multivalent polymers, dendrimers, and liposomes have successfully targeted pathogenic interactions. While a high synthetic effort was often needed for the development of such therapeutics, the integration of multiple ligands onto nanostructures turned to be a viable alternative. Particles modified with multiple ligands have the additional advantage of creating a high local concentration of binding molecules. This review article will summarize the different nanoparticle-based approaches currently available for the treatment of viral infections.

Pharmacokinetics and dose recommendations for cyclosporine and tacrolimus when coadministered with ABT-450, ombitasvir, and dasabuvir

ABT-450, ombitasvir, and dasabuvir are direct-acting antiviral agents (DAAs) that have been developed for combination treatment of chronic hepatitis C virus (HCV) infection. Because these DAAs have metabolic and transporter profiles that overlap with cyclosporine and tacrolimus disposition, there is potential for drug interactions. Two Phase 1 studies assessed effects of ABT-450 (150 mg coadministered with ritonavir 100 mg once daily), ombitasvir (25 mg once daily), and dasabuvir (400 mg twice daily) on the pharmacokinetics, safety, and tolerability of a single dose of cyclosporine (30 mg) or tacrolimus (2 mg) in healthy volunteers (N = 12 per study). In the presence of steady-state concentrations of all 3 DAAs, dose-normalized cyclosporine concentration at 24 hours (C₂₄), and area under the concentration-time curve from time 0 to infinity (AUC(∞)) were 15.8-fold and 5.8-fold, respectively, and dose-normalized tacrolimus C₂₄ and AUC(∞) were 17-fold and 57-fold, respectively, of either agent alone. Cyclosporine and tacrolimus half-lives increased from 7 to 25 h and 32 to 232 h, respectively. There were no major safety or tolerability issues in these studies. The results suggest that cyclosporine and tacrolimus doses and dosing frequency should be reduced in HCV-infected posttransplant patients being treated with this 3-DAA regimen.

Acute pulmonary hypertension after transjugular intrahepatic portosystemic shunt: a potentially deadly but commonly forgotten complication

Hepatitis C virus (HCV) is a common cause of chronic liver disease and is the most common indication for liver transplantation in the United States. As increasing numbers of the population experience complications from chronic liver disease, management of these complications comes into focus. One such management technique is a transjugular intrahepatic portosystemic shunt (TIPS). As the number of patients with HCV cirrhosis increases, the proportion of TIPS procedures performed will also increase. It is, therefore, paramount to understand the potential adverse effects of this increasingly used procedure. This case report focuses on a 52-year-old man with HCV cirrhosis who developed the complication of acute pulmonary hypertension after receiving a TIPS procedure. In this case report, we discuss this important but commonly missed complication of TIPS, including incidence, diagnosis, and treatment.

The relationship between HLA-G and viral loads in non-responder HCV-infected patients after combined therapy with IFN-α2α and ribavirin

Hepatitis C disease is a virus mediated infection causing major health problem worldwide. Conversions of immune surveillance play an important role in response to virus clearance. Immune modulating molecules such as HLA-G and IL-10 that convert immune response toward Th2 may play a role to inhibit response from combined therapy with IFN-α2α and ribavirin. The objective of this study was to investigate the expression of HLA-G and IL-10 in responder and non-responder HCV positive patients. In this study, characteristics of the virus and 48 responder and non-responder patients in response to the combined therapy with IFN-α2α and ribavirin were analyzed. The expression levels of HLA-G and IL-10 were conducted using real-time PCR. Also, soluble HLA-G in both groups of patients and healthy individuals were determined by enzyme-linked immunosorbent assay. According to the obtained data, HCV 1a was the predominant genotype in responder and non-responder patients. Expression levels of HLA-G and IL-10 in non-responder group was significantly more than responder and control groups (P<0.001). Additionally, expression levels of HLA-G and IL-10 were remarkably higher compared to healthy individuals at the beginning of treatment. Soluble HLA-G in non-responder patients was noticeably increased in comparison to responder patients after treatment (P<0.05). These findings suggest that elevation of HLA-G and IL-10 in HCV infected patients may play an important role in response to combined therapy with IFN-α2α and ribavirin.