A multicellular liver organoid model for investigating hepatitis C virus infection and nonalcoholic fatty liver disease progression.

Background And Aims: HCV infection can be successfully managed with antiviral therapies; however, progression to chronic liver disease states, including NAFLD, is common. There is currently no reliable in vitro model for investigating host-viral interactions underlying the link between HCV and NAFLD; although liver organoids (LOs) show promise, they currently lack nonparenchymal cells, which are key to modeling disease progression.

Approach And Results: Here, we present a novel, multicellular LO model using a coculture system of macrophages and LOs differentiated from the same human pluripotent stem cells (PSCs).

Identification of Zika virus NS2B-NS3 protease and NS5 polymerase inhibitors by structure-based virtual screening of FDA-approved drugs.

Zika virus (ZIKV) is a mosquito-borne human flavivirus responsible that causing emergency outbreaks in Brazil. ZIKV is suspected of causing Guillain-Barre syndrome in adults and microcephaly. The NS2B-NS3 protease and NS5 RNA-dependent RNA polymerase (RdRp), central to ZIKV multiplication, have been identified as attractive molecular targets for drugs.

Selected ginsenosides interfere efficiently with hepatitis B virus mRNA expression levels and suppress viral surface antigen secretion.

Ginsenosides are a class of natural steroid glycosides and triterpene saponins found in . After screening of a commercial ginsenoside compound library for low cellular cytotoxicity and the ability to mediate efficient reductions in hepatitis B virus (HBV) mRNA expression levels in HepG2.2.

Optimization of BRET saturation assays for robust and sensitive cytosolic protein-protein interaction studies.

Bioluminescence resonance energy transfer (BRET) saturation is a method of studying protein-protein interaction (PPI) upon quantification of the dependence of the BRET signal on the acceptor/donor (A:D) expression ratio. In this study, using the very bright Nluc/YFP BRET pair acquired respectively with microplate reader and automated confocal microscopy, we significantly improved BRET saturation assay by extending A:D expression detection range and normalizing A:D expression with a new BRET-free probe. We next found that upon using variable instead of fixed amount of donor molecules co-expressed with increasing acceptor concentrations, BRET saturation assay robustness can be further improved when studying cytosolic protein, although the relative amounts of dimers (BRETmax) and the relative dimer affinity (BRET50) remain similar.

Mono- and combinational drug therapies for global viral pandemic preparedness.

Broadly effective antiviral therapies must be developed to be ready for clinical trials, which should begin soon after the emergence of new life-threatening viruses. Here, we pave the way towards this goal by reviewing conserved druggable virus-host interactions, mechanisms of action, immunomodulatory properties of available broad-spectrum antivirals (BSAs), routes of BSA delivery, and interactions of BSAs with other antivirals. Based on the review, we concluded that the range of indications of BSAs can be expanded, and new pan- and cross-viral mono- and combinational therapies can be developed.

Drug repurposing through virtual screening and in vitro validation identifies tigecycline as a novel putative HCV polymerase inhibitor.

The repurposing of marketed drugs for new indications is an elegant strategy to quickly and cost-efficiently address unmet medical needs. The hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp) has been shown to be a valid drug target. We performed structure-based virtual screening to assess the off-label utilization of existing drugs as novel HCV inhibitors.

Design of a multi-epitope Zika virus vaccine candidate - an study.

Zika virus (ZIKV), an RNA virus, rapidly spreads mosquito-borne sickness. Currently, there are neither effective vaccines nor therapeutics available to prevent or treat ZIKV infection. In this study, to address these unmet medical needs, we aimed to design B- and T-cell candidate multi-epitope-based subunit against ZIKV using an approach.

Synergistic Interferon-Alpha-Based Combinations for Treatment of SARS-CoV-2 and Other Viral Infections.

Background: There is an urgent need for new antivirals with powerful therapeutic potential and tolerable side effects.

Methods: Here, we tested the antiviral properties of interferons (IFNs), alone and with other drugs in vitro.

Results: While IFNs alone were insufficient to completely abolish replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), IFNα, in combination with remdesivir, EIDD-2801, camostat, cycloheximide, or convalescent serum, proved to be more effective.

Determination of infectious hepatitis B virus particles by an end-point dilution assay identifies a novel class of inhibitors.

The quantification of infectious virus particles is fundamental to perform in vitro virology studies. To determine the number of hepatitis B virus (HBV) genome-containing particles in vitro, the genome equivalents (GEq) are measured using quantitative PCR (qPCR). However, in addition to infectious virions, HBV DNA-containing, non-infectious HBV particles are also produced in vitro, which can lead to an over-estimation of the number of infectious HBV particles when analyzed by qPCR.

A new high-content screening assay of the entire hepatitis B virus life cycle identifies novel antivirals.

Background & Aims: Chronic hepatitis B is an incurable disease. Addressing the unmet medical need for therapies has been hampered by a lack of suitable cell culture models to investigate the HBV life cycle in a single experimental setup. We sought to develop a platform suitable to investigate all aspects of the entire HBV life cycle.

Screening of FDA-Approved Drugs Using a MERS-CoV Clinical Isolate from South Korea Identifies Potential Therapeutic Options for COVID-19.

Therapeutic options for coronaviruses remain limited. To address this unmet medical need, we screened 5406 compounds, including United States Food and Drug Administration (FDA)-approved drugs and bioactives, for activity against a South Korean Middle East respiratory syndrome coronavirus (MERS-CoV) clinical isolate. Among 221 identified hits, 54 had therapeutic indexes (TI) greater than 6, representing effective drugs.

Thiophen urea derivatives as a new class of hepatitis C virus entry inhibitors.

To develop unique small-molecule inhibitors of hepatitis C virus (HCV), thiophen urea (TU) derivatives were synthesised and screened for HCV entry inhibitory activities. Among them, seven TU compounds exhibited portent anti-viral activities against genotypes 1/2 (EC < 30 nM) and subsequently, they were further investigated; based on the pharmacological, metabolic, pharmacokinetic, and safety profiles, was selected as the optimised lead compound as an HCV entry inhibitor. possesses effective multi-genotypic antiviral activity.

Molecular basis of the interaction of the human tyrosine phosphatase PTPN3 with the hepatitis B virus core protein.

Interactions between the hepatitis B virus core protein (HBc) and host cell proteins are poorly understood, although they may be essential for the propagation of the virus and its pathogenicity. HBc has a C-terminal PDZ (PSD-95, Dlg1, ZO-1)-binding motif (PBM) that is responsible for interactions with host PDZ domain-containing proteins. In this work, we focused on the human protein tyrosine phosphatase non-receptor type 3 (PTPN3) and its interaction with HBc.

Structure-guided discovery approach identifies potential lead compounds targeting M of SARS-CoV-2.

The ongoing coronavirus disease 19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become fatal for the world with affected population crossing over 25 million in more than 217 countries, consequently declared a global pandemic by the World Health Organization. Unfortunately, neither specific prophylactic or therapeutic drugs nor vaccines are available. To address the unmet medical needs, we explored a strategy identifying new compounds targeting the main protease (M) of SARS-CoV-2.

Nanobodies: an unexplored opportunity to combat COVID-19.

Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). This virus is capable of human-to-human transmission, and is spreading rapidly round the globe, with markedly high fatality rates. Unfortunately, there are neither vaccines nor specific therapies available to combat it, and the developments of such approaches depend on pursuing multiple avenues in biomedical science.

Identification and Tracking of Antiviral Drug Combinations.

Combination therapies have become a standard for the treatment for HIV and hepatitis C virus (HCV) infections. They are advantageous over monotherapies due to better efficacy, reduced toxicity, as well as the ability to prevent the development of resistant viral strains and to treat viral co-infections. Here, we identify new synergistic combinations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), echovirus 1 (EV1), hepatitis C virus (HCV) and human immunodeficiency virus 1 (HIV-1) in vitro.

Advanced Therapeutics, Vaccinations, and Precision Medicine in the Treatment and Management of Chronic Hepatitis B Viral Infections; Where Are We and Where Are We Going?

The management of chronic hepatitis B virus (CHB) infection is an area of massive unmet clinical need worldwide. In spite of the development of powerful nucleoside/nucleotide analogue (NUC) drugs, and the widespread use of immune stimulators such as interferon-alpha (IFNα) or PEGylated interferon-alpha (PEG-IFNα), substantial improvements in CHB standards of care are still required. We believe that the future for CHB treatment now rests with advanced therapeutics, vaccination, and precision medicine, if all are to bring under control this most resilient of virus infections.

A Simple and Cost-Effective DNA Preparation Method Suitable for High-Throughput PCR Quantification of Hepatitis B Virus Genomes.

Hepatitis B virus (HBV) is a para-retrovirus that reverse transcribes its pregenomic RNA into relaxed circular DNA inside viral nucleocapsids. The number of HBV genomes produced in vitro is typically quantified using commercial silica-membrane-based nucleic acid purification kits to isolate total DNA followed by HBV-specific quantitative PCR (qPCR). However, despite the convenience of commercial kits, this procedure is costly and time-consuming due to multiple centrifugation steps, which produce unnecessary waste.

Immuno-informatics-based Identification of Novel Potential B Cell and T Cell Epitopes to Fight Zika Virus Infections.

Background: Globally, the recent outbreak of Zika virus (ZIKV) in Brazil, Asia Pacific, and other countries highlighted the unmet medical needs. Currently, there are neither effective vaccines nor therapeutics available to prevent or treat ZIKV infection.

Objective: In this study, we aimed to design an epitope-based vaccine for ZIKV using an in silico approach to predict and analyze B- and T-cell epitopes.

Benzimidazole Derivatives as Novel Zika Virus Inhibitors.

We have synthesized 50 benzimidazole (BMZ) derivatives with 1,2-phenylenediamines and aromatic aldehydes under mild oxidation conditions by using inexpensive, nontoxic inorganic salt sodium metabisulfite in a one-pot condensation reaction and screened their ability to interfere with Zika virus (ZIKV) infection utilizing a cell-based phenotypic assay. Seven BMZs inhibited an African ZIKV strain with a selectivity index (SI=CC /EC ) of 9-37. Structure-activity relationship analysis demonstrated that substitution at the C-2, N-1, and C-5 positions of the BMZ ring were important for anti-ZIKV activity.

The Beginning of Ending Hepatitis C Virus: A Summary of the 26th International Symposium on Hepatitis C Virus and Related Viruses.

Hepatitis C virus (HCV) infects ~71 million people worldwide, and 399,000 people die annually due to HCV-related liver cirrhosis and hepatocellular carcinoma. The use of direct-acting antivirals results in a sustained virologic response in >95% of patients with chronic HCV infection. However, several issues remain to be solved to eradicate HCV.

An Engineered Microvirin Variant with Identical Structural Domains Potently Inhibits Human Immunodeficiency Virus and Hepatitis C Virus Cellular Entry.

Microvirin (MVN) is one of the human immunodeficiency virus (HIV-1) entry inhibitor lectins, which consists of two structural domains sharing 35% sequence identity and contrary to many other antiviral lectins, it exists as a monomer. In this study, we engineered an MVN variant, LUMS1, consisting of two domains with 100% sequence identity, thereby reducing the chemical heterogeneity, which is a major factor in eliciting immunogenicity. We determined carbohydrate binding of LUMS1 through NMR chemical shift perturbation and tested its anti-HIV activity in single-round infectivity assay and its anti-hepatitis C virus (HCV) activity in three different assays including HCVcc, HCVpp, and replicon assays.

Identification and characterization of a novel hepatitis B virus pregenomic RNA encapsidation inhibitor.

Currently, therapies to treat chronic hepatitis B (CHB) infection are based on the use of interferon-α or nucleos(t)ide analogs (NAs) to prevent viral DNA synthesis by inhibiting the reverse transcriptase activity of the hepatitis B virus (HBV) polymerase (Pol). However, these therapies are not curative; thus, the development of novel anti-HBV agents is needed. In accordance with this unmet medical need, we devised a new target- and cell-based, high-throughput screening assay to identify novel small molecules that block the initial interaction of the HBV Pol with its replication template the viral pregenomic RNA (pgRNA).

Common Nodes of Virus-Host Interaction Revealed Through an Integrated Network Analysis.

Viruses are one of the major causes of acute and chronic infectious diseases and thus a major contributor to the global burden of disease. Several studies have shown how viruses have evolved to hijack basic cellular pathways and evade innate immune response by modulating key host factors and signaling pathways. A collective view of these multiple studies could advance our understanding of virus-host interactions and provide new therapeutic perspectives for the treatment of viral diseases.

Novel Antiviral Activities of Obatoclax, Emetine, Niclosamide, Brequinar, and Homoharringtonine.

Viruses are the major causes of acute and chronic infectious diseases in the world. According to the World Health Organization, there is an urgent need for better control of viral diseases. Repurposing existing antiviral agents from one viral disease to another could play a pivotal role in this process.