Search Results (628)

Background: Hepatitis B and C viral infections remain a significant global health challenge, despite the implementation of an effective direct-acting antiviral (DAAs) and nucleos(t)ide analogues (NAs). Current HBV therapy is not curative as stopping therapy usually leads to active disease in most patients requiring long-term treatment. Although current HCV-DAAs are highly effective they fall short due to arising drug-resistance and have limited ability to avert re-infections. Furthermore, current HCV DAA treatments lead to the reactivation of occult HBV infection, compromising the effectiveness of current antiviral therapies, and increasing the risk of severe liver complications like cirrhosis and hepatocellular carcinoma. In addition, current treatments do not restore the immune dysfunction, a characteristic of chronic HBV infection. Given the global burden of disease, there is an urgent need for more effective therapy that can shorten the duration of treatment and achieve high rates of HBsAg reduction. Combining an antiviral to reduce viral antigen burden and an immunomodulator to boost the immune response could provide an effective treatment for HBV/HCV infections. Methods: In this study, we explored the potential of a novel bacterial therapeutic agent, heat-killed Caulobacter crescentus (HKCC), as an alternative and/or adjunct host-based therapy for HCV and HBV infections. Here, we have investigated the antiviral effects of the HKCC-stimulated human PBMCs using in vitro HCV and HBV infection models to assess viral replication, viral relapse responses, protein expression, and cytotoxicity. Results: Our findings reveal that HKCC induced a multi-functional cytokine response (IFN, TNF, IL-2, IL-10, IL-6, IL-17A, and IL-22) in PBMCs obtained from multiple healthy donors. Supernatants collected from these HKCC-stimulated human PBMCs, alone and in combination with antivirals, strikingly inhibited HCV replication and viral relapse responses without inducing any cytotoxic effects on HCV-1a replicon cells. In addition, these PBMC supernatants, with or without antivirals, led to the suppression of HBV DNA replication and inhibited HBsAg and HBeAg production in HepG 2.2.15 cells. Conclusions: In conclusion, HKCC is a promising candidate for eliminating HBV and HCV infections, and warrants further investigation to potentially contribute to the development of a novel host-based immunotherapy. Full article

Background: Patients with liver cirrhosis remain at a persistent risk of developing hepatocellular carcinoma (HCC) and liver decompensation even after hepatitis C virus (HCV) eradication. Objectives: We aimed to assess survival, the occurrence of recompensation and de novo decompensation events, and hepatic and extrahepatic malignancies in patients with liver cirrhosis during long-term observation (LTO) after direct-acting antiviral (DAA) treatment. Methods: The study population consisted of 326 consecutive HCV-infected patients with liver cirrhosis treated with DAAs between 1 July 2015 and 30 June 2025 at a single tertiary hepatology center, of whom we followed 298 individuals for a median (IQR) of 4.4 (2.4–8.1) years after treatment completion. Results: Men predominated in the study population, with a median age of 60 (48–69) years. The vast majority of patients had at least one comorbid condition. Fifty of them (16.8%) developed malignancies during LTO, including 33 cases of HCC and 17 with extrahepatic malignancies. New cases of HCC were documented as late as 9 years after DAA therapy. Overall, 103 patients (34.6%) died during LTO; 51 deaths occurred in patients with malignancies. Liver recompensation was observed in 27.8% of patients, while 9.9% experienced de novo decompensation events during LTO. The survival curve showed a gradual decline in survival probability from 0.96 at 1–2 years to 0.70 at 5 years and 0.51 at 10 years. Conclusions: Patients with cirrhosis should remain under long-term hepatological monitoring after antiviral treatment, as they are still at risk of liver decompensation and the development of de novo HCC. Full article

Pollen constitutes the primary source of proteins, amino acids, lipids, sterols, vitamins, and minerals for honey bees. However, not all pollen types provide the same resources or have the same biological value. Its chemical composition changes according to botanical origin, geographic location, and environmental conditions. This variability can influence metabolism, the immune system, oxidative balance, and the ability to resist or tolerate infections. This article examines the available evidence on the relationship between pollen chemical quality and the dynamics of Deformed Wing Virus (DWV) infection in Apis mellifera. The analysis is approached from molecular, physiological, ecological, and seasonal perspectives. Current findings suggest that more diverse and higher-quality pollen diets are generally associated with greater colony survival and improved health status, although their effects on viral load are more heterogeneous and context-dependent. In some studies, pollen intake is linked to a reduction in DWV, whereas in others viral loads remain stable or even increase despite improvements in survival, physiological condition, or colony performance. These differences suggest that pollen may act not only by enhancing resistance to the virus but also by increasing tolerance to infection-associated damage. The potential role of pollen bioactive compounds, particularly flavonoids and phenolic acids, is also discussed. Nevertheless, evidence of direct antiviral action of these compounds in bees remains limited, as many proposed mechanisms derive from other organisms. This synthesis provides an integrative perspective on pollen nutrition and its relevance for colony resilience against viral infections. Full article

Background: Abnormalities in energy and amino acid metabolism are potentially involved in hepatocellular carcinoma (HCC) development. This study aimed to identify serum metabolites predictive of HCC following sustained virological response (SVR) with hepatitis C virus (HCV) treatment. Methods: Comparative metabolomics was conducted using time-course serum samples from patients who failed interferon-based therapy but subsequently achieved SVR with direct-acting antivirals (DAAs), minimizing inter-individual variability. Predictive biomarkers for post-SVR HCC were extracted from the results and validated by comparing 29 patients who developed post-SVR HCC with 58 age-matched patients who remained HCC-free during follow-up. Results: Metabolite concentrations changed more markedly after treatment in SVR cases than in non-SVR cases. Significant changes in methionine (Met), methionine sulfoxide (MetO), and ornithine (Orn) levels before and after treatment (Pre- and Post-Tx) were found only in the non-HCC group. Regression and survival analyses identified high levels of Pre- and Post-Tx Orn, Pre-Tx Met, and Post-Tx MetO as predictors of post-SVR HCC and enabled risk stratification. The integration of these metabolites with the fibrosis-4 (FIB-4) index and alpha-fetoprotein (AFP) facilitated risk stratification and discriminated between high- and low-risk patients. The Pre-Tx FIB-4/Met model and the Post-Tx AFP/MetO/Orn model identified low- and high-risk groups with 3-year HCC incidence rates of 6.4% and 81.8%, respectively. Conclusions: Serum Met, MetO, and Orn were identified as candidate biomarkers associated with post-SVR HCC development, which remains a concern in the fight against hepatitis C. Combining these metabolites with established clinical markers may improve post-SVR HCC risk stratification. Full article

Background/Objectives: Chronic hepatitis C (CHC) infection is an independent risk factor for developing type 2 diabetes mellitus (T2DM). However, it is unknown if antiviral treatment, especially with direct-acting antivirals (DAAs), changes long-term glycemic outcomes. Methods: We conducted a retrospective comparative cohort study of 2489 patients with chronic hepatitis C (CHC) in southern Taiwan between 2005 and 2022 who underwent treatment with either an interferon (IFN)-based or direct-acting antiviral agent (DAA) regimen. Given the distinct treatment eras of IFN and DAA therapies, potential temporal confounding was considered in the analytical design. Patients with existing diabetes or co-infections were excluded. The incidence of new-onset T2DM and longitudinal HbA1c levels were compared between treatment groups over a mean follow-up period of 2.56 years. Results: DAA-treated patients demonstrated a lower crude cumulative incidence of T2DM compared with IFN-treated patients (2.46% vs. 6.91%). However, adjusted analyses did not demonstrate a statistically significant difference between treatment groups. The cumulative risk appeared to plateau after the third year among DAA recipients. Post-therapy, HbA1c levels remained stable in both groups at between 5.5% and 6.5% over as long as five years. Splitting regression revealed that BMI ≥ 30 kg/m², and not treatment type or achieved SVR, was an independent T2DM risk factor. The lowest rates of diabetes incidence were associated with pan-genotypic DAA regimens. Conclusions: DAA-treated patients showed lower crude T2DM incidence than IFN-treated patients; however, this difference was not consistently significant after adjustment for baseline factors. Viral eradication may be associated with favorable metabolic trends; however, the present findings do not establish a causal protective effect against incident T2DM. While increased BMI remained an independent predictor of post-treatment diabetes risk. Full article

Although antiviral development against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been dominated by replication-directed strategies, structural and accessory proteins offer a complementary and increasingly important opportunity for small-molecule intervention. These proteins control key processes outside the core replication machinery, including viral entry, membrane remodelling, virion assembly, egress, and host immune modulation, thereby expanding the mechanistic scope of antiviral design. However, many of these targets are membrane-associated, oligomeric, conformationally dynamic, or function through protein–protein interactions, creating distinct challenges in target validation, assay design, and chemical optimisation. In this review, we comprehensively and critically evaluate the structural and accessory proteomes of SARS-CoV-2, with a strict focus on small-molecule tractability and translational relevance. We highlight the most credible direct-acting opportunities, focusing on the membrane (M), envelope (E), and nucleocapsid (N) structural proteins, together with the accessory protein open reading frame 3a (ORF3a), for which emerging chemical matter strengthens confidence in druggability. In contrast, Spike (S) and several host-interface accessory proteins, including ORF6, ORF8, ORF9b, and ORF10, are best viewed as more selective or earlier-stage opportunities that require stronger on-target chemical validation. Emphasis is placed on structural accessibility, mechanism-based assay systems, evidence quality, cellular and in vivo activity, and developability constraints relevant to exposure at the infection site. Rather than replacing replication-directed antivirals, these non-canonical targets are best considered adjunctive or complementary components of future combination strategies designed to broaden antiviral coverage, enhance robustness, and improve pandemic preparedness. Full article

Viruses cause a great number of infectious diseases with medical, veterinary, agricultural, social and economic impact. Their unique mechanisms to spread, overcome and resist the existing countermeasures require innovative and smart antiviral strategies such as the effective disinfection of enclosed environments with ensured broad-spectrum efficacy and minimized risks associated with handling liquid biocides. Formic acid (FA) is a well-established natural acaricide used in beehives with an antiviral potential; however, its application in a liquid form is hindered by severe corrosiveness and rapid, uncontrolled evaporation. This study describes a novel formulation of FA, using a cryogel carrier for achieving a vapor-phase inactivation of viruses, thus eliminating the need for direct contact between the disinfectant and the pathogen. Firstly, a poly(N-isopropylacrylamide) (PNIPAm) cryogel was synthesized by a procedure involving cryogenic treatment, photochemical crosslinking, and freeze-drying, and then the cryogel was swollen with 65% FA or _ddH₂O as a control. After an exposure of a panel of animal and human viruses to FA, evaporated by the polymer carrier for time intervals between 15 min and 12 h, they were neutralized completely as follows: Poliovirus (PV) as a surrogate for major bee viral pathogens for 60 min by 5.1 ∆lg; Feline calicivirus (FCV) for 60 min by 5.3 ∆lg; Adenovirus 5 (AdV5) for 12 h by 4.0 ∆lg; and Influenza virus A (IAV) for 15 min by 5.1 ∆lg. Results were recorded after titration, 48–72 h incubation, cytopathic effect estimation and NR uptake assay. Our results suggest that 65% FA, when delivered via the PNIPAm cryogel matrix, acts as a powerful agent for fumigation-like disinfection. This “dry” delivery strategy offers significant practical advantages: it eliminates the need for open liquid containers, prevents spill-related hazards, and provides an alternative for controlled, long-term release of active vapors. Full article

Direct-acting antivirals (DAAs) have revolutionized hepatitis C virus (HCV) therapy, yet resistance-associated substitutions (RASs) remain a concern in specific clinical contexts. Here, we present a database-derived global overview of HCV RASs by analyzing 19,449 publicly available sequences across multiple genotypes and subtypes, encompassing both untreated and previously treated infections, in the NS3, NS5A, and NS5B genomic regions. We demonstrate a markedly heterogeneous distribution of RASs shaped by viral genotype, geographic origin, and treatment era. Importantly, RASs against pan-genotypic NS3 protease inhibitors (glecaprevir and voxilaprevir) were rare (generally <1% across genotypes). In contrast, NS5A inhibitors showed greater vulnerability, with the Y93H substitution detected at notable frequencies in major genotypes (3.2–7.0%) and near-universal resistance-associated substitutions (e.g., 100% Q30S) observed in the rare genotype 8. The NS5B nucleotide analogue sofosbuvir retained a high genetic barrier, with the canonical S282T substitution detected only sporadically (2.1% of genotype 4 sequences). At the population level, geographic heterogeneity was evident, with higher RAS frequencies observed in specific regions, alongside pronounced data gaps in high-prevalence areas of Africa. Temporal analyses revealed an increase in NS3 and NS5A RASs following the introduction of first-generation DAAs, with NS5A substitutions persisting into the current interferon-free era, whereas NS5B resistance remained consistently rare across all treatment periods. Together, these findings provide a global, population-level overview of resistance-associated HCV diversity and reinforce the durability of high-barrier regimens while highlighting persistent genotype-specific vulnerabilities with implications for antiviral resistance surveillance and HCV elimination efforts. Full article

The SARS-CoV-2 non-structural proteome remains the most clinically validated and strategically important landscape for direct-acting small-molecule antiviral drug discovery. The success of inhibitors targeting the main protease (M^pro, Nsp5) and RNA-dependent RNA polymerase (RdRp, Nsp12) has firmly established viral replication enzymes as tractable, druggable, and therapeutically relevant targets, while setting clear benchmarks for translational antiviral development. Building on this foundation, a second wave of non-structural protein (Nsp) targets has emerged with increasing translational promise, including the papain-like protease (PL^pro), the bifunctional Nsp14 proofreading and capping machinery, Nsp16 2′-O-methyltransferase, Nsp13 helicase, and Nsp15 endoribonuclease. In parallel, additional components such as Nsp1 and the Mac1 domain of Nsp3 continue to expand the antiviral design space, although they remain at earlier stages of chemical validation. In this review, we comprehensively assess SARS-CoV-2 non-structural proteins through a medicinal chemistry and translational lens, with an emphasis on structural tractability, mechanism of action, quality of chemical matter, cellular and in vivo antiviral evidence, evolutionary conservation, resistance liabilities, and developability. Particular attention is given to the features that distinguish tool compounds from genuinely actionable leads and to the opportunities for rational combination regimens that extend beyond first-generation protease- and polymerase-centred therapy. Collectively, the non-structural proteome offers the strongest foundation for next-generation and potentially broader-spectrum coronavirus antivirals with improved resilience to viral evolution. Full article

Background: Hepatitis C virus (HCV) remains a major cause of preventable liver-related mortality in the United States despite highly effective direct-acting antivirals (DAAs). Contemporary assessment of mortality trends and disparities is essential for elimination efforts. Methods: Using CDC WONDER multiple cause-of-death data (1999–2023), we identified HCV-related deaths using ICD-10 codes for acute and chronic HCV (B17.1, B18.2) and calculated age-adjusted mortality rates (AAMRs) per 100,000 (2000 US standard). Rates were stratified by sex, race/ethnicity, census region, and 2013 NCHS urban–rural classification. Joinpoint regression quantified temporal inflection points and annual percent changes (APCs). Results: Overall HCV-related AAMR increased from 1.8 (1999) to a peak of 5.0 (2014), then declined to 2.3 (2023), with a marked post-2014 decrease (APC −8.2%). Mortality was consistently higher in males than females (2023 rate ratio 2.57). In 2023, American Indian/Alaska Native individuals had the highest mortality (AAMR 8.7; rate ratio 3.48 vs. non-Hispanic White), followed by non-Hispanic Black individuals (AAMR 6.2; rate ratio 2.48). Mortality remained highest in the West and was higher in non-metropolitan than metropolitan counties (AAMR 2.8 vs. 2.3; rate ratio 1.22), with a slower post-2014 decline in non-metropolitan areas. Conclusions: Our findings indicate that while the DAA era has been associated with a substantial reduction in HCV-related mortality at the national level, this progress has not been uniform across all populations. Persistent excess mortality among Native American and non-Hispanic Black individuals may reflect inequities in the HCV care cascade, including screening, confirmatory testing, linkage to specialty care, insurance-related restrictions, and the high cost of antiviral therapy. These results highlight the need for policies and public health strategies that improve equitable and affordable access to curative HCV treatment. Full article

The innate immune system, particularly the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway, is a major early defense barrier against influenza A virus infection. However, excessive immune responses can trigger lethal cytokine storms and severe immune-mediated pathology. In this study, we performed a genome-wide CRISPR/dCas9 gene activation screen in human lung epithelial (A549) cells by using an A/Puerto Rico/8/1934 (H1N1) reporter virus, and identified the ubiquitin-specific protease USP17L13 as a novel negative regulator of innate immunity that promotes influenza virus replication. Overexpression of USP17L13 significantly enhanced the replication of multiple subtypes of influenza viruses in A549 cells, including a human pandemic H1N1 virus, seasonal H3N2 viruses, as well as a globally circulating clade, 2.3.4.4b, of the highly pathogenic avian H5N1 virus. Transcriptomic analysis demonstrated that USP17L13 suppresses host antiviral defenses by downregulating nuclear factor kappa B (NF-κB) signaling and arachidonic acid metabolism, while upregulating pathways associated with ribosomal translation and oxidative phosphorylation to facilitate viral production. Mechanistically, USP17L13 attenuates the host interferon (IFN) response by promoting the degradation of the key viral RNA sensors, RIG-I, and melanoma differentiation-associated protein 5 (MDA5). Further analysis revealed that USP17L13 is inducible by type I and type II interferons as well as inflammatory cytokines, suggesting that it may act as a negative-feedback regulator to limit excessive inflammation. Collectively, our findings identify USP17L13 as a previously unrecognized proviral host factor and provide new insight into how host deubiquitinases shape influenza virus-host interactions, with potential implications for host-directed approaches to controlling excessive inflammation during viral infection and improving influenza vaccine production. Full article

RNA viruses exhibit high mutation rates, necessitating antivirals targeting conserved infection mechanisms. In this study, viral hemorrhagic septicemia virus (VHSV), a non-human pathogenic negative-sense RNA virus, was used as a surrogate model to enable high-throughput antiviral screening under reduced biosafety conditions. A recombinant VHSV expressing enhanced green fluorescent protein was used to screen 17,265 compounds, 2000 plant extracts, and 100 marine extracts. Among the candidates, the leaf extract of Phellodendron amurense Rupr. (PL extract) exhibited antiviral activity with low cytotoxicity (selectivity index ≈ 10). The extract reduced viral infectivity in a dose-dependent manner and showed cross-activity against snakehead rhabdovirus. Mechanistic analyses indicated that the PL extract acts primarily at early stages of infection. Virucidal assays demonstrated direct, time-dependent inactivation of viral particles, while pre-treatment reduced host cell susceptibility. Time-of-addition experiments confirmed that antiviral activity was restricted to early infection, suggesting interference with viral attachment or entry rather than intracellular replication. Fractionation revealed that activity was associated with the non-polar n-hexane fraction, implicating lipophilic compounds that may disrupt viral envelope integrity or membrane interactions. These findings suggest that P. amurense leaf extract is a promising candidate for broad-spectrum antivirals targeting conserved entry processes in enveloped RNA viruses. Full article

Dengue virus (DENV) and SARS-CoV-2 are emerging viral pathogens that share overlapping clinical features, including fever, fatigue, and respiratory symptoms, complicating differential diagnosis in endemic regions. Their co-circulation has increased the risk of co-infections, which may result in unpredictable disease progression, increased morbidity, and mortality. This overlap presents a significant challenge in managing outbreaks, as both viruses pose a major public health threat. Vaccines and direct-acting antivirals may be rendered ineffective by viral mutations, making it difficult to address evolving strains. Host-directed antivirals offer a promising alternative, potentially maintaining efficacy against a multitude of variants. Both DENV and SARS-CoV-2 rely on host proteases for viral maturation and entry, with furin playing a crucial role in viral glycoprotein cleavage. In DENV, furin cleaves the prM protein, facilitating virion maturation, while in SARS-CoV-2, the polybasic furin cleavage site in the spike protein enhances viral entry. This makes furin a compelling pan-viral target, where inhibiting furin could reduce viral fitness without relying on viral mutations. This review highlights the therapeutic rationale for targeting furin and discusses luteolin, a furin inhibitor showing antiviral activity against both viruses. Furin-targeted therapies may offer a durable antiviral strategy effective across DENV serotypes, SARS-CoV-2 variants, and co-infection settings. Full article

Although ombitasvir/paritaprevir/ritonavir plus dasabuvir (OPrD) therapy is highly effective for chronic hepatitis C (CHC), clinicians frequently encounter transient hyperbilirubinemia, which can be misidentified as hepatotoxicity. This study investigated the role of SLCO1B1 (OATP1B1) and SLCO1B3 (OATP1B3) genetic polymorphisms in predicting bilirubin spikes and distinguishing transporter-mediated interference from hepatocellular injury. In this prospective study of 65 patients with HCV genotype 1, genotyping for OATP1B1 (c.388A>G, c.521T>C) and OATP1B3 (c.334T>G, c.699G>A) was performed using PCR-RFLP and capillary electrophoresis (QIAxcel Advanced System). Clinical and biochemical parameters were monitored over a 12-week treatment period. Hyperbilirubinemia (total bilirubin >1.1 mg/dL) developed in 18.5% of the cohort, typically within the first month. A distinct ‘AST-dominant’ biochemical signature, elevated bilirubin and AST paired with stable ALT, was identified, suggesting transporter-specific interference rather than hepatocyte damage. Statistical analysis pinpointed the OATP1B3 c.699G>A (rs7311358) variant as the sole genetic driver (p = 0.007). Carriers of the c.699G>A allele faced a 6.3-fold higher risk of developing hyperbilirubinemia (OR: 6.30, 95% CI: 1.48–26.80, p = 0.032), while no significant associations were found for OATP1B1 variants. We conclude that OATP1B3 c.699G>A is a potent predictor of OPrD-induced hyperbilirubinemia. Identifying this genotype pre-treatment allows clinicians to anticipate transient, benign bilirubin elevations and prevent unnecessary drug discontinuation, thereby mitigating therapeutic inertia and ensuring treatment continuity for CHC patients. Full article

Objectives: The World Health Organization (WHO) goal of eradicating hepatitis C virus (HCV) infection by 2030 has encouraged healthcare providers to implement proactive strategies to improve diagnosis and treatment. The aims of this retrospective cohort study were to assess a program designed to improve the HCV care cascade and facilitate access to treatment, within a national healthcare provider in Israel, Maccabi Healthcare Services (MHS). Methods: Included were adult patients newly diagnosed with HCV infection before and after the implementation of a screening and care optimization program. Patients diagnosed in 2017 served as the reference group (RG), while those diagnosed in 2019 (following the program implementation) comprised the intervention group (IG). Study outcomes included completion of HCV laboratory testing, time to consultation with gastroenterologist/hepatologist (GE), and initiation of treatment with direct-acting antivirals (DAAs). Results: The study sample included 356 HCV Ab+ patients in the RG (median age = 46 years; 41% females), and 328 in the IG (median age = 48 years; 39% females). Compared to RG, IG demonstrated higher rates of patient visiting GE visit (78.1% vs. 63%) and initiating DAA treatment (66.3% vs. 35.5%). Conclusions: Implementation of a restructured HCV care cascade was associated with a greater proportion of patients receiving expert consultation and higher DAA treatment uptake, important steps towards HCV eradication. Full article