Search Results (286)

Marburg virus (MARV), a highly pathogenic member of the Filoviridae family, causes severe hemorrhagic fever with a high case fatality rate and currently lacks effective therapeutics. The viral entry process, mediated by the interaction between the MARV glycoprotein (GP) and host receptor C-type lectin domain family 4 member M (CLEC4M) (L-SIGN), represents a critical target for early-stage intervention. The active compounds from BindingDB and the decoy from DUDE were used. The RDKit was used for feature engineering. Machine learning models were trained on an initial dataset consisting of 56 active chemicals and 1232 decoys. Among the tested algorithms, the Random Forest model demonstrated superior performance, achieving the highest discriminative ability (AUC = 0.93, MCC = 0.88) on the test set. Virtual screening of 11,032 phytochemicals resulted in 120 predicted actives, of which 42 compounds satisfied drug-likeness criteria. Subsequent molecular docking identified three lead compounds (PubChem IDs: 42608095, 5281601, and 11243993) with moderate-to-promising binding affinities (−6.3 to −6.5 kcal/mol) toward the CLEC4M binding site. ADMET analysis revealed favorable pharmacokinetic and toxicity profiles for the selected lead compounds. DFT calculations of the three compounds highlighted their electronic stability and reactive nature, indicating that PubChem IDs 42608095 and 5281601 possess particularly stable electronic properties conducive to favorable target interactions. Combining machine learning models with molecular docking and Molecular Dynamics (MD) simulations worked well in finding promising phytochemical inhibitors. The MM/GBSA binding free energy calculations further confirmed binding affinities, with values of −10.83 and −11.08 kcal/mol, respectively, suggesting favorable complex stability. These findings provide a pathway for developing new antiviral agents against MARV, pending further experimental validation and optimization. Full article

During the pre-Omicron phases of the COVID-19 pandemic, patients with hematological neoplasms were characterized by very high morbidity and mortality rates. Remdesivir, a viral RNA-polymerase inhibitor, interferes with key SARS-CoV-2 enzymes, preventing the virus from multiplying. The use of convalescent plasma (CP) in treating patients with COVID-19 has been shown to be beneficial in patients with an impaired humoral response to infection, including most of those on active treatment for hematologic malignancies. This retrospective, non-interventional study was performed using the Croatian Cooperative Group for Hematological Diseases database of patients with hematological malignancies infected with SARS-CoV-2. Patients treated with remdesivir and/or CP were matched to those untreated according to age, disease type, and antineoplastic therapy. We identified 119 patients treated with remdesivir and/or CP fulfilling entry criteria and matched 116 according to our established criteria to one of the 374 untreated patients. Treatment significantly reduced COVID-19 mortality. The beneficial effect of antiviral therapy was limited to those who started antiviral treatment within 7 days of the onset of symptoms. Due to the exclusive enrolment of hematological patients with COVID-19, our study provides unique insights into the benefits of early application of both antiviral and CP therapy. It emphasizes the need for early administration before the infection has transformed into the hyperinflammatory phase. Full article

Oncolytic viruses (OVs) exploit key hallmarks of cancer to selectively replicate in malignant cells, leading to tumor cell lysis, modulation of the tumor microenvironment, and induction of antitumor immunity. These viral platforms have been engineered to enhance tumor specificity, intratumoral spread, and immunotherapeutic efficacy. Among them, rhabdoviruses, particularly vesiculoviruses, have emerged as promising candidates due to their rapid replication, high titers, and amenability to genetic manipulation. Maraba virus, a recently identified vesiculovirus, is a single-stranded negative-sense RNA virus with a favorable safety profile and minimal pre-existing immunity in humans. It demonstrates selective tumor tropism partly through low-density lipoprotein receptor (LDLR)-mediated entry and impaired antiviral responses in cancer cells. Genetic engineering of the wild-type Maraba virus led to the development of the MG1 strain, characterized by enhanced tumor selectivity, increased replication capacity, and potent cytolytic activity. Preclinical studies have demonstrated its efficacy as a monotherapy, a cancer vaccine vector expressing tumor-associated antigens, and in combination with chemotherapy and immune checkpoint inhibitors. MG1 also reshapes the tumor microenvironment, converting immunologically “cold” tumors into “hot” tumors, thereby enhancing immune-mediated tumor clearance. Compared to vesicular stomatitis virus, Maraba virus exhibits improved safety and reduced neurovirulence while maintaining strong oncolytic potential. This review aims to comprehensively summarize the biological characteristics of the MG1 Maraba virus, its genetic development, mechanisms of action, and current preclinical and clinical applications as a novel oncolytic immunotherapeutic agent. Full article

Human cytomegalovirus (HCMV) remains an important medical problem in multiple patient settings despite the availability of antivirals. In part, this is linked to resistance, cost and restrictions on use in several patient settings. More generally, it remains attractive to increase our arsenal of anti-viral approaches to target HCMV. We previously characterized a potent inhibitor of HCMV infection, DIDS, that displays cysteine reactivity, allowing it to bind virions and neutralize HCMV infection of fibroblasts. We now show that DIDS is inhibitory to cell-free and cell-associated infection of multiple cell types, including cells of the haematopoietic lineage—cells important for latency and dissemination. Consistent with this broad activity, DIDS partially inhibited gB (but not SARS-CoV-2 spike) fusion activity. Intriguingly, further characterization of DIDS activity in myeloid cells revealed that, unlike in all other cell types, DIDS blocked a post-entry event in CD14+ monocytes and also dendritic cell derivatives. Despite viral entry, entry was largely silent, with a failure to activate innate immunity and cell survival pathways known to be activated by HCMV. In contrast, HCMV infection was observed to activate host miRNA expression in CD14+ cells, suggesting a DIDS-insensitive viral function was responsible or, alternatively, that host miRNA expression is a potential anti-viral response to viral internalization. Thus, we report the further characterization of a broad-acting inhibitor of HCMV infection, which may also prove a useful tool to study unique events for the infection of monocytic cells by HCMV—a cell type that is crucial for HCMV dissemination and pathogenesis in vivo. 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

The sodium-taurocholate cotransporting polypeptide (NTCP) plays a critical dual role in liver function: maintaining bile acid (BA) enterohepatic circulation and acting as a receptor for the entry of hepatitis B and D viruses into hepatocytes. This review outlines the impact of various post-translational modifications (PTMs) of NTCP—including phosphorylation, oligomerization, ubiquitination, and glycosylation—on its dynamic regulatory network. These modifications coordinate the modulation of NTCP’s membrane localization, stability, conformational state, and protein interactions, precisely controlling its functions in BA uptake and viral invasion. Targeting this PTM network presents a promising strategy for next-generation therapies that selectively inhibit viral infection while preserving BA transport, overcoming the limitations of conventional inhibitors that indiscriminately disrupt virus–NTCP interactions. By synthesizing recent insights into NTCP PTM research, this article highlights its role as a central regulator of its bifunctional properties and reveals potential avenues for precision therapies in viral hepatitis, cholestasis, and related liver diseases. However, most existing evidence is derived from in vitro or cell-based models, whereas in vivo studies and clinical validation remain limited; thus, the translational feasibility of strategies targeting post-translational modifications of NTCP still requires further investigation. Full article

This review critically examines the inhibition of viral entry as an emerging disease-modifying strategy in chronic hepatitis B (HBV) and delta (HDV) virus infection, with particular emphasis on bulevirtide, the first-in-class of the sodium taurocholate cotransporting polypeptide entry inhibitor. This paper summarizes the analysis of 7 clinical trials that either underpinned the registration of bulevirtide or are important European real-life trials. We synthesize virological, pathophysiological and clinical evidence, highlighting the impact of this novel bulevirtide-based therapy on virological control, liver inflammation, fibrosis dynamics and long-term prognosis, as well as the limitations of this therapy. The observation of these trials is a greater than 2 log decrease from baseline in hepatitis D virus ribonucleic acid (HDV RNA) in 54–92% of patients and normalization of alanine transaminase (ALT) in 48.8–74% of patients after 23–144 weeks of treatment, and a significant decrease in liver fibrosis, as quantified by Fibroscan, at 12 months of treatment. The conclusion of the study is that this therapy represents an important leap in the etiological approach to chronic HDV infection and in improving the prognosis of these patients, but future clinical studies are needed to define the criteria for discontinuation of therapy, the long-term impact, as well as studies targeting new therapies that can intervene in other stages of the HDV and HBV life cycle not only to achieve HDV RNA negativity but also HBsAg clearance. Full article

Respiratory syncytial virus (RSV) is a major pathogen responsible for severe lower respiratory tract infections in infants, the elderly, and immunocompromised individuals. Because the RSV F protein mediates viral entry and 15-lipoxygenase (15-LOX) amplifies virus-induced inflammatory responses, dual targeting of these proteins may provide both antiviral and anti-inflammatory benefits. In this study, we combined computational prediction with experimental validation to identify natural dual-target inhibitors from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP). A total of 13,131 natural compounds were screened by drug-likeness evaluation, molecular docking, ADME assessment, and molecular dynamics simulations, yielding 31 potential dual-target candidates with favorable drug-like properties. Among them, rhoeadine (MOL001473) maintained stable binding conformations with both targets throughout 100 ns simulations. In BEAS-2B cells, rhoeadine exhibited significant anti-RSV activity (EC50 = 1.82 µM), low cytotoxicity (IC50 = 34.50 µM), and a selectivity index (SI) of 18.97. Time-of-addition experiments suggested that rhoeadine primarily acts at the early stage of viral infection. Additionally, ELISA results indicated that rhoeadine significantly inhibited RSV-induced secretion of CCL5 and IL-6, highlighting its anti-inflammatory potential. In summary, this study identified rhoeadine as a promising natural compound with antiviral and anti-inflammatory activities against RSV. Computational analyses suggested its potential association with RSV F protein and 15-LOX, although direct target-level validation is still required. Full article

Ebola virus disease remains one of the most serious viral infections with no approved small-molecule treatments. The Ebola virus glycoprotein (EBOV-GP), which enables the virus’s entry to host cells, is a promising target for drug discovery. In this study, a multistage computer-aided drug discovery approach was used to identify new specific EBOV-GP inhibitors. A reliable QSAR model was built using 55 terpenoid derivatives. This model was able to predict the activity of newly designed compounds with good accuracy and validated statistical metrics ($R_{tr}^2$= 0.70; $R_{ext}^2$ = 0.73). It was subsequently applied to screen over 15,500 newly generated compounds from three lead molecules by fragment-based design tools. Predicted activity, binding affinity toward EBOV-GP, and good ADMET drug-like properties prioritized the eleven most promising hits. Through 150 ns molecular dynamics simulations, these compounds remained stable in the EBOV-GP binding site. Further binding free energy analysis (MM/PBSA) showed strong binding affinities, especially for the compounds L-60, L-832, M-1618, and L-1366. This study showed how combining QSAR, fragment-based design, docking, ADMET, and molecular dynamics could help in identifying potent and safe small molecules against the EBOV-GP. The top compounds are ready for further experimental and in vitro biological testing. Full article

The rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the need for antivirals that are resilient to resistance. Current Food and Drug Administration (FDA)-approved therapies primarily target single viral mechanisms, leaving gaps in efficacy. Here, we developed a Deep Learning-based Activity Screening Model (DLASM), which integrates graph convolutional network with machine learning to identify SARS-CoV-2 inhibitors, using experimental 3-chymotrypsin-like (3CL) main protease assay data. The optimized DLASMs virtually screened ~170,000 compounds from diverse in-house collections and yielded novel hits, several of which not only inhibited the 3CL protease but also blocked viral entry by interfering with heparan sulfate-mediated host interactions. These activities were validated through multiple assays, including 3CL enzymatic inhibition, SARS-CoV-2 pseudotyped particle entry, α-synuclein fibril uptake as a proxy for endocytosis, live virus cytopathic effect, heparan sulfate-dependent entry assay, and a 3D human lung mucociliary tissue model. Molecular docking studies elucidated binding modes at the 3CL protease active site, while molecular dynamics simulations provided insights into compound–heparan sulfate interactions. The identified compounds represent early-stage hits with moderate potency that demonstrate dual-mechanism antiviral activity. Together, these findings establish dual-target inhibition as a promising antiviral strategy, offering not only enhanced potency but also reduced risk of resistance. Moreover, our DLASM framework provides a generalizable pipeline for identifying chemically diverse scaffolds and for broader applications beyond SARS-CoV-2. Full article

Canine coronavirus (CCoV), an alphacoronavirus belonging to the Coronaviridae family, is primarily associated with enteric infections in dogs. The ongoing evolution of coronaviruses through genetic recombination and mutation leads to the emergence of novel strains with increased pathogenicity, thereby raising the risk of cross-species transmission and spillover events. In this context, viral entry inhibitors represent a promising strategy, as they can serve as pivotal tools to prevent initial infection and subsequent viral replication. The S2 subunit of the spike (S) glycoprotein contains two heptad repeat regions (HRN and HRC), which play essential roles in the conformational changes required for viral fusion. In this study, we describe the design, synthesis, and functional evaluation of a peptide derived from the HRC domain of the CCoV S glycoprotein. First, we assessed the cytotoxicity of the CCoV-HRC peptide in two cell lines, HE293T and A72, and determined CC₅₀ values > 100 μM. At non-toxic concentrations, the peptide effectively blocked membrane fusion mediated by the CCoV S glycoprotein and significantly reduced viral infection, as demonstrated both in cell–cell fusion assays and in live virus experiments. These findings were supported by in silico docking and molecular dynamics simulations, which provided structural insight into the interaction between CCoV-HRC and the S fusion core. Then, molecular analyses were conducted to evaluate the expression of the gene encoding the viral S protein, confirming the antiviral potential of CCoV-HRC peptide. Overall, these findings provide a solid foundation for the development of peptide-based therapeutics to treat or prevent CCoV infections. Full article

Viruses are an indispensable part of the environment we live in. The occurrence of seasonal and pandemic infections underscores the urgent need to develop new antiviral drugs or repurpose existing ones. Among the methods used in research on new antiviral molecules, surface plasmon resonance (SPR) has a well-established position due to its diverse applications in interaction analysis. It can be used to investigate various molecules (proteins, nucleic acids, small-molecular drugs) in different configurations and in real time. Although it is a gold-standard method for biomolecular interaction analysis, it is not free of constraints. Here, we review research on SPR in antiviral drug discovery. We focus on experimental design and discuss the application of SPR to investigate key stages of viral infection and to characterize antiviral interactions. In addition, we address the main limitations and challenges associated with SPR measurements and consider strategies for adapting the technique to meet the specific needs of antiviral research. Full article

The MERS-CoV (Middle East respiratory syndrome coronavirus) is a zoonotic virus with a high mortality rate and a lack of antiviral drugs, underscoring the need for effective therapeutic methods. Viral entry depends on interactions between viral surface proteins and human receptors, with Dipeptidyl Peptidase-4 (DPP4), a transmembrane glycoprotein, acting as the receptor for MERS-CoV. We employed Molecular Dynamics (MD) Simulations to identify critical interface residues under a high-performance computing (HPC) workflow for accelerated results. Target residue pairs were identified through analysis of salt bridge and hydrogen bond occupancy. The stability of these residues was confirmed through three independent MD Simulations at human body temperature and constant pressure. Additionally, binding affinity predictions were calculated to determine the interaction strength between the virus and human receptors. Applying the scientific threshold criteria, we narrowed our results to seven key interaction pairs; two of the identified pairs (Asp510-Arg317, and Arg511-Asp393) are consistent with findings published in previous research studies, and five novel interactions are proposed for future experimental studies with our active collaborators in Pharmacology. The results provide a molecular basis for targeted mutation-based experiments and support the rational design of structure-based inhibitors aimed at disrupting the MERS-CoV-DPP4 complex, thereby facilitating the translation of computational findings into antiviral drug discovery. Full article

Novel duck reovirus encodes a new nucleus-localized protein, p18. We aimed to investigate whether the nuclear entry of p18 is dependent on viral replication, identify the cellular proteins that interact with p18, and determine the transporters involved in the nuclear import. The subcellular localization of p18 was observed by confocal microscopy. Cellular proteins interacting with p18 were identified through data-independent acquisition qualitative proteomics. The interaction between p18 and importin α was determined by confocal microscopy, co-immunoprecipitation (Co-IP) and molecular docking. We observed that p18 was localized to the nucleus in transfected cells. Importin α1, α3, α4, α5, and α7 were colocalized and co-immunoprecipitated with p18. The importin α/β1 pathway inhibitor reduced the nuclear distribution of p18. The truncated form of p18, lacking the C-terminal region, was predominantly distributed in the cytoplasm. Collectively, our research suggests that the nuclear entry of p18 is independent of viral infection, importin α is implicated in the nuclear import of p18, and the C-terminal region of p18 is crucial for nuclear localization. Full article

To identify pancoronaviral inhibitors, we sought to identify peptides that bound the evolutionarily conserved SARS-CoV-2 spike fusion peptide (FP). We screened the NEB PhD-7-mer random combinatorial phage display library against FP, synthesised as a D-peptide, to identify peptides from the L-library to be synthesised as proteolytically resistant D peptides. We selected the top ten peptides that were not seen in another published screen with this library, as these were more likely to be specific. All ten D-peptides had no impact on the infection of Vero-E6/TMPRSS2 cells by SARS-CoV-2. Screening of a proteomic-derived phage display library from the disordered regions of human proteins identified two overlapping 14mer peptides from a region of OTUD1. While a synthetic peptide based on their sequences failed to markedly inhibit viral entry, molecular dynamics structural modelling highlighted a stable binding mode where positive residues on one side of the OTUD1 helix interacted with hydrophobic residues of the FP triple-helical wedge. Thus, while the two phage display strategies failed to yield peptide sequences that are themselves strong inhibitors of viral infection, they led to the development of a computational model that can underpin future designs of potential pancoronaviral FP disruptors. Full article