SARS-CoV-2 PLpro Inhibition: Evaluating in Silico Repurposed Fidaxomicin's Antiviral Activity Through In Vitro Assessment.

The emergence of drug-resistant viruses and novel strains necessitates the rapid development of novel antiviral therapies. This need was particularly demanding during the COVID-19 pandemic. While de novo drug development is a time-consuming process, repurposing existing approved medications offers a more expedient approach. In our prior in silico screening of the DrugBank database, fidaxomicin emerged as a potential SARS-CoV-2 papain-like protease inhibitor. This study extends those findings by investigating fidaxomicin's antiviral properties in vitro. Our results support further exploration of fidaxomicin as a therapeutic candidate against SARS-CoV-2, given its promising in vitro antiviral activity and favorable safety profile.

4-(3-Phenylsulfonylindol-2-yl)-1-(pyridin-2-yl)piperazinyl-methanones as Potent Inhibitors of both SARS-CoV-2 and HCoV-OC43 Viruses.

SARS-CoV-2 and HCoV-OC43 belong to the same ß genus of the Coronaviridae family. SARS-CoV-2 was responsible for the recent COVID-19 pandemic, and HCoV-OC43 is the etiological agent of mild upper respiratory tract infections. SARS-COV-2 and HCoV-OC43 co-infections were found in children with respiratory symptoms during the COVID-19 pandemic. The two ß-coronaviruses share a high degree of homology between the 3CLpro active sites, so much so that the safer HCoV-OC43 has been suggested as a tool for the identification of new anti-SARS-COV-2 agents. Compounds 5 and 24 inhibited effectively both Wuhan and British SARS-CoV-2 patient isolates in Vero E6 cells and the HCoV-OC43 in MRC-5 cells at low micromolar concentrations. The inhibition was apparently exerted via targeting the 3CLpro active sites of both viruses. Compounds 5 and 24 at 100 µM inhibited the SARS-CoV-2 3CLpro activity of 61.78 and 67.30%, respectively. These findings highlight 5 and 24 as lead compounds of a novel class of antiviral agents with the potential to treat SARS-COV-2 and HCoV-OC43 infections.

A comprehensive model to better screen out antiviral treatment candidates for chronic hepatitis B patients.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is a serious human health threat given its high morbidity and mortality. Timely and effective antiviral treatment can postpone liver disease progression and reduce the occurrence of HBV-related end-stage liver disease. At present, the antiviral treatment criteria are mainly based on alanine transaminase (ALT) levels, HBV DNA levels and HBV e antigen levels according to the American Association for the Study of Liver Diseases treatment guidelines. However, some chronic hepatitis B (CHB) patients not meeting the above criteria still experience liver disease progression without antiviral treatment. It is urgent to identify a more comprehensive tool to screen out more antiviral treatment candidates as soon as possible. METHODS: Considering the vital role of the immune response in the development of HBV infection and CHB cure, we collected data from 335 treatment-naïve CHB patients and comprehensively analysed their clinical and immune traits (including innate and adaptive responses). The immune parameters were obtained by flow cytometry. Finally, we established a model that can better distinguished CHB patients who need treatment through machine learning and LASSO regression of serological and immune parameters. RESULTS: Through a series of analyses, we selected four important clinical parameters (ALT, HBV DNA, the Fibroscan value, and the A/G ratio) and four immune indicators (NKbright + NKp44+, NKbright + NKG2A+, NKT+GranzymeB+, and CD3 + CD107a + ) from more than 200 variables and then successfully established a mathematical model with high sensitivity and specificity to better screen out antiviral treatment candidates from all CHB patients. CONCLUSIONS: Our results developed a refined model to better screen out antiviral treatment candidates from all CHB patients by combining common clinical parameters and important immune indicators, including innate and adaptive immunity. These findings provide more information for improving treatment guidelines and have potential implications for the timing of antiviral therapy to achieve better virus control and reduce the occurrence of end-stage liver disease.

TRIM35 Negatively Regulates the cGAS-STING-Mediated Signaling Pathway by Attenuating K63-Linked Ubiquitination of STING.

The cGAS-STING-mediated antiviral response plays an important role in the defense against DNA virus infection. Tripartite motif protein 35 (TRIM35), an E3 ubiquitin ligase, was identified as a positive regulator of RLR-mediated antiviral signaling in our previous study, but the effect of TRIM35 on the cGAS-STING signaling pathway has not been elucidated. Herein, we showed that TRIM35 negatively regulates the cGAS-STING signaling pathway by directly targeting STING. TRIM35 overexpression significantly inhibited the cGAMP-triggered phosphorylation of TBK1 and IRF3, attenuating IFN-ß expression and the downstream antiviral response. Mechanistically, TRIM35 colocalized and directly interacted with STING in the cytoplasm. TRM35 removed K63-linked ubiquitin from STING through the C36 and C44 sites in the RING domain, which impaired the interaction of STING with TBK1 or IKKε. In addition, we demonstrated that the RING domain is a key region for the antiviral effects of TIRM35. These results collectively indicate that TRIM35 negatively regulates type I interferon (IFN-I) production by targeting and deubiquitinating STING. TRIM35 may be a potential therapeutic target for controlling viral infection.

A deep learning drug screening framework for integrating local-global characteristics: A novel attempt for limited data.

At the beginning of the "Disease X" outbreak, drug discovery and development are often challenged by insufficient and unbalanced data. To address this problem and maximize the information value of limited data, we propose a drug screening model, LGCNN, based on convolutional neural network (CNN), which enables rapid drug screening by integrating features of drug molecular structures and drug-target interactions at both local and global (LG) levels. Experimental results show that LGCNN exhibits better performance compared to other state-of-the-art classification methods under limited data. In addition, LGCNN was applied to anti-SARS-CoV-2 drug screening to realize therapeutic drug mining against COVID-19. LGCNN transcends the limitations of traditional models for predicting interactions between single drug targets and shows new advantages in predicting multi-target drug-target interactions. Notably, the cross-coronavirus generalizability of the model is also implied by the analysis of targets, drugs, and mechanisms in the prediction results. In conclusion, LGCNN provides new ideas and methods for rapid drug screening in emergency situations where data are scarce.

Dynamics of Virological and Clinical Response Parameters of Bulevirtide Treatment for Hepatitis D: Real-World Data.

Background and Aims: The entry inhibitor bulevirtide represents the first specific treatment for hepatitis-D virus (HDV)-infected patients. In clinical trials, around 80% of patients achieve normalization of alanine aminotransferase (ALT) with about 60% virological response after 1 year, but little is known about the dynamics of responses and clinical predictors of treatment outcomes. We report our single-center data from 15 patients and describe response dynamics, clinical outcomes, and predictive factors for treatment response. Methods: Retrospective data from 15 patients have been analyzed at our department who started treatment with bulevirtide between 10/2020 and 08/2022. According to our standard procedures, laboratory parameters were controlled monthly; transient elastography was performed every 3 months, and the treatment duration was 12 months. Results: Treatment response rates after 1 year of treatment were similar to published data from clinical trials. ALT normalization usually occurs between months 2-6 of treatment, followed by a virological response after ≥6 months. Patients with more severe hepatitis at the start of treatment were less likely to respond in the first year of treatment. Loss of HDV-RNA was observed in one-third of patients after ≥1 year of treatment. Low body mass index and high alpha-fetoprotein at baseline were possible predictors of a delayed treatment response. Conclusion: Bulevirtide is a safe treatment option for HDV, leading to a fast hepatological response. Of note, decrease in transaminases precedes virological response. Patients with high viral load and ALT levels respond slower, but nonresponders (as classified by Food and Drug Administration criteria) still show a reduction in viremia. Longer observation periods are required to determine the optimal duration of bulevirtide monotherapy.

Multiple myeloma exosomal miRNAs suppress cGAS-STING antiviral immunity.

DNA virus infection is a significant cause of morbidity and mortality in patients with multiple myeloma (MM). Monocyte dysfunction in MM patients plays a central role in infectious complications, but the precise molecular mechanism underlying the reduced resistance of monocytes to viruses in MM patients remains to be elucidated. Here, we found that MM cells were able to transfer microRNAs (miRNAs) to host monocytes/macrophages via MM cell-derived exosomes, resulting in the inhibition of innate antiviral immune responses. The screening of miRNAs enriched in exosomes derived from the bone marrow (BM) of MM patients revealed five miRNAs that negatively regulate the cGAS-STING antiviral immune response. Notably, silencing these miRNAs with antagomiRs in MM-bearing C57BL/KaLwRijHsd mice markedly reduced viral replication. These findings identify a novel mechanism whereby MM cells possess the capacity to inhibit the innate immune response of the host, thereby rendering patients susceptible to viral infection. Consequently, targeting the aberrant expression patterns of characteristic miRNAs in MM patients is a promising avenue for therapeutic intervention. Considering the miRNA score and relevant clinical factors, we formulated a practical and efficient model for the optimal assessment of susceptibility to DNA viral infection in patients with MM.

Bioequivalence and Safety of Generic Glecaprevir/Pibrentasvir Compared to a Branded Product: A Randomized, Crossover Study in Healthy Volunteers.

This was an open-label, randomized, single-dose, 2-period, crossover clinical trial with an adaptive design to evaluate the bioequivalence and comparative pharmacokinetics of generic glecaprevir/pibrentasvir versus the brand name product in healthy White male and female volunteers under fed conditions. Safety profiles were also assessed. A total of 56 healthy adult volunteers were enrolled and randomly assigned in a 1:1 ratio to receive a single dose of either the generic or reference formulation. After a 7-day washout period, subjects received the alternate product. Blood samples were collected at pre-specified time points up to 48 hours post-dosing. Plasma concentrations of glecaprevir and pibrentasvir were determined using a validated high-performance liquid chromatography-tandem mass spectrometry method. The geometric mean ratios of the test to the reference formulation for maximum plasma concentration (Cmax) and area under the concentration-time curve from drug administration to the last measurable concentration (AUC0-t) fell within the predefined bioequivalence range of 80%-125%. Both formulations demonstrated comparable pharmacokinetic profiles for glecaprevir and pibrentasvir, and can be considered bioequivalent. No adverse events were reported, and both formulations were well tolerated by all participants.

Efficacy of COVID-19 Oral antivirals in hospitalised oldest-old with high morbidity burden: a target trial emulation study.

BACKGROUND: Molnupiravir and nirmatrelvir-ritonavir are orally administered pharmacotherapies for mild to moderate COVID-19. However, the effectiveness of these drugs among very old (≥80 years), hospitalised patients remains unclear, limiting the risk-benefit assessment of these antivirals in this specific group. This study investigates the effectiveness of these antivirals in reducing mortality among this group of hospitalised patients with COVID-19. METHODS: Using a territory-wide public healthcare database in Hong Kong, a target trial emulation study was conducted with data from 13 642 eligible participants for the molnupiravir trial and 9553 for the nirmatrelvir-ritonavir trial. The primary outcome was all-cause mortality. Immortal time and confounding bias was minimised using cloning-censoring-weighting approach. Mortality odds ratios were estimated by pooled logistic regression after adjusting confounding biases by stabilised inverse probability weights. RESULTS: Both molnupiravir (HR: 0.895, 95% CI: 0.826-0.970) and nirmatrelvir-ritonavir (HR: 0.804, 95% CI: 0.678-0.955) demonstrated moderate mortality risk reduction among oldest-old hospitalised patients. No significant interaction was observed between oral antiviral treatment and vaccination status. The 28-day risk of mortality was lower in initiators than non-initiators for both molnupiravir (risk difference: -1.09%, 95% CI: -2.29, 0.11) and nirmatrelvir-ritonavir (risk difference: -1.71%, 95% CI: -3.30, -0.16) trials. The effectiveness of these medications was observed regardless of the patients' prior vaccination status. CONCLUSIONS: Molnupiravir and nirmatrelvir-ritonavir are moderately effective in reducing mortality risk among hospitalised oldest-old patients with COVID-19, regardless of their vaccination status.

MAVS Cys508 palmitoylation promotes its aggregation on the mitochondrial outer membrane and antiviral innate immunity.

Cysteine palmitoylation or S-palmitoylation catalyzed by the ZDHHC family of acyltransferases regulates the biological function of numerous mammalian proteins as well as viral proteins. However, understanding of the role of S-palmitoylation in antiviral immunity against RNA viruses remains very limited. The adaptor protein MAVS forms functionally essential prion-like aggregates upon activation by viral RNA-sensing RIG-I-like receptors. Here, we identify that MAVS, a C-terminal tail-anchored mitochondrial outer membrane protein, is S-palmitoylated by ZDHHC7 at Cys508, a residue adjacent to the tail-anchor transmembrane helix. Using superresolution microscopy and other biochemical techniques, we found that the mitochondrial localization of MAVS at resting state mainly depends on its transmembrane tail-anchor, without regulation by Cys508 S-palmitoylation. However, upon viral infection, MAVS S-palmitoylation stabilizes its aggregation on the mitochondrial outer membrane and thus promotes subsequent propagation of antiviral signaling. We further show that inhibition of MAVS S-palmitoylation increases the host susceptibility to RNA virus infection, highlighting the importance of S-palmitoylation in the antiviral innate immunity. Also, our results indicate ZDHHC7 as a potential therapeutic target for MAVS-related autoimmune diseases.

Multi-omics analysis of antiviral interactions of Elizabethkingia anophelis and Zika virus.

The microbial communities residing in the mosquito midgut play a key role in determining the outcome of mosquito pathogen infection. Elizabethkingia anophelis, originally isolated from the midgut of Anopheles gambiae possess a broad-spectrum antiviral phenotype, yet a gap in knowledge regarding the mechanistic basis of its interaction with viruses exists. The current study aims to identify pathways and genetic factors linked to E. anophelis antiviral activity. The understanding of E. anophelis antiviral mechanism could lead to novel transmission barrier tools to prevent arboviral outbreaks. We utilized a non-targeted multi-omics approach, analyzing extracellular lipids, proteins, metabolites of culture supernatants coinfected with ZIKV and E. anophelis. We observed a significant decrease in arginine and phenylalanine levels, metabolites that are essential for viral replication and progression of viral infection. This study provides insights into the molecular basis of E. anophelis antiviral phenotype. The findings lay a foundation for in-depth mechanistic studies.

Discovery of new quinoline derivatives bearing 1-aryl-1,2,3-triazole motif as influenza H1N1 virus neuraminidase inhibitors.

Sporadically and periodically, influenza outbreaks threaten global health and the economy. Antigen drift-induced influenza virus mutations hamper antiviral drug development. Thus, a novel antiviral agent is urgently needed to address medication inefficacy issues. Herein, sixteen new quinoline-triazole hybrids 6a-h and 9a-h were prepared and evaluated in vitro against the H1N1 virus. In particular, 6d, 6e, and 9b showed promising H1N1 antiviral activity with selective index (SI) CC50/IC50 values of 15.8, 37, and 29.15. After that, the inhibition rates for various mechanisms of action (virus replication, adsorption, and virucidal activity) were investigated for the most efficient candidates 6d, 6e, and 9b. Additionally, their ability to inhibit neuraminidase was evaluated. With an IC50 value of 0.30 µM, hybrid 6d demonstrated effective and comparable inhibitory activity to Oseltamivir. Ultimately, molecular modeling investigations, encompassing molecular docking and molecular dynamic simulations, were conducted to provide a scientific basis for the observed antiviral results.

Herpes Simplex Virus-1 and Hand Sanitizer: A pilot study.

Purpose Herpes Simplex Virus type 1 (HSV-1) is a highly contagious virus that manifests as a painful lesion and recurrences can be distressing to patients. The purpose of this pilot study was to determine if the use of a 70% ethanol alcohol hand sanitizer alters the duration, size of the lesion, level of pain upon administering treatment, and overall daily discomfort during outbreak.Methods This study was a double-blind randomized controlled trial (RCT) using 70% ethanol alcohol hand sanitizer for the experiment and medical grade mineral oil for the control group. The treatment and the control were dispensed in lip gloss applicators for applying medicament. Data was collected through the initial examination, a daily journal, photographs, and a reexamination day. Descriptive statistics and the independent sample t-test were used to analyze data (p=0.05).Results A total of 20 individuals completed the research study: ten in the experimental group and ten in the control group. The mean duration of HSV-1 lesions for the control group was 10.3 days while the mean duration of the HSV-1 lesions for the experimental group was 7.6 days. The mean size of lesions for the control group was 4.87 mm; the mean size for the experimental group was 4.25 mm. The mean pain score for the control group was 1.08 and the mean pain score for the experimental group was 2.74. The mean discomfort score for the control group was 1.33 while the mean discomfort score for the experimental group was 1.72. There was no statistically significant difference between the experimental and control groups in terms of duration, size of lesions, pain, and discomfort.Conclusion Based on the results of this pilot study, 70% ethanol alcohol hand sanitizer did not demonstrate statistical significance in the treatment and management of HSV-1 lesions. Additional research is needed with a larger sample size to determine if statistical differences can be measured.

The interplay of COVID-19 and HIV: A comprehensive review of clinical outcomes and demographic associations.

AIM: The COVID-19 pandemic posed unprecedented challenges to global healthcare, particularly affecting respiratory systems and impacting individuals with pre-existing conditions, including those with HIV. METHOD: HIV's impact on clinical outcomes was assessed in four Statistical Population, synchronized with control groups. The study also explored the influence of SARS-CoV-2 and COVID-19 treatments. Ultimately, a comparison was drawn between patients with and without HIV. RESULTS: In the first Statistical Population of COVID-19 patients with HIV, predominantly African-American men with risk factors such as obesity, hypertension, and diabetes were present. Diagnostic results showed no significant differences between the two groups. In the second Statistical Population, half of the patients were asymptomatic, with diagnoses mostly based on clinical symptoms; 6 individuals developed severe respiratory illness. In the third Statistical Population, 81 % of patients were treated at home, and all hospitalized patients had CD4+ lymphocyte counts above 350 cells/mm³. Most patients improved, with fatalities attributed to comorbid conditions. In the fourth Statistical Population, HIV patients were less likely to benefit from antimicrobial drugs, and mortality was higher, though synchronized analysis did not reveal significant differences. CONCLUSION: HIV patients are more susceptible to COVID-19, but the direct impact is less significant than other factors. Additional factors contribute to increased risk, while early improvement, accurate diagnosis, and intensive care reduce fatalities.

Recent developments in understanding RIG-I's activation and oligomerization.

Insights into mechanisms driving either activation or inhibition of immune response are crucial in understanding the pathology of various diseases. The differentiation of viral from endogenous RNA in the cytoplasm by pattern-recognition receptors, such as retinoic acid-inducible gene I (RIG-I), is one of the essential paths for timely activation of an antiviral immune response through induction of type I interferons (IFN). In this mini-review, we describe the most recent developments centered around RIG-I's structure and mechanism of action. We summarize the paradigm-changing work over the past few years that helped us better understand RIG-I's monomeric and oligomerization states and their role in conveying immune response. We also discuss potential applications of the modulation of the RIG-I pathway in preventing autoimmune diseases or induction of immunity against viral infections. Overall, our review aims to summarize innovative research published in the past few years to help clarify questions that have long persisted around RIG-I.

In vitro and in vivo evaluation of thapsigargin as an antiviral agent against transmissible gastroenteritis virus.

Swine enteric coronaviruses (SeCoVs) pose a significant threat to the global pig industry, but no effective drugs are available for treatment. Previous research has demonstrated that thapsigargin (TG), an ER stress inducer, has broad-spectrum antiviral effects on human coronaviruses. In this study, we investigated the impact of TG on transmissible gastroenteritis virus (TGEV) infection using cell lines, porcine intestinal organoid models, and piglets. The results showed that TG effectively inhibited TGEV replication both in vitro and ex vivo. Furthermore, animal experiments demonstrated that oral administration of TG inhibited TGEV infection in neonatal piglets and relieved TGEV-associated tissue injury. Transcriptome analyses revealed that TG improved the expression of the ER-associated protein degradation (ERAD) component and influenced the biological processes related to secretion, nutrient responses, and epithelial cell differentiation in the intestinal epithelium. Collectively, these results suggest that TG is a potential novel oral antiviral drug for the clinical treatment of TGEV infection, even for infections caused by other SeCoVs.

In vitro assessment of the anti-adenoviral activity of artemisinin and its derivatives.

Adenoviral infections, particularly in children, remain a significant public health issue with no approved targeted treatments. Artemisinin and its derivatives, well-known for their use in malaria treatment, have shown antiviral activities in recent studies. However, their efficacy against human adenovirus (HAdV) remains unexplored. This study aimed to assess the activity of artemisinin and its derivatives against HAdV infection in vitro using cell lines and primary cells. Our data revealed that artemisinin exhibited dose-dependent anti-HAdV activity with no apparent cytotoxicity over a wide concentration range. Mechanistically, artemisinin did not affect viral attachment or entry into target cells, nor the viral genome entry into cell nucleus. Instead, it inhibited HAdV through suppression of viral DNA replication. Comparative analysis with its derivatives, artesunate and artemisone, showed distinct cytotoxicity and anti-adenoviral profiles, with artemisone showing superior efficacy and lower toxicity. Further validation using a primary airway epithelial cell model confirmed the anti-adenoviral activity of both artemisinin and artemisone against different virus strains. Together, our findings suggest that artemisinin and its derivatives may be promising candidates for anti-HAdV treatment.

Assessing the antiviral activity of antimicrobial peptides Caerin1.1 against PRRSV in Vitro and in Vivo.

The Porcine reproductive and respiratory syndrome (PRRS) causes severe financial losses to the global swine industry. Due to continuous virus evolution, the protection against the PRRS provided by current vaccines is limited. In order to find new antiviral strategies, this study investigated the antiviral potential of antimicrobial peptides (AMPs) against PRRSV. Given the diversity of PRRSV strains and the limited effectiveness of existing vaccines in controlling PRRSV, this study evaluated the inhibitory effects of KLAK, Cecropin B, Piscidin1, and Caerin1.1 on 3 strains of PRRSV (lineage 5 classical strain, lineage 8 highly pathogenic strain, and lineage 1 NADC30-like strain). Caerin1.1 exhibited significant dose-dependent antiviral activity, with an effective concentration (EC50) of 7.5 µM. Caerin1.1 effectively inhibited PRRSV replication when added before or in early infection but showed reduced effectiveness when added in late infection, indicating its potential involvement in targeting early transcription mechanisms of viral RNA polymerase and significantly upregulating cytokine gene expression. In the NADC30 strain-based animal infection model, Caerin1.1 treatment significantly reduced lung viral loads and inflammation in the lungs of PRRSV-infected pigs, with a mortality rate of 0 % (0/5) in the treated group compared to 66.67 % (4/6) in the untreated group, indicating a reduction in the mortality rate. Additionally, compared with the untreated group, the Caerin1.1-treated group showed significant improvements, such as lighter fever, more daily weight gain, less clinical symptoms, less viral load in blood, and less virus oral shedding (P < 0.05). These findings reveal the potential of antimicrobial peptides as PRRSV therapeutic agents and suggest that Caerin1.1 is a promising candidate for a novel anti-PRRSV drug.

Broad-Spectrum Antiviral Agents against SARS-CoV-2 Variants Inhibit the Conserved Viral Protein Nsp1-RNA Interaction.

The ongoing global threats posed by COVID-19 pandemic, catalyzed by SARS-CoV-2, underscores the pressing need for effective antiviral strategies. The viral non-structural protein 1 (Nsp1) significantly influences pathogenicity by impeding host protein expression and enhancing viral RNA translation through its interaction with the stem-loop 1 (SL1) in the 5' untranslated region (UTR). We have developed a novel dual-luciferase reporter assay, designed to investigate the critical Nsp1-SL1 interaction, and identified P23E02 as a potential inhibitor. Our investigation, combining molecular docking studies and alanine mutagenesis, has unveiled that P23E02 disrupts Nsp1-40S ribosomal subunit interaction, liberating translational inhibition and empowering host antiviral responses. P23E02 exhibits antiviral efficacy against various sarbecoviruses, making it a promising candidate for combatting COVID-19 and related diseases. This study underscores the therapeutic potential of targeting the Nsp1/SL1 axis and lays the foundation for innovative antiviral interventions, ultimately fortifying global preparedness against future viral threats.