Investigation of Protein Lysine Acetylation in Antiviral Innate Immunity.

Protein lysine acetylation involved in the antiviral innate immunity contributes to the regulation of antiviral inflammation responses, including type 1 interferon production and interferon-stimulated gene expression. Thus, investigation of acetylated antiviral proteins is vital for the complete understanding of inflammatory responses to viral infections. Immunoprecipitation (IP) assay with anti-targeted-protein antibody or with acetyl-lysine affinity beads followed by immunoblot provides a classical way to determine the potential modified protein in the antiviral innate pathways, whereas mass spectrometry can be utilized to identify the accurate acetylation lysine residues or explore the acetyl-proteomics. We demonstrate here comprehensive methods of protein lysine acetylation determination in virus-infected macrophages and embryonic fibroblast cells or proteins-overexpressed HEK 293 T cells in the context of antiviral innate immunity.

Antiviral activity of Morus alba L. extract against pseudorabies virus.

ETHNOPHARMACOLOGICAL RELEVANCE: Morus alba L. are widely used as ethnomedicine and functional food in China, Japan, Korea and other Asian countries. Morus alba L. have a variety of pharmacological activity such as antiviral, antioxidation, anti-cholesterol, anticancer, hypoglycemia, and neuroprotection. Morus alba L. has demonstrated antiviral efficacy against influenza viruses, SARS-CoV-2 and so on, but its potential activity against pseudorabies virus (PRV) remains uncertain. AIM OF THE STUDY: This study endeavors to delve into the anti-pseudorabies virus (PRV) potential of the ethanol extract of Morus alba L. leaves (MLE), while simultaneously elucidating its underlying mechanism of action. MATERIALS AND METHODS: The anti-PRV activities of Morus alba L. extracts at different concentrations were evaluated by qPCR and immunoblotting. The inhibitory effects of MLE on PRV replication in three distinct treatment modes (pretreatment, co-treatment, and post-treatment) were detected by qPCR and indirect immunofluorescence assays. qPCR was used to investigate the effects of MLE on PRV attachment, entrance, and cytokine expression in PRV-infected cells. The chemical components in MLE were analyzed by UPLC-MS/MS. RESULTS: MLE significantly inhibits PRV replication and protein expression in a dose-dependent manner. MLE displays inhibitory effects against PRV at three different modes of treatment. The most significant inhibitory effect of MLE was observed when used in co-treatment mode, resulting in an inhibition rate of 99.42%. MLE inhibits PRV infection in the early stage. MLE inhibits PRV infection by affecting viral attachment and viral entry. Furthermore, MLE exerts its inhibition on PRV replication by mitigating the heightened expression of cytokines (TNF-α and IFN-α) triggered by PRV. Analysis of its chemical composition highlights phenolic acids and flavonoids as the principal constituents of MLE. CONCLUSION: The results illustrate that MLE effectively impedes PRV infection by suppressing viral adsorption and entry, while also curbing the expression of antiviral cytokines. Therefore, MLE may be a potential resource for creating new medications to treat human and animal PRV infections.

From tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF): perspectives in pediatric patients.

INTRODUCTION: Hepatitis B virus (HBV) affects hundreds of millions globally, with many cases stemming from perinatal transmission. Chronic hepatitis B (CHB) in children can progress to cirrhosis and hepatocellular carcinoma (HCC) in adulthood. Treatment options include interferons and nucleos(t)ide reverse transcriptase inhibitors (N[t]RTIs) such as tenofovir alafenamide (TAF). AREAS COVERED: This review covers the epidemiology of pediatric CHB and current treatments, with a focus on tenofovir-based therapies, particularly tenofovir disoproxil fumarate (TDF) and TAF. TDF has been used for years, but its risks of bone mineral density loss and renal impairment have raised concerns. TAF, with lower systemic exposure, appears to mitigate these risks. Ongoing trials are evaluating TAF's safety in younger children. There are knowledge gaps in long-term safety and the potential for combination therapies. EXPERT OPINION: TAF offers a safer alternative to TDF for children with CHB, showing high antiviral efficacy and fewer side effects. However, more data is needed on its use in younger children and long-term safety. The future of CHB treatment in pediatrics may include combination therapies and personalized approaches, potentially improving outcomes and minimizing risks over a lifetime of treatment. As research progresses, TAF is likely to become a cornerstone in pediatric CHB management.

Autophagy plays an antiviral defence role against tomato spotted wilt orthotospovirus and is counteracted by viral effector NSs.

Autophagy, an intracellular degradation process, has emerged as a crucial innate immune response against various plant pathogens, including viruses. Tomato spotted wilt orthotospovirus (TSWV) is a highly destructive plant pathogen that infects over 1000 plant species and poses a significant threat to global food security. However, the role of autophagy in defence against the TSWV pathogen, and whether the virus counteracts this defence, remains unknown. In this study, we report that autophagy plays an important role in antiviral defence against TSWV infection; however, this autophagy-mediated defence is counteracted by the viral effector NSs. Transcriptome profiling revealed the up-regulation of autophagy-related genes (ATGs) upon TSWV infection. Blocking autophagy induction by chemical treatment or knockout/down of ATG5/ATG7 significantly enhanced TSWV accumulation. Notably, the TSWV nucleocapsid (N) protein, a major component of the viral replication unit, strongly induced autophagy. However, the TSWV nonstructural protein NSs was able to effectively suppress N-induced autophagy in a dose-dependent manner. Further investigation revealed that NSs inhibited ATG6-mediated autophagy induction. These findings provide new insights into the defence role of autophagy against TSWV, a representative segmented negative-strand RNA virus, as well as the tospoviral pathogen counterdefence mechanism.

Timing of antiviral therapy in patients with hepatitis B virus related hepatocellular carcinoma undergoing hepatectomy.

Globally, hepatocellular carcinoma (HCC) is among the most prevalent and deadly cancers. Hepatitis B virus (HBV) infection is an important etiology and disease progression factor for HCC. Hepatectomy is a widely accepted curative treatment for HCC, but the long-term survival rate is still unsatisfactory due to the high recurrence rate after resection. Preoperative or postoperative antiviral therapy plays an important role in improving the prognosis for HBV-related HCC patients who underwent hepatectomy. However, many patients miss out on the chance to receive long-term preoperative antiviral medication because their HBV and HCC infections are discovered concurrently, necessitating the start of remedial antiviral therapy in the perioperative phase. Therefore, it is of great value to know when antiviral therapy is more appropriate and whether perioperative rescue antiviral therapy can achieve the effect of preoperative long-term antiviral therapy.

A critical review on phytochemicals as antiviral medications for SARS-CoV-2 virus infection.

A pandemic of acute respiratory infection, which was specified as coronavirus disease 2019, was instigated by a different strain of the virulent coronavirus SARS-CoV-2 that first appeared in late 2019. Since viral infections spread fast and there is presently no effective treatment, the use of plants with a long history of use in treating these infections has been explored regularly. The pandemic of coronavirus disease 2019 (COVID-19) has brought to light the dearth of medications with approval to treat acute viral illnesses. Because of this, the illness had a high fatality rate. The mortality rate was initially quite high and varied according to the patient's geographic location. For instance, among Chinese patients, the rate was 3·6%, whereas 1·5% of COVID-19-related deaths were documented outside of China. As of 2020, India has a 1.4% case fatality rate (CFR) of COVID-19 mortality, compared to 2.8% in Brazil and 1.8% in the USA. Many studies are being conducted to create pharmaceutical compounds specifically targeting important SARS-CoV-2 proteins. Several drug discovery initiatives are being undertaken to find powerful inhibitors by combining biochemical assay and computer-aided drug design techniques. Although plant-derived compounds have not had much success in the dominion of antivirals, plants are, however, believed to be a limitless supply of medications for a variety of diseases and clinical conditions. The scientific foundation required for developing novel natural source medications is provided by the chemical characterization and analysis of plant components. Most viral infections treated by ethnobotanical applications and historical literature on ayurveda, and traditional medicine are generally attributed to phytochemicals, which are compounds derived from medicinal plants. In this review, we have described the application of vascular plant-derived chemicals, such as tannins, polyphenols, alkaloids, and flavonoids, as antivirals, especially for managing COVID-19. This article discusses novel bioactive compounds and their molecular structures that target the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as prospective candidates for anti-coronavirus disease drugs. Moreover, to confirm the effectiveness of the phytochemicals that have demonstrated antiviral activity, clinical trials would need to be conducted in addition to the preclinical research that has already been done. To ensure spectacular findings, more applications of the compound would need to be studied to fully understand the effects of those phytochemicals whose clinical usefulness has already been established.

Inhibiting KSHV replication by targeting the essential activities of KSHV processivity protein, PF-8.

Kaposi's Sarcoma Herpesvirus (KSHV) is the causative agent of several human diseases. There are no cures for KSHV infection. KSHV establishes biphasic lifelong infections. During the lytic phase, new genomes are replicated by seven viral DNA replication proteins. The processivity factor's (PF-8) functions to tether DNA polymerase to DNA, so new viral genomes are efficiently synthesized. PF-8 self-associates, interacts with KSHV DNA replication proteins and the viral DNA. Inhibition of viral DNA replication would diminish the infection within a host and reduce transmission to new individuals. In this review we summarize PF-8 molecular and structural studies, detail the essential protein-protein and nucleic acid interactions needed for efficient lytic DNA replication, identify future areas for investigation and propose PF-8 as a promising antiviral target. Additionally, we discuss similarities that the processivity factor from Epstein-Barr virus shares with PF-8, which could promote a pan-herpesvirus antiviral therapeutic targeting strategy.

Risk of de novo HCC in patients with MASLD following direct-acting antiviral-induced cure of HCV infection.

BACKGROUND & AIMS: Data are limited on the risk of de novo hepatocellular carcinoma (HCC) in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) after achieving sustained virologic response (SVR12) using direct-acting antivirals (DAAs) for hepatitis C virus (HCV). METHODS: 1598 eligible patients received biannual alpha-fetoprotein (AFP) and liver imaging surveillance to detect de novo HCC beyond achieving SVR12. MASLD was defined as presence of controlled attenuation parameter (CAP) ≥ 248 dB/m and ≥ one cardiometabolic risk factor (CMRF). Cumulative HCC incidence was compared between patients with/without MASLD. We built univariable and multivariable Cox proportional hazards models to evaluate factors associated with HCC. Sensitivity analysis was performed using the Fine-Gray subdistribution hazards model. Additionally, we evaluated the mediation effect of MASLD on CMRFs and of CMRFs on MASLD for HCC using mediation analysis with bootstrapping. RESULTS: The incidence rate of HCC was 1.44 per 100 person-years of follow-up (PYFU) [95% confidence interval (CI): 1.19-1.74]. Patients with MASLD had a higher cumulative HCC incidence than those without MASLD (log-rank test, p < 0.001). Multivariable Cox regression analysis revealed that in addition to age, sex, LSM, platelet count, and AFP, MASLD (adjusted hazard ratio (aHR): 2.07 [95% CI:1.36-3.16], p < 0.001) was independently associated with HCC. This finding was confirmed by the Fine-Gray model, which showed a subdistribution HR (sHR) of 2.07 (95% CI: 1.34-3.19, p < 0.001) for MASLD. MASLD significantly mediated CMRFs for HCC development. CONCLUSION: After achieving SVR12, patients with MASLD exhibited an increased HCC risk compared to those without MASLD. Vigilant HCC surveillance and control of CMRFs to mitigate the effect MASLD on HCC remain crucial for this population. IMPACT AND IMPLICATIONS: The risk of de novo HCC among patients with MASLD, a novel nomenclature of steatotic liver disease (SLD), after the attaining of SVR12 using DAAs remains to be confirmed. In this study recruiting 1598 patients in Taiwan, individuals with MASLD exhibited approximately a two-fold increased risk of de novo HCC, compared to those without MASLD after achieving SVR12. MASLD significantly mediated CMRFs for HCC development. Our findings underscore the critical importance of pharmacological interventions and proactive lifestyle modifications to control CMRFs in patients with MASLD, as well as the need for vigilant HCC surveillance to ensure favorable outcomes following HCV eradication.

Inhibition of HIV-1 infection with curcumin conjugated PEG-citrate dendrimer; a new nano formulation.

BACKGROUND: Nano-drug delivery systems have become a promising approach to overcoming problems such as low solubility and cellular uptake of drugs. Along with various delivery devices, dendrimers are widely used through their unique features. PEG-citrate dendrimers are biocompatible and nontoxic, with the ability to improve drug solubility. Curcumin, a naturally occurring polyphenol, has multiple beneficial properties, such as antiviral activities. However, its optimum potential has been significantly hampered due to its poor water solubility, which leads to reduced bioavailability. So, the present study attempted to address this issue and investigate its antiviral effects against HIV-1. METHOD: The G2 PEG-citrate dendrimer was synthesized. Then, curcumin was conjugated to it directly. FTIR, HNMR, DLS, and LCMS characterized the structure of products. The conjugate displayed an intense yellow color. In addition, increased aqueous solubility and cell permeability of curcumin were achieved based on flow cytometry results. So, it could be a suitable vehicle for improving the therapeutic applications of curcumin. Moreover, cell toxicity was assessed using XTT method. Ultimately, the SCR HIV system provided an opportunity to evaluate the level of HIV-1 inhibition by the curcumin-dendrimer conjugate using a p24 HIV ELISA kit. RESULTS: The results demonstrated a 50% up to 90% inhibition of HIV proliferation at 12 µm and 60 µm, respectively. Inhibition of HIV-1 at concentrations much lower than CC50 (300 µM) indicates a high potential of curcumin-dendrimer conjugate against this virus. CONCLUSION: Thereby, curcumin-dendrimer conjugate proves to be a promising tool to use in HIV-1 therapy.

Verteporfin is an effective inhibitor of HCMV replication.

Human cytomegalovirus (HCMV), a double-stranded DNA virus from the Betaherpesvirinae subfamily, constitutes significant risks to newborns and immunocompromised individuals, potentially leading to severe neurodevelopmental disorders. The purpose of this study was to identify FDA-approved drugs that can inhibit HCMV replication through a drug repositioning approach. Using an HCMV progeny assay, verteporfin, a medication used as a photosensitizer in photodynamic therapy, was found to inhibit HCMV production in a dose-dependent manner, significantly reducing replication at concentrations as low as 0.5 µM, approximately 1/20th of the concentration used in anti-cancer research. Further analysis revealed that verteporfin did not interfere with HCMV host cell entry or nuclear transport but reduced viral mRNA and protein levels throughout the HCMV life cycle from the immediate-early stages. These results suggest that verteporfin has the potential to be rapidly and safely developed as a repurposed drug to inhibit HCMV infection.

Sustained antiviral response against in vitro HIV-1 infection in peripheral blood mononuclear cells from people with chronic myeloid leukemia treated with ponatinib.

HIV-1 infection cannot be cured due to long-lived viral reservoirs formed by latently infected CD4+ T cells. "Shock and Kill" strategy has been considered to eliminate the viral reservoir and achieve a functional cure but the stimulation of cytotoxic immunity is necessary. Ponatinib is a tyrosine kinase inhibitor (TKI) clinically used against chronic myeloid leukemia (CML) that has demonstrated to be effective against HIV-1 infection in vitro. Several TKIs may induce a potent cytotoxic response against cancer cells that makes possible to discontinue treatment in people with CML who present long-term deep molecular response. In this longitudinal study, we analyzed the capacity of ponatinib to induce an antiviral response against HIV-1 infection in peripheral blood mononuclear cells (PBMCs) obtained from people with CML previously treated with imatinib for a median of 10 years who changed to ponatinib for 12 months to boost the anticancer response before discontinuing any TKI as part of the clinical trial NCT04043676. Participants were followed-up for an additional 12 months in the absence of treatment. PBMCs were obtained at different time points and then infected in vitro with HIV-1. The rate of infection was determined by quantifying the intracellular levels of p24-gag in CD4+ T cells. The levels of p24-gag+ CD4+ T-cells were lower when these cells were obtained during and after treatment with ponatinib in comparison with those obtained during treatment with imatinib. Cytotoxicity of PBMCs against HIV-infected target cells was significantly higher during treatment with ponatinib than during treatment with imatinib, and it was maintained at least 12 months after discontinuation. There was a significant negative correlation between the lower levels of p24-gag+ CD4+ T-cells and the higher cytotoxicity induced by PBMCs when cells were obtained during and after treatment with ponatinib. This cytotoxic immunity was mostly based on higher levels of Natural Killer and Tγδ cells seemingly boosted by ponatinib. In conclusion, transient treatment with immunomodulators like ponatinib along with ART could be explored to boost the antiviral activity of cytotoxic cells and contribute to the elimination of HIV-1 reservoir.

Human endogenous retroviruses and exogenous viral infections.

The human genome harbors many endogenous retroviral elements, known as human endogenous retroviruses (HERVs), which have been integrated into the genome during evolution due to infections by exogenous retroviruses. Accounting for up to 8% of the human genome, HERVs are tightly regulated by the host and are implicated in various physiological and pathological processes. Aberrant expression of HERVs has been observed in numerous studies on exogenous viral infections. In this review, we focus on elucidating the potential roles of HERVs during various exogenous viral infections and further discuss their implications in antiviral immunity.

Cytomegalovirus in haematopoietic cell transplantation - The troll is still there.

Patients undergoing allogeneic haematopoietic cell transplantation are prone to complications caused by viral infections. Cytomegalovirus (CMV) considerably impacts transplantation as it frequently requires antiviral intervention that evokes substantial side effects depending on the antiviral drug. Intermittent antiviral treatment may become necessary if CMV DNAemia cannot be permanently suppressed, and drug resistance may emerge that hampers and prolongs treatment. Despite sedulous endeavours, vaccination against CMV is not yet available. This review concisely summarises current approaches in managing CMV infection comprising risk factors, diagnostics including indications for resistance testing, and therapeutic options from antiviral drugs to virus-specific T cells.

Discovery of new pesticide candidates from nature: design, synthesis and bioactivity research of rutaecarpine derivatives.

BACKGROUND: The invasion of viruses and fungi can cause pathological changes in the normal growth of plants and is an important factor in causing plant infectious diseases. These pathogenic microorganisms can also secrete toxic metabolites, affecting crop quality and posing a threat to human health. In this work, we selected the natural product rutaecarpine as the lead compound to achieve the total synthesis and structural derivation. The antiphytoviral activities of these compounds were systematically studied using tobacco mosaic virus (TMV) as the tested strain, and the structure-activity relationships were summarized. RESULT: The anti TMV activities of compounds 5a, 5n, 6b, and 7c are significantly higher than that of commercial antiviral agent ningnanmycin. We chose 5n for further antiviral mechanism research, and the results showed that it can directly act on viral particles. The molecular docking results further confirmed the interaction of compound 5n and coat protein (CP). These compounds also exhibited broad-spectrum fungicidal activities against eight plant pathogens. Especially compounds 5j and 5p have significant anti-fungal activities (EC50: 5j, 1.76 µg mL-1; 5p, 1.59 µg mL-1) and can be further studied as leads for plant-based anti-fungal agents. CONCLUSION: The natural product rutaecarpine and its derivatives were synthesized, and evaluated for their anti-TMV and fungicidal activities. Compounds 5n and 5p with good activities emerged as new antiviral and anti-fungal candidates, respectively. This study provides important information for the research and development of the novel antiviral and fungicidal agents based on rutaecarpine derivatives. © 2024 Society of Chemical Industry.

Comparative analysis of RNA interference and pattern-triggered immunity induced by dsRNA reveals different efficiencies in the antiviral response to potato virus X.

Antiviral responses induced by double-stranded RNA (dsRNA) include RNA interference (RNAi) and pattern-triggered immunity (PTI), but their relative contributions to antiviral defence are not well understood. We aimed at testing the impact of exogenous applied dsRNA on both layers of defence against potato virus X expressing GFP (PVX-GFP) in Nicotiana benthamiana. Co-inoculation of PVX-GFP with either sequence-specific (RNAi) or nonspecific dsRNA (PTI) showed that nonspecific dsRNA reduced virus accumulation in both inoculated and systemic leaves. However, nonspecific dsRNA was a poor inducer of antiviral immunity compared to a sequence-specific dsRNA capable of triggering the RNAi response, and plants became susceptible to systemic infection. Studies with a PVX mutant unable to move from cell to cell indicated that the interference with PVX-GFP triggered by nonspecific dsRNA operated at the single-cell level. Next, we performed RNA-seq analysis to examine similarities and differences in the transcriptome triggered by dsRNA alone or in combination with viruses harbouring sequences targeted or not by dsRNA. Enrichment analysis showed an over-representation of plant-pathogen signalling pathways, such as calcium, ethylene and MAPK signalling, which are typical of antimicrobial PTI. Moreover, the transcriptomic response to the virus targeted by dsRNA had a greater impact on defence than the non-targeted virus, highlighting qualitative differences between sequence-specific RNAi and nonspecific PTI responses. Together, these results further our understanding of plant antiviral defence, particularly the contribution of nonspecific dsRNA-mediated PTI. We envisage that both sequence-specific RNAi and nonspecific PTI pathways may be triggered via topical application of dsRNA, contributing cumulatively to plant protection against viruses.

From Nature to Drug: Overview and CADD Approach of Anacardic Acid to Propose their Biological Potential.

Anacardic acids are natural compounds found in various plant families, such as Anacardiaceae, Geraniaceae, Ginkgoaceae, and Myristicaceae, among others. Several activities have been reported regarding these compounds, including antibacterial, antioxidant, anticancer, anti-inflammatory, and antiviral activities, showing the potential therapeutic applicability of these compounds. From a chemical point of view, they are structurally made up of salicylic acids substituted by an alkyl chain containing unsaturated bonds, which can vary in number and position, determining their bioactivity and differentiating them from the various existing forms. Our work aimed to explore the potential of anacardic acids, based on studies that address the bioactivity of these compounds, as well as to establish a greater understanding of the structure-activity relationship of these compounds through in silico methods, with a focus on the elucidation of a possible drug target through the application of computer-aided drug design, CADD.

Safety of remdesivir in the treatment of acute SARS-CoV-2 infection in pediatric patients.

BACKGROUND: Transaminase and creatinine elevations have been well described in adults treated with remdesivir for COVID-19. It is hypothesized that a similar safety profile exists in children with COVID-19 treated with remdesivir, but available data are limited, especially in children < 12 months. The primary aim of this study was to determine the prevalence and timing of elevations in transaminases and creatinine in children with COVID-19 who were treated with remdesivir. METHODS: This was a retrospective, observational cohort study including all pediatric patients admitted to a single, freestanding children's hospital who were positive for COVID-19 and received at least 1 dose of remdesivir between 1/1/2020 and 5/31/2022. Available baseline and peak transaminase and creatinine concentrations were evaluated. Multivariable logistic regression analysis was performed to identify risk factors for transaminase elevation. RESULTS: A total of 180 patients met inclusion criteria. Creatinine elevation of any grade was noted in 16% and remained elevated only in those with underlying chronic kidney disease. Transaminase elevation of any grade was noted in 58% of patients and remained elevated in only 1%. Older age and critical respiratory disease were associated with higher risk of significant transaminase elevation, whereas non-Hispanic ethnicity was strongly associated with protection against significant transaminase elevation. CONCLUSIONS: In our cohort of hospitalized children with COVID-19 who were treated with remdesivir, most patients experienced only mild transaminitis and normal creatinine concentrations. A limited number of patients experienced laboratory abnormalities which were transient, suggesting a favorable safety profile for remdesivir use in pediatrics.

Comparative Emergence of Maribavir and Ganciclovir Resistance in a Randomized Phase 3 Clinical Trial for Treatment of Cytomegalovirus Infection.

BACKGROUND: Among 547 patients receiving maribavir or valganciclovir for first-episode cytomegalovirus infection after hematopoietic cell transplant, the treatment response rate was 69.6% and 77.4% respectively. Development of maribavir and ganciclovir resistance was compared after receiving either drug. METHODS: Viral mutations conferring drug resistance were analyzed in plasma DNA extracts at baseline and post-treatment. RESULTS: Prior antiviral drug exposure was limited, with only 2 instances of baseline drug resistance detected. An equal number (n=241) received valganciclovir or maribavir for at least 21 days (median 55-56 days). Among them, drug resistance mutations were detected in 24 (10%) maribavir recipients at 35-125 days (median 56) after starting therapy, including in 12 of 14 who experienced a viral load rebound while on therapy. Ganciclovir resistance mutations developed in 6 (2.5%) valganciclovir recipients at 66-110 days (median 90). One maribavir recipient developed a novel UL97 gene mutation (P-loop substitution G343A) that conferred strong maribavir and ganciclovir resistance in vitro. Viral clearance was confirmed in 17 (74%) of 23 patients with emergent maribavir resistance after re-treatment with an alternative CMV antiviral drug. CONCLUSION: After 3-8 weeks of therapy, maribavir resistance emerged earlier and more frequently than ganciclovir resistance but was usually treatable using alternative therapy. CLINICAL TRIALS REGISTRATION: NCT02927067 (AURORA).

Clinical and economic value of bulevirtide in the treatment of chronic hepatitis D.

BACKGROUND/AIMS: Bulevirtide (Hepcludex®) is the first drug approved for the treatment of chronic hepatitis D (CHD), unlike the current off-label treatment (PEG-IFN-α), limited in clinical practice and associated with post-treatment relapses. In a hypothetical cohort of CHD patients in Spain, the study aim was to compare the efficiency of bulevirtide with PEG-IFN-α in terms of clinical events avoided and associated cost savings. METHODS: A validated economic model reflecting the natural history of the disease was used to project lifetime liver complications and costs for two hypothetical cohorts treated with bulevirtide or PEG-IFN-α. The model considered progression to complications such as decompensated cirrhosis (DCC), hepatocellular carcinoma (HCC), liver transplantation (LT), and death. The efficacy rates used at 24 and 48 weeks were defined as the combined response rate for bulevirtide and undetectable HDV RNA to PEG-IFN-α. The numbers of clinic events and associated costs were evaluated from the perspective of the National Healthcare System. RESULTS: In a hypothetical cohort of 3882 patients, bulevirtide reduced the numbers of complications events in comparison to PEG-IFN-α (152 DCC, 113 HCC, 11 LT, and 321 deaths over a lifetime). This was associated with a reduction of event-related costs of €11,837,044 (DCC €1,138,059; HCC €1,503,583; LT €7,834,291; and death €1,361,111). CONCLUSION: In patients with CHD, bulevirtide could prevent a significant number of clinical events compared to PEG-IFN-α and contribute to cost savings through these reduction in liver complications. Further testing for hepatitis D virus is needed so that more patients can benefit from bulevirtide.

Inhibition Effect of STING Agonist SR717 on PRRSV Replication.

The porcine reproductive and respiratory syndrome virus (PRRSV) belongs to the Arteriviridae family and is a single-stranded, positively stranded RNA virus. The currently available PRRSV vaccines are mainly inactivated and attenuated vaccines, yet none of the commercial vaccines can provide comprehensive, long-lasting, and effective protection against PRRSV. SR717 is a pyridazine-3-carboxamide compound, which is commonly used as a non-nucleoside STING agonist with antitumor and antiviral activities. Nevertheless, there is no evidence that SR717 has any antiviral effects against PRRSV. In this study, a dose-dependent inhibitory effect of SR717 was observed against numerous strains of PRRSV using qRT-PCR, IFA, and WB methods. Furthermore, SR717 was found to stimulate the production of anti-viral molecules and trigger the activation of the signaling cascade known as the stimulator of interferon genes (STING) pathway, which contributed to hindering the reproduction of viruses by a certain margin. Collectively, these results indicate that SR717 is capable of inhibiting PRRSV infection in vitro and may have potential as an antiviral drug against PRRSV.