Antiviral Activity Research Articles

Vemurafenib inhibits the replication of diabetogenic enteroviruses in intestinal epithelial and pancreatic beta cells

Enteroviruses, which infect via the gut, have been implicated in type 1 diabetes (T1D) development. Prolonged faecal shedding of enterovirus has been associated with islet autoimmunity. Additionally, enteroviral proteins and viral RNA have been detected in the pancreatic islets of individuals with recent-onset T1D, implicating their possible role in beta cell destruction. Despite this, no approved antiviral drugs currently exist that specifically target enterovirus infections for utilisation in disease interventions.Drug repurposing allows for the discovery of new clinical uses for existing drugs and can expedite drug discovery. Previously, the cancer drug Vemurafenib demonstrated unprecedented antiviral activity against several enteroviruses. In the present study, we assessed the efficacy of Vemurafenib and an analogue thereof in preventing infection or reducing the replication of enteroviruses associated with T1D. We tested Vemurafenib in intestinal epithelial cells (IECs) and insulin-producing beta cells. Additionally, we established a protocol for infecting human stem cell-derived islets (SC-islets) and used Vemurafenib and its analogue in this model.Our studies revealed that Vemurafenib exhibited strong antiviral properties in IECs and a beta cell line. The antiviral effect was also seen with the Vemurafenib analogue. SC-islets expressed the viral receptors CAR and DAF, with their highest expression in insulin- and glucagon-positive cells, respectively. SC-islets were successfully infected by CVBs and the antiviral activity of Vemurafenib and its analogue was confirmed in most SC-islet batches.In summary, our observations suggest that Vemurafenib and its analogue warrant further exploration as potential antiviral agents for the treatment of enterovirus-induced diseases, including T1D.

Unveiling the Latest Breakthroughs: A Comprehensive Review of the Therapeutic Activity and Safety Profile of Aloe vera.

The use of herbal drugs as alternative and complementary medicine has increased in popularity, raising concerns about their safety profile. Aloe vera, a plant with diverse therapeutic properties, has been extensively used for centuries. This review aims to assess the therapeutic activity and safety profile of Aloe vera. A comprehensive literature search was conducted to gather relevant information from various biomedical databases. The chemical composition, mechanism of action, and therapeutic activities of Aloe vera were analyzed. Aloe vera contains numerous active components such as vitamins, enzymes, minerals, sugars, lignin, saponins, and anthraquinones. Its mechanisms of action involve collagen synthesis, anti-inflammatory effects, immune modulation, laxative properties, and antiviral activity. Aloe vera has demonstrated potential therapeutic benefits in wound healing, diabetes management, liver and kidney protection, and glycemic control. However, it is essential to consider potential side effects, such as skin irritation and allergic reactions. This review provides evidence-based information to improve patient safety and promote informed decisions regarding the use of Aloe vera as a therapeutic agent.

Akt Inhibitors Prevent CyHV-2 Infection In Vitro

Cyprinid herpesvirus 2 (CyHV-2) is a double-stranded DNA virus that infects goldfish (Carassius auratus) and crucian carp (C. carassius), resulting in substantial mortality rates and significant epidemiological implications. To gain deeper insights into CyHV-2-host interactions and identify potential therapeutic targets, quantitative proteomics analysis was conducted on CyHV-2-infected Ryukin goldfish fin (RyuF-2) cells. Our findings revealed significant alterations in the expression of proteins associated with the PI3K/Akt signaling pathway, which were up-regulated upon viral infection. Building on these observations, we employed LY294002, a specific inhibitor of PI3K, to investigate its impact on viral replication by inhibiting the PI3K/Akt pathway in GiCF cell line derived from the caudal fin of Carassius auratus gibelio (Bloch). Our results demonstrated the inhibition of both CyHV-2 replication and Akt phosphorylation within this pathway. Quercetin, a plant-derived analogue of LY294002, was further investigated for its anti-CyHV-2 effects in vitro as well as its underlying mechanism. The results suggested that quercetin exhibits antiviral properties against CyHV-2 and may exert its effects through mechanisms similar to those observed with LY294002. Given that aquaculture water serves as a vector for aquaculture viral diseases and the release of chemical compounds can lead to pollution of the aquatic environment, our study shifted focus to crude extracts obtained from plants. We confirmed crude quercetin extract derived from Cuminum anisum has antiviral activity against CyHV-2 in vitro. Therefore, based on our identification of the involvement of PI3K/Akt signaling pathway in CyHV-2 replication, along with verification of its antiviral mechanism using LY294002, we propose natural dietary quercetin as a promising candidate for development into a novel anti-CyHV-2 drug.

Targeting Diabetes with Azole-derived Medicinal Agents.

Azoles have long been regarded as an ideal scaffold for the development of numerous innovative therapeutic agents as well as other incredibly adaptable and beneficial chemicals with prospective uses in a variety of fields, including materials, energetics (explosophores), and catalysis (azole organocatalytic arbitration). Azoles exhibit promising pharmacological activities, including antimicrobial, antidiabetic, antiviral, antidepressant, antihistaminic, antitumor, antioxidant, antiallergic, antihelmintic, and antihypertensive activity. According to a database analysis of U.S. FDAapproved medications, 59% of specific medications are connected to small molecules that have heterocycles having nitrogen atoms. The azole moiety has impressive electron abundance. Azoles promptly attach to various receptors as well as enzymes in the physiological environment via distinct specialized interactions, contributing to their anti-diabetic potential. This review encompasses the recent research progress on potent azole-derived antidiabetic agents that can be used as an alternative for the management of type-2 diabetes.

Phyllanthus-derived Naturally-occurring Products: An Overview of their Effects against Viruses in Cell Models

Background: Infectious diseases are considered a global public health problem, with viruses being the predominant infectious agents afflicting the human population. The most used control alternatives are the search and development of vaccines and drugs. Nevertheless, their efficacy has limitations related to the immune response stimulation, resistance mechanisms, costeffort ratio, development, and production. An alternative to these drawbacks is the search for compounds isolated from plants with antiviral and/or virucidal properties. The genus Phyllanthus is a plant group producing compounds that gathers an antiviral and virucidal spectrum on different biological models. However, there is no complete review of their properties against viruses in cell models. Objective: To compile and analyse the more relevant information on the antiviral and virucidal activity in cell models, phytochemical composition, and generalities of the genus Phyllanthus. Method: The information was assembled from a general search for articles in various databanks, and the information was organized, tabulated, and discussed. Results: The taxonomic classification of the genus Phyllanthus showed discrepancies between different authors and publications. The antiviral and virucidal effects of Phyllanthus naturallyoccurring compounds on cell models showed a broad spectrum and a high chemical diversity mainly related to phenols and polyphenols. Conclusion: Antiviral and virucidal properties of Phyllanthus-derived compounds showed promising results as controlling agents against viral infections in different cell models, particularly in the viral replication and translation processes. Further studies are required to elucidate the specific mechanisms involved in these natural alternatives to expand their efficient and effective applications.

Dasatinib interferes with HIV-1 proviral integration and the inflammatory potential of monocyte-derived macrophages from people with HIV

HIV-1 infection is efficiently controlled by the antiretroviral treatment (ART) but viral persistence in long-lived reservoirs formed by CD4 + T cells and macrophages impedes viral eradication and creates a chronic inflammatory environment. Dasatinib is a tyrosine kinase inhibitor clinically used against chronic myeloid leukemia (CML) that has also showed an anti-inflammatory potential. We previously reported that dasatinib is very efficient at interfering with HIV-1 infection of CD4 + T cells by preserving the antiviral activity of SAMHD1, an innate immune factor that blocks T-cell activation and proliferation and that is inactivated by phosphorylation at T592 (pSAMHD1). We observed that short-term treatment in vitro with dasatinib significantly reduced pSAMHD1 in monocyte-derived macrophages (MDMs) isolated from people with HIV (PWH) and healthy donors, interfering with HIV-1 infection. This inhibition was based on low levels of 2-LTR circles and proviral integration, while viral reverse transcription was not affected. MDMs isolated from people with CML on long-term treatment with dasatinib also showed low levels of pSAMHD1 and were resistant to HIV-1 infection. In addition, dasatinib decreased the inflammatory potential of MDMs by reducing the release of M1-related cytokines like TNFα, IL-1β, IL-6, CXCL8, and CXCL9, but preserving the antiviral activity through normal levels of IL-12 and IFNγ. Due to the production of M2-related anti-inflammatory cytokines like IL-1RA and IL-10 was also impaired, dasatinib appeared to interfere with MDMs differentiation. The use of dasatinib along with ART could be used against HIV-1 reservoir in CD4 and macrophages and to alleviate the chronic inflammation characteristic of PWH.

The Potential Effectiveness of an Ancient Chinese Herbal Formula Yupingfeng-San for Prevention of COVID-19: A Systematic Review

The COVID-19 has been spreading all over the world, and human health is at stake. Conventional medicine played an important role in the treatment and syndrome relief, while there is limited research evidence to support any prevention or antiviral treatment for COVID-19. YupingfengSan is a classic formula with the effect of replenishing qi, consolidating exterior, and arresting sweating. YupingfengSan has been widely used to treat various diseases in China and Southeast Asia for hundreds of years. Accumulating evidence suggests that YPFS has both immune-regulatory and anti-virus effects clinically, but leaving the mechanism elusive. In this paper, we reviewed the recent progress of YupingfengSan in immune-regulatory and anti-virus activities, including the effect on mucosal immunity, biological antagonism, macrophages, adaptive immunity, and NK cells. From this systematic review, we speculate that YPFS can play an effective role in the prevention of SARS-CoV-2, but further experimental studies are expected to investigate the specific mechanisms. This review suggests an alternative direction for the prevention of COVID-19.

Supramolecular Self-Assembled Hydrogel for Antiviral Therapy through Glycyrrhizic Acid-Enhanced Zinc Absorption and Intracellular Accumulation.

Respiratory syncytial virus (RSV) is a common pathogen that causes respiratory infections in infants and children worldwide, significantly impacting hospitalization rates in this age group. Zinc ions are considered to have broad-spectrum antiviral potential against RNA viruses, including RSV. However, poor organism absorption and low intracellular accumulation of zinc require repeated high-dose supplementation, which may lead to unnecessary toxic side effects. In this research, a Zn2+-mediated glycyrrhizinic acid (GA)-based hydrogel (ZnGA Gel) was introduced and potentially developed to be a clinically available drug candidate for RSV therapy. ZnGA Gel was fabricated based on the cooperation of two potential RSV inhibiting molecules (Zn2+ and GA), where Zn2+ promoted self-assembly of GA and reduced its gel concentration and GA promoted zinc absorption and distribution in lung tissue in vivo. The facile construction of supramolecular hydrogel by the self-assembled coordination complex made it an injectable, temperature-sensitive, and pH-responsive controlled-release drug delivery for Zn2+. Most importantly, GA was observed to enhance organism absorption and intracellular accumulation of Zn2+ and was identified as a zinc ionophore for the first time. GA can colonize on the cell membrane and disturb cell membrane potential, resulting in an enhanced cell membrane permeability. In the presence of GA, more than 4.7-fold increasing Zn2+ concentrations materialized in the intracellular cytoplasm, compared to Zn2+ alone administration. This intracellular Zn2+ accumulation directly boosted the antiviral activities through improved inhibition of RSV replication-associated proteins and significantly inhibited RSV replication. Oral administration of ZnGA Gel on the RSV-infected mice model achieved an ideal therapeutic effect by effectively lowering viral load in the lungs, alleviating lung injury symptoms, and reducing inflammatory cell infiltration at pathological sites. The mechanism involved the inhibition of RSV replication-related proteins, aligning with our in vitro results. Additionally, ZnGA Gel had demonstrated biocompatibility, and reasonable supplementation of zinc was acceptable and effective for infants and children in clinical practice. Hence, the ZnGA Gel developed by us holds promise as an effective anti-RSV medicine in the future.

IFN-treated macrophage-derived exosomes prevents HBV-HCC migration and invasion via regulating miR-106b-3p/PCGF3/PI3K/AKT signaling axis

BackgroundStudies revealed that exosomes from IFN-α-treated liver non-parenchymal cells (IFN-exo) mediate antiviral activity. MiR-106b-3p has been shown to play a paradoxical role in disease progressing from different studies. However, its specific role in HBV-related hepatocellular carcinoma (HBV-HCC) and the underlying mechanism remains unclear.MethodHuh7 cells transient transfected with plasmids of HBV-C2 and B3 were co-cultured with IFN-exo. Cell supernatants were collected to detect miR-106b-3p, HBsAg, HBeAg and HBV DNA levels. Cell proliferation, apoptosis, migration and invasion were analyzed. The putative targets of miR-106b-3p were identified by a dual-luciferase reporter system. The expression of PCGF3, migratory proteins(MMP2/9), and the PI3K/AKT signaling pathway-related proteins were assessed by western blot. The expression of PCGF3 mRNA was quantitative analyzed by using 52 pairs of paraffin-embedded tissues from HCC patients. siRNAs-PCGF3 were used to knocked-down PCGF3 expression.ResultsThe expression of miR-106b-3p was significantly higher in THP-1 cells and supernatants treated with IFN-exo than those untreated. Significantly increased expression of miR-106b-3p and decreased expression of HBsAg and HBV DNA were observed in Huh7-C2/B3 cells treated with IFN-exo. In addition, miR-106b-3p was directly target to PCGF3. Scratch healing assay and transwell assay showed that either IFN-exo or miRNA-106-3p over-expression, or siRNAs-PCGF3 inhibited migration and invasion of Huh7-C2/B3 cells, and subsequently resulted in suppression of p-AKT/AKT and p-PI3K/PI3K. Notably, the expression level of PCGF3 was significantly lower in HBeAg (+)-HCC tumor tissues than HBeAg (-)-HCC tumor.ConclusionIFN-α-induced macrophage-derived miR-106b-3p inhibits HBV replication, HBV- Huh7 cells migration and invasion via regulating PCGF3/PI3K/AKT signaling axis. miR-106b-3p and PCGF3 were potential biomarkers in the prevention and treatment of HBV-HCC.

Phaleria macrocarpa Fruit Protein Aqueous Extract Affects Viral Entry, Virucidal Activity, and Progeny Release

Presence of acyclovir (ACV) resistant virus posed a major problem in treating virus infection. Alternative treatment with the ability to encounter infection of acyclovir-resistant virus is thus needed and possibly with a different mode of action from ACV. Hence, this study evaluates the antiviral effect of Phaleria macrocarpa (Scheff.) Boerl fruit protein aqueous extract (PMFPAE) against three different strains of human herpesvirus type-1 (HHV-1) including a clinical strain, a less pathogenic strain (KOS-1), and acyclovir (ACV) resistant mutant (UKM-1). PMFPAE displayed antiviral activity towards all the HHV-1 strains when post-treated with high selective indices (SIs) of 80.6, 50, and 35, respectively. Plaque reduction percentages were reduced in attachment and penetration assays following treatment with PMFPAE indicating the ability to deactivate the early phases of the HHV-1 replication cycle. The virucidal activity was also noted following treatment of the virus with PMFPAE and this is supported by damages to the virus envelope as observed by transmission electron microscopy (TEM). Incubation of virus-treated cells with PMFPAE for 24 hr, reduced progeny release in a dose-dependent manner. The study confirms the antiviral mode of action of P. macrocarpa fruit against HHV-1 strains and the ACV-mutant strain includes inhibition during virus entry represented as the early stages of viral replication, virucidal activity, and interfering with progeny release. PMFPAE mode of action is hence different from ACV and worthy for the development of future antiviral drugs.

Antipathogenic Activity of Betainized Polyethyleneimine Sprays Without Toxicity

Background/Objectives: The design of alternative antipathogenic sprays has recently attracted much attention due to the limitations of existing formulations, such as toxicity and low and narrow efficacy. Polyethyleneimine (PEI) is a great antimicrobial polymer against a wide range of pathogens, but toxicity limits its use. Here, betainized PEI (B-PEI) was synthesized to decrease the toxicity of PEI and protonated with citric acid (CA), boric acid (BA), and HCl to improve antimicrobial activity. Methods: Cytotoxicity of the PEI-based solutions was determined on L929 fibroblast cells. Antibacterial/fungal activity of PEI-based antipathogenic sprays was investigated by microtiter and disc diffusion assays, in addition to bacterial viability and adhesion % of common bacteria and fungi on the PEI-treated masks. Furthermore, the antiviral effect of the PEI-based solutions was determined against SARS-CoV-2 virus. Results: The biosafe concentration of PEI was determined as 1 μg/mL with 75 ± 11% cell viability, but B-PEI and its protonated forms had great biocompatibility even at 1000 μg/mL with more than 85% viability. The antibacterial/fungal effect of non-toxic B-PEI was improved by protonation with BA and HCl with 2.5–10 mg/mL minimum bactericidal/fungicidal concentrations (MBCs/MFCs). Bacterial/fungal viability and adhesion on the mask was almost eliminated by using 50 μL with 5–10 mg/mL of B-PEI-BA. Both protonated bare and betainized PEI show potent antiviral activity against SARS-CoV-2 virus. Conclusions: The toxicity of PEI was overcome by using betainized forms of PEI (B-PEI). Furthermore, the antimicrobial and antiviral efficacy of PEI and B-PEI was improved by protonation with CA, BA, and HCl of amine groups on B-PEI. B-PEI-BA spray solution has great potential as an antipathogenic spray with broad-spectrum antimicrobial potency against harmful bacteria, fungi, and viruses without any toxicity.

Dual Antimicrobial Activity of HTCC and Its Nanoparticles: A Synergistic Approach for Antibacterial and Antiviral Applications Through Combined In Silico and In Vitro Studies

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC), a quaternized chitosan derivative, has been shown to exhibit a broad spectrum of antimicrobial activity, especially against bacteria and enveloped viruses. Despite this, molecular docking studies showing its atomic-level mechanisms against these microorganisms are scarce. Here, for the first time, we employed molecular docking analyses to investigate the potential antibacterial activity of HTCC against Staphylococcus aureus and its antiviral activity against human immunodeficiency virus 1 (HIV-1). According to the findings, HTCC exhibited promising antibacterial activity with high binding affinities; however, it had limited antiviral activity. To validate these theoretical outcomes, experimental studies were conducted. Different derivatives of HTCC were synthesized and characterized using NMR, XRD, FTIR, and DLS. The in vitro assays validated the potent antibacterial efficacy of HTCC against S. aureus, whereas the antiviral studies did not show good antiviral activity. However, our research also revealed a promising avenue for further exploration of the antimicrobial activity of HTCC nanoparticles (NPs), since, thus far, no studies have been conducted to show the antiviral activity of HTCC NPs against HIV-1. The nanosized HTCC exhibited superior antiviral performance compared to the parent polymers, with complete (100%) inhibition of HIV-1 viral activity at the highest tested concentration (0.33 mg/mL).

Coumarin Derivatives: Pioneering New Frontiers in Biological Applications

Abstract: Coumarins are a vital class of compounds recognized for their significant therapeutic potential, both in their natural forms and as synthetic derivatives. Characterized by a benzene ring fused to an α-pyranose ring, coumarins have garnered considerable attention from the scientific community due to their diverse pharmacological activities. This review article highlights the importance of coumarin hybrids, showcasing their enhanced biological properties and reactivity compared to traditional coumarin structures. We explore the pharmacological profiles of various coumarin derivatives, including their anti-cancer, anti-inflammatory, antiviral, antioxidant, antibacterial, and anti-tuberculosis activities, among others. The review examines how the incorporation of different functional groups on the coumarin scaffold can modulate its effectiveness against various diseases, particularly cancer. Furthermore, we discuss promising results from coumarin-based hybrids, such as coumarinpyridine, coumarin-uracil, and coumarin-quinoline derivatives, demonstrating their efficacy against a range of pathogens. This comprehensive overview serves as a valuable resource for researchers interested in the potential of coumarin derivatives in therapeutic applications.

Genetic and phenotypic changes to Venezuelan equine encephalitis virus following treatment with β-D-N4-hydroxycytidine, an RNA mutagen

The high mutation rate of RNA viruses provides viral populations with the ability to adapt to new environments but also makes them vulnerable to extinction due to the deleterious effects of mutations, which is the conceptual basis for the antiviral activity of RNA mutagens. However, there are still gaps in the quantitative understanding of the dynamics between the mutations induced by an RNA mutagen and its effects on viral fitness. To address this, we used Venezuelan Equine Encephalitis Virus (VEEV) and the potent RNA mutagen β-d-N4-hydroxycytidine (NHC) as a model to analyze virus replication competency and mutation frequency following treatment in the total and replication-competent viral populations separately. We found that NHC induced transition mutations in a concentration dependent manner in the total population, while the replication-competent population maintained itself within an increased, yet narrow, mutation spectrum. The incorporation of NHC mainly happened during the positive sense RNA synthesis of VEEV. A growth kinetic analysis of VEEV population treated with NHC pointed to a lower but more diverse distribution in mutational fitness, demonstrating that NHC-induced mutations negatively and broadly affect the fitness of the virus. Together, our study provides mechanistic insight into how RNA mutagens affect viral population landscape and the potential of RNA mutagens as an antiviral strategy for alphaviruses.

Rhizomatoflavonoid D and Other Flavonoids from the Twigs of Ochna Rhizomatosa as a Potential Inhibitor of HIV-1

AbstractCurrently, HIV morbidity and mortality in sub-Saharan Africa remain a huge concern and awaiting interventions. Even though the combination antiretroviral therapy (cART) has recorded significant success, drug resistance and limited access to available therapeutics are major factors responsible for the low impact of cART in several African communities. Herein, as part of our continuous effort on the investigation of bioactive metabolites of Ochna rhizomatosa, we report the isolation of a new flavonoid; Rhizomatoflavonoid D (1), alongside with four known ones (2–5). The structures of these compounds were elucidated by using spectroscopic techniques (1H NMR, 13C NMR, HSQC, HMBC, 1H-1H COSY, and ROESY) and mass spectrometry. The antiviral activity of the resulting compounds was assessed using deCIPhR assay run in parallel with the Alamar Blue based cytotoxicity assay. This assay revealed a moderate activity for compound 4 (72% inhibition at 2.5 µg/mL) while compound 1 had minimal activity (36% inhibition at 2.5 µg/mL). The prominent inhibitory effect on HIV-1 was showed by compound 4 (IC50 = 3.1 µM). Unfortunately, compound 4 proved to be non-selective as it demonstrated also a CC50 = 5.2 µg/mL (Selectivity index of 1.7). The prominent inhibitory effect on HIV-1 showed by compound 4 (IC50 = 3.1 µM) could be due the presence of a methoxy group at C-7, since this group enhances the lipophilicity of biflavonoids, thereby improving its incorporation into cells.

Rational Design of Macrocyclic Noncovalent Inhibitors of SARS-CoV-2 Mpro from a DNA-Encoded Chemical Library Screening Hit That Demonstrate Potent Inhibition against Pan-Coronavirus Homologues and Nirmatrelvir-Resistant Variants.

The recent global COVID-19 pandemic has highlighted treatments for coronavirus infection as an unmet medical need. The main protease (Mpro) has been an important target for the development of SARS-CoV-2 direct-acting antivirals. Nirmatrelvir as a covalent Mpro inhibitor was the first such approved therapy. Although Mpro inhibitors of various chemical classes have been reported, they are generally less active against nirmatrelvir-resistant variants and have limited pan-coronavirus potential, presenting a significant human health risk upon future outbreaks. We here present a novel approach and utilized DNA-encoded chemical library screening to identify the noncovalent Mpro inhibitor 5, which demonstrated a distinct binding mode to nirmatrelvir. A macrocyclization strategy designed to lock the active conformation resulted in lactone 12 with significantly improved antiviral activity. Further optimization led to the potent lactam 26, which demonstrated exceptional potency against nirmatrelvir-resistant variants as well as against a panel of viral main proteases from other coronaviruses.

The structure of lipopeptides impacts their antiviral activity and mode of action against SARS-CoV-2 in vitro.

This study advances our understanding of how lipopeptides, which are molecules mostly produced by bacteria, with both fat and protein components, can be used to fight viruses like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). By analyzing 15 different lipopeptides, researchers identified key structural features that make some of these molecules particularly effective at reducing viral levels while being less harmful to cells. Specifically, lipopeptides with certain charged amino acids were found to have the strongest antiviral effects. This research lays the groundwork for developing new antiviral treatments that are both potent against viruses and safe for human cells, offering hope for better therapeutic options in the future.

Antiviral Effects of Avian Interferon-Stimulated Genes

Interferons (IFNs) stimulate the expression of numerous IFN-stimulating genes via the Janus kinase-signal transducers and activators of the transcription (JAK-STAT) signaling pathway, which plays an important role in the host defense against viral infections. In mammals, including humans and mice, a substantial number of IFN-stimulated genes (ISGs) have been identified, and their molecular mechanisms have been elucidated. It is important to note that avian species are phylogenetically distant from mammals, resulting in distinct IFN-induced ISGs that may have different functions. At present, only a limited number of avian ISGs have been identified. In this review, we summarized the identified avian ISGs and their antiviral activities. As gene-editing technology is widely used in avian breeding, the identification of avian ISGs and the elucidation of their molecular mechanism may provide important support for the breeding of avians for disease resistance.

EDP-938 Has a High Barrier to Resistance in Healthy Adults Experimentally Infected with Respiratory Syncytial Virus.

EDP-938 is an oral once-daily RSV nucleoprotein (N) inhibitor with potent antiviral activity. In a human RSV challenge trial, EDP-938 significantly reduced viral load and symptom severity. During antiviral development, it is critical to understand the propensity for resistance to develop. In vitro studies of EDP-938 suggest a higher barrier to resistance as compared to RSV fusion inhibitors. We evaluated the development of viral resistance to EDP-938 in a human challenge trial. A subset of the 124 participants with RSV infection were chosen for genetic analysis; 159 nasal wash samples from 48 participants were analyzed using next-generation sequencing of the N gene of RSV. Of the 48 participant sampled, 37 were from EDP-938-treated and 11 were placebo-treated participants, representing 45% and 26% of the participants, respectively. The effects of treatment-emergent mutations on viral load, EDP-938 efficacy, and viral fitness were evaluated. Two of the 37 EDP-938-treated participants with samples sequenced had treatment-emergent mutations: N:L139I and N:E112G. From in vitro analysis, N:L139I reduced sensitivity to EDP-938 by approximately 10-fold, while N:E112G had no effect. However, N:L139I was associated with a reduction in viral fitness, suggesting clinical resistance is associated with fitness costs. Neither of these variants were associated with reduced viral clearance. In human RSV infections treated with EDP-938, emergence of RSV variants with reduced sensitivity to EDP-938 occurred in only 1 participant and was associated with reduced viral fitness. EDP-938's high barrier to resistance highlights its robust mechanism of action. NCT03691623.

HIV-induced RSAD2/Viperin supports sustained infection of monocyte-derived macrophages.

HIV infection of macrophages is a barrier to HIV cure and a source of neurocognitive pathology. We found that HIV induces RSAD2/Viperin during sustained infection of macrophages. While RSAD2/Viperin is an interferon-stimulated gene with known antiviral activity, we find RSAD2/Viperin promotes HIV infection in macrophages through multiple mechanisms, including interferon signaling. Therefore, RSAD2/Viperin may be a therapeutic target for the treatment of HIV-infected macrophages.