Virology Journal最新文献

Background: Dengue virus (DENV) infects millions of individuals annually, yet no specific antiviral therapy exists. Autophagy, a conserved cellular degradation pathway, is activated during DENV infection and supports the production of infectious virions. Although autophagy modulation has emerged as a potential antiviral strategy, few small-molecule autophagy inhibitors with both potent anti-dengue activity and low cytotoxicity have been reported. Thus, identifying novel, safe, and effective autophagy-targeting compounds remains an important unmet need for host-directed antiviral development.

Methods: We performed a high-content imaging screen of a natural product-derived compound library to identify autophagy inhibitors. Candidate compounds were evaluated for autophagy inhibition and anti-dengue activity using LC3 puncta quantification and plaque assays. The most potent compound was further characterized by immunoblotting to assess autophagy inhibition. Its effects on DENV genome replication, viral protein expression, and infectious particle production were examined by qRT-PCR, immunofluorescence imaging, flow cytometry, and plaque assays. Cytotoxicity was assessed using the MTS assay.

Results: The screen identified HM-013, a 1,4-naphthoquinone derivative structurally related to lawsone, lapachol, juglone, and plumbagin, as a potent autophagy inhibitor. HM-013 reduced autophagosome formation in a dose-dependent manner at low micromolar concentrations and significantly suppressed DENV infectious particle production. Mechanistically, HM-013 did not inhibit viral genome replication but instead blocked a late stage of the viral life cycle. The compound demonstrated low cytotoxicity in human liver and monocytic cells.

Conclusions: HM-013 is a promising autophagy inhibitor with potent anti-DENV activity and low cytotoxicity, supporting its further development as a potential dengue therapeutic.

Antiretroviral therapy (ART) has transformed HIV infection into a manageable chronic condition but remains non-curative and requires lifelong adherence. Rare cases of long-term remission following stem cell transplantation (SCT) have demonstrated the possibility of viral eradication, yet this approach is not scalable or safe for global implementation. A unique subset of people living with HIV, known as elite controllers (ECs), can naturally suppress replication-competent HIV without ART, often for decades, while maintaining stable CD4 + T cell counts and showing no signs of disease progression. Their ability to sustain treatment-free viral suppression provides compelling evidence that durable remission is biologically achievable, offering a model for cure research. This review synthesizes current evidence on the biology of ECs, encompassing viral, intrinsic antiviral, genetic, and immune mechanisms that underlie natural control. It also examines demographic and clinical characteristics, landmark case reports, and the broader public health implications of elite control. Finally, insights from EC biology are discussed in relation to translational strategies such as gene editing, immune modulation, therapeutic vaccination, and reservoir-targeting approaches designed to mimic or reinforce natural control mechanisms. Understanding the determinants of viral suppression in ECs provides a biological blueprint for the development of a functional cure. As the field advances toward scalable, safe, and durable remission strategies, lessons from ECs remain central to achieving long-term viral control and ultimately ending the HIV epidemic.

Background: Gammaherpesviruses co-evolve with their hosts, resulting in species-specific associations and restricted host tropism. In lagomorphs, six herpesviruses (LeHV-1 to LeHV-6) have been identified, with LeHV-4 being associated with mortality in European rabbits (Oryctolagus cuniculus), while the others cause asymptomatic infections. LeHV-5 has been hypothesized to contribute to high morbidity and mortality in Iberian hares (Lepus granatensis) when in presence of concomitant infections such as myxomatosis. However, herpesvirus infections in wild and domestic lagomorphs remain poorly understood.

Methods: Here, we conducted the first large-scale screening for herpesviruses in lagomorphs. Using a generalist PCR, we analyzed over 1,000 DNA samples from European rabbits, hares (Lepus spp.), cottontails (Sylvilagus spp.), pikas (Ochotona spp.), pygmy rabbits (Brachylagus idahoensis), volcano rabbits (Romerolagus diazi), Amami rabbits (Pentalagus furnessi), and riverine rabbits (Bunolagus monticularis).

Results: Herpesviruses were detected in 75 samples (7.24%), revealing a putative novel virus in pikas, with ~ 80% similarity to known gammaherpesviruses. We further show circulation of LeHV-5 in European and mountain hares for the first time.

Conclusions: These findings expand the current knowledge of herpesvirus diversity in lagomorphs. Given their potential role in immunosuppression and disease interactions, particularly with myxoma virus, further research is needed to assess their impact on host health and population dynamics.

Background: Hepatitis B virus (HBV) is a major human pathogen and chronically infects over 250 million people globally. The objective of our study is to investigate the mechanism of RBM15 in HBV replication, providing novel targets for HB treatment.

Methods: Huh-7 cells were treated with pHBV1.3. pHBV1.3 replication in Huh-7 cells was verified by detection of HBV RNAs, HBV pgRNA and HBx levels. The expression of RBM15, HULC and BRD4 was detected by qRT-PCR or WB. After RBM15 intervention, the effect of RBM15 on HBV replication was evaluated by detections of HBV DNA and HBV RNAs via q-PCR or qRT-PCR, HBsAg and HBeAg through ELISA. Total m6A levels were analyzed by m6A quantification. The m6A enrichment on HULC was analyzed by MeRIP. Bindings of HULC to ELAVL1, and ELAVL1 to BRD4 mRNA were examined by RIP. BRD4 stability was evaluated following actinomycin D treatment. HULC or BRD4 overexpression was combined with RBM15 inhibition to validate the mechanism. Finally, the HBV replication mouse model was established for mechanism verification.

Results: RBM15 was overexpressed during HBV replication. RBM15 inhibition suppressed HBV replication. RBM15 enhanced the m6A modification on HULC and stabilized HULC expression. HULC bound to ELAVL1 and elevated BRD4 protein expression. HULC or BRD4 overexpression partially reversed the inhibitory effect of RBM15 on HBV replication.

Conclusions: RBM15 enhances HBV replication by promoting the binding of HULC to ELAVL1 through m6A modification, and increasing BRD4 expression.

Human metapneumovirus is one of the viral causes of respiratory illness that can range from mild to life-threatening diseases. In December 2024, there was news about increased cases of human metapneumovirus (HMPV) in China, when 6.2% and 5.4% of positive respiratory illnesses and admissions, respectively, were linked to HMPV, surpassing adenovirus, rhinovirus, and COVID-19. There have been concerns about it becoming another epidemic, and by implication, a pandemic, especially as the world is gradually recovering from COVID-19 and its devastating impacts. Currently, there is no directly acting antiviral drug targeting HMPV, and this has left a gap in its treatment and management, especially in the young, elderly, and immunocompromised, who are prone to having severe manifestations. As the immune system is crucial in fighting and eliminating the infection, modulating the immune system directly or indirectly can treat HMPV. The lung that was initially known to be sterile is now found to house different populations of microorganisms, including bacteriome, virome, and mycobiome. The lung microbiome modulates HMPV infection. The presence of pathobionts like H. influenzae enhances HMPV infection and severity. The detection of the microbiome was made possible by the advent of cutting-edge technologies like next-generation sequencing and bioinformatics tools. The combination of Recombinase Polymerase Assay, CRISPR-Cas12a, and Fluorescence Assay has been used in the rapid detection of HMPV in China. The microbiome plays a crucial role in shaping the immune system. Exploring such can be a way of managing HMPV. Probiotics, prebiotics, and postbiotics are ways in which the microbiota can be manipulated to limit adverse drug reactions. These can be explored in HMPV diagnosis, treatment, and prevention.

Background: Plant-infecting viruses cause severe crop losses throughout the world. The frequent occurrence of mixed infection (co-existence of multiple viruses in a single infected plant) in the field makes the situation more alarming. Mixed infection of two viruses often boosts the fitness of either of the viruses and thus increases disease severity. Maize lethal necrosis disease and rice tungro disease are some devastating examples. This study focused on the mixed viral infection between begomovirus, a ssDNA virus, and potato virus X (PVX), a ssRNA virus.

Results: V2 protein encoded by a monopartite begomovirus, pepper leaf curl Bangladesh virus (PepLCBV), promotes the accumulation of PVX. When Nicotiana benthamiana plants were infected with both PVX and PepLCBV, aggravated PVX-induced symptoms and increased PVX titre were detected compared to plants infected with PVX alone. This observation suggests that PepLCBV promotes the viral titre of PVX during mixed infection. Next, when PepLCBVΔV2 infectious clone was co-infiltrated with PVX, no increase in PVX-associated symptoms was observed in the plants, which confirmed that the V2 protein plays a pivotal role in mediating the interaction between these two viruses. PepLCBV-V2 was experimentally identified as a potent suppressor of post-transcriptional gene silencing. Its interaction with suppressor of gene silencing 3 (NbSGS3) was confirmed through yeast two-hybrid and BiFC. Silencing of NbSGS3 facilitated PVX pathogenesis. Next, specific amino acids responsible for the suppressor activity of the V2 protein were identified, and the silencing suppressor mutant V2 failed to boost the PVX titre. A similar observation was recorded when the association of PVX with a bipartite begomovirus, tomato leaf curl New Delhi virus, was checked in both N. benthamiana and tomato.

Conclusion: The present study, for the first time, reports that begomoviruses promote the pathogenesis of potato virus X during mixed infection and identifies begomoviral pre-coat protein (V2/AV2) as a key player in mediating this virus-virus interaction. We further demonstrated that the silencing suppression activity of V2 is important for regulating PVX titre in mixed-infected plants.

Background: Certification and disease management practices are reliant on accurate pathogen detection assays. Effective nucleic acid extraction is the cornerstone of various molecular detection techniques, and many virus and viroid RNA extraction protocols have been developed, each with accompanying advantages and limitations. The extraction method influences the type, quantity and quality of RNA and, therefore, the overall sensitivity of the assay.

Methods: Plants from two citrus types were infected with multiple viruses and viroids. Ten plants from each were selected. RNA was extracted from bark and leaf samples using four protocols: CL (CTAB/LiCl), CE (CTAB/ethanol), TL (acid phenol buffer/LiCl and isopropanol) and SI (SDS/isopropanol). Extracts were subjected to RT-qPCR for pathogen quantitation. Results were confirmed with Illumina high-throughput sequencing (HTS). Leaf material from a citrus type was resampled, RNA extracted with CE, SI and CP (CTAB/isopropanol) and pathogen quantities determined with RT-qPCR. An additional five plants were also selected and subjected to RNA extraction with CP, SI and a modified CE. RT-qPCRs and HTS were applied to all of these extracts. Protocols were evaluated based on pathogen quantities and various bioinformatic approaches. Reference genes and CTV genotypes were also assessed with HTS.

Results: The extraction protocol had a remarkable influence on RT-qPCR and HTS pathogen detection ability. The CL method performed best for CTV while SI proved more sensitive for the other viruses. Viroid detection had increased variability with CE extracts containing more viroid RNA although CL extracts showed comparable amounts of CDVd. The CE protocol indicated potential debilitating effects on virus detection. The additional sampled plants subjected to the modified CE protocol, showed increased virus and decreased viroid amounts. The extraction protocol did, however, not significantly influence CTV genotype composition and the investigation of reference genes provided insight into appropriate genes to be used as internal controls for cross sample comparisons.

Conclusions: Despite the differential pathogen extraction amongst protocols, all target pathogens could be detected with appropriate RT-qPCR replicates and combined bioinformatic approaches. This study emphasises that although multiple protocols can be effective, further selection and optimisation could enhance the performance. Present research serves as a foundation for the refinement of diagnostic pipelines in citrus pathology.

Norovirus (NoV) is a major global cause of acute viral gastroenteritis, responsible for both sporadic infections and widespread outbreaks affecting individuals across all age groups. Although typically self-limiting, gastrointestinal illness, characterized by nausea, vomiting, and diarrhea, recent evidence points to its potential role in causing nonintestinal complications. Central nervous system (CNS) manifestations such as febrile seizures, convulsions, and encephalopathy have been increasingly associated with norovirus, albeit infrequently. During a large Guillain-Barré Syndrome (GBS) outbreak in January-March 2025 in the southwestern region of Pune, India, a 40-year-old male developed progressive weakness of the limbs beginning on January 18th and was admitted to a tertiary care center in a nearby town for evaluation. Molecular testing of stool samples confirmed the presence of Norovirus Group II RNA, while screening for other enteric pathogens, including Campylobacter jejuni (C. jejuni), the most recognized infectious trigger for GBS, was negative. While C. jejuni remains the primary pathogen linked to GBS, our findings support growing speculation about norovirus as an emerging, albeit rare, trigger. Further studies are needed to investigate the underlying mechanisms and to clarify the role of norovirus in GBS pathogenesis, particularly during community outbreaks.

Despite significant advances in treatment and prevention, HIV remains a major global health challenge affecting millions worldwide. In this study, we developed a pipeline combining single-cell RNA sequencing (scRNA-seq) analysis with molecular modeling to identify potential biomarkers and therapeutic targets in HIV infection. Analysis of scRNA-seq data from individuals with HIV revealed 69 differentially expressed genes. Protein-protein interaction network analysis identified five hub genes (STAT1, ISG15, MX1, BCL2, and TNFSF10). Regulatory network analysis identified transcription factors and microRNAs governing the expression of these hub genes. Molecular docking simulations identified Dolutegravir and Luteolin as compounds capable of binding to STAT1, ISG15, and MX1, with favorable ADMET profiles. These compounds may potentially modulate chronic inflammation associated with persistent interferon signaling in HIV infection. Our study demonstrates an integrative approach to scRNA-seq data analysis, transforming transcriptomic data into actionable insights by identifying specific gene targets and potential candidate compounds that could inform the design of targeted experimental studies.