Biology and Life Sciences

Abstract: Positive-sense RNA viruses are commonly classified by genome organization, entry route, tissue tropism, and clinical syndrome, but these categories do not explain how viruses construct protected replication niches or route infectious material between cells. The endoplasmic reticulum (ER) provides a shared platform for viral translation, replication-organelle formation, membrane curvature, lipid remodeling, innate immune regulation, and vesicular trafficking. Within this framework, reticulon-3 (RTN3) has emerged as a candidate regulator linking ER-based RNA-virus replication to the generation of infectious extracellular-vesicle cargo. Hepatitis C virus (HCV) and dengue virus (DENV) provide the strongest comparative evidence for this model despite their distinct transmission routes, tissue tropisms, disease courses, and immune pathophysiology. HCV most clearly demonstrates that exosome-enriched fractions can transfer replication-competent viral RNA with defined host cofactors, whereas DENV extends this mechanism to an acute viral infection. Both viruses nevertheless replicate within remodeled ER membranes and can transfer infection-competent material in vesicle-associated form. Current evidence supports a context-dependent model in which RTN3-associated membrane curvature, ER–endosome communication, and cargo routing influence whether replication-associated viral RNA is retained, degraded, assembled into virions, or exported in biologically active extracellular vesicles. Related membrane-remodeling and vesicle-associated processes in Zika virus, West Nile virus, enteroviruses, SARS-CoV-2, and hepatitis A virus illustrate broader exploitation of host membrane organization, although direct evidence for RTN3-dependent infectious extracellular-vesicle transfer varies across these systems. In the best characterized models, vesicles protect viral genomes or replication-associated complexes and deliver biologically active cargo to recipient cells. Advances in isolation and characterization, including density-gradient or size-exclusion separation, immunoaffinity selection, particle and marker profiling, membrane-protection assays, and recipient-cell infectivity testing, now permit more rigorous identification of defined vesicle populations, protected cargo, and biological activity. Nevertheless, RTN3 should not be considered a universal RNA-virus dependency, nor should extracellular-vesicle release be assumed to generate uniformly infectious populations. Instead, HCV and DENV show that divergent viral pathophysiologies can converge on host membrane factors such as RTN3 while retaining virus-specific molecular partners and pathways for replication and vesicular transmission. Defining these shared and virus-specific dependencies may reveal host–virus interfaces suitable for broad-spectrum or resistance-resilient intervention, provided that infection-selective reliance, a measurable therapeutic window, and preservation of essential host-cell functions can be demonstrated.

Abstract: Bats harbor a remarkable diversity of viruses, yet much of their virome remains unexplored, particularly in South American species. Here, we characterized the RNA virome in fecal samples of three arthropodophagous bat species roosting in Argentina (Eumops bonariensis, Molossus molossus, Tadarida brasiliensis), and evaluated variation in viral communities across habitats and seasons. Metagenomic sequencing generated 161,871,196 high-quality read pairs, which were assembled into 32,816 contigs longer than 500 bp. BLAST-based analyses identified 11,056 viral contigs, but only 4.6% could be assigned to viral orders or families. Sequences classified at basal ranks were further analyzed using profile-based HMMER searches together with viral dark matter analysis. This approach increased the proportion of viral contigs assigned to orders or families to 45.2% and identified 30 viral families overall. Viral community composition showed species-specific patterns, with habitat-associated differences in E. bonariensis, temporal variation in T. brasiliensis, and comparatively low and homogeneous diversity in M. molossus, although these patterns were not statistically significant. Divergent viruses of bunya-, hepe-, stella-, flavi-, rhabdo-, and reo-like lineages were further characterized. Our findings highlight the value of integrating similarity- and profile-based approaches to improve viral taxonomic resolution and reveal the diversity of RNA viruses associated with South American bats.

Abstract: Salmonella enterica (S. enterica) is a leading cause of foodborne illness worldwide, and the accelerating spread of multidrug-resistant serovars has renewed interest in bacteriophages as therapeutic agents. Phages infecting S. enterica exhibit an extraordinary diversity of virion architectures, ranging from compact, non-tailed microviruses with circular, single-stranded DNA genomes to jumbo phages with large, double-stranded DNA genomes and elaborately layered capsid–tail assemblies. Here, we review this architecture by morphotype: microviruses (Microviridae), podoviruses, siphoviruses, myoviruses and jumbo phages. Each section centers on representative, structurally characterized phages as focal case studies. By integrating available cryo-electron microscopy (cryo-EM) reconstructions with complementary biochemical and genomic evidence, we distinguish features conserved within a morphotype from those reflecting lineage-specific adaptation. For each morphotype, we further discuss how these architectures address key functional imperatives, including protection of the genome in the extracellular environment and recognition of diverse Salmonella surface receptors. By linking virion architecture to function, this review identifies key gaps for future mechanistic studies and informs the rational selection and engineering of phages against multidrug-resistant Salmonella.

Abstract: Antimicrobial resistance (AMR) in Ecuador extends across human health, animal production, agriculture, and the environment, yet national evidence on bacteriophages as an alternative has remained scattered across indexed articles, theses, and institutional repositories. We mapped that evidence through a One Health lens, following the PRISMA extension for scoping reviews (PRISMA-ScR). Five bibliographic databases and publisher platforms (Web of Science, ScienceDirect, Springer, Scopus, and SciELO) and 21 Ecuadorian repositories were searched for studies published between 2021 and 2026. From 592 records, 38 reports met the eligibility criteria: 6 peer-reviewed articles and 32 gray-literature documents (7 postgraduate and 25 undergraduate). Inter-reviewer agreement was 89.1% (Fleiss' kappa = 0.773; 95% CI, 0.635-0.912). Research concentrated in animal health (44.7%) and human health (31.6%), with fewer reports in agriculture (10.5%), poultry (5.3%), aquaculture (5.3%), and the environment (2.6%). Institutional output was highest in Pichincha, Tungurahua, and Guayas; journal articles were affiliated with institutions in Pichincha, Guayas, and Azuay. No included reports were assigned to institutions in the Amazon or Galapagos regions. The most studied hosts were Salmonella enterica, Escherichia coli, Klebsiella pneumoniae, Vibrio spp., Listeria spp., and Ralstonia solanacearum. Methodologically, the corpus spans phenotypic characterization, PCR- and restriction-based differentiation, whole-genome sequencing, and functional validation, but these approaches coexist rather than form a maturation gradient. Genomic safety claims rested mainly on the absence of known lysogeny, resistance, and virulence genes, and functional transduction assays were largely absent. Ecuadorian bacteriophage research has begun to shift from demonstrating lysis toward molecularly defined products, but translational readiness is limited by fragmented publication, geographic concentration, and incomplete characterization. Decentralized laboratory capacity, national phage collections with deposited genomes, and standardized characterization pipelines would strengthen the field.

Abstract: Porcine reproductive and respiratory syndrome (PRRS) is a major economically important disease affecting the global swine industry. Its etiological agent, porcine reproductive and respiratory syndrome virus (PRRSV), exhibits substantial genetic diversity driven by mutation, recombination, and selective pressures. Following taxonomic revisions by the International Committee on Taxonomy of Viruses, PRRSV isolates are classified into Betaarterivirus europensis and Betaarterivirus americense. In Peru, the molecular and epidemiological evolution of PRRSV in Lima’s swine farms remains insufficiently characterized. This review aimed to characterize the evolutionary dynamics of PRRSV variants circulating in Lima through 2026. A narrative review with a systematic search strategy was conducted following PRISMA 2020 principles. Searches of PubMed/MEDLINE, Scopus, Web of Science, SciELO, Redalyc, LILACS, and GenBank identified 200 records, of which 60 met the eligibility criteria. Studies addressed global taxonomy and molecular biology (50.0%), international evolutionary dynamics (25.0%), South American epidemiology (8.3%), and PRRSV evolution in Lima (16.7%). Evidence suggests three periods: European-genotype detection (1998-2012); increased epidemiological characterization and reports of genetically distinct or highly virulent lineages (2013-2022); and diversification of B. americense, including NADC34-like sublineages and field-strain recombination evidence (2022-2026). These findings support sustained genomic surveillance, whole-genome sequencing, and coordinated molecular monitoring across South America.

Abstract: Sex hormones shape reproductive tract immunity and influence host defense against viral infection. However, much of our understanding of hormone-mediated immunity derives from cisgender populations and systemic studies. Comparatively less is known about the effects of sustained hormonal change within reproductive tissues. This gap is particularly relevant to transgender men (TGM) taking testosterone-based gender-affirming hormone therapy (GAHT) and to menopausal women using menopause hormone therapy (MHT). Although biologically distinct, these populations provide complementary contexts for examining how sustained androgen exposure, ovarian hormone decline, and therapeutic hormone use influence reproductive tract immunity. In this review, we examine hormone-associated changes in reproductive tract epithelial, stromal, and immune cells including the reproductive tract microbiome and virome. We consider their implications for the acquisition, replication, persistence and pathogenesis of HIV-1, HPV, HSV and CMV. Understanding these tissue specific, hormone-immune-virus interactions may help identify gaps in viral prevention, screening, vaccination, and treatment efforts across diverse hormonal and reproductive contexts.

Abstract: The persistence of human immunodeficiency virus type 1 (HIV-1) in the central nervous system (CNS) remains a major barrier to a cure and a key driver of HIV-associated neurocognitive disorders (HAND). For decades, progress in understanding HIV-1 neuropathogenesis has been limited by the lack of experimental models capable of recapitulating the complexity of the human brain. The development of three-dimensional (3D) brain organoids derived from human induced pluripotent stem cells (iPSCs) has significantly advanced the field by providing a physiologically relevant and clinically translatable platform for studying HIV-1 infection in the CNS. This review summarizes the evolution of brain organoid technologies, from self-organizing cultures to immune-competent organoids and multi-region assembloids. We highlight their contributions to understanding HIV-1 neuroinflammation, neuronal injury, and CNS reservoir establishment. We also discuss emerging advances integrating organoids with bioengineering and single-cell omics approaches to overcome current limitations and accelerate the development of therapeutic and curative strategies targeting HIV-1 persistence in the CNS.

Abstract: Hepatitis B virus (HBV) infection remains a significant global public health concern. Data suggest that HBV genotypes/sub-genotypes and virulence-associated mutations can influence the natural history and treatment outcomes of HBV infection. However, the dearth of full-length HBV genome sequences in Kenya limits complete understanding of emerging variants and recombination events. Here, we sequenced and analyzed 165 HBV DNA whole-genome sequences from HBsAg-positive serum samples of voluntary blood donors across different geographic regions of Kenya between 2019 and 2023 to provide deeper insights into the virus’s genomic diversity, virulence-associated mutations, recombinations, and drug resistance profiles. Genomic analysis revealed a predominance of HBV genotype A in Kenya (77.0%), followed by genotype D (19.4%) and genotype E (3.6%) during the study period. Within genotype A, sub-genotype A1 predominated (99%), while A2 was a minority. Among genotype D, sub-genotype D7 was most common (97%), followed by D1 (3%). Recombination was detected in 4.2% of the sequenced isolates and involved genotype A/D, A/E, D/A, and D/E recombinant forms. None of the sequenced isolates harbored mutations linked to resistance to approved nucleos(t)ide analogues in the reverse transcriptase region of the polymerase gene. However, genetic variation associated with a higher risk of hepatocellular carcinoma (HCC), vaccine immune escape, and occult hepatitis B virus infection (OBI) were detected across genomic regions, including HCC-linked mutations G1896A in 81.3% (26/32; 95% CI: 63.6–92.8) of genotype D and 50% (3/6; 95% CI: 11.8–88.2) of genotype E isolates (FDR-adjusted p < 0.001); and G1899A in 17.0% (28/165; 95% CI: 11.6–23.6, FDR-adjusted p < 0.05) in the precore gene region of all isolates. Additionally, those present in the basal core promoter region included C1773T in 80.0% (132/165; 95% CI: 73.1–85.8, FDR-adjusted p < 0.001) and A1762T/G1764-double mutation in 29.1% (48/165; 95% CI: 22.3–36.7) of all isolates. Immune escape-linked amino acid variation within the “a” determinant of the major hydrophilic region (MHR) in the S gene region, included T131N in 99.2% (126/127; 95% CI: 95.7–100, FDR-adjusted p < 0.001) of genotype A and T126A/S in 16.7% (1/6; 95% CI, 0.4–64.1, FDR-adjusted p > 0.05) of genotype E isolates, while those related to occult-HBV infection (OBI) included P127H/L in 3.6% (6/165; 1.3–7.7, FDR-adjusted p < 0.001) of all isolates. Overall, our findings indicate that HBV genotype A (sub-genotype A1) predominates in Kenya, followed by genotypes D (sub-genotype D7) and E. Moreover, the detection of HBV variants harboring genetic markers associated with immune escape, occult hepatitis B (OBI), and liver disease complications highlights the need for public health countermeasures such as immunization of infants and scaling up of adult vaccination to reduce infections. Furthermore, wider integration of molecular real-time PCR testing into the national blood screening algorithm is advised to reduce the risk of horizontal transmission from asymptomatic HBV blood donors harboring occult HBV infection mutations and ensure the safety of blood and blood products.

Abstract: We report two cases of equine encephalomyelitis associated with the recently emerged European Shamonda virus type 1 (SHAV-EU1). Shamonda virus has not yet been described in horses but has caused an unprecedented outbreak in cattle in Western Europe this summer (2026). Both horses showed neurological deficits and lymphocytic cerebrospinal fluid pleocytosis associated with encephalomyelitis, vasculitis and hemorrhages in brain and spinal cord. Pan-Simbu RT-qPCR confirmed viral RNA in brain tissue, and Metatranscriptomic sequencing identified full-genome SHAV-EU1 sequences, proofing correlation to the outbreak in Swiss cattle.

Abstract: More than 40 years after its discovery, HIV-1/AIDS remains a major global health threat, with nearly 41 million people living with HIV worldwide at the end of 2025. Antiretroviral therapy (ART) remains the only effective treatment; however, access to ART is still limited in many low- and middle-income countries due to inadequate infrastructure, high costs, and recent cuts in international funding. Despite advances in vaccine development, an effective prophylactic HIV-1 vaccine remains elusive, with no new efficacy trials currently planned. Consequently, the focus has shifted toward therapeutic HIV-1 vaccines as an adjunct to ART. Such vaccines may provide temporary immunological control of viral replication during ART interruption or failure and may reduce treatment costs by limiting the number of ART components. This review summarizes recent advances in therapeutic HIV-1 vaccines, including approaches that mimic T-cell responses of elite controllers, elicit broadly neutralizing antibodies, or redirect immunity toward viral epitopes essential for viral fitness, including drug-resistance mutations. To assess whether therapeutic vaccination may become a viable option for PLWH, we also review experience from routine vaccination in this population. This analysis provides a framework for designing therapeutic vaccination strategies, including dosage, regimens (priming/boosting), and durability of immune responses, thereby helping to determine revaccination needs. Although therapeutic HIV-1 vaccines alone are unlikely to achieve a sterilizing cure or sustained ART-free remission, accumulating evidence indicates that they can substantially enhance HIV-specific immunity, delay viral rebound following ART interruption, and complement various HIV-1 treatment strategies, making them an important component of combination approaches aimed at achieving a functional HIV-1 cure.

Abstract: The apparent yield of “full” recombinant adeno-associated virus (rAAV) capsids is a key manufacturing metric. Yet it can substantially overstate the fraction of particles that contain a single intact, transduction-competent genome. I propose that a stochastic occupancy ceiling constrains authentic full-capsid yield, a limit that bulk production assays often neglect. Single-particle and single-molecule studies show that the density- and mass-defined “full” population is heterogeneous, containing truncated, rearranged, and multi-DNA species alongside intact genomes, implying stochastic rather than deterministic loading. In the resulting occupancy model, the fraction of capsids containing exactly one intact genome is p(1) = m·e^(-m), where m is the mean number of genome-equivalents per capsid. This fraction maximizes at m = 1, imposing an e^(-1) ≈ 36.8% ceiling on authentic single-genome capsids in any independent, batch-loading regime. Increasing genome supply beyond this point cannot increase authentically-full yield; instead, it converts empty capsids into physically full but functionally defective multi-occupancy particles that co-purify with authentic capsids and evade density-, size-, and bulk-DNA assays. Reports of high-percentage full-capsid fractions should therefore be interpreted with caution unless supported by sequence-level evidence of single intact genomes. The model also identifies the only route to exceed this ceiling: occupancy-dependent protection, represented by the relative second-capture parameter, σ, combined with decoupled, low-instantaneous-MOE (Multiplicity-Of-Encapsidation) loading. This framework reframes rAAV filling from a separations problem to a quantitative loading-control problem. Single-molecule sequencing of the full-capsid density fraction generated under varied genome supply would be the decisive analytical test of the hypothesis.

Abstract: A novel lytic bacteriophage, designated vB_ValS-L9, infecting the potential pathogenic bacterium Vibrio alginolyticus L4, was isolated from a coastal aquaculture area in Beihai, China. Transmission electron microscopy revealed that vB_ValS-L9 possesses an icosa-hedral head (56.50 ± 4.19 nm in diameter) and a long tail (143.03 ± 5.32 nm in length), ex-hibiting a typical siphovirus-like morphology within the class Caudoviricetes. The phage demonstrated wide stability across various temperatures, pH levels, and salinities. Genomic sequencing showed that vB_ValS-L9 has a circular double-stranded DNA genome of 43,884 bp with a G+C content of 43.55% and 61 predicted ORFs. No tRNA, virulence, or antibiotic resistance genes were identified. Genomic and phylogenetic analyses, including ANI, VICTOR, VIRIDIC, and conserved protein phylogenies, identified vB_ValS-L9 as a novel species that, together with Vibrio phages Artemius and VapS30, forms a new genus in the class Caudoviricetes, for which the name Artemiovirus is proposed. Furthermore, in vivo trials using juvenile pearl oysters (Pinctada martensii) revealed that vB_ValS-L9 pro-vides substantial prophylactic and therapeutic protection against V. alginolyticus L4 infec-tion, especially when the phage was administered before bacterial challenge. Collectively, these findings suggest that vB_ValS-L9 shows potential as a safe, environmentally robust, and promising biocontrol candidate for managing vibriosis in aquaculture.

Abstract: Porcine deltacoronavirus (PDCoV) is an emerging enteric coronavirus that causes severe mortality in neonatal piglets that results in significant economic burden to the global swine industry. The spike protein, particularly the C-terminal domain of S1 subunit (S1-CTD), contains immunodominant epitopes and represents an attractive target for antibody development. In this study, we expressed and purified recombinant PDCoV S1-CTD proteins in Escherichia coli and used it to immunize BALB/c mice for generating S1-CTD-specific antibodies. Following hybridoma production, we successfully established four monoclonal antibodies (2B7-G10, 2C7-F6, 7G3-G8, and 4H4 mAbs) that specifically recognized recombinant S1-CTD as well as native PDCoV spike protein. We further engineered a single-chain variable fragment derived from clone 4H4 (4H4-scFv) that retained antigen-binding ability to against S1-CTD and native PDCoV spike. Collectively, these findings demonstrate a practical framework for generating targeted mAbs and scFvs while expanding the repertoire of available reagents for future PDCoV S-targeted studies.

Abstract: Background/Objectives: Although the COVID-19 pandemic has ended, emerging SARS-CoV-2 variants remain a future threat. This study evaluated the safety and efficacy of an intranasal live attenuated vaccine (LAV) prototype based on a temperature-sensitive (ts) Omicron-like SARS-CoV-2 mutant in a Syrian hamster COVID-19 model. Methods: SARS-CoV-2 Dubrovka (Wuhan-like), Otradnoe (BA.1.1) and FEB2 (BA.5.2) strains and the ts F-F3 mutant derived from FEB2 were characterized by electron microscopy, nanopore sequencing, cytopathic effect titration, and RT-PCR. In vitro studies used Vero CCL-81 cells; in vivo transmissibility and efficacy studies were assessed in female Syrian hamsters. Serum antibody titers were measured by ELISA and neutralization assays. Immunization efficacy was assessed by weight change, viral loads in the lungs, nasal passages, and brain, and histological examination of the lungs at day 4 post-challenge. Safety criteria included evaluation of pathogenicity and transmissibility in hamsters and ts phenotype stability during prolonged in vitro cultivation. Results: The F-F3 strain displayed a stable ts phenotype in vitro, did not infect hamster lungs or brain, and showed no transmission from immunized to naïve co-housed animals. A single intranasal dose induced seroconversion, reduced pneumonia severity by 75% (p < 0.01), protected lungs and nasal passages against infection, and prevented viral transmission after homologous BA.5.2 challenge. Following heterologous Wuhan-like challenge, immunization prevented weight loss and significantly reduced viral loads in the lungs, nasal passages, and brain; however, protection against pneumonia was only modest. Conclusions: Preclinical evaluation of the F-F3-based LAV prototype demonstrated a favorable balance between safety and protective efficacy. These characteristics support its further consideration as a candidate strain for COVID-19 LAV development.

Abstract: Human papillomavirus (HPV) infection and oral microbiota alterations have been independently associated with oral disease in people living with HIV (PLHIV). However, the relationship between alpha-HPV (α-HPV), beta-HPV (β-HPV), and the oral microbiome remains poorly understood. Aim: This cross-sectional study aimed to describe the association between oral HPV infection and the oral and oropharyngeal microbiome in Mexican PLHIV with sustained virologic control and immune reconstitution. Methods: Oral and oropharyngeal samples were obtained by rinsing and gargling, and participants were classified into HPV-negative, α-HPV, and β-HPV groups. The V3–V4 region of the 16S rRNA gene was sequenced using the Illumina MiSeq platform. A total of 65 participants were included in the final analysis: 19 HPV-negative, 16 -α-HPVpositive, and β-HPV 30 -positive. Results: Alpha diversity was significantly increased in both HPV-positive groups compared with the HPV-negative group, with the highest diversity observed in the α-HPV positive group. The α-HPV group also showed a higher Fusobacteriota/Bacteroidota ratio and enrichment of Fusobacteriota-related taxa. In addition, predicted functional analysis showed enrichment of pathways related to lysine and pyruvate fermentation to butyrate in the α-HPV group. These findings suggest that α- and β-HPV infections may be associated with different oral microbial ecosystems in PLHIV.

Abstract: In 2022, Yolles and Frieden argued that viruses are alive by moving the criterion for life from metabolism to organisation, arguing the genome–capsid couple to be autopoietic. This study reframes that conclusion with two constructs of Fisher-Generative Informational Realism (FGIR): the CAS/CAAS boundary, separating a Complex Adaptive System (CAS), adaptive but not self-sustaining, from a self-sustaining Complex Adaptive Autopoietic System (CAAS); and the coercivity law, which requires a system’s protoenergy, the informational effort of holding a configuration in persistent form, to exceed a threshold. The verdict “viruses are not autopoietic” conflates two conditions. Viruses satisfy the topological condition, the couple being a genuine self-producing network, but fail the resourcing condition, since the capacity to maintain it belongs to the host: “borrowed closure”, which we derive formally. Identifying the viral protoenergy with the draw on the host, and letting self-supply return only when the lineage’s translation machinery is complete, yields a host-budget equation with a saddle-node bifurcation at a critical completion fraction. Given a near-all-or-nothing return of self-supply, the barrier is structural rather than statistical, and it survives stochastic, epidemiological and delayed reformulations; its value is illustrative. The account is falsifiable and taxonomically agnostic, as the ribosome-encoding but host-dependent bacterium Carsonella ruddii shows, and crossings into self-sufficiency are observed only downward.

Abstract: Foot-and-mouth-disease is a highly contagious disease affecting cloven hoofed animals, having an important direct and indirect socio-economic impact in livestock industry. The disease has been successfully eradicated from some regions, but it is still endemic in most of the world. The use of vaccines that contain strains that match antigenically with the FMD strains circulating in the field is one of the main tools, together with a good epidemiology plan for its eradication. Supplying information in relation to characterization of circulating strains is useful to maintain antigen banks updated in order to be prepared to attend eventual incursions. Previously, information has been published in relation to genetic changes in the evolution of type O circulating lineages in Vietnam and other countries of Southeast Asia. Here we present genetic and antigenic characterization of type O viral strains circulating in Vietnam during 2019 until 2024, vaccine matching tests were performed using a swine sera pool collected from animals vaccinated with a monovalent vaccine containing O1 Campos strain at 28 days-post-vaccination (dpv). High neutralizing antibody titers were registered for type O isolates with r1 values over 0.3 in most of the cases, indicating good cross-reactivity. Furthermore, a swine challenge test performed against one of field isolates from the Mya-98 lineage exhibited 100% protection even with a single vaccine dose. All together these results demonstrate that high potency O1 Campos vaccines could be used for controlling outbreaks in endemic regions with circulation of multiple type O topotypes and lineages.

Abstract: Zoonotic viral diseases continue to pose major challenges to global health, particularly as environmental, social and economic changes increasingly influence interactions among humans, animals, vectors, and ecosystems. This review explores Rift Valley fever virus (RVFV), Crimean-Congo hemorrhagic fever virus (CCHFV), and hantaviruses (HTVs) within the framework of One Health, emphasizing the ecological and epidemiological factors that govern their emergence and transmission. Despite their distinct transmission cycles, these viruses share important determinants of zoonotic risk. RVFV is primarily maintained through interactions among mosquitoes, livestock, wildlife, and humans; CCHFV is sustained within complex tick–vertebrate systems involving Hyalomma ticks, domestic animals, and wildlife; while HTVs are predominantly maintained through persistent infections in mammalian reservoir hosts, particularly rodents. Climate variability, habitat alteration, agricultural expansion, livestock movement, urbanization, and other anthropogenic pressures can modify these transmission systems and create new opportunities for pathogen spillover. Effective prevention and control therefore require integrated surveillance that encompasses human disease, animal populations, vectors or wildlife reservoirs, and environmental conditions. Advances in molecular diagnostics, genomic epidemiology, ecological modeling, remote sensing, and climate-based forecasting provide valuable opportunities for improving early detection and outbreak preparedness. Ultimately, the experiences of RVFV, CCHFV, and HTVs that reducing the burden of zoonotic viral diseases requires sustained collaboration among human and veterinary health professionals, ecologists, entomologists, environmental scientists, and public health authorities. A coordinated One Health approach is consequently essential for anticipating emerging threats, strengthening preparedness, and protecting human, animal, and ecosystem health.

Abstract: Hantaviruses cause haemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome, together responsible for more than 200,000 cases annually, but no specific antiviral therapy is approved. We developed a three-stage computational framework for systematic drug repurposing. Transcriptomic analysis of Hantaan virus-infected human umbilical vein endothelial cells (GEO GSE133751) identified 203 differentially expressed genes dominated by interferon-stimulated genes. A STRING protein–protein interaction network (176 nodes, 3,210 edges) and composite master-regulator centrality score identified 15 hubs, including ISG15, IRF1, CXCL10, STAT1, and DDX58. Open Targets analysis identified six druggable hubs and 12 repurposing candidates in four priority tiers. An ordinary differential equation model of type I interferon signalling then evaluated eight drug perturbations. Early IFN-β achieved the fastest viral clearance (3.5 days) with reduced CXCL10 immunopathology. Early JAK inhibition delayed clearance (4.9 days) and increased CXCL10, an effect that follows from modelling CXCL10 as an IRF1-driven rather than STAT1-driven output. Combining IFN-β with an anti-CXCL10 monoclonal antibody produced the best balance between antiviral efficacy and immunopathology control, although in the present model the antiviral gain of this combination derives entirely from its interferon component. This mechanistically grounded, evidence-ranked framework prioritises candidate therapies and phase-specific combinations for preclinical hantavirus studies.

Abstract: Schlafen proteins are interferon-responsive regulators of cellular and antiviral pathways that can profoundly influence viral replication and host defense. Diverse viral infections are known to induce expression of Schlafen (SLFN) family members in human cells, while infection studies in mice have been primarily limited to mSlfn2, a group I SLFN protein without a clear ortholog in humans. RNA-seq analysis of three distinct infection models reveals that mouse Slfns are induced in response to murine gammaherpesvirus 68 (MHV68) in fibroblasts, B cells, and primary peritoneal macrophages. Further, mSlfn8 is induced during MHV68 infection only under conditions with robust interferon signaling, suggesting that its expression is limited by viral interferon antagonism. To assess whether mSlfn8 or related Slfns impact MHV68 replication, we performed siRNA-mediated knockdown and CRISPR/Cas9 knockout of mSlfn2, mSlfn8, and mSlfn9 in NIH 3T3 cells. Two independent clonal mSlfn2 and mSlfn8 cell lines supported higher viral titer, indicating that these mSlfns are restriction factors for MHV68 replication in murine fibroblasts. Collectively, these results demonstrate that mSlfn2 and mSlfn8 function as antiviral effectors during MHV68 infection and support a model in which MHV68 counteracts interferon-induced mSlfn expression to promote efficient replication.