Abstract: Extracellular vesicles (EVs) can disseminate replication-competent viral genomes complexed with selected host proteins, enabling stealth cell-to-cell transfer within lipid membrane-enclosed bubbles. In addition to complementing free-virion spread, EV-associated genomes can be protected from neutralizing antibodies and persist under conditions in which classical virion production decreases. Here, we propose a route-resolved framework in which interconnected cellular secretory pathways, including endoplasmic reticulum (ER) remodeling, multivesicular body (MVB) biogenesis, secretory autophagy, and plasma-membrane budding, jointly generate EV heterogeneity and create discrete opportunities for the capture, protection, and export of infectious cargo. We highlight reticulon-3 (RTN3), an ER-shaping protein, as an upstream regulator that can couple infection-induced ER microdomains to endosomal docking and autophagy-linked trafficking decisions that bias intermediates toward secretion rather than degradation. Supporting this view, transmission electron microscopy of dengue virus-infected cells reveals extensive vesicular remodeling, including irregular MVBs adjacent to the plasma membrane and autophagosome-like double-membrane structures, consistent with altered vesicular routing following RTN3 perturbation. Collectively, these route-resolved, spatially organized spatio-organelle changes support a pathomechanistic model in which RTN3-mediated ER remodeling reshapes ER-endosome-autophagy trafficking interfaces, creating regulated decision points that can be leveraged to stratify infectious EV subsets (with infectivity-linked single-vesicle and quantitative proteomics approaches) and to inform host-directed strategies that curb non-lytic viral dissemination.

Abstract: TBEV is a major cause of viral central nervous system infections in Europe, with heterogeneous geographical distribution and substantial underdiagnosis in low-incidence regions. This study aimed to evaluate the validity of regional TBE risk classification in Poland by combining surveillance-based incidence data with serological markers of TBEV exposure. Plasma samples from 5,541 blood donors residing in nine regions were tested by anti-TBEV IgG ELISA, followed by confirmatory VNT, IFA and anti-NS1 IgG ELISA to differentiate infection-induced from vaccine-induced antibodies. Regions were classified based on average TBE incidence from 2015–2019. Overall, anti-TBEV IgG screening reactivity was detected in 4.9% of donors, with significant regional variation (p < 0.001). The highest seroprevalence was observed in highly affected regions; however, unexpectedly elevated seroprevalence was also detected in regions classified as low affected. Markers consistent with TBEV infection (anti-NS1 IgG) were identified in only 2.6% of donors, whereas vaccine-induced immunity accounted for the majority of seropositive results. Male sex was independently associated with higher odds of seropositivity. Our findings suggest that passive surveillance data alone may insufficiently capture population-level exposure to TBEV, particularly in regions considered non-endemic. Integrating sero-epidemiological data with surveillance systems may improve risk assessment and inform targeted prevention strategies.

Abstract: The severe acquired respiratory coronavirus–2 (SARS–CoV-2) infection has initiated both acute and chronic COVID–19 disease between 2020 and 2023, currently evolving with other homologous prior coronavirus strains of the Nidoviridae order, which encompasses other prevalent alpha/ beta coronaviruses, but also the Middle East Respiratory Syndrome (MERS-CoV) and SARS-CoV-1, with recent SARS–CoV–2 variants, increasing demands for effective immunogens and therapeutic approaches that will reduce global disease burden and further infection from SARS–CoV-2 affected individuals that may experience post acute sequelae (PASC) or “Long COVID”. Following a worldwide programme of prophylactic vaccination, there is still a dilemma in the efforts to find prophylactic and early therapeutic approaches that would treat novel SARS-CoV-2 variants and prevent future epidemics or pandemics within host human and animal populations, where zoonotic or cross species transfer naturally occurs. Concerns about viral immune escape intersect at a specific point; a gained evolutionary ability of several viruses to co–infect and compete against previous scientific advances since 1796 that remain undetected or asymptomatic during the early stages of infection progressing to symptomatic and severe disease via the double methylation of the 5' end of eukaryotic DNA or RNA-based viral genomes, the 7-MeGpppA2’-O-Me cap, and its double methylation capping process is performed by the activated viral 2’ - O - Methyltransferase (MTase) enzyme, a complex of two viral non-structural proteins (NSPs) joined together through an activation process (NSP10/16) and by N7-Methyltransferase (N7-MTase/NSP14), respectively. Moreover, it was discovered that polymorphic viruses translate NSP1, which prevents the activation of various Pattern Recognition Receptors (PRRs), and consequently, detection of Pathogen-Associated Molecular Patterns (PAMPs) and Damage-Associated Molecular Patterns (DAMPs) alike. NSP1 also silences important interferon-encoding genes (INGs) and interferon-stimulated genes (ISGs), is signalled in a paracrine manner to neighbouring cells, and that induces the apoptosis of host cells, inducing an effect of “trace erase” effect and making the viral infection as immunologically “invisible” as possible during the initial, key stages of viral replication and distribution, all such mechanisms occurring independently of the viruses in cause. Another important viral NSP is NSP14, as it plays two functional roles that are independent of each other; to produce new viral genetic material for the purpose of maintaining the validity of the viral genome as well, and not just transfer a methyl group to the 5’ end of the viral genome. Other viral NSPs share a role with NSP1, 10, 14 and 16 in directly suppressing the activation of PRRs and ISGs, and all such viral proteins help the virus in its process of self-camouflaging against first- and second-line immunity, thereby often severely impacting the quality of the produced adaptive immune responses. The outcome of all such phenomena is the sharp decrease in the host Type I and Type III interferons' (IFNs) rate of synthesis by the host cells, that would usually occur and affect homeostatic cellular pathways, resulting in further viral replication and induced apoptosis. Nonetheless, effects of microbial immune evasion during the development of other viral or carcinogenic pathologies are not widely known. In short, polymorphic viruses developed a proportionate evolutionary response against developed adaptive immune responses, by currently relying on gaps mostly situated in the natural immune system in their process of molecular self-camouflaging. Scientists developed numerous approaches of early treatment that generally showed good success rates and fewer risks of adverse events, and the still early present stages of COVID-19 research should also be taken into consideration whilst filtering for the most appropriate solutions. For example, the administration of recombinant human interferons I and III into the nasal mucosa cellular layer, as key mediators of anti–viral activity, can simulate intracellular infection and stimulate cellular activity in a timely manner, training the innate and adaptive immune system cells to develop and appropriately stimulate an adequate immune response through B and T cells. Another example could involve the treatment of natural and adaptive lymphocytes with a low dose of IFNs I and possibly III, prior to their insertion into the host lymphatic system, possibly alongside additional recruitment of plasmacytoid dendritic cells (pDCs) as further interferon “factories”, all with the purpose of early infection management. It might be that focusing on directly offering the immune system the information about the genetics and protein structure of the pathogen, rather than training its first-line mechanisms to develop faster, excessively increases its specificity, making it reach a level that brings the virus the opportunity to evolve and escape previously-developed host immune mechanisms. With regards to efforts to delay the onset of malignant diseases, approaches of chrono-biological oncotherapies that include a combination of Type I and Type III Interferon-based “immune re-awakening” and low-dose SSRI or SNRI approaches, could display meaningful extents of efficacy, at least in effective delays in the onset of malignant diseases. Such overall approaches could also be considerably effective in efforts to delay and/or even prevent a number of acquired immunodeficiencies (i.e. HIV-1-induced AIDS) and diverse forms of malignant cancer, potentially helping to notably decrease the overall burden of disease worldwide in the long run. It is until the scientific community realises this potentially crucial aspect that large proportions of the world population will probably continue to face serious epidemics and pandemics of respiratory diseases over the coming several decades, evidenced with dengue fever and more recently, monkeypox and possibly avian flu. Of note, it has been indicated that IFN I and / or III display significant immunising, early therapeutic and clinical disease onset-attenuating effects for many other microbial evoked diseases, as well as for a number of oncological diseases. Microbial agents could undergo loss-of-function research upon genes responsible for inducing clinical illness whilst keeping genes responsible for microbial reproduction and transmission at least generally as functional, CRISPR-Cas9 genome editing to have genes encoding proteins suppressive of the host interferon system eliminated prior to human genes encoding Pattern Recognition Receptor activator or agonist proteins, such as outer membrane proteins of Neisseria meningitidis, as well as Type I, Type III and possibly even Type IV Interferons and various ISGs inserted into the microbial genome. Importantly, the present study is theoretical and conceptual in nature and does not advocate for any practical steps or deployment into any real-world context. Such an approach is imagined as a potential prophylactic and early therapeutic method based upon the model of editing genes of harmless bacteria to transform such them into “producers” and “distributors” of human insulin, and could turn several microbial agents into clinically harmless, transmissible “factories” for various key elements of the host interferon system, potentially placing such microbes into a reverse evolutionary path that would be deemed as “natural de-selection”, visibly reducing the average burden of disease and metabolic stresses, which in turn could gradually increase average human and animal lifespans worldwide.

Abstract: Glucose and ascorbate transport and their opposite effects on the physiological processes, explain the pathophysiology of the Ebola virus. The virus impairs intracellularly the interferon (IFN) signalling. The present article will focus on the viral factors (VP24, VP35, VP40 proteins, nucleoprotein NP) that operate in the inner of the cell, subsequently to the viral entry. The haemorrhagic fever syndrome could be understood as a state of oxidative stress, driven by hyperglycaemia and the activation of NF-kB pathway and inflammatory cytokines. High glucose levels in plasma contributes to oxidative stress. It has also an inhibitory effect on Interferon (IFN) signalling. Conversely, ascorbate can counteract the IFN blocking exerted by the virus and interfere virus budding. A treatment strategy would focus on the administration of ascorbate and glutathione, glucose or insulin at convenience, in order to maintain constant and normal levels of glucose in plasma, to combat the oxidative and inflammatory stress.

Abstract: Translational virology, characterized as “from bench to bedside”, covers all issues from basic research through clinical evaluation and final registration and drug/vaccine approval. It covers the identification of the cause of disease, screening of potential prophylactic or therapeutic agents, evaluation in animal models, confirmation of activity in human clinical trials, registration and approval. The recent COVID-19 pandemic represents a perfect example of translational virology, which demonstrated an unprecedented cooperation from the identification of the SARS-CoV-2 to the rapid development of potential repurposed and novel drugs and vaccines for both prophylactic and therapeutic applications. After confirmation of therapeutic and prophylactic efficacy in animal models, clinical phase I-III evaluation was carried out in an overlapping strategy, reducing the development time significantly. To maximize the chances of success, vaccines based on whole viruses, protein and peptide subunits, viral vectors and nucleic acids were developed in parallel. Based on good safety profiles and robust immune responses, COVID-19 vaccine candidates were granted emergency use authorization worldwide allowing the start of mass vaccinations. More than 13.6 billion COVID-19 vaccine doses have been administered, and although severe adverse events have been registered millions of lives have been saved. Due to emerging SARS-CoV-2 variants vaccine re-engineering has been required as part of translational virology. Vaccine production, storage, transport and distribution have also been given attention.

Abstract: This review explores a hypothetical and previously underexplored ecological pathway that may contribute to virus dispersal, including human pathogens, through passive transport involving free-living nematodes and migratory animals. Available data on nematode-associated viruses, nematode survival in diverse environments, and mechanisms of passive dispersal are synthesized to propose a conceptual framework for long-distance pathogen movement. Particular attention is given to the ecological interactions among nematodes, animals, and viruses, and to the potential role of these interactions in shaping pathogen distribution patterns under environmental and anthropogenic pressures. The article discusses a theoretical model of possible virus transfer across ecological niches and highlights key gaps requiring experimental validation. This study highlights a previously underestimated route of potential virus transmission, including human pathogens, through possible long-distance dispersal (500 km or more) by free-living nematodes and migratory birds. Data on the spread of viruses of nematodes of the genus Caenorhabditis spp., the survival of nematodes in various conditions, and their spread by various groups of animal carriers, including their ability to pass through the gastrointestinal tract of birds in a viable state, are analyzed. The role of a number of migratory bird species as biological carriers not only of free-living nematodes themselves over considerable distances, but also of viruses hypothetically associated with nematodes on/inside their bodies, is considered as a potential mechanism. This work raises questions about previously underestimated biological risk factors associated with this potential route of passive pathogen dispersal to new territories and ecological niches, especially in conditions of environmental stress, intensive animal husbandry, and global movement of wild animals. The article discusses a hypothetical scenario in which SARS-CoV-2 and other viruses could be passively dispersed through ecological interactions involving nematodes and migratory birds. Understanding the ecological dynamics of the interaction between birds, nematodes, and virusesmay contribute to ecological risk assessment and understanding of emerging pathogen dynamics. This manuscript presents a conceptual ecological hypothesis and should not be interpreted as evidence of confirmed transmission pathways.

Abstract: This study evaluated IndiMix JOE with intype IC-RNA as an alternative PCR chemistry to the National Animal Health Laboratory Network (NAHLN) Influenza A virus (IAV) PCR surveillance assay using AgPath-ID One Step PCR reagents in avian swabs and tissues and bovine milk. In avian samples, IndiMix JOE with intype IC-RNA using a fast reduced-volume (FRV, 20 µL) protocol had comparable results to NAHLN standard PCR assays (with and without intype IC) using standard NAHLN thermocycling conditions (25 µL). Precision was high, with coefficients of variation ≤ 2.61% for IAV targets and ≤ 2.03% for intype IC-RNA. Following detection of IAV in U.S. dairy cattle, a six-way comparison of PCR chemistries and exogenous internal controls in milk illustrated no significant differences in mean CT values (ANOVA, p = 0.9938). Additional experiments in avian, milk and semen samples were performed, resulting in comparable analytical sensitivity in limits of detection (LOD), linearity (R² > 0.977), and PCR efficiencies, and lacked significant differences in mean CT values (ANOVA, p > 0.05). Diagnostic sensitivity and specificity were 100% across matrices. These findings validate IndiMix JOE and intype IC-RNA as a reliable alternative reagents that enhances testing flexibility, efficiency, and outbreak response capacity.

Abstract: During cholera outbreaks in Zambia, diagnostic strategies that rely on single-plex or targeted assays risk overlooking concomitant infections with other clinically important enteric pathogens. We estimated the prevalence of rotavirus and described co-detected enteropathogens and rotavirus genotypes among patients admitted with clinically suspected cholera during Zambia’s 2023–2024 cholera outbreak.We conducted a sub-analysis of diarrhoeal specimens collected from patients admitted to five cholera treatment centres who met the syndromic suspected cholera case definition. Stool samples were tested using the Bosphore® Gastroenteritis Panel v2, a multiplex PCR enteric panel, to detect rotavirus and other gastrointestinal pathogens. Rotavirus-positive specimen with sufficient viral load were further characterised by RT-PCR genotyping and Sanger sequencing targeting VP7 and VP4 genes. Among 319 suspected cholera admissions, rotavirus was detected in 18 patients, yielding a prevalence of 5.6% (95% CI 3.4%, 8.8%). Rotavirus detections occurred predominantly in children aged < 5 years (87.5%) and 6-15 years (80.0%). Co-infection was common - 93.7%, (15/16) of rotavirus-positive samples showed co-infection with at least one additional enteric pathogen, primarily Campylobacter. Genotyping was successful in five samples and showed heterogenous circulating strains, including G1P[8], G2P[4], G3P[6], G12P[6], and a rare G1P[6] reassortant. During a large 2023–2024 cholera outbreak in Zambia, rotavirus accounted for a modest but clinically important fraction of the suspected cholera admissions and was typically identified within mixed enteric infections. These findings highlight the limitations of syndromic diagnosis in outbreak settings and support integrating multi-pathogen diagnostics and sustained molecular surveillance to improve case management, antimicrobial stewardship, and vaccine-era monitoring.

Abstract: Parvoviruses are small, non-enveloped DNA viruses, several of which have been adapted as vectors for gene therapy. Adeno-associated virus (AAV) is clinically established but constrained by limited genome capacity and pre-existing immunity. Human bocaviruses (HBoVs) possess larger packaging potential and airway tropism, motivating exploration of AAV-HBoV hybrid architectures. We modeled a chimeric construct (AAV-HB3) in which the α-helix and βH/βI strand of AAVGo.1 were replaced with the corresponding regions from HBoV3. AlphaFold2 predictions (pLDDT > 80, pTM > 0.75) confirmed reten-tion of the β-barrel scaffold, and RoseTTAFold2 refinement produced energetically stable conformations. 100 ns molecular-dynamics simulations showed distinct dynamic profiles: the AAVGo.1 VP1 control remained conformationally rigid (RMSD ≈ 0.03 nm), whereas AAV-HB3 exhibited increased flexibility at VR-VIII, VR-IV, and the HI loop, with loop dis-placements of ~43–54 Å localized near the three-fold and five-fold symmetry axes. These structure-based analyses define how cross-genus substitutions redistribute local flexibility within the parvoviral capsid, providing a predictive framework for engineering next-generation vectors with assessing structural tolerance relevant to capsid.

Abstract: Wheat streak mosaic (WSM), historically attributed to wheat streak mosaic virus (WSMV) and transmitted by the wheat curl mite (WCM; Aceria tosichella), remains a major cause of yield loss in the Texas High Plains. In recent years, Triticum mosaic virus (TriMV), also transmitted by WCM, has emerged as an increasingly important component of the WSM disease complex. Under field conditions, TriMV is most frequently detected in mixed infections with WSMV. Management of WSM relies primarily on resistant cultivars carrying genes such as Wsm1 or Wsm2. Although synergistic interactions between WSMV and TriMV have been documented under controlled conditions, their dynamics during natural field infections—particularly during the latent phase between initial infection and symptom development—remain poorly understood. Moreover, the extent to which host genotype influences virus–virus interactions and vector acquisition dynamics in the field has not been fully resolved. Replicated field trials conducted over two growing seasons were used to quantify temporal accumulation patterns and relative ratios of WSMV and TriMV in susceptible (TAM 304) and resistant cultivars differing in resistance source (BT [Wsm1] and Joe [Wsm2]) under natural disease spread. WSMV remained the predominant virus in mixed infections across cultivars, sampling times, and disease stages. However, as plants aged and entered senescence, WSMV titers declined more rapidly than TriMV titers, resulting in a progressive reduction in the WSMV-to-TriMV ratio. From early in-fection through disease development, the Wsm1 cultivar (BT) consistently supported significantly lower TriMV accumulation than the Wsm2 cultivar (Joe), providing a mechanistic explanation for the comparatively stronger disease suppression associated with WSM. Mites feeding on BT also acquired lower TriMV titers. Although viral con-centrations in wheat tissue were strongly correlated with those detected in feeding mites, substantial differences in plant-level WSMV-to-TriMV ratios among cultivars were not mirrored within the vector. These findings indicate that while host resistance regulates absolute virus accumulation, vector-associated factors may influence the relative pro-portions of viruses detected following acquisition, with important implications for WSM epidemiology and resistance deployment in field systems.

Abstract: Following the COVID-19 pandemic in 2020, there has been growing interest in investigating the transmission routes of SARS-CoV-2 and identifying the potential reservoirs in wildlife. To date, the virus has been detected in a wide range of wildlife animals. SARS-CoV-2 has also been demonstrated the ability to infect dogs, raising concerns that other carnivores, such as free-living canids, might serve as a potential sources of infection. The aim of this study was to investigate the presence of specific IgG antibodies against SARS-CoV-2 in golden jackals (Canis aureus) and red foxes (Vulpes vulpes) in Serbia. A total of 165 individuals from ten districts including the City of Belgrade were collected and examined from the beginning of August 2024 to the end of March 2025. Of this number, 17 samples were positive (17/165), which represents 10.3% of all specimens tested. Among 83 red foxes, antibodies against SARS-CoV-2 were detected in 11 animals (13.3%), whereas reactive sera were identified in 6 of 82 jackals (7.3%). The analyses were performed using a commercial multi-species ELISA (IDVet, France), with results confirmed by an in-house ELISA, previously developed for the detection of COVID-19 in humans and adapted for canids. Our findings confirm that wild animals are indeed exposed to SARS-CoV-2 infection, and that golden jackals and red foxes may serve as competent hosts for infection, posing a threat for human health. These results represent the first detection of SARS-CoV-2 seroconversion in wild carnivores in Serbia, highlighting the need for further surveillance and investigation.

Abstract: Natural product (NP)-based chemical libraries are a rich source of antiviral compounds that can serve as the basis for new therapeutic leads to treat viral diseases, particularly toward individuals lacking sustained access to existing vaccines and therapeutics. To identify new NP-based inhibitors of SARS-CoV-2 cellular entry and viral replication, we screened the pan-African Natural Products Library (p-ANAPL), a collection of over 500 physical pure compounds obtained from African medicinal plants, for NPs that can dis-rupt the in vitro interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with its host ACE2 entry receptor. This screen identified three compounds – oleanolic acid, poinsettifolin B, and rhuschalcone III – which disrupt RBD/ACE2 interactions with half-maximal inhibitory concentrations (IC50s) of 0.5 – 2.4 µM but do not disrupt an unre-lated PD-1/PD-L1 host ligand/receptor binding pair. Oleanolic acid and rhuschalcone III, but not poinsettifolin B, additionally inhibited SARS-CoV-2 replication in Vero cells without cytotoxicity at low micromolar concentrations. Computational modelling indi-cated that all three compounds interact with numerous residues of RBD and ACE2, in-cluding a subset of residues that remain conserved across SARS-CoV-2 variants of con-cern. Taken together, we identify three NPs that selectively interfere with factors involved in SARS-CoV-2 entry and/or viral replication, representing new antiviral leads for COVID-19 management in resource-limited areas.

Abstract: Viral hemorrhagic fevers (VHFs) are severe infectious diseases caused by RNA viruses of the families Arenaviridae, Filoviridae, Flaviviridae, and Hantaviridae, characterized by high morbidity, significant case-fatality rates, and frequent diagnostic uncertainty in early disease stages. For military medical services, timely clinical recognition and laboratory confirmation are essential to guide patient management, prevent nosocomial transmission, and maintain operational continuity, particularly in endemic or resource-limited deployment settings. This review critically examines current diagnostic approaches to VHF-causative agents, emphasizing their use in clinical and field medical settings. The diagnostic process from exposure through specimen collection, laboratory testing, and result interpretation is analyzed, including the use of molecular, serological, and antigen-based assays. Particular attention is given to deployable diagnostic platforms and their role in bridging the gap between frontline clinical suspicion and definitive laboratory confirmation. Biosafety requirements and infection prevention measures are discussed as integral components of clinical diagnostic workflows, aligned with guidance from the World Health Organization and the Centers for Disease Control and Prevention. Comparative analyses of virus-specific diagnostic timelines and laboratory requirements are presented to support differential diagnosis and clinical decision-making. Emerging technologies, including rapid molecular assays and genomic methods, are evaluated for their potential to improve early diagnosis and patient outcomes. This review highlights the central role of diagnostic readiness in clinical management of VHFs and provides evidence-based considerations to support military clinicians facing high-risk febrile illnesses in operational environments.

Abstract: Vaccination represents the cornerstone of Newcastle disease control. Nanotechnology offers a promising approach to improve the effectiveness of DNA vaccines, supporting their use as an alternative to conventional platforms. Herein, the virulent Orthoavulavirus javaense (OAV-j) fusion (F) gene was cloned into a DNA expression plasmid (pDNA). After validating the constructed pDNA-F and confirming robust intracellular protein expression in vitro, three polymeric nanoparticles (NPs)–based formulations were generated using Chitosan (Cs), poly(lactic-co-glycolic) (PLGA), and poly(amidoamine) (PAMAM)-Dendrimers. Physicochemical and morphological analyses confirmed excellent formulation characteristics, including optimal nanoscale size, formulation-specific surface charge, and effective DNA–carrier interactions. Encapsulation/loading and release profiles further confirmed their successful preparation. In vivo experiments were conducted to assess the immunogenicity and protective efficacy of these formulations compared to naked pDNA-F using various administration routes. Following intramuscular administration, PAMAM-Dendrimers-pDNA-F demonstrated superior efficacy, with 100% survival, the highest post-challenge antibody titers, and a pronounced reduction in viral shedding. Moreover, intranasal administration of PLGA-NPs-pDNA-F demonstrated enhanced efficacy, with 90% survival. Interestingly, naked pDNA-F surpassed the Cs-NPs-pDNA-F in both immune response and clinical protection, with Cs-NPs-pDNA-F exhibiting the lowest overall performance. These findings underscore the importance of route-dependent formulation performance and demonstrate that a well-designed carrier significantly improves DNA vaccines effectiveness.

Abstract: Interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral factors that restrict the entry of many enveloped viruses, including HIV-1, by modifying host membrane properties and trapping fusion at the hemifusion stage. Beyond blocking entry in target cells, IFITMs also reduce the infectivity of virions produced from IFITM-expressing cells, a phenomenon termed “negative imprinting”. Conserved motifs, such as the amphipathic helix and oligomerization motifs, have been reported to be essential for IFITM-mediated protection of target cells from viral infection. Yet, the impact of IFITM incorporation on progeny virion infectivity remains poorly defined. Here, we show that IFITM3 mutants defective in target cell protection activity still markedly impair HIV-1 fusion/infection upon incorporating into virions, without affecting viral maturation or Env incorporation. Immunofluorescence studies suggest mislocalization of the IFITM3 mutants as the reason for the lack of antiviral activity in target cells. Testing the antiviral activity of chimeras between antiviral and non-antiviral IFITM orthologs failed to clearly identify a domain responsible for reduction of HIV-1 infectivity, suggesting that multiple domains may be required for negative imprinting. Interestingly, co-incorporation of non-antiviral dog IFITM1 with human IFITM3 did not interfere with IFITM3’s negative imprinting activity, despite forming mixed hetero-oligomers. This finding implies a dominant, oligomerization-independent antiviral phenotype of IFITM3 in virions. Our findings suggest that IFITMs may protect target cells and negatively imprint progeny virions through distinct mechanisms, underscoring the need to further characterize the molecular basis for the reduced fusion competence of IFITM-containing HIV-1 particles.

Abstract: Feline immunodeficiency virus (FIV) is a lentivirus sharing significant structural and pathological similarities to human immunodeficiency virus (HIV), making it a valuable surrogate model for HIV vaccine design and development. Currently, there is no available effective vaccine could protect cats against FIV infection. This study aims to use some artificial intelligence and immunoinformatic to design a novel multi-epitope DNA vaccine targeting some conserved regions of FIV’s gag, pol, and env genes. The mapped B and T-cell epitopes across the key proteins of the FIV genomes were screened for their ability to trigger strong immune responses, while avoiding allergenic or toxic responses and were linked to the immune adjuvant PADRE. Analysis of the vaccine construct revealed a stable, soluble, and biocompatible vaccine construct with a well-folded tertiary structure capable of binding toll-like receptor 9 (TLR9) and eliciting a robust humoral and cellular immune response. These results demonstrate a promising FIV vaccine candidate with potential insight into future directions in next generation HIV vaccines. Further experimental validation is required to confirm the potential protective power of these putative vaccines in the protection of cats against FIV natural field infection.

Abstract: Pregnancy represents a distinct immunological and physiological state that modifies maternal susceptibility to SARS-CoV-2 and influences the clinical and biological course of COVID-19. Accumulating evidence indicates that the interaction between viral entry determinants, gestation-specific immune modulation, placental endocrine–angiogenic pathways, and systemic inflammatory responses underlies the characteristic manifestations of SARS-CoV-2 infection during pregnancy. This review consolidates current understanding of SARS-CoV-2 viral structure, receptor biology, and the gestational regulation of key entry cofactors, including ACE2, TMPRSS2, NRP1, CTSL and FURIN, within reproductive and placental tissues. The review further integrates documented mechanisms of cytokine-mediated immune dysregulation, endothelial injury, thrombo-inflammation, and steroidogenic alteration observed in affected pregnancies, and examines their contribution to placental malperfusion, preeclampsia-like presentations, fetal growth abnormalities and preterm birth. Published molecular and computational studies characterising trophoblast antiviral defenses, receptor expression patterns, and structural determinants of Spike–ACE2 affinity are synthesised to contextualise the biological basis of placental susceptibility and the rarity of confirmed transplacental transmission. Current evidence on maternal clinical outcomes, fetal and neonatal consequences, vaccination efficacy, therapeutic considerations and contemporary management guidelines is also critically reviewed. By integrating molecular, immunological, pathological and clinical insights, this article provides a comprehensive framework for understanding the interaction between SARS-CoV-2 infection and pregnancy-specific physiology, with implications for risk assessment, preventive strategies and maternal–fetal care.

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection elicits highly heterogeneous immune responses that influence both acute disease severity and long-term immunological outcomes. While effective antiviral immunity leads to viral clearance in many individuals, a subset develops persistent immune dysregulation characterized by chronic inflammation, immune exhaustion, and impaired tissue repair, hallmarks of long COVID. These immune alterations are parallel to established mechanisms of carcinogenesis and tumor progression, including sustained cytokine signaling, oxidative stress, metabolic reprogramming, and disruption of antitumor immune surveillance. Emerging evidence suggests that SARS-CoV-2 may further interact with cancer biology through direct or abortive infection of tumor or stromal cells, as well as through viral protein–mediated activation of oncogenic and inflammatory signaling pathways such as NF-κB, MAPK/ERK, JAK/STAT3, and Toll-like receptor signaling. In addition, immune evasion strategies observed in both chronic viral infection and cancer, including immune checkpoint upregulation, impaired antigen presentation, and the establishment of immunosuppressive microenvironments, may be reinforced following SARS-CoV-2 infection. SARS-CoV-2 vaccination limits severe disease and persistent immune activation, thereby potentially mitigating long-term tumor-permissive immune states without evidence of oncogenic risk. These observations position SARS-CoV-2 infection as a non-classical but biologically relevant modifier of cancer-associated immune landscapes. Elucidating the long-term consequences of post-infectious immune remodeling will be essential for defining cancer risk, optimizing surveillance strategies, and informing therapeutic interventions in COVID-19 survivors.

Abstract: The Zika virus (ZIKV), a pathogenic member of the orthoflavivirus family, is raising serious health concerns worldwide. Like Dengue (DENV) and Chikungunya (CHIKV) viruses, it is one of the arboviruses that poses an emerging threat to areas where its main vectors, Aedes mosquitoes, proliferate, well beyond tropical and subtropical regions. Although often asymptomatic or mild, ZIKV infection has been responsible for a worrying increase in serious congenital syndromes, including microcephaly. The ability of ZIKV to be transmitted sexually and its long persistence in body fluids suggests its incomplete clearance in particular tissues, linked to recurrent infection. Among its clinical presen-tations, ZIKV infection has been associated with ocular complications, including macu-lopathy, retinopathy, uveitis, and optic neuropathy, which can lead to lasting visual impairment. The blood-retinal barrier (BRB), primarily composed of retinal pigment epithelium (RPE) and endothelial cells, plays a crucial role in shielding the retina from pathogens. Its disruption has been linked to viral retinal infections. In vitro monitoring of infection on hTERT RPE-1 cells revealed an ability of ZIKV to persist for up to 30 days in nearly 10% of the cells. This prolonged infection was marked by moderate cytopathic effects and notable morphological changes throughout the cell layer, suggestive of an epithelial-mesenchymal transition (EMT). Long-lasting viral replication and production were associated with reduced expression of epithelial genes and increased expression of certain mesenchymal genes, suggesting that the integrity of the RPE layer may be compromised. These results indicate that viral persistence and phenotypic transition observed in vitro in RPE cells could provide clues to understanding the late onset of ocular pathophysiological manifestations in Zika virus-related diseases.

Abstract: Infectious laryngotracheitis virus (ILTV) is a highly contagious respiratory pathogen of poultry that causes significant economic losses to the poultry industry worldwide. Live attenuated vaccines have been used for decades to control ILTV outbreaks. Among the ILTV live attenuated vaccines, SA2 and A20 have been frequently used as commercial vaccines. Frequent changes occur in the ILTV genome due to its possibility of genome drift and recombination. The major goal of this study is to monitor genomic variations in recently circulating ILTV field isolates recovered from vaccinated chicken flocks. Tissue samples collected from an infected chickens flock suspected of ILTV were examined by real-time PCR. Samples with high viral load were selected for next-generation sequencing (NGS). Full length genome of three ILTV isolates (B1, B3, and B4) were obtained and submitted to GenBank with accession numbers PX492157, PX496590, and PX522223, respectively. The complete viral genome size of ILTV-B1, ILTV-B3, and ILTV-B4 was 152975, 152978, and 152978 nucleotides, respectively. These three ILTV isolates show 99.9% similarity with the Australian vaccinal strain SA2. The multiple sequence alignment showed that ILTV-B1, ILTV-B3, and ILTV-B4 belong to wild-type genotype VI-IX, which clustered together with Austrian isolates SA2 and A20, and American isolates S2.816 and 6.48.88 isolated in 2017. However, ILTV-B1, ILTV-B3, and ILTV-B4 also showed amino acid substitutions in the gB and gJ glycoproteins when compared with SA2, A20, and the USDA reference strain. Furthermore, most notable mutations were reported in the gB, gJ, ICP4, gG, gD, and gI when compared with American, Australian, and European vaccinal strains. Together, this study indicates the circulation of novel ILTV field isolates with the possible genomic divergence potentially associated with live vaccine-derived drift.