Search Results (987)

Organoid and organ-on-chip technologies are rapidly evolving platforms for viral research that integrate stem cell biology, tissue engineering, and microfluidics to recapitulate key structural, mechanical, biochemical, and cellular features of human and animal physiology. By incorporating multicellular organoids into perfused microfluidic systems, these models can provide complex, dynamic, and physiologically relevant micro-environments for investigating virus–host interactions that are difficult to capture in conventional two-dimensional cultures and static organoids. Controlled flow, shear stress, extracellular matrix organization, tissue–tissue interfaces, and multicellular signaling enable mechanistic investigation of viral infectivity, dissemination, tissue injury and immune activation. Integration of real-time imaging and biosensors further permits longitudinal monitoring of viral replication, host responses, and tissue integrity, expanding the potential of these platforms for antiviral drug discovery. Recent organoid-on-chip studies using brain, skin, vaginal, respiratory, and intestinal models have demonstrated how tissue architecture, mechanical forces, glycocalyx dynamics, and immune–stromal interactions influence viral tropism and pathogenesis. In this review, we provide a mechanistic and translational overview of organoid and organ-on-chip technologies for studying viral infections, with particular emphasis on models of herpes simplex virus (HSV)-mediated disease. We further examine advances in immune integration, multi-organ systems, biosensing, and computational approaches that are expanding the complexity and predictive potential of these models. Importantly, patient-derived organoids and organ-on-chip platforms can capture interindividual differences in viral susceptibility, host responses, and therapeutic efficacy, providing pharmaceutical research with more precise, patient-relevant data to support drug prioritization and precision antiviral medicine. Finally, we discuss key barriers to broader adoption, including organoid maturation, biological and technical variability, reproducibility, scalability, biosafety, cost, standardization, and regulatory validation. Collectively, these advances position organoid and organ-on-chip technologies as powerful human-relevant models that bridge reductionist in vitro systems and human disease, while continued optimization, standardization, and validation will be essential to realize their full potential for mechanistically informed antiviral discovery, therapeutic development, and precision medicine. Full article

Sexually transmitted infections (STIs) are common and probably underreported causes of proctitis and colitis. Bacterial (chlamydia, gonorrhoea, syphilis, Mycoplasma genitalium), viral (herpes simplex virus, mpox), and amoebic (Entamoeba histolytica) pathogens can cause inflammatory proctitis or colitis, which, depending on the pathogen, can mimic inflammatory bowel disease both on endoscopy and histopathology. Rectal and colonic masses are uncommon, but important manifestations of these infections, especially with chlamydia, syphilis, and E. histolytica. Testing for HIV is important in this context, since it allows for the inclusion of opportunistic pathogens into the differential diagnosis. Chronic diarrhoea can be a feature of chronic HIV infection. Enteric pathogens, such as Salmonella spp., Shigella spp., or Campylobacter spp., can be transmitted during sex, especially during oral–anal contact (“rimming”). The most common STI, human papillomavirus, is not associated with colitis, but is important because of its causal association with genital warts and anal cancer. Full article

A lifelong career devoted to the development of specific antiviral agents eventually yielded, besides (almost) 3000 publications, about ten antiviral compounds that were approved and marketed as antiviral drugs, i.e., DHPA (Duviragel^®), BVDU (Zostex^®, Mevir^®, Brivir^®…), VACV (Zelitrex^®, Valtrex^®), d4T (Stavudine^®), emivirine (Coactinon^®), rilpivirine (Edurant^®), HPMPC (Vistide^®), PMEA (Hepsera^®), tenofovir (Viread^®) and AMD-3100 (Mozobil^®), with the latter as a hematopoietic stem cell mobilizer. The targeted viruses for these compounds were herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), human immunodeficiency virus (HIV), and hepatitis B virus (HBV). For other viruses, such as filo-, rhabdo-, arena-, myxo-, polyoma- and papillomaviruses, strategies have been elaborated that should facilitate future developments of antiviral drugs. Full article

Background and Clinical Significance: Eczema herpeticum (EH), or Kaposi’s varicelliform eruption, is a dermatologic emergency characterized by the abrupt onset of painful monomorphic vesiculopustules with potential for rapid dissemination. Atopic dermatitis (AD) is the main predisposing condition due to skin barrier dysfunction and impaired antiviral immunity. Early recognition is essential because delayed treatment may result in avoidable complications, including ocular involvement and systemic disease. Current recommendations emphasize immediate systemic acyclovir based on clinical suspicion, without awaiting laboratory confirmation. Case Presentation: A 4-year-old boy with moderate AD presented with a 6-day history of fever, malaise, and a rapidly progressive vesiculopustular eruption involving both eczematous and previously unaffected skin. The patient had a recent AD flare, molluscum contagiosum, and had initially received oral amoxicillin-clavulanate for presumed bacterial superinfection without improvement. Physical examination revealed widespread painful monomorphic umbilicated vesiculopustules with hemorrhagic crusts and mild bilateral conjunctival injection. Oral acyclovir was initiated within one hour of evaluation. Laboratory investigations showed mild inflammatory abnormalities without renal or hepatic involvement. Because lesional PCR was unavailable, complementary blood-based investigations were performed; HSV-1 IgM serology and blood PCR provided additional retrospective findings compatible with HSV-1 infection, while Gram stain and bacterial cultures were negative. Fever resolved within 24 h, no new lesions developed after day 3, and complete re-epithelialization was achieved after a 10-day course of acyclovir. Conclusions: This case highlights the importance of bedside recognition of eczema herpeticum in children with atopic dermatitis, particularly when painful monomorphic vesiculopustules are accompanied by fever and rapid dissemination. Early initiation of systemic acyclovir based on clinical suspicion remains the cornerstone of management. While PCR from vesicular lesions is the preferred diagnostic test when available, laboratory confirmation should not delay treatment. This report also illustrates common real-world challenges, including initial misdiagnosis as bacterial infection and limited access to optimal virological testing. Full article

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) cause recurrent skin infections that are difficult to treat because of the limited solubility and permeability of acyclovir (ACV). This study developed electrospun polymeric membranes based on polycaprolactone (PCL), poly(lactic acid) (PLA), and cellulose acetate (CA) as controlled ACV delivery systems using uniaxial and coaxial fiber architectures. In the coaxial configuration, ACV-loaded PCL was used as the core and a PLA/CA blend as the shell. Continuous, randomly oriented, bead-free fibers with diameters ranging from 0.68 ± 0.32 µm to 1.45 ± 0.57 µm were obtained. Spectroscopic and thermal analyses confirmed successful drug incorporation, polymer compatibility, and good thermal stability. Coaxial membranes exhibited improved mechanical properties compared with uniaxial systems. Drug release studies showed a prolonged, pH-dependent profile, with greater ACV release at pH 7.3 than at pH 5.5, indicating the effective modulation of drug diffusion by the shell layer. Release kinetics were mainly governed by diffusion and anomalous transport mechanisms. All membranes maintained a cell viability above 80%, demonstrating good in vitro cytocompatibility. These findings support the potential of coaxial electrospun membranes for controlled antiviral drug delivery in skin applications. Full article

Neurotropic viruses can alter neuronal responses in the central nervous system (CNS), significantly affecting viral clearance and disease progression. Herpes simplex virus type 1 (HSV-1) brain infection may lead to life-threatening severe acute encephalitis in untreated patients and neurological sequelae in survivors despite antiviral treatment. Notably, asymptomatic brain infection occurs in an important proportion of healthy individuals (>35%) and is associated with residual chronic neuroinflammatory responses that may lead to neurodegeneration. Therefore, understanding the molecular basis of these detrimental effects and finding and advancing new therapeutic strategies to manage HSV-1 brain infections are needed. Neuropeptides are pleiotropic neuroimmune mediators expressed throughout the CNS that modulate glial activation, cytokine production, and neuronal survival. However, their regulation during HSV-1 brain infections remains largely unexplored. Here, we sought to investigate the expression dynamics of two neuropeptides, neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP), in two mouse strains that model human traits of symptomatic and asymptomatic HSV-1 brain infections (BALB/c and C57BL/6, respectively), as well as in the human neuroblastoma cell line SH-SY5Y, to uncover potential differences that could help explain the susceptibility of some individuals to develop severe HSV-1 infection. Our findings provide evidence that HSV-1 brain infection modulates NPY and VIP mRNA expression in a neurovirulence- and host-susceptibility-dependent manner, which may be associated with disease severity and chronic damage, warranting further evaluation. Full article

Virus-based cancer therapy (virotherapy) is currently being researched as a novel form of immunotherapy and has already entered the clinical application phase. Among various types of virotherapy, oncolytic virotherapy involves infecting tumors with tumor-selective viruses, such as herpes simplex virus, adenoviruses, and vaccinia virus, and utilizing their replicative capacity to induce cell destruction within tumors. In addition, this therapy aims to enhance tumor immunity by changing the tumor microenvironment through viral infection. Genetic deletion in viruses is used to reduce their virulence and confer tumor selectivity, while the expression of foreign genes is utilized to enhance antitumor effects. Oncolytic viruses for head and neck cancer (HNC) are administered locally or systemically and are sometimes used as adjuvant therapy or in combination with immune checkpoint inhibitors. Another form of virotherapy involves non-replicating viruses, which are used to produce antitumor cytokines or as cancer vaccines expressing tumor antigens. Research on the efficacy of cancer vaccines in preventing postoperative recurrence is currently underway. A number of challenges have yet to be overcome for further advances in virotherapy, including the efficient delivery of viruses to tumor cells, avoiding viral inactivation in the bloodstream, ensuring efficient replication of the virus, and enhancing antitumor immunity. The development of effective strategies based on the findings of clinical studies will lead to improvements in virotherapy for HNC. Full article

Herpes simplex virus type 1 (HSV-1) causes recurrent mucocutaneous lesions, yet existing animal models incompletely recapitulate characteristic skin manifestations. Here, we established a mouse model of cutaneous HSV-1 infection by combining epithelial barrier disruption with localized viral inoculation. Superficial scarification of the ear followed by HSV-1 exposure resulted in consistent lesion formation. Administration of hydrocortisone further increased the incidence of lesions, highlighting the critical roles of epithelial integrity and host immune regulation in the pathogenesis of HSV-1 infection. Using this model, we evaluated the antiviral efficacy of Acyclovir. Treatment significantly reduced lesion severity, lesion size, and viral gene expression, indicating partial suppression of viral replication. Notably, acyclovir treatment was associated with increased expression of T-bet and Foxp3 in lymphoid tissues, suggesting modulation of both effector and regulatory immune responses. Collectively, this model successfully reproduces localized HSV-1 skin lesions, serving as a useful platform for investigating viral pathogenesis and evaluating antiviral therapies. However, further studies, including direct viral quantification and histopathological analysis, are required. Full article

[Background] Herpesvirus infections can induce diverse visual impairments with permanent sequelae, yet systematic data on their clinical spectrum and outcomes remain scarce. [Methods] We conducted a single-center retrospective cohort study at the Department of Neurology, Beijing Tongren Hospital, Capital Medical University. Thirteen consecutive patients (19 affected eyes) with herpesvirus-related visual impairment admitted between January 2016 and January 2025 were enrolled. Demographic data, clinical manifestations, etiological tests (polymerase chain reaction [PCR], metagenomic next-generation sequencing [mNGS], serology), neuroimaging, treatment regimens, and visual outcomes were analyzed. [Results] The cohort had a mean age of 50.4 years (range 31–66), with male predominance (84.6%, 11/13). Varicella zoster virus (VZV) was the leading pathogen (76.9%, 10/13), followed by herpes simplex virus type 1 (HSV-1), Epstein–Barr virus (EBV), and pseudorabies virus (PRV). Eight patients (61.5%) developed optic neuritis (ON) secondary to VZV infection, and five patients (38.5%) suffered from acute retinal necrosis (ARN), which was caused by VZV (n = 2), HSV-1 (n = 2), and PRV (n = 1). Bilateral involvement occurred in 46.2% (6/13) of patients. ARN was associated with the most severe visual loss. At the disease nadir, 46.2% of patients (6/13) presented with no light perception (NLP). Notably, five of these six NLP cases were diagnosed with ARN. Etiological confirmation was achieved in only 38.5% (5/13) of cases. mNGS of cerebrospinal and vitreous fluid, alongside aqueous humor PCR, are pivotal for diagnosing HSV-1/EBV mixed infections and rare PRV infection. All patients received antiviral therapy, 11 of whom (84.6%) were treated with intravenous antiviral agents. Glucocorticoids were administered as combination therapy to all patients. However, only one of eight VZV–ON eyes showed genuine visual improvement. In VZV–ARN, the initially involved eyes stayed NLP at final follow-up, while the fellow eyes recovered vision. Still, all non-VZV ARN patients had persistent bilateral NLP during follow-up. [Conclusions] Herpesvirus-associated visual impairment is dominated by VZV, manifests as ON or ARN, and carries a high risk of severe permanent vision loss—particularly in ARN. The emergence of zoonotic PRV underscores the need for heightened clinical vigilance. Diagnostic delays and insufficient interdisciplinary collaboration contribute substantially to poor outcomes. Full article

Immunocompromised patients face increased morbidity and mortality from central nervous system (CNS) opportunistic viral infections, with risk level driven by specific immune defects. While our diagnostic capacity expands, immunocompromised patients may present atypically or with mild symptoms, delaying or complicating diagnosis. Treatment options are often limited, although novel agents show promise. This review discusses why immunocompromised patients carry higher immunologic risk and how certain viral classes display neurotropism to invade the CNS. We outline the utility and limitations of current and emerging diagnostic strategies. We discuss specific opportunistic viral pathogens, denoting specific epidemiology or pathogenesis, clinical presentation, diagnostic findings, and treatment and prevention methods. While there still remain knowledge and treatment gaps, advancements in diagnostics and understanding of pathogens have begun to improve outcomes. Full article

The herpes simplex virus 1 (HSV-1) US3 is a multifunctional serine/threonine kinase that promotes HSV-1 replication and spread. But its role and the mechanisms by which US3 regulates actin cytoskeletal remodeling remain poorly defined. We combined flow cytometry, confocal microscopy, immunoprecipitation-mass spectrometry (IP-MS), protein complex mapping, and machine learning to characterize US3-mediated F-actin dynamics. Flow cytometry and confocal microscopy showed that wild-type HSV-1 induces significant F-actin remodeling, while the ΔUS3 mutant displays F-actin levels comparable to uninfected cells, identifying US3 as a key regulator. IP-MS identified 47 high-confidence US3 interactors enriched in conserved actin regulatory complexes, including Arp2/3 nucleation machinery, formin-associated assemblies, cofilin severing complexes, and Rho-family GTPase modules. Mapping interactors to the CORUM database revealed clustering within actin nucleation, polymerization, and severing complexes, indicating that US3 operates through organized cellular machines. Machine-learning classifiers trained on label-independent mass-spectrometry features were used to prioritize interactors resembling known actin regulators; under protein-group-aware cross-validation, logistic regression performed best (average precision 0.24; ROC-AUC 0.66), and the analysis was interpreted as prioritization rather than de novo discovery. Pharmacological inhibition of Arp2/3 and formin pathways significantly attenuated US3-dependent F-actin remodeling, supporting the functional involvement of these pathways. Together, these findings are consistent with an inferred hierarchical axis in which US3 modulates Rho GTPase signaling and cofilin activation to promote F-actin disassembly, coordinating cytoskeletal remodeling required for efficient viral egress and spread. Full article

Background: Congenital infections included in the TORCH complex remain an important cause of fetal and neonatal morbidity and mortality, being associated with miscarriage, intrauterine growth restriction, congenital malformations, neurological impairment, and long-term developmental sequelae. Prenatal serological screening may contribute to the early identification of maternal infections and facilitate preventive and therapeutic interventions. However, data regarding the utilization of TORCH screening and associated socio-demographic determinants in Romania remain limited. Objective: This study aimed to evaluate the self-reported uptake of prenatal serological testing for one or more infections included in the TORCH complex, particularly Toxoplasma gondii, rubella virus, cytomegalovirus (CMV), herpes simplex virus (HSV), and syphilis, and to identify socio-demographic, obstetrical, and prenatal care-related factors associated with TORCH testing among pregnant women in Romania. Materials and Methods: A cross-sectional observational study was conducted using an online self-administered questionnaire completed by 1301 pregnant women from Romania. Data collection was performed between August 2022 and March 2023 through digital platforms, including social media and pregnancy-related forums. The primary outcome was self-reported performance of serological testing for at least one TORCH-related infection during pregnancy. Associations between explanatory variables and TORCH testing were evaluated using chi-square tests and multivariable binary logistic regression models. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Results: Overall, 75.6% of participants reported undergoing serological testing for at least one infection included in the TORCH complex during pregnancy, while 49.3% reported a complete TORCH panel. The most frequently reported investigations were for Toxoplasma gondii (92.8%) and rubella virus (89.9%), whereas HSV testing was less commonly reported (42.5%). Lower educational level was the strongest independent factor associated with reduced likelihood of TORCH testing (adjusted OR = 0.08; 95% CI: 0.03–0.19; p < 0.001) (adjusted OR—aOR). Unemployment status (aOR = 0.70; 95% CI: 0.50–0.99; p = 0.045) and multiparity (aOR = 0.62; 95% CI: 0.49–0.77; p < 0.001) were also associated with lower testing uptake. In contrast, participation in prenatal education programs was associated with increased likelihood of TORCH testing (aOR = 1.37; 95% CI: 1.04–1.80; p = 0.024). The number of prenatal consultations was not independently associated with testing uptake. Conclusions: The uptake of prenatal serological screening for congenital infections (assessed using an expanded Romanian panel that includes hepatitis B and HIV in addition to the classical TORCH agents) in Romania appears to be influenced predominantly by socio-educational and behavioral factors rather than by the quantitative utilization of prenatal care services alone. Given the online recruitment strategy and the predominantly urban and highly educated sample, the reported uptake rates may overestimate population-level coverage. Significant inequalities in access to preventive prenatal investigations were observed, particularly among women with lower educational and socio-economic status. Strengthening prenatal education programs and improving equitable access to standardized prenatal screening may contribute to optimizing congenital infection prevention and maternal–fetal health outcomes. Full article

In recent years, the growing interest in microbiota, supported by increasing evidence from next-generation sequencing (NGS)-based studies, has led to the hypothesis that multifactorial conditions such as male infertility may have their bases in its imbalance. Despite rapid advances in the field over the past decade, findings remain fragmented and sometimes inconsistent. Furthermore, analyses frequently exclude non-bacterial components, such as viruses (e.g., human papillomavirus and herpes simplex virus), protozoa (e.g., Trichomonas vaginalis) and fungi (e.g., Candida spp.), with a few studies focusing on the influence of individual components. This review provides an integrative and critical synthesis of current knowledge on the composition and functional relevance of the male reproductive tract microbiota, including both bacterial and non-bacterial components. Particular attention is given to the methodological strengths and limitations of NGS approaches, the main bacterial taxa identified in seminal samples, and the emerging roles of viruses, protozoa, and fungi. The review also explores proposed mechanisms linking microbial dysbiosis to impaired spermatozoa function, the potential anatomical origins of seminal microorganisms, and evidence for microbiota exchange between sexual partners. By integrating recent data and addressing underexplored components beyond bacteria, this work provides a coherent framework to support future research on the role of the seminal microbiome in male infertility. Full article

Ensuring viral safety is a critical aspect of biopharmaceutical production, requiring sensitive and reliable methods for detecting adventitious agents. In this study, we systematically evaluated the performance of selected cell line–virus combinations to identify optimal models for in vitro viral detection assays. Three cell lines (Vero, MRC-5 and BHK-21 [C-13]) and representative model viruses (Reovirus type 3, Adenovirus type 5, Human parainfluenza virus type 3, and Herpes simplex virus) were analyzed in terms of cytopathic effect (CPE) kinetics, morphology, and detection sensitivity. All tested systems demonstrated high analytical sensitivity, with limits of quantification (LOQ) reaching 0.01 TCID₅₀/mL for selected viruses. However, substantial differences were observed in infection dynamics and CPE morphology depending on the cell line–virus combination. BHK-21 [C-13] cells exhibited the most rapid and pronounced CPE for Reovirus type 3, enabling early and unambiguous detection. Vero cells provided robust and reproducible detection of Adenovirus type 5, characterized by well-defined cytopathic progression. MRC-5 cells showed controlled and consistent infection kinetics for both Human parainfluenza virus type 3 and Herpes simplex virus, allowing improved temporal resolution and interpretability. These findings demonstrate that assay performance depends not only on sensitivity but also on the kinetics and morphology of infection. Based on combined evaluation criteria, the following optimal cell line–virus pairs were identified: BHK-21 [C-13]/Reovirus type 3, Vero/Adenovirus type 5, and MRC-5/Human parainfluenza virus type 3 and Herpes simplex virus. The proposed approach supports rational selection of detection models and provides a preliminary descriptive framework for the development of routine visual screening assays in biopharmaceutical quality control. Full article

Background: Opportunistic infections remain a significant cause of morbidity among people living with HIV (PLHIV) in sub-Saharan Africa despite expanded access to antiretroviral therapy (ART). This study evaluated the association between immune status, viral load suppression, ART adherence, and the risk of opportunistic infections among HIV-positive patients receiving ART in the rural Eastern Cape, South Africa. Methods: A retrospective cross-sectional study was conducted using clinical records of HIV-positive patients attending an HIV clinic in Mthatha between January 2021 and December 2024. Demographic characteristics, CD4 counts, viral load results, ART regimens, adherence status, and documented opportunistic infections were extracted. Viral load suppression was defined according to WHO guidelines as <1000 copies/mL. CD4 counts were categorized as <200, 200–499, and ≥500 cells/mm³. Multivariable logistic regression analysis was performed to identify independent predictors of opportunistic infections. Results: A total of 155 patients (105 females, 50 males) were included. Females demonstrated significantly higher mean CD4 counts than males (p = 0.037) and better ART adherence (p < 0.001). Tuberculosis, hepatitis B virus, and herpes simplex virus infections were more prevalent among males, whereas candidiasis was significantly more common among females (p = 0.034). In multivariable analysis, CD4 count < 200 cells/mm³, unsuppressed viral load, and poor ART adherence were independently associated with increased odds of opportunistic infections. Conclusions: Immune suppression and suboptimal ART adherence significantly increase the risk of opportunistic infections among HIV-positive patients in rural South Africa. Strengthening adherence interventions and early immune monitoring may reduce infection burden in high-prevalence settings. Full article