Search Results (661)

Programmed cell death (PCD) pathways of innate immunity serve to protect host cells from invading viruses. Parthanatos is a novel form of PCD triggered by excessive host cell DNA damage that leads to overactivation of poly(ADP-ribose) polymerase-1 (PARP-1) which in turn stimulates poly(ADP-ribose) (PAR) polymer formation. PAR translocates to the cytoplasm, where it induces release of apoptosis-inducing factor (AIF) from mitochondria, that then travels back to the nucleus, where it mediates large-scale DNA fragmentation and cell death. Little information is available regarding parthanatos as a cell death mechanism to dampen herpesvirus replication at the host cell level. A series of studies were therefore performed to clarify a possible role for parthanatos during productive replication of murine cytomegalovirus (MCMV) and herpes simplex virus type 1 (HSV-1) in diverse cell types. These included mouse embryo fibroblasts, mouse lung fibroblasts, mouse microglial (BV-2) cells, and human retinal pigment epithelial (ARPE-19) cells. We report that PAR protein production is surprisingly cell type specific. Moreover, MCMV or HSV-1 infection may suppress parthanatos as observed for other PCD pathways, such as apoptosis, necroptosis, and pyroptosis, in a dose-dependent and cell type-specific manner. We conclude that the operation of parthanatos at the host cell level during herpesvirus replication is more complex than originally thought but offers new targets for possible therapeutic interventions. Full article

Viral infections of the central nervous system produce memory impairment through mechanisms that extend beyond acute neuronal injury. Herpes simplex virus type 1, human immunodeficiency virus, varicella zoster virus, cytomegalovirus, Epstein–Barr virus, influenza, SARS-CoV-2, West Nile virus, and Zika virus each enter or engage the brain through distinct routes, yet converge on four shared molecular pathways that selectively damage hippocampal circuits: mitochondria-associated membrane (MAM) dysfunction, chronic neuroinflammation, blood–brain barrier (BBB) disruption, and impaired CREB-BDNF signaling. These pathways specifically compromise the dentate gyrus, CA3, and CA1 subfields, producing predictable deficits in pattern separation, associative retrieval, and temporal memory binding. Antiretroviral and antiviral therapies suppress viral replication but fail to reverse organelle-level dysfunction, leaving most hippocampal injury unaddressed. Emerging plasma biomarkers, p-tau217, neurofilament light chain, and GFAP, combined with hippocampal subfield MRI, now enable mechanistic stratification before irreversible circuit loss occurs. This review proposes, as a unifying hypothesis, that virus-associated memory impairment represents a convergent hippocampal syndrome driven by shared downstream pathways, and that combination therapies targeting these pathways simultaneously offer greater therapeutic promise than pathogen-specific approaches alone. The evidentiary basis for this framework varies across pathogens and conditions; direct mechanistic evidence, mechanistic analogy, and preclinical data are distinguished throughout. Full article

Human cytomegalovirus (HCMV) remains an important medical problem in multiple patient settings despite the availability of antivirals. In part, this is linked to resistance, cost and restrictions on use in several patient settings. More generally, it remains attractive to increase our arsenal of anti-viral approaches to target HCMV. We previously characterized a potent inhibitor of HCMV infection, DIDS, that displays cysteine reactivity, allowing it to bind virions and neutralize HCMV infection of fibroblasts. We now show that DIDS is inhibitory to cell-free and cell-associated infection of multiple cell types, including cells of the haematopoietic lineage—cells important for latency and dissemination. Consistent with this broad activity, DIDS partially inhibited gB (but not SARS-CoV-2 spike) fusion activity. Intriguingly, further characterization of DIDS activity in myeloid cells revealed that, unlike in all other cell types, DIDS blocked a post-entry event in CD14+ monocytes and also dendritic cell derivatives. Despite viral entry, entry was largely silent, with a failure to activate innate immunity and cell survival pathways known to be activated by HCMV. In contrast, HCMV infection was observed to activate host miRNA expression in CD14+ cells, suggesting a DIDS-insensitive viral function was responsible or, alternatively, that host miRNA expression is a potential anti-viral response to viral internalization. Thus, we report the further characterization of a broad-acting inhibitor of HCMV infection, which may also prove a useful tool to study unique events for the infection of monocytic cells by HCMV—a cell type that is crucial for HCMV dissemination and pathogenesis in vivo. Full article

Background: Emerging evidence suggests that antiviral treatment targeting human cytomegalovirus (HCMV) may improve outcomes in patients with glioblastoma (GBM). In this study, we analyzed serological data from the placebo-controlled VIGAS1 trial (Eudra number 2006-002022-29), which assessed the effect of valganciclovir (VGCV) on GBM progression in 42 patients, for impact of VGCV in preventing HCMV reactivation. Methods: VIGAS1 patients had undergone radical surgery and were randomized to receive either VGCV (n = 22) or placebo (n = 20) alongside standard radiochemotherapy. Blood was prospectively collected at baseline and 3-, 12- and 24-week follow-up visits. GBM cell lines and a cytomegalovirus-infected murine brain cancer model were used to validate the clinical findings. Results: Over the 24-week study period, we found that HCMV reactivation, as inferred from IgM seropositivity, occurred in 58.3% of patients in the placebo group, whereas this was completely prevented in the VGCV-treated group except for one patient with no treatment compliance (p = 0.0005). HCMV reactivation was linked to early recurrence. IgG-positive patients treated with VGCV showed a significantly longer time to progression (TTP) than those receiving placebo (6.7 vs. 3.7 months, p = 0.0408). We found a significant association between higher steroid doses and enhanced reactivation in the placebo group. In vitro and murine studies confirmed that corticosteroids, combined with radiation therapy, enhanced cytomegalovirus reactivation, which was mitigated by antiviral treatment. Conclusions: These findings suggest that preventing HCMV reactivation with antiviral therapy may improve patient outcomes, especially in HCMV-seropositive GBM patients, and further support the hypothesis that HCMV is a tumor-promoting virus. Full article

Adenoviruses have been implicated in childhood cancers, primarily leukemia, yet prior neonatal investigations have rarely examined other pediatric tumor types. This study evaluated whether adenoviral early region (E1A) sequences can be detected in archival neonatal Guthrie cards from children who later developed diverse pediatric tumors and in corresponding paraffin-embedded tissues. DNA extraction was optimized for long-stored dried blood spots, and PCR conditions were refined for both Guthrie card and paraffin-derived DNA. Adenoviral E1A was analyzed using conventional and nested PCR, and sequencing of representative amplicons confirmed correspondence to human adenovirus species C. E1A PCR positivity was found in 43% of Guthrie cards from cases (n = 54) and 34% of controls (n = 32), and in 41% of tumor tissues (n = 75) compared with 5% of non-tumor paraffin controls (n = 20). Detection occurred across multiple tumor categories without a clear association with tumor type. Partial concordance was observed between paired neonatal and tumor samples, and cytomegalovirus markers were detected in a subset of E1A-positive specimens. These findings confirm the suitability of Guthrie cards for retrospective viral DNA detection and extend previous leukemia-focused neonatal studies to broader pediatric tumors. The data suggest a potential association between birth-stage adenoviral detection and childhood cancer, though a causal link remains unproven and requires further longitudinal investigation. Full article

The rectal mucosa houses a large number of viruses with important roles in shaping the local microbial communities and modulating immune responses, which could influence host susceptibility to infection and other diseases. Unique composition of the gut microbiome, including the predominance of clinically significant eukaryotic viruses like herpesviruses, cytomegalovirus, and human papillomavirus, has been described in both people with HIV (PWH) and men who have sex with men (MSM) vulnerable to HIV. Despite these insights, the rectal virome and the clinical implications of virome–bacteriome–immune interactions in the rectal mucosa remain poorly understood. In this review, we synthesize existing data on the composition of the rectal virome, its interactions with the bacteriome and the immune system, and implications on clinical outcomes in people living with or vulnerable to HIV. We also highlight the gaps and research needed to further explore and unravel these relationships. Full article

Human cytomegalovirus (HCMV) remains a significant cause of morbidity in immunocompromised patients, necessitating the development of improved antivirals. Using an integrated in silico and in vitro approach, we identified a novel ligand (NL) as a letermovir analog with enhanced binding affinity and reduced cytotoxicity. A pUL56 terminase subunit model generated with AlphaFold 3 was used for the virtual screening of a 15,000-compound library. Among the 73 candidates with structural similarity to letermovir (Tanimoto ≥ 0.6), NL exhibited superior predicted binding affinity (ΔG_bind = −10.7 kcal/mol). In silico toxicity prediction (ProTox 3.0) classified NL as having low toxicity (class 4, LD50 ≈ 1000 mg/kg), which was confirmed in vitro, where NL demonstrated 158-fold less toxic (CC50 = 2.69 mg/mL) in MRC-5 cells than letermovir (0.017 mg/mL). Molecular dynamics simulations over 500 ns revealed that the pUL56-NL complex forms a more thermodynamically stable interaction, with a lower calculated free energy of binding (MMGBSA: −40.89 ± 7.40 kcal/mol vs. −32.76 ± 4.96 kcal/mol) and a narrower free energy landscape. These results establish NL as a promising, low-cytotoxicity candidate with enhanced target engagement, warranting further investigation as a potential anti-HCMV therapeutic. Full article

Polyamines are small, positively charged molecules essential for fundamental cellular processes, including transcription, translation, and membrane fluidity. In the central nervous system (CNS), these molecules serve as homeostatic gatekeepers by modulating neuroreceptors like NMDA and supporting autophagic clearance. While basal polyamine levels are necessary for proper neuronal differentiation and memory formation, their dysregulation is a hallmark of neurodegenerative pathologies such as Alzheimer’s and Parkinson’s diseases. Neurotropic viruses, including poliovirus, Zika virus, and human cytomegalovirus are significant human pathogens that rely on cellular metabolites for their replication, including polyamines. These pathogens exploit polyamines at multiple stages of their life cycles, relying on them for virion stability, cellular attachment, and the stimulation of viral enzyme activity. Notably, diverse viral families share this dependence, making polyamine biosynthesis a prime target for broad-spectrum antiviral therapies. This review covers the current understanding of polyamine metabolism in virus infection and CNS health and disease, as well as considering antiviral therapies targeting host polyamines to limit neurotropic virus infection. Full article

Background: Prostate cancer (PCa) arises from complex interactions among host genetics, androgen signaling, and microbial communities. Emerging genomic evidence supports the presence of microbial consortia within prostate tissue, suggesting that microbial genes, metabolites, and host–microbe interactions may contribute to chronic inflammation, oncogenic signaling, and therapeutic resistance. Methods: We conducted a narrative review using targeted searches of PubMed and Google Scholar for studies published between 2020 and 2025, complemented by selected mechanistic reports published in March 2026. Human studies and experimental research providing mechanistic insights into prostate models were prioritized. Due to the heterogeneous methodologies, evidence was synthesized qualitatively, with an emphasis on genomic and signaling perspectives. Results: Low-biomass microbial DNA is consistently detected in prostate tissue. Proteomic analyses of Corpora amylacea suggest a “fossil record” of past infections through sequestered microbial DNA and antimicrobial proteins, potentially priming tissue for long-term carcinogenic processes, although contamination remains a key limitation. Recurrent bacterial and viral signals, including Cutibacterium acnes, Escherichia coli, Pseudomonas, Acinetobacter, human papillomavirus, Epstein–Barr virus, and cytomegalovirus, appear to converge on a restricted set of tumor-relevant pathways, including TLR–NF-κB, MAPK, PI3K/AKT/mTOR, cGAS–STING, and p53/pRb disruption. These interactions may promote cytokine production, oxidative stress, DNA damage, epithelial–mesenchymal transition, extracellular matrix remodeling, immune evasion, and resistance to therapy. The gut–prostate axis further links intestinal dysbiosis and microbial metabolites with systemic IGF-1 signaling and castration resistance. Conclusions: Microbial genomic consortia in the prostate and gut may shape inflammatory, metabolic, and immune networks that influence PCa initiation and progression. However, most available data remain correlative and are limited by low-biomass sampling, contamination risk, and heterogeneous study designs. Future research should prioritize rigorous contamination control, longitudinal and prostate-specific mechanistic studies, and integrated multi-omic approaches to clarify causality and identify actionable microbial targets for prevention, diagnosis, and therapy. Full article

Background: Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne viral disease with a high fatality rate, and no licensed vaccines are currently available. The nucleoprotein (NP) of the Crimean-Congo hemorrhagic fever virus (CCHFV) plays a critical role in viral replication and immune recognition, making it a promising target for vaccine development. This study aimed to design and evaluate a multiepitope recombinant DNA vaccine targeting the NP of CCHFV. Methods: Cytotoxic T lymphocyte (CTL) epitopes from the NP were predicted via immunoinformatics approaches and systematically assessed for antigenicity, allergenicity, toxicity, hydrophobicity, and global population coverage. The selected epitopes were incorporated into four DNA vaccine constructs driven by a cytomegalovirus promoter, adjuvanted with human β-defensin 3 (hBD3), and fused to the reporter protein mRuby3. The constructs were evaluated in vitro using a fluorescent reporter system designed to provide a readout of TCR signaling upon the co-culture of T lymphocytes with differentiated monocytic cells expressing antigens. In vivo immunogenicity and protective efficacy were assessed in BALB/c (exploratory pilot) and IFNAR^−/− mice, a highly susceptible model for viral infection. Cytokine responses were measured to assess immunogenicity. Results: In vitro assays showed predominantly antigen-independent T-cell activation, suggesting that nonspecific stimulation inherent to the reporter co-culture system likely obscured the detection of antigen-specific TCR signaling. In vivo analyses in BALB/c mice revealed that the constructs elicited only modest systemic cytokine profiles while CCHFV-specific IgG and IFN-γ secretion remained undetectable, indicating that antigen-specific T-cell and antibody responses were limited. In the IFNAR^−/− challenge model, several peptide groups achieved significant 2–3 log reductions in tissue viral RNA and infectious titers (p < 0.05 vs. sham). However, the observed viral modulations were insufficient to reach the protective threshold and did not translate to a survival benefit (0%). Conclusion: Despite a rational in silico foundation, the multiepitope DNA vaccine constructs demonstrated limitations in inducing potent, antigen-specific immunity across both mouse models. The lack of antigen-specific responses indicates limitations in epitope selection, construct design, and delivery strategies, requiring optimization of next-generation epitope-based vaccines. These findings highlight the complexity of translating computational epitope predictions into functional vaccines, and provide benchmark data as a framework to guide future optimizations. Full article

Background: Viral infections represent a major challenge in modern medicine, including diseases caused by human papillomavirus (HPV), cytomegalovirus (CMV), and rotavirus, which are among the most prevalent viral pathogens. The rapid transmission and high mutation rates of these viruses contribute to substantial health burdens and socio economic consequences. Silver nanoparticles (Ag NPs) and titanium dioxide nanoparticles (TiO₂-NPs) are effective antiviral agents. The major objective of this investigation was to measure the antiviral activity of titanium dioxide nanoparticles (TiO₂-NPs) and green-produced silver nanoparticles (Ag NPs) against rotavirus, HPV, and CMV. Methods: UV-Vis spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) were used to characterize the nanoparticles. Cytotoxicity and antiviral activity were evaluated using a crystal violet assay in infected cell cultures. Results: The main findings indicate that both Ag NPs and TiO₂-NPs exhibited pronounced antiviral activity against HPV, CMV, and rotavirus. Ag NPs exhibited strong antiviral activity, with lower IC₅₀ values against HPV and CMV; however, this effect was associated with lower cytotoxic concentration (CC₅₀) and selectivity index (SI) values, indicating higher cytotoxicity. In contrast, TiO₂-NPs demonstrated a favorable safety profile, as indicated by higher CC₅₀ value particularly against CMV (863.90 µg/mL) and rotavirus (386.84 µg/mL)—and low cytotoxicity toward host cells—highlighting their strong antiviral selectivity and therapeutic potential. Conclusions: Overall, these findings suggest that, while Ag-NPs possess strong antiviral efficacy, TiO₂ NPs offer a more balanced combination of antiviral effectiveness and biosafety and may therefore be more promising candidates for antiviral applications. Full article

Glioblastoma is the most aggressive tumor among gliomas, and recurrence remains inevitable despite aggressive therapies. Resistance to existing treatment modalities is attributed in part to the presence of glioma stem cells, which comprise a distinct cell subpopulation that sustains cell renewal and tumor evasion through multiple mechanisms. Therapeutic strategies using herpesviruses have been evaluated following the discovery of differential human cytomegalovirus (HCMV) expression in glioblastoma tumor cells. The absence of expression in normal brain tissue led to multiple clinical trials demonstrating the potential clinical utility of targeted HCMV via herpesvirus-based oncolytic therapeutic strategies. This review provides a comprehensive overview of existing studies evaluating the expression and biological significance of HCMV within glioma stem cells. Targeting HCMV in this cellular compartment may disrupt the continuous cellular support and resilience of glioblastoma stem cells, thereby enhancing the efficacy of current treatments. Full article

Background: Oral gene delivery vectors, such as those derived from attenuated Salmonella strains, have shown great promise in oral vaccine development against various human diseases. Human cytomegalovirus (CMV) is a herpesvirus capable of affecting the global population and establishing lifelong infection. Generation of an anti-CMV vaccine is a major public health priority. Methods: This study reports the development of a novel weakened Salmonella strain, S713, and the effects of this strain as an oral vaccine candidate against murine cytomegalovirus (MCMV) infection in mice. Results: The weakened Salmonella strain S713 was attenuated in killing mice in vivo by >500,000 fold compared to a clinical strain, following intragastric instillation in animals. Mice intragastrically immunized with S713 that produced MCMV M24 protein exhibited elevated anti-MCMV mucosal IgA and serum IgG titers and enhanced anti-MCMV T cell responses. Moreover, immunization with the generated vaccine in MCMV-challenged mice not only suppressed viral replication in lungs, spleens, livers, and salivary glands but also increased animal survival. Conclusions: These findings demonstrate strong and effective anti-MCMV immune responses induced by the generated M24-expressing vaccine. Furthermore, our results reveal the promising capability of weakened strain S713 expressing different CMV proteins to act as oral vaccines against CMV infections and diseases. Full article

Human cytomegalovirus (HCMV) and Human Immunodeficiency Virus (HIV) are two pathogens known to have dramatic consequences when contracted early in life. In addition to having a significant impact when acquired individually, these two viruses are known to frequently cause coinfections. Indeed, also in the modern era, HCMV remains one of the most prevalent coinfections in newborns of mothers living with HIV, including both HIV-positive children regardless of their immune status, and those exposed to HIV but uninfected (HEU). In children with HIV infection, HCMV coinfection has historically been associated with AIDS-defining disease, high mortality, and prolonged, elevated HCMV viral load. Although timely administration of antiretroviral therapy prevents immunodeficiency in people living with HIV and thus reduces the incidence of full-blown HCMV disease in cases of coinfection, emerging data suggest that HCMV-induced immune activation and aging persist, potentially contributing to long-term, non-AIDS-related comorbidities. Growing evidence indicates that also HCMV amplifies HIV susceptibility, disease progression, and immune dysregulation through multiple synergistic mechanisms. Moreover, congenital and early postnatal HCMV infections occur at significantly higher rates in HEU newborns than in HIV-unexposed children and are associated with worse clinical outcomes, particularly when HCMV viral loads are high. This review summarizes current knowledge on the epidemiology, clinical impact, and immunopathogenetic interactions of early HCMV–HIV coinfection in pediatric populations. By integrating recent findings with historical evidence, it highlights critical mechanistic and epidemiological gaps that warrant further investigation. Full article

Background: Alemtuzumab is a recombinant DNA-derived humanized monoclonal antibody directed against the 21–28 kd cell surface glycoprotein, CD52. Alemtuzumab is used as an organ anti-rejection therapy in transplant recipients. Neuro-ophthalmic adverse effects are rarely described, and, to our knowledge, accommodative spasm has not previously been reported in a transplant recipient. Case Description: A thirty-nine-year-old woman with genetically confirmed NPHP1-associated nephronophthisis, with stage F3 fibrosis, developed persistent bilateral blurred vision 72 h following alemtuzumab administration for a biopsy-proven acute cellular rejection, approximately six to seven weeks post-transplant. Initial attribution to hyperglycaemia and tacrolimus toxicity delayed recognition. Cycloplegic refraction confirmed a marked hyperopic shift (+2.75 D right eye, +2.50 D left eye) with significant improvement in visual acuity, consistent with accommodative spasm. Systemic evaluations excluded hyperglycaemia-related lens changes, calcineurin inhibitor neurotoxicity, and cytomegalovirus retinitis. MRI was not pursued in the absence of red flag neurological features, and because a definitive ophthalmic diagnosis had been made. Management and Outcome: The patient was managed expectantly, as cycloplegic refraction had already confirmed the diagnosis, and symptoms were improving. Therapeutic cycloplegia (e.g., atropine) was withheld to avoid impairing near vision and driving ability. Full resolution occurred within 4 to 6 weeks without intervention. Drug exposure to onset of symptoms was 72 h; onset of symptoms to diagnostic confirmation was 22 days; total symptom duration was 5.5 weeks, and recovery was 2 weeks after diagnosis. Conclusions: This case represents the first reported transplant case of alemtuzumab-associated accommodative spasm. Causality assessment supports a WHO-UMC classification of “Probable”, aligning with five Bradford–Hill considerations (temporality, biological plausibility, consistency, specificity, and analogy), but without statistical “strength of association” given that this is a single case report. Early cycloplegic refraction should be incorporated into the evaluation of post-alemtuzumab visual complaints, and clinicians should contribute to pharmacovigilance through structured reporting to capture these rare but important events. Full article