Introduction:COVID-19 presents with various symptoms, including fever, dyspnea, and respiratory failure. Understanding its pathogenesis is crucial, particularly the role of early immune responders such as neutrophils.Objectives:The study aimed to investigate neutrophil phenotypes and activation in patients with severe COVID-19, focusing on the expression of key activation markers and their potential role in disease severity.Methods:A case-control study was conducted in Makkah City involving 88 participants. The study group consisted of 48 PCR-confirmed severe COVID-19 patients with elevated C-reactive protein (CRP) levels and proinflammatory cytokine levels, and the control group included 40 healthy individuals. EDTA-anticoagulated whole blood samples were collected from all participants. Neutrophil counts were obtained, and flow cytometry was performed to assess the expression of activation markers CD64 and HLA-DR on neutrophils.Results:Severe COVID-19 patients exhibited significantly elevated neutrophil counts compared to healthy controls. Flow cytometric analysis revealed significantly increased CD64 and HLA-DR mean fluorescence intensity on neutrophils from patients with severe COVID-19 compared with healthy controls, indicating a heightened state of neutrophil activation.Conclusion:Severe COVID-19 was associated with increased neutrophil activation, reflected by elevated CD64 and HLA-DR expression. These findings support the potential value of neutrophil immunophenotyping in characterizing innate immune dysregulation during severe COVID-19.

Human herpesvirus-6 (HHV-6) is involved in immune modulation and contributes to cancer development through interactions with host genetic factors. Hepcidin (HAMP) and NRAMP1 genes play essential roles in iron metabolism and innate immunity, yet their polymorphisms remain poorly investigated in HHV-6-associated cancers. This study investigated the association between HAMP and NRAMP1 gene polymorphisms and HHV-6 infection in 40 confirmed HHV-6-positive cancer patients compared with 40 non-cancer, HHV-6-negative controls. Genomic DNA was extracted and verified by agarose gel electrophoresis. Hepcidin polymorphisms were analyzed using Tetra-ARMS PCR, while NRAMP1 (3'UTR) polymorphism was detected by PCR-RFLP. Cancer patients exhibited wild-type, mutant, and heterozygous hepcidin genotypes, whereas controls predominantly showed the wild-type genotype. Although allele frequency analysis revealed no statistically significant difference for the G and TG[+] alleles between groups (p = 0.23), the hepcidin A allele (521 bp) was more frequent among cancer patients, suggesting a possible association with increased cancer susceptibility (odds ratio = 2.111). For NRAMP1, three genotypic patterns were identified (TG-/TG-, TG+/TG+, and TG-/TG+), and while no significant between-group difference was detected (p = 0.23), the TG+ allele demonstrated a potential two-fold increased cancer risk among carriers. These findings suggest that specific allelic variants-particularly the hepcidin A allele and NRAMP1 TG+ allele-may contribute to cancer susceptibility in HHV-6-infected individuals, highlighting a possible genetic-viral interaction that influences immune and iron-regulatory pathways in cancer development.

The diversity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine platforms and widespread natural exposure have created a complex landscape of humoral immunity requiring detailed characterization. Here, we compare nucleocapsid (N)- and spike (S)-specific antibody responses in sera from infected humans (IH) during the first pandemic wave (April-August 2020) and in vaccine recipients (Sinopharm, Sinovac, or AstraZeneca) using commercial ELISA kits. Among naturally IH, the IgG-positivity rate was higher for N (80.9%) than S (42.8%), with significantly elevated N-specific IgG levels compared to prepandemic controls (p-value <0.05), while IgM responses showed no significant differences. Strong positive correlations were observed between S- and N-specific antibody responses, particularly for IgG and its subclasses. Vaccinated cohorts exhibited high IgG positivity rate (83-100%) against both antigens with low IgM levels, and overall IgG and subclass responses were significantly elevated relative to pre-pandemic controls (p-value <0.05), with consistently strong inter-antigen correlations across groups. Overall, natural infection induces a coordinated humoral response biased toward the nucleocapsid antigen, supporting its utility as a marker of recent infection, whereas vaccination elicits a robust multi-subclass antibody response with platform-dependent differences in antigen recognition and subclass distribution.

Background:Herpes zoster (HZ) is a common neurotropic infectious disease caused by the reactivation of varicella-zoster virus (VZV), primarily triggered by declining host immune function. While circulating immune cells play key roles in antiviral defense, the causal contributions of distinct blood cell functional phenotypes to HZ risk remain unclear.Objective:To investigate potential causal associations between genetically predicted blood cell functional traits under ex vivo stimulation and the risk of HZ using a two-sample Mendelian randomization (MR) framework.Methods:We employed genome-wide association analysis summary statistics of 91 stimulation-induced blood cell traits published in 2024 as exposures, and HZ outcome data from the FinnGen R12 release (7,132 cases and 480,316 controls). The inverse variance weighted method was used for primary causal inference, complemented by alternative MR approaches and sensitivity analyses to assess robustness. No formal multiple testing correction was applied due to a single significant result.Results:Among 85 eligible traits, the forward scatter standard deviation (FSC-SD) of red blood cells under nigericin stimulation was significantly associated with increased HZ risk (OR = 1.13, 95% CI: 1.06-1.20, p = 1.02 × 10-4). No other traits reached nominal significance. Sensitivity analyses revealed no evidence of horizontal pleiotropy or heterogeneity.Conclusion:This study provides novel genetic evidence that nigericin-induced red blood cell membrane stress responses, operating through NLRP3-dependent inflammatory cascades, are causally linked to VZV reactivation susceptibility. The nigericin-stimulated red blood cells FSC-SD phenotype may serve as a functional biomarker for viral reactivation risk stratification and individualized immune monitoring.

The half-life (HL) of specific antibodies produced by the human body against various viruses varies from about 4 months to 11,000 years. Due to their short half-lives, multiple-dose vaccinations and annual revaccination are usually required for most viruses, which cause a large economic burden, especially in developing countries with limited storage of vaccines. Protein assemblies with a high degree of repetitiveness and organization are known to induce strong and long-lasting immune responses. However, the detailed quantitative law is still unknown. Through epitope analysis of representative viruses, we found that the longevity of immunological memory may be correlated with the number of epitopes with similar sequences (EWSS). Accordingly, a vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with 4.5-times higher antibody titers and over 100 months of HL was developed in a rabbit model. The decay pattern of antibodies against each epitope or the entire SARS-CoV-2 spike protein was roughly correlated with the number of EWSS in immunization treatments, that is, for every additional EWSS, the HL of the antibody would be doubled. This study also discusses improvement measures for vaccines against other viruses.

Mammalian reoviruses are promising oncolytic agents, but most preclinical and clinical work has focused on the type 3 Dearing (T3D) prototype, potentially underestimating the therapeutic relevance of broader reovirus genetic diversity. Because reoviruses possess a segmented double-stranded RNA genome, reassortment can generate progeny with novel combinations of traits influencing infectivity, replication, and cytotoxicity. Here, we evaluated a panel of previously generated T1L × T3D reassortants and recombinant reoviruses across three epithelial tumor models: A549 lung adenocarcinoma and the oral squamous carcinoma cell lines OECM-1 and CAL-27. Across all three models, the tested viruses displayed marked cell line-dependent heterogeneity in both cytotoxicity and infectivity. Several reassortants reduced viability more effectively than the parental T1L and T3D strains in one or more cell lines, and DB62 emerged as the most broadly active candidate across the panel. Infectivity and cytotoxicity overlapped only partially, indicating that efficient infection alone does not fully predict oncolytic potency. Together, these findings show that reassortment can generate reoviruses with enhanced or selective activity across epithelial tumor contexts and support future studies examining how segment-dependent differences in interferon antagonism, entry, and cell death shape oncolytic potency.

It is widely known that numerous enveloped viruses can produce multinucleated cells (syncytia) as a result of viral entry-related membrane fusion events. By protecting the virus from the host's immune reaction, these syncytia are thought to promote viral reproduction. Syncytia are collections of merged cells. A viral spike protein (S) on the surface of an infected cell interacts with receptors on nearby cells to cause the syncytia response. The innate immune system's response to viruses affects how syncytia form. Some interferon-stimulated genes change the membrane in a way that reduces the likelihood of fusion. The severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus is quickly changing; also, several mutations occurred in its S protein. Individually and together, the Alpha, Beta, Gamma, and Delta variants carry mutations that significantly affect S function and syncytia formation. The function of syncytia in newly emerging variant diseases is still unknown, though. Syncytia could cause disease through promoting viral transmission, cytopathicity, immunological evasion, and inflammatory responses. The SARS-CoV-2 S protein variations include several changes that improve receptor interactions, fusogenicity, and antibody reactivity. A wide range of clinical symptoms, including moderate febrile sickness, severe respiratory distress, and occasionally deadly lung damage, can be brought on by an infection with SARS-CoV-2. Several of these lung illnesses (MERS-CoV) are linked to both the Middle East Respiratory Syndrome (MERS) and the severe acute respiratory syndrome coronavirus (SARS-CoV). Compared to acute respiratory syndromes, the lung thrombosis brought on by Coronavirus disease 2019 (COVID-19) is incredibly severe. In this review we focused on innate immunological elements that prevent syncytia from forming and the molecular triggers of S-mediated fusion.

Background:The ongoing spillover of highly pathogenic avian influenza H5N1 virus into mammalian species, including recent outbreaks in dairy cattle, underscores an urgent need for broadly effective therapeutics. Nanobody, the variable domain of heavy chain-only antibody, offers unique advantages for viral neutralization due to its small size, stability, and accessibility to cryptic epitopes.Methods:In this study, we isolated a human nanobody, nAb35, targeting the hemagglutinin of the dairy cattle H5N1 virus A/Texas/37/2024 (clade 2.3.4.4b) via phage display of a human nanobody library. After three rounds of panning against the recombinant H5 ectodomain, a dominant clone (nAb35) was highly enriched. Then nAb35 was fused with a human IgG1 Fc fragment and expressed as a bivalent dimer.Results:Biochemical characterization demonstrated that nAb35 specifically binds to H5 under both denaturing and native conditions and recognizes a linear epitope accessible on H5 expressed on the cell surface. In vitro neutralization assays using H5 pseudovirus showed that nAb35 inhibited viral entry with a half-maximal effective concentration of approximately 10 μg/mL, as determined by both luciferase reporter and immunofluorescence assays.Conclusion:These findings identify nAb35 as a promising candidate for further therapeutic development against emerging H5N1 virus.

Rustrela virus (Rubivirus strelense) is a single-stranded, non-segmented RNA virus that causes brain diseases in animals, especially encephalitis and meningoencephalitis. Its rapidly mutating RNA genome complicates control, making a vaccine imperative. Immunoinformatics approaches were employed to make the polyepitope vaccine (PEV) for RuV control. Epitopes for cytotoxic T lymphocytes (CTL), helper T lymphocytes (HTL), and B cells were made from most immunogenic parts i.e., E1, E2, and capsid structural proteins of RuV. Epitopes that were antigenic, not allergic, IFN simulators, and not toxic were selected. This led to the selection of 6 CTL, 6 HTL, and 13 B cell epitopes, which were then used to construct the PEV with appropriate linkers and CTB as an adjuvant for immunological modulation. The physiochemical analyses demonstrated that the PEV was safe, stable, hydrophilic, and soluble. The secondary structure prediction has indicated mostly coiled and alpha helix in the PEV. The 3D scans revealed a solid and stable structure. The interactions and stability between the vaccine, TLR3, TLR4, and TLR7 were revealed by molecular docking. The vaccine candidate's minimal deformability and high stability were verified by molecular dynamics modeling. The developed PEV vaccine demonstrated a strong immunological response in in silico immune simulation. RuV-PEV is predicted to be efficiently produced in E. coli following in silico codon optimization and vector cloning. It elicited strong antigen-specific humoral and cellular responses, indicating promise as a Rustrela virus vaccine. Its precise effectiveness, safety, and immunogenicity profile may be confirmed by further experimental validations.

This study aimed to explore the molecular alterations in airway epithelial cells in children with wheezing infected by respiratory syncytial virus (WheezeRSV). This study extracted the single-cell sequencing data of two control and wheezeRSV samples from GSE286262 dataset. The monocle2 was performed for analyzing evolution process of basal cells along disease progression. Kyoto encyclopedia of genes and genomes and gene ontology were carried out to identify the function enrichment of differentially expressed genes (DEGs) between WheezeRSV and control groups. Additionally, human nasal epithelial cells (HNECs) were harvested, and quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression levels of key genes. Six cell types including ciliated cells, KRT5 + basal cells, TP63 + basal cells, KRT80 + epithelial cells, goblet cells, and club cells. The differentiation trajectory analysis on basal cells indicated two distinct branches including ciliary assembly and keratinization. Then, function analysis indicated that ciliated cells were involved in leukocyte transendothelial migration, cellular senescence and angiogenesis. Goblet cells were associated with IL-17 signaling pathway, apoptosis, and ferroptosis, and club cells were enriched in the apoptotic process and innate immune response. The qRT-PCR results revealed that the mRNA expression levels of TEKT2, SPRR3, ITGB1, CDKN1A, ACSL1, and CXCL8 were markedly upregulated in the WheezeRSV group (p < 0.01). Basal cells differentiated into keratinocytes and ciliated cells as the disease progresses, thereby enhancing defense and repairing the epithelial barrier. Meanwhile, wheezeRSV enhanced the activity of apoptosis and inflammatory response of ciliated cells, goblet cells, and club cells.

The hyperinflammatory response in COVID-19 is a major factor contributing to morbidity. Pentoxifylline, a methylxanthine derivative, has immunomodulatory properties, but its effects on inflammatory markers in COVID-19 remain unclear. This meta-analysis aims to evaluate the efficacy of pentoxifylline supplementation on CRP and interleukin-6 (IL-6) levels in these patients. A systematic search was conducted across multiple databases for randomized controlled trials (RCTs) published up to September 2025. Four RCTs, including 178 cases and 321 controls for CRP, and two RCTs, including 70 cases and 70 controls for IL-6, were included. Two reviewers independently performed data extraction and assessed the risk of bias using the Cochrane tool. Pooled standardized mean differences (SMDs) were calculated using a random-effects model. Heterogeneity was analyzed through meta-regression, and the conclusiveness of the evidence was evaluated using Trial Sequential Analysis (TSA). Pentoxifylline did not significantly reduce C-reactive protein (CRP) levels compared to the control group (SMD = -0.89; 95% CI: -1.85 to 0.07; p = 0.07). However, substantial heterogeneity was noted across the studies (I2 = 95.3%). Similarly, a nonsignificant trend toward reduction was observed for IL-6 (SMD = -0.22; 95% CI: -0.96 to 0.52; p = 0.55), accompanied by significant heterogeneity (I2 = 79.1%). Given the limited number of studies included, the results are inherently fragile, and one additional trial could substantially shift the pooled estimate. Meta-regression analysis indicated that patient age and publication year did not account for the heterogeneity, although there was a nonsignificant trend suggesting that a longer treatment duration might be associated with greater CRP reduction. TSA for CRP showed that cumulative evidence suggested futility and a lack of meaningful effect, confirming a significant lack of effect. The included studies generally had a low risk of attrition and reporting bias. Current evidence does not support the use of pentoxifylline for significantly reducing CRP or IL-6 levels in COVID-19 patients. The findings regarding CRP are considered conclusive, but the limited number of studies suggests that further trials on this outcome may alter this conclusion.

In the intricate world of aquatic ecosystems, infectious pancreatic necrosis virus (IPNV) and viral hemorrhagic septicemia virus (VHSV) emerge as formidable threats to marine life, posing diverse diseases that reverberate through shared host species (Salmon, trout fishes). The coexistence of these viruses amplifies health risks, compelling the pursuit of inventive intervention strategies. Recognizing the urgency, a current and optimistic initiative strives to craft a revolutionary combined vaccine, offering protection against both IPNV and VHSV. This innovative endeavor, driven by an immunoinformatics approach, identifies immune-dominant epitopes from CadB and LamB proteins, ensuring the final vaccine's immunogenicity, non-allergenicity, and enhanced solubility. Molecular dynamics simulations validate its binding stability and structural integrity. In a pivotal move, codon optimization using Escherichia coli K12 as a model result in an ideal guanine-cytosine content and a higher Codon Adaptation Index value, seamlessly integrating into the cloning vector pET2+ (a). In essence, our outcomes underscore the potential of this proposed peptide vaccine to elicit a robust immune response against both IHNV and VHSV, marking a breakthrough in the holistic management of infectious diseases in aquatic environments.

The potential role of bovine leukemia virus (BLV), a zoonotic deltaretrovirus, in human breast carcinogenesis remains controversial, and evidence from seroepidemiological studies is limited. This study aimed to evaluate BLV IgG seroprevalence in women with malignant breast cancer and benign breast lesions and to explore the possible association between BLV exposure and breast cancer development. In this cross-sectional comparative study, a total of 124 women aged ≥18 years who presented to Ankara Etlik City Hospital between May and July 2024 were included. The malignant group comprised 82 women with histopathologically confirmed breast cancer, while the control group included 42 women with benign breast lesions. Serum samples were analyzed for BLV-specific IgG antibodies using a commercial enzyme-linked immunosorbent assay kit. Overall BLV IgG seroprevalence was 12.9% (16/124), with rates of 13.4% in the malignant group and 11.9% in the benign group, showing no statistically significant difference (p = 0.812). In the malignant group, BLV IgG seropositive patients were significantly older than seronegative patients, and seropositivity increased with age (p < 0.01). Although higher BLV IgG seropositivity were observed in invasive mucinous carcinoma cases, this association did not reach statistical significance in logistic regression analysis. Hematological parameters were evaluated to investigate potential systemic immune or inflammatory responses associated with BLV exposure; however, no significant associations were identified between BLV IgG seropositivity and these parameters. These findings suggest that BLV exposure, as reflected by humoral immune response, is not directly associated with breast cancer development but may represent cumulative or long-term exposure. Further large-scale, multicenter studies integrating molecular and serological approaches are warranted to clarify the potential role of BLV in human breast cancer etiology.

Maternal antibodies protect mink kits early in life, but their duration and impact on subsequent SARS-CoV-2 exposure remain unclear. We longitudinally characterized passive immunity in kits born to mothers previously infected with lineage B.1.1.305 on a commercial farm in Greece and related antibody kinetics to a later heterologous virus incursion. Breeder animals showed a 93.3% seropositivity rate after the initial outbreak. On day 20 postpartum, 81.4% of mothers and 69.8% of kits were positive for SARS-CoV-2 nucleocapsid (N)-specific antibodies by enzyme-linked immunosorbent assay (ELISA); a maternal S/P% >160.1% was associated with kit seropositivity at the same time-point (area under the curve 0.985; sensitivity 90%; specificity 100%). Kit seropositivity declined to 2.4% by D*56, consistent with the rapid waning of maternally derived antibodies. On D*87, 97.6% of kits had seroconverted, and 90.0% of mothers were seropositive; Analysis of oropharyngeal swabs by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and next generation sequencing (NGS) confirmed introduction of lineage B.1.177. No clinical signs or excess mortality were observed during this reinfection event. These data demonstrate efficient passive transfer, rapid loss of detectable antibodies by ∼8 weeks, and farm-wide seroconversion after re-exposure to a new lineage. The absence of disease despite widespread seroconversion suggests maternally acquired immunity may have mitigated illness but did not prevent infection. Silent SARS-CoV-2 circulation can therefore occur in partially immune mink farms, with important implications for biosecurity and targeted SARS-CoV-2 surveillance. To our knowledge, this is the first longitudinal study to track the dynamics of maternally derived SARS-CoV-2 antibodies in mink kits and link them to subsequent exposure outcomes.

The SEN virus (SENV), a DNA virus that has been linked to blood transfusion, is a major cause of post-transfusion hepatitis. SENV-D and SENV-H are non-A to E hepatitis viruses. The present study was conducted to investigate the prevalence of SENV-D/H among dialysis patients and blood donors as control group in Diyala province/Iraq. This study includes 120 participants: 80 dialysis patients who have been attending the Ibn-Sina Dialysis Center-Diyala Directorate of Health were previously diagnosed with the disease, and 40 individuals as controls were selected at random from blood donors at the Central Blood Bank during the period from 1/5/2025 to 30/11/2025. Full information had been taken directly from the patients, and the information had been arranged in an informative formula sheet, which includes age and gender. All study subjects were screened for nested polymerase chain reaction. The SENV-D prevalence was 10 (12.50%) and 0.00% for dialysis patients and controls, respectively, and SENV-H was 5 (6.25%) and 1 (2.50%) for dialysis patients and controls, respectively. The SENV co-infection rate of genotypes D and H was 3 (7.50%) in the dialysis group, and no cases in the control group were found. A very strong association was found between the distinct SENV genotypes and Hepatitis B virus (HBV) or Hepatitis C virus (HCV) status. Positivity for SENV was also correlated with high serum Aspartate Aminotransferase (AST) and Alanine aminotransferase (ALT). SENV-D and SENV-H were more prevalent among hemodialysis patients than in normal blood donors. The presence of SEN-V in both groups indicates its categorization as a blood-borne virus and suggests risk for transmission by blood exposure.