Search Results (454)

Background: Presence of milk, fruits, eggs, fish, nuts and wheat antigens in the amniotic fluid is described in the literature. Studies show a contradictory relationship between maternal exposure to allergens and early sensitization of the fetus to allergens. Hemochorionic type of the human placenta allows for easier transfer of nutrients and antibodies from the mother’s blood to the fetal circulation through the direct contact of maternal blood with the fetal chorion. During the third trimester of pregnancy, immunoglobulin G (IgG) is actively transferred through the placenta into the fetal via neonatal FcRN receptor (FcRN). In addition, monomeric immunoglobulin E (IgE) cannot cross the placenta Aim: The objective of our study is to track intrauterine sensitization to essential food proteins at birth in umbilical cord blood in mothers with established peripheral blood eosinophilia and in their infants using allergen-specific IgE and IgG. Methods: An observational study was carried out in a cohort of 22 mothers with eosinophilia and their babies. Differences in expression between groups were assessed. Blood samples were collected to determine serum IgE and IgG specific to a set of inhalant and food allergens. Results: We did not find a significant correlation between specific IgE to cow’s milk (p = 0.857), egg white (p = 0.926) and egg yolk (p = 0.096) in umbilical cord blood and maternal blood samples taken immediately before birth. Spearman’s correlation of the specific IgE and IgG in umbilical cord blood showed no dependence between the two variables. In contrast, statistical analysis showed that maternal eosinophilia in peripheral blood could be a risk factor for the development of allergy in the offspring (χ², p = 0.0347). However, given the small number of patients, this claim needs to be confirmed with further studies. Conclusions: Due to the functional immaturity of the developing immune system of the fetus, the generation and maintenance of an independent immune response to allergens are incomplete. Maternal IgG (specific) passes to the baby and high maternal IG to a specific allergen reduces babies IgE production. In addition, low maternal specific IgG may promote IgE production in the baby under the influence of microenvironmental factors (cytokine background). The main limitation of our study is the small number of patients. Further research is needed in this direction to clarify the mechanisms and risk factors for early sensitization in newborns. Full article

Background: The apicomplexan parasite Toxoplasma gondii causes serious diseases in animals and humans. The in vitro efficacy of the antimicrobial peptide mixture tyrothricin, composed of tyrocidines and gramicidins, against T. gondii tachyzoites was investigated. Methods: Effects against T. gondii were determined by monitoring inhibition of tachyzoite proliferation and electron microscopy, host cell and splenocyte toxicity was measured by Alamar blue assay, and early embryo toxicity was assessed using zebrafish embryos. Differential affinity chromatography coupled to mass spectrometry and proteomics (DAC-MS-proteomics) was employed to identify potential molecular targets in T. gondii cell-free extracts. Results: Tyrothricin inhibited T. gondii proliferation at IC₅₀s < 100 nM, with tyrocidine A being the active and gramicidin A the inactive component. Tyrothricin also impaired fibroblast, T cell and zebrafish embryo viability at 1 µM. Electron microscopy carried out after 6 h of treatment revealed cytoplasmic vacuolization and structural alterations in the parasite mitochondrion, but these changes appeared only transiently, and tachyzoites recovered after 96 h. Tyrothricin also induced a reduction in the mitochondrial membrane potential. DAC-MS-proteomics identified 521 proteins binding only to tyrocidine A. No specific binding to gramicidin A was noted, and four proteins were common to both peptides. Among the proteins binding specifically to tyrocidine A were several SRS surface antigens and secretory proteins, mitochondrial inner and outer membrane proteins associated with the electron transfer chain and porin, and several calcium-binding proteins putatively involved in signaling. Discussion: These results suggest that tyrocidine A potentially affected multiple pathways important for parasite survival and development. Full article

Background/Objectives: Long-term serological studies are essential to understand how repeated antigenic exposure affects the specific humoral immune response. The aim of this study was to investigate the long-term SARS-CoV-2 antibody dynamics in Austrian blood donors, as representatives of healthy adults, over a period of 36 months after the first SARS-CoV-2 infection. Methods: SARS-CoV-2 anti-N antibody levels were determined in more than 146,000 blood donations collected between 2020 and 2025. In addition, SARS-CoV-2 anti-N and anti-S antibody dynamics were examined in 204 individual blood donors at predefined points in time over a period of 36 months. Reinfections were inferred from increases in anti-N levels within an individual. Vaccination history and self-reported infection data were documented. Results: Anti-N seroprevalence was over 90% from the beginning of 2023 and remained at this level until 2025. Among the longitudinally observed participants, 97% had at least one serologically detected reinfection and 50% had two or more. While anti-N levels continued to increase over time, suggesting cumulative antigenic stimulation, anti-S concentrations and in vitro antibody functionality remained consistently high. Self-reported reinfections underestimated the actual incidence by a factor of six. Symptom profiles shifted toward mild respiratory manifestations, with significantly fewer cases of hyposmia or dysgeusia reported compared to the initial infection. Conclusions: After three years of observation, SARS-CoV-2 immunity is characterized by sustained antibody activity. The results show a transition from persistent, but inherently declining, to a repeatedly rebuilding, enhanced humoral immunity, indicating that SARS-CoV-2 has become endemic in Austria. Full article

Baker’s yeast beta-glucan (BYBG) supplementation improves various aspects of immune system function, readiness, and response. The purpose of this study was to determine if the expression of immune maturation mRNA was also changed over the course of 6 weeks of BYBG supplementation at rest. In this exploratory study, a small group of participants (N = 20) were randomized into two groups: BYBG (weeks 0–2 = 50 mg/d; 2–4 = 125 mg/d; and 4–6 = 250 mg/d) or placebo. Blood samples were collected at 0, 2, 4, and 6 weeks and analyzed for the expression of 785 mRNA (NanoString nCounter platform and Nanotube software; R v3.3.2). A total of 42 mRNAs in 21 annotated pathways (antigen presentation, apoptosis, B cell memory, cell cycle, chemokine signaling, cytotoxicity, DAP12 signaling, hypoxia response, IL-1 signaling, IL-10 signaling, MAPK signaling, myeloid immune response, NF-kB signaling, NK activity, Notch Signaling, PD1 signaling, Senescence/Quiescence, T cell checkpoint signaling, TCR signaling, TLR signaling, and TNF signaling), were significantly affected by BYBG at various time points. It is reasonable to speculate that the observed mRNA and associated pathways may underlie previously reported improvements in immune function with BYBG. Full article

Background: Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven disease of the esophagus that causes considerable morbidity. Elimination of allergenic foods from a patient’s diet is a highly effective treatment. However, existing allergen testing modalities are not effective at identifying EoE-causal foods. We sought to determine the extent to which positive results for two functional T-cell assays, the EoE Milk Test and EoE Soy Test, associated with the clinical outcomes of EoE milk allergy and EoE soy allergy, respectively. Methods: Subjects were enrolled into one of two study designs: a prospective observational study or a retrospective case/control study. Additional control samples were obtained from an institutional core. The EoE Milk and Soy Tests were performed on peripheral blood samples, and the association between positive tests and clinical outcomes was determined using Receiver Operating Characteristic curves and other performance measures. Results: The EoE Milk Test maintained reliability regardless of disease activity or recent milk consumption and had 87% sensitivity and 83% specificity for EoE milk allergy in all study subjects (control and EoE). The EoE Soy Test had 90% sensitivity and 93% specificity in all subjects. Conclusions: Our evaluation of the EoE Milk and Soy Tests demonstrates that these functional T-cell assays hold promise as a predictive tool for identifying causal allergens in eosinophilic esophagitis patients. Full article

This study evaluated the formulation and stability of a quadrivalent glycoconjugate Shigella vaccine candidate based on four predominant strains (S. flexneri; 2a, 3a, and 6, and S. sonnei) covering ~64% of global Shigella infections. Each glycoconjugate antigen consists of a strain-specific O-polysaccharide (O-PS) covalently linked to the carrier protein IpaB, a component of the Shigella type III secretion system. First, selective competitive ELISAs were developed to measure antigenicity of the four O-PS-IpaB conjugates formulated with different adjuvants (i.e., Alhydrogel^®, AH; Adju-phos^®, AP; and CpG-1018^®, CpG). Next, the monovalent S. sonnei O-PS-IpaB conjugate was studied to elucidate interactions with aluminum salt adjuvants (AH, AP) under different solution conditions. Third, the stability profiles of AH- or AP-adjuvanted S. sonnei O-PS-IpaB conjugate in various formulations (±CpG) were determined at different temperatures. Interestingly, incubation at 25 °C for 2 weeks resulted in increased antigenicity values when the antigen was bound to AP or AH, suggesting increased epitope exposure upon adjuvant binding. When bound to AP adjuvant at pH 5.8, the best glycoconjugate antigen stability was observed at elevated temperatures. The CpG adjuvant under these conditions, however, displayed incompatibility (i.e., material loss), presumably from precipitation due to lack of interaction with AP and presence of the detergent LDAO from the bulk antigen buffer. In contrast, the glycoconjugate antigen and CpG adjuvant were both bound to the AH adjuvant and stable at 2–8 °C, pH 7.0. This AH-CpG formulation of the O-PS-IpaB conjugate antigens was identified as a promising candidate for future animal immunogenicity testing. Full article

No vaccines are licensed against enterotoxigenic Escherichia coli (ETEC), a leading diarrheal cause in children and travelers. ETEC adhesins and enterotoxins are the virulence determinants and become the primary targets in ETEC vaccine development. However, ETEC strains produce > 25 adhesins and two potent enterotoxins, particularly the poorly immunogenic heat-stable toxin (STa), greatly hindering ETEC vaccine development. To overcome these challenges, we developed a multiepitope-fusion-antigen (MEFA) platform. MEFA presented multiple adhesin epitopes on a backbone and generated a polyvalent adhesin immunogen, CFA/I/II/IV MEF. CFA/I/II/IV protected against the seven ETEC adhesins (CFA/I, CS1-CS6) associated with two-thirds of ETEC diarrheal cases. We further used toxoids as safe antigens and created a toxoid fusion, 3xSTa_N12S-mnLT_R192G/L211A. This antigen induced antibodies neutralizing the enterotoxicity of STa and heat-labile toxin (LT), which, alone or together, cause all ETEC diarrheal cases. By combining two polyvalent proteins, we developed a multivalent ETEC vaccine, MecVax, that protects against seven ETEC adhesins and two enterotoxins. MecVax is broadly immunogenic. MecVax prevents intestinal colonization by ETEC strains expressing any of the seven adhesins and protects against clinical diarrhea from ETEC strains producing LT or STa enterotoxin preclinically, becoming a broadly protective ETEC vaccine candidate against children’s diarrhea and travelers’ diarrhea. Full article

Antibodies against low-molecular-weight compounds exhibit cross-reactivities (CRs) with their structural analogs, varying by orders of magnitude for different substances. This variability limits the informativeness of antibody applications as analytical reagents and for other aims when samples contain several members of the same family, their derivatives, or partial degradation products. Therefore, there is a demand to find some criteria for understanding the relationships between the structural characteristics of antigens of a given chemical class and their immunochemical activity. This study presents an experimental and theoretical investigation of the properties of a monoclonal antibody (MAb) against the S-stereoisomer of gatifloxacin, a member of the widely used (fluoro)quinolone (FQ) family of antibiotics, characterized by high structural diversity. The aim was to determine FQs that form complexes with MAb and suggest a methodology to predict their CRs in silico. For this, the interaction of MAb with 26 FQs was studied using the enzyme-linked immunosorbent assay and presented as CR values to the target antigen. The most pronounced CRs were observed for lomefloxacin, sarafloxacin, and ciprofloxacin. Molecular dynamics (MD) simulations were performed to identify differences in analyte interactions at the MAb antigen-binding site, which determines binding affinity. It has been shown that molecular docking fails to discriminate cross-reactive from non-cross-reactive compounds because FQs have similar cores. Therefore, advanced analysis of MD trajectories was carried out. It allowed for clarification of the dynamic features of analyte–antibody interactions responsible for binding. It was shown by the dynamical network analysis that the sum of betweenness centrality between a node corresponding to the quinolone ring and nodes representing MAb amino acids is higher for cross-reactive haptens. The found regularities can be transferred to other analyte–antibody systems as a binary classifier that discriminates cross-reactive and non-cross-reactive compounds. Full article

Background: Hepatitis B virus (HBV) and Plasmodium falciparum infections remain major public health concerns in sub-Saharan Africa, especially among pregnant women, who are particularly vulnerable due to physiological immunomodulation. While mono-infections are well documented, the burden and biological consequences of HBV–P. falciparum co-infection during pregnancy remain under-investigated in Gabon. Aim: To determine the prevalence, clinical relevance, and biochemical impact of HBV–P. falciparum co-infection among pregnant women in Libreville, Gabon, and to explore the interaction between viral and parasitic replication. Methods: A prospective cross-sectional study was conducted between May 2022 and May 2023 at the CHUME-FJE Laboratory in Libreville. Serum samples were tested for HBsAg using rapid diagnostic tests and ELISA confirmation; HBV surface antigen (HBsAg) levels were quantified by electrochemiluminescence (ECLIA). Parasitemia was assessed by rapid diagnostic test, microscopy, and the Lambaréné thick blood film method. Liver function parameters (ALT, AST, ALP, and GGT) were evaluated using an automated biochemistry analyzer. Statistical analysis included Mann–Whitney U tests, chi-square tests and Spearman’s rank correlation coefficient with significance set at p < 0.05. Results: Of the 222 pregnant women enrolled, HBV infection was detected in 9 cases (4.05%). Among these, 6 (2.7% of the study population) were mono-infected with HBV, while 3 (1.35%) were co-infected with Plasmodium falciparum. P. falciparum parasitemia was detected in 58 cases (26.1%). Biochemical profiles revealed elevated transaminases (AST) in HBV mono-infected women, while liver enzymes remained within normal ranges in co-infected individuals. Quantitative analyses demonstrated an inverse relationship between HBV surface antigen levels and P. falciparum parasitemia. This observation could suggest an antagonistic replication dynamic. However, the relationship was not statistically significant (Spearman’s ρ = −0.5, p = 0.67). Conclusions: HBV and P. falciparum co-infection occurs in a small but clinically relevant proportion of pregnant women in Gabon. The observed inverse replication pattern suggests a potential biological antagonism that may modulate disease severity. These findings although preliminary, could highlight the need for integrated screening and management strategies during pregnancy to improve maternal and fetal outcomes. Full article

Background/Objectives: Sublingual vaccination offers a non-invasive route for inducing both systemic and mucosal immunity, yet the formulation properties that govern its success remain poorly defined. This study investigated the relationships among key formulation parameters for sublingual vaccines, such as viscosity, mucoadhesion, and mucosal residence, to understand their impact on in vivo immune responses in the sublingual delivery context. Methods: Ovalbumin (OVA)-based vaccine formulations containing cholera toxin B (CTB) adjuvant and mucoadhesive excipients such as hydroxypropyl methylcellulose (HPMC) or methylglycol chitosan (MGC), were evaluated for: (1) their respective rheological properties—characterized by viscosity and mucoadhesion parameters, as well as (2) in situ mucosal retention (assessed using Cy7-labeled formulations tracked by IVIS in vivo imaging system) and (3) in vivo immunogenicity via systemic (IgG) and mucosal (IgA) responses measured by ELISA, following sublingual administration to mice. Correlations between rheology, in situ/ex situ mucosal residence, and in vivo immune outcomes were determined. Results: Sublingual vaccine formulations containing HPMC exhibited the highest viscosity, mucoadhesion, and mucosal retention profiles, but paradoxically elicited the weakest systemic and mucosal antibody responses. In contrast, chitosan-based formulations enhanced immune responses even at reduced antigen and adjuvant doses, likely due to its permeation-enhancing and adjuvant effects. Correlation analyses revealed that while formulation viscosity and mucoadhesive strength were positively associated with mucosal retention, both rheological and retentive properties showed a significant inverse relationship with immunogenicity in the context of sublingual vaccine delivery. Conclusions: While viscosity and mucoadhesion are essential for in situ retention of sublingual vaccines, prolonged residence driven by excipient’s excessive rheological strength was found to reduce vaccine immunogenicity—likely due to restricted antigen release and mucosal uptake. Accordingly, HPMC appears suboptimal as a sublingual vaccine excipient, while chitosan shows promise for sublingual delivery as a permeation-enhancing adjuvant. These findings may shift the design paradigm for sublingual vaccine formulations, highlighting the need to balance mucosal retention with efficient antigen absorption for maximizing immune responses. Full article

Rapid blood type detection in point-of-care testing (POCT) scenarios is crucial for various clinical treatments. In this study, we present a sensitive, cost-effective, and straightforward biosensing approach for visual blood typing that notably simplifies the procedure by eliminating any need for blood sample pretreatment. Our technique achieves this by directly trapping and accumulating red blood cell (RBC) clusters within a photolithography-based microfluidic chip, thereby bypassing complex preprocessing. By employing an antigen–antibody assay involving isoagglutinins A, B, and/or D on the RBC surface and their corresponding antibodies, we effectively determine blood types. When antibodies are present, the corresponding RBCs bind to the antibody-conjugated RBC clusters, which are subsequently trapped within the microfluidic accumulation chip, resulting in the formation of a visible bar. The blood group can then be readily identified by observing this visual bar with the naked eye or under microscopy. Notably, we integrate two continuous mixing units (Z and S) at the entrance of the biochip to improve mixing efficiency and accelerate the antigen–antibody interaction. This method demonstrates high selectivity, accuracy, and stability across various clinical blood samples. Moreover, the sensor operates with minimal sample volume (as low as 10 μL) and delivers results within 5 min. The fabrication cost of the PDMS-based biochip is approximately $0.2 per chip, and the limit of detection (LOD) is determined to be 3 × 10⁶ cells/mL, indicating excellent sensitivity and affordability for practical use. Overall, this biochip provides a fast, low-cost, and reliable solution for emergency blood typing, particularly in resource-limited settings. Full article

Cancer immunotherapy has redefined oncology’s goals, aiming for durable systemic immunity rather than mere cytoreduction. However, many solid tumors remain refractory due to immunosuppressive microenvironments and antigenic heterogeneity. Local tumor ablation techniques—including radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, irreversible electroporation (IRE), and high-intensity focused ultrasound (HIFU)—are being re-evaluated beyond their historic cytoreductive role. This comprehensive review synthesizes the paradigm of tumor ablation as an in situ vaccination strategy, a concept that leverages the tumor itself as a source of antigens and the ablation process to generate endogenous adjuvants. We detail the mechanistic underpinnings, highlighting how ablation induces immunogenic cell death (ICD), releasing damage-associated molecular patterns (DAMPs) such as calreticulin, ATP, HMGB1, and cytosolic DNA. These signals activate innate immunity via pathways like cGAS-STING, promote dendritic cell maturation, and facilitate epitope spreading. We critically examine the determinants of efficacy, including the critical impact of ablation modality on the “DAMP signature,” the necessity of complete ablation, and the pivotal role of the host’s immune contexture. Furthermore, we explore the induction of tertiary lymphoid structures (TLS) as a key anatomical site for sustained immune priming. Translational strategies are extensively discussed, focusing on optimizing procedural techniques, rationally combining ablation with immune checkpoint inhibitors (ICIs) and innate immune agonists, and developing a robust biomarker framework. By adopting the core principles of vaccinology—meticulous attention to antigen, adjuvant, route, and schedule—ablation can be engineered into a reproducible platform for systemic immunotherapy. This review concludes by addressing current limitations and outlining a roadmap for clinical translation, positioning interventional oncology as a central discipline in the future of immuno-oncology. Full article

Men with high-risk localized prostate cancer (PCa) often have poor long-term outcomes, underscoring the need for improved neoadjuvant strategies beyond the current standard of care. Radioligand therapy with ¹⁷⁷Lutetium-PSMA-617 (¹⁷⁷Lu-PSMA-617) has emerged as a promising method to eliminate occult micrometastases while enhancing immune-mediated clearance of the primary tumor. Initial trials have affirmed the treatment’s feasibility and safety; however, they have consistently reported a lack of pathological complete response. This absence of profound initial tumor reduction necessitates further therapeutic advancements. The underlying rationale for future strategies is clear, as ¹⁷⁷Lu-PSMA-617 promotes immunogenic cell death, potentially sensitizing immunologically “cold” tumors to checkpoint inhibitors. However, caution is warranted. The synergy observed between these therapies in advanced, metastatic castration-resistant PCa stems from a different biological context, and similar outcomes cannot be presumed in treatment-naïve, localized disease without rigorous validation. Continued progress hinges on developing improved metrics for success and patient selection. Simple prostate-specific antigen reductions have demonstrated minimal correlation with significant pathological outcomes in this setting, underscoring the critical need for validated surrogate endpoints and predictive biomarkers. Ultimately, large-scale randomized trials are essential to determine whether this investigational approach impacts key clinical outcomes—namely, metastasis-free and overall survival. While the strategy is theoretically sound, its capacity to enhance cure rates for high-risk localized PCa remains unverified. Full article

Background: The global health burden of mosquito-borne viruses, including dengue, yellow fever, Zika, and chikungunya, is rising due to climate change and globalisation, which favour mosquito habitat expansion. The genetic diversity of these viruses complicates the development of virus-specific vaccines or antivirals, highlighting the need for pan-viral strategies. As the common vector for these pathogens, mosquitoes and specifically their salivary proteins represent a promising target for such interventions. Mosquito saliva, secreted into the skin during biting, has immunomodulatory effects that can enhance host susceptibility to infection, but these mechanisms are not well defined in humans. Methods: The objective of this study was to determine whether AGS-v PLUS, a vaccine targeting mosquito salivary antigens, could modulate the human skin immune response to mosquito biting and potentially promote antiviral bystander immunity. In a Phase I trial, healthy volunteers were vaccinated with AGS-v PLUS (with or without adjuvant) or placebo, and three weeks later, they were exposed to bites from Aedes albopictus and Aedes aegypti mosquitoes. Skin biopsies from bitten and unbitten sites were analysed by transcriptomic profiling. Results: In placebo recipients, mosquito biting elicited a marked adaptive immune response at 48 h, characterised by CD4⁺ Th1 and CD8⁺ T cell signatures and leukocyte recruitment. While responses to Ae. aegypti and Ae. albopictus bites were broadly similar, those to Ae. albopictus were stronger. Vaccination with AGS-v PLUS, particularly with adjuvant, enhanced Th1 and CD8⁺ T cell-associated gene expression while suppressing pathways linked to neutrophilic inflammation and epithelial stress, which together may provide enhanced antiviral capacity. Conclusions: These findings demonstrate that targeting the host response to mosquito saliva via vaccination can reprogram the skin’s immune response to mosquito bites, supporting a novel and broadly applicable pan-viral strategy to mitigate the impact of arboviral diseases. Full article

A shift in the public health goal for onchocerciasis from control to elimination implies that the treatment of onchocerciasis must be extended to communities that are hypoendemic for the disease. However, in such communities, the majority of the population may not manifest the symptoms of onchocerciasis. As a result, they may be reluctant to take part in epidemiological surveys aimed at monitoring parasite transmission, particularly due to the invasive nature of the currently approved diagnostic tests. This reluctance is compounded by the absence of visible, severe manifestations of the disease in these areas. On the other hand, diagnostic methods that utilize samples collected by a non-invasive procedure, such as urine, are generally painless and not risky. In this context, we evaluated the diagnostic performances of OvMANE1 and OvMCBL02 multiepitope antigens using urine samples. The evaluation of total IgG and IgG subclass responses revealed IgG3 as the most effective IgG for the OvMANE1 test (sensitivity = 87.5%, specificity = 100.0%), total IgG for the OvMCBL02 test (sensitivity = 92.5%, specificity = 100.0%), and IgG3 for the OvMANE1_OvMCBL02 cocktail test (sensitivity = 92.5%, specificity = 100.0%). These tests have the potential to meet the criteria of a diagnostic test’s target product profile to map onchocerciasis in low-prevalence areas, where a sensitivity of ≥60.0% and specificity of ≥99.8% are recommended. Furthermore, the OvMCBL02 and OvMANE1_OvMCBL02 cocktail tests may have the features of a diagnostic test’s target product profile to determine treatment endpoints (recommended sensitivity ≥ 89.0%, specificity ≥ 99.8%) as reported by the Diagnostics Technical Advisory Group for Neglected Tropical Diseases of the World Health Organization. Consequently, further characterization of these multiepitope antigens may enable urine, which can be collected non-invasively, to be used in the OvMANE1 and OvMCBL02 tests for the field evaluation of onchocerciasis. Full article