Search Results (3,906)

Objective: The aim of this study was to develop and evaluate non-antibiotic strategies against Helicobacter pylori by establishing a bovine immune milk platform and designing a synergistic multi-antigen immunogen to enhance humoral immune responses. Methods: Inactivated Helicobacter pylori (H. pylori) was used to immunize dairy cows, and the resulting immune milk was characterized for antibody specificity, acid stability, and target antigens via ELISA, Western blot, agglutination assays, and mass spectrometry. Key identified antigens (UreA, UreB, UreE, UreG, HypA, FlaA, and FlaB) were produced as recombinant proteins. Their immunogenicity was evaluated in a murine model, comparing single antigens with various protein combinations. Immune responses were assessed by antigen-specific IgG ELISA, bacterial agglutination titers, flow cytometry for T-cell activation, and histopathology for safety. Results: Immune milk contained high-titer, acid-stable IgG antibodies targeting multiple H. pylori virulence factors. In mice, while single proteins induced specific IgG, a multi-antigen cocktail (FlaA + FlaB + HypA + UreA + UreB + UreE + UreG) elicited significantly higher serum agglutination titers (~7 × 10³) than single antigens or inactivated whole-cell vaccine, alongside robust CD4⁺ T-cell activation. No formulations showed any hepatorenal or splenic toxicity. Conclusion: Bovine immune milk is a viable platform for acid-stable antibody delivery. A rationally designed multi-antigen cocktail synergistically enhances functional humoral immunity in vivo, providing a promising foundation for developing antibody-based or subunit vaccine strategies against H. pylori. Full article

Borrelia burgdorferi sensu lato is a complex of spirochetes that includes the main pathogenic species B. burgdorferi sensu stricto, B. afzelii, and B. garinii, the causative agents of Lyme disease. Our aim was to determine the seroprevalence of anti-Borrelia IgG antibodies and assess associated risk factors among blood donors from Western Romania. We conducted a cross-sectional study of 1347 consecutive donors at the Regional Blood Transfusion Center in Timisoara, Western Romania, between November and December 2018. Participants completed an epidemiological questionnaire and serum samples were tested for IgG antibodies against B. burgdorferi sensu lato using the VIDAS^® Lyme IgG assay. The overall seroprevalence was 2.08% (28/1347). Individuals aged 46–55 years had the highest prevalence (3.79%) and a more than fivefold increased risk compared to those aged 18–25 years (aOR = 4.77; 95% CI: 1.24–18.27; p = 0.023). Soil exposure was also independently associated with higher seropositivity (aOR = 2.37; 95% CI: 1.10–5.09; p = 0.027). Other factors, including residence, gender, and pet ownership, showed no significant associations. Our findings provide new epidemiological data for Romania and emphasize the importance of environmental exposures in shaping Borrelia seroprevalence. Full article

Impairment of the blood–nerve barrier (BNB) is associated with the pathogenesis of chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). This research analyzes the molecular mechanisms of immunoglobulin (Ig) G in patients with typical CIDP, CIDP variants (multifocal CIDP), and multifocal motor neuropathy in BNB-endothelial cells. IgG was purified from the sera of patients with typical CIDP (n = 15), multifocal CIDP (n = 14), multifocal motor neuropathy (MMN; n = 12), and healthy controls (HCs; n = 14). Molecular changes in the RNA-seq/high-content imaging system and permeability were evaluated after the incubation of human peripheral nerve microvascular endothelial cells (PnMECs) with IgG. RNA-seq and a pathway analysis using PnMECs showed that TNF-α, CCL20 (MIP-3α), and ICAM-1 were the centers of the upregulated gene pathways in patients with typical CIDP. TNF-α, VCAM-1, NF-κB, and CSF2 (GM-CSF) are important molecules in patients with multifocal CIDP. The high-content imaging system demonstrated that MIP-3, GM-CSF, and VCAM-1 increased after exposure to typical CIDP-IgG, claudin-5 decreased after exposure to IgG from patients with multifocal CIDP, and TNF-α and VCAM-1 increased after exposure to IgG from patients with MMN. The 10 kDa dextran permeability using coculture with PnMECs and pericytes increased after exposure to IgG from patients with typical CIDP and multifocal CIDP. This effect was reversed after incubation with GM-CSF neutralizing antibodies. Upregulation of MIP-3, GM-CSF, and VCAM-1 may contribute to the infiltration of leukocytes/lymphocytes/monocytes across the BNB into the PNS in typical CIDP. IgG from typical CIDP and multifocal CIDP may decrease barrier properties through autocrine GM-CSF from PnMECs. VCAM-1 upregulation through autocrine TNF secretion in PnMECs may induce lymphocyte entry across the BNB in MMN. Full article

Background/Objectives: While tick-borne encephalitis virus (TBEV) is genetically relatively conserved, the significant antigenic divergence between its main circulating subtypes hinders the development of broadly effective antiviral treatments and vaccines. Current inactivated TBEV vaccines offer limited cross-protection against heterologous strains, as evidenced by cases among vaccinated individuals in endemic regions. The aim of this study was to design a candidate mRNA vaccine and evaluate the breadth of protective immunity it elicits. Methods: Ten candidate mRNA-PrM/E-LNP vaccines were comparatively evaluated for immunogenicity and protective efficacy in BALB/c mice. Immunogenicity was assessed by measuring antigen-specific IgG titers via ELISA and neutralizing antibody titers against a panel of TBEV strains using a virus-neutralization test. Protective efficiency was determined in a lethal challenge model, where immunized mice were challenged with one of seven distinct TBEV strains. Results: Vaccination with all tested mRNA-PrM/E-LNP candidates conferred 100% survival in mice following a lethal challenge with each of the seven TBEV strains (100 LD₅₀). The construct mRNA-PrM/E—Krasny Yar-8 demonstrated the highest immunogenicity, inducing antigen-specific antibodies with a geometric mean titer (GMT) of 1:6625, as well as the broadest virus-neutralizing activity against both homologous and heterologous TBEV strains in vitro. Conclusions: The mRNA platform represents a promising strategy for developing TBEV vaccines, demonstrating high immunogenicity and cross-protective efficacy against diverse viral strains. Full article

Diabetic nephropathy (DN) is the most common cause of kidney failure worldwide. Mesenchymal stromal cells (MSCs) have demonstrated promise for treating DN by promoting kidney repair and regulating inflammation. Allogeneic (Allo)-MSCs may have similar or superior anti-inflammatory effects to autologous (Auto)-MSCs but also have potential to elicit adverse immune responses due to major histocompatibility complex (MHC) mismatches. To better understand how MSC-delivered allo-antigens influence therapeutic effects of Allo-MSCs compared to Auto-MSCs in DN, lentiviral transduction was used to generate adipose-derived MSCs (ADSCs) from DBA/2J (H-2^d) mice which expressed an allogeneic class I MHC protein (H-2K^b). H-2K^b-ADSCs were injected intravenously into male DBA/2J mice at 11 and 13 weeks after initiation of diabetes, and their effects on renal functional and structural indices were compared at week 15 with those of diabetic DBA/2J recipients of vehicle alone or of empty vector-transduced DBA/2J ADSCs (EV-ADSCs). Both EV-ADSCs and H-2K^b-ADSCs resulted in reduced kidney/total body weight ratio, blood urea nitrogen (BUN), urine albumin creatinine ratio (uACR), mesangial matrix expansion (MME) and renal fibrosis compared to vehicle alone, without influencing glycemia or survival. However, H-2K^b-ADSCs recipients had greater reductions in BUN and uACR, reduced intra-renal myeloid cell infiltration, increased splenic regulatory T cell (Treg) proportions and increased intra-renal Treg infiltration and FOXP3 and IL-10 mRNA. Nonetheless, recipients of H-2K^b-ADSCs also had decreased splenic CD4/CD8 T cell ratios, increased circulating anti-H-2K^b IgG antibodies and histological and biochemical evidence of inflammatory liver injury. These novel findings demonstrated that ADSCs expressing an MHC-I allo-antigen had superior beneficial effects on DN than fully autologous ADSCs. Improved DN severity was associated with immune modulation, including Treg enhancement, but also had potentially detrimental immunological effects in mice with established diabetes. The results highlight the need for further investigation of the immune modulatory effects of Allo-MSCs in diabetes and its organ-specific complications. Full article

Background/Objectives: Respiratory Syncytial Virus (RSV) causes severe disease in infants, the elderly, and immunocompromised individuals, with reinfections linked to poor induction of durable mucosal immunoglobulin A (IgA). We investigated the role of IgA in immunity and protection induced by a RSV subunit vaccine candidate, tFrsc/TriAdj, which consists of a truncated RSV fusion protein (tFrsc) with a tri-component adjuvant (TriAdj). Methods: Wild-type (IgA⁺/⁺) and IgA-deficient (IgA⁻/⁻) BALB/c mice were immunized intranasally and subsequently challenged with RSV. Results: Vaccination with tFrsc/TriAdj induced robust systemic and mucosal IgG, and high lung and serum neutralizing antibodies, in both IgA⁺/⁺ and IgA⁻/⁻ mice. As expected, IgA⁻/⁻ mice lacked IgA and exhibited modest reductions in nasal IgG compared to IgA^+/+ mice following challenge, correlating to failure to clear RSV from the upper respiratory tract. In contrast, viral replication in the lungs was fully suppressed in both genotypes, indicating that IgG alone was sufficient for lower respiratory tract protection. Isotype analysis revealed diminished Th1-associated IgG2a and elevated IgG1 across mucosal and systemic compartments in IgA⁻/⁻ mice, suggesting a Th2 bias. Flow cytometric analysis confirmed reduced recruitment of IFN-γ⁺ CD4⁺ T cells in the lungs of immunized IgA⁻/⁻ mice. Interestingly, IL-17 production and numbers of IL-17⁺ CD4⁺ T cells in the lungs were increased, suggesting an enhanced Th17 response. Furthermore, IgA-deficient mice displayed reduced splenic IgG⁺ B cell populations, which is also a novel observation. Conclusions: Collectively, these findings demonstrate that although tFrsc/TriAdj confers lower airway protection in the absence of IgA, vaccine-induced IgA is critical for upper airway protection, Th1/balanced immune responses, and optimal B cell responses. Full article

Anti-GQ1b antibody syndrome (AGABS) unifies triad-defined Miller Fisher syndrome (MFS), Bickerstaff brainstem encephalitis (BBE), and the ophthalmoplegic variant of Guillain–Barré syndrome (GBS-O) under a post-infectious immune mechanism centered on IgG to disialosyl gangliosides. The spectrum also encompasses triad-minus phenotypes—acute ophthalmoparesis without ataxia, acute vestibular syndrome, optic involvement, and acute sensory-ataxic neuropathy. A molecular-mimicry model with complement-mediated nodal/paranodal dysfunction explains severe early deficits despite bland limb nerve conduction studies (NCSs), the cranial/proprioceptive predilection, and generally favorable treatment responsiveness to immunotherapy. In practice, a serology-first strategy, complemented by targeted electrophysiology—blink and H-reflex testing, and, where feasible, paired SEP–ABR showing a literature-supported dissociation (normal ABR with impaired median-nerve cortical SEPs), which, in our series, was documented in one illustrative BBE case—and by structured neuro-otologic examination, mitigates the “normal-NCS trap” and enables timely treatment. Intravenous immunoglobulin (IVIg) is first-line; plasma exchange (PLEX) is an alternative in severe or IVIg-ineligible cases; and intravenous methylprednisolone (IVMP) may be added selectively for central/optic-weighted phenotypes without routine oral taper. We consolidate actionable diagnostic and therapeutic steps and examine them in an institutional series of 16 consecutive seropositive patients (2015–2025): all were anti-GQ1b-positive with frequent GT1a co-reactivity; most reported an antecedent infection—typically upper respiratory, less often gastrointestinal—within the two weeks before onset; limb NCSs were often nondiagnostic whereas reflex/evoked-potential studies were informative; two required intubation in addition to IVIg; outcomes were generally favorable with early immunotherapy. The practical message: order anti-GQ1b at first contact, pair targeted electrophysiology with neuro-otology, and treat early to exploit reversible nodal/paranodal dysfunction. Full article

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

This study investigates the glycosylation patterns of serum IgG antibodies in relation to COVID-19 infection and vaccination, highlighting the potential of specific glycan profiles as biomarkers for immune responses. Using Spearman correlation analysis, distinct associations among glycan levels and various clinical laboratory parameters were identified, revealing complex, non-linear interactions that influence immune dynamics. Significant differences were observed in sialylated glycan profiles across patient groups, indicating that vaccination and natural infection elicit unique immune mechanisms and suggesting that vaccination induces favorable glycosylation changes. Notably, high-mannose glycans were found to correlate with other glycan types, underscoring their critical role in the immune response and suggesting their potential as biomarkers to differentiate between infection- and vaccination-induced immunity. The findings suggest that understanding these glycosylation dynamics may enhance diagnostic and therapeutic strategies, providing valuable tools for differentiating between immune responses elicited by infection and vaccination. Overall, this study contributes to the understanding of glycosylation’s impact on immune function in the context of COVID-19, emphasizing the importance of specific glycan markers, such as sialylated and high-mannose structures, in clinical applications. Full article

Background: We report an uncommon presentation of Lyme disease and highlight the importance of a detailed history in a patient with new-onset sixth nerve palsy. Methods: Case report and literature review. Results: A 46-year-old man receiving infliximab presented to the ophthalmology emergency department with horizontal binocular diplopia. History revealed a diffuse headache that had begun three weeks earlier. Ophthalmologic examination demonstrated a left sixth cranial nerve palsy. The workup showed positive Borrelia serum IgG, which was interpreted as a likely false-positive result given the limited specificity of serologic testing. At follow-up, the patient reported left-sided peripheral facial palsy, and worsening headache and diplopia. Further history revealed prior erythema migrans treated with doxycycline four months earlier. Considering these new findings, a lumbar puncture was performed and demonstrated intrathecal production of Borrelia antibodies. Neuroborreliosis, a neurologic involvement secondary to systemic infection by the spirochete Borrelia burgdorferi, was diagnosed. The patient was treated with oral doxycycline for 28 days with complete resolution of symptoms. Conclusions: Lyme disease may present with progressive neuro-ophthalmologic symptoms, underscoring the crucial role of ophthalmologists in its diagnosis. Moreover, immunosuppression may delay diagnosis and allow neurological progression, highlighting the need for careful history taking and close follow-up. Full article

The landscape of first-line treatment for metastatic non-small cell lung cancer (NSCLC) without actionable driver mutations is rapidly evolving, currently dominated by pembrolizumab-based regimens. This review discusses the unique molecular characteristics of cemiplimab, a newer anti-PD-1 antibody, and defines its optimal positioning against established standards. Cemiplimab is a fully human IgG4 monoclonal antibody distinguished by two key features: an engineered hinge-region mutation that prevents Fab-arm exchange, ensuring exceptional molecular stability which minimizes anti-drug antibody (ADA) risks associated with unstable molecules; and a unique interaction with PD-1 glycosylation sites, potentially enhancing binding efficacy. These structural advantages may be particularly relevant in histologies like squamous NSCLC, where accumulating somatic mutations drive high neoantigen loads and heightened immune responses, creating an environment historically prone to ADA formation. Based on data from the pivotal EMPOWER-Lung program, we highlight cemiplimab’s exceptional promise in specific populations. Firstly, in the EMPOWER-Lung 1 trial, cemiplimab monotherapy demonstrated extraordinary survival benefits in a pre-specified analysis of the distinct “ultra-high” PD-L1 expression subgroup (TPS ≥90%), potentially surpassing historical benchmarks. Secondly, cemiplimab displays consistent, robust efficacy in challenging-to-treat squamous histology, both as monotherapy for patients with high PD-L1 expression and in combination with chemotherapy for patients with PD-L1 < 50%. In conclusion, cemiplimab establishes a unique therapeutic niche for patients with squamous histology and ultra-high PD-L1 expression, likely driven by its distinct structural stability and reduced immunogenicity. Full article

A huge amount of waste is produced annually by the food processing industry which must be valorized into high-value products. Therefore, the aim of this work involves the use of such wastes for production of β-glucans from medicinal basidiomycete strains which are powerful biological response modifiers in several clinical disorders. The production of β-glucans from basidiomycete strains in submerged fermentation was monitored by using monoclonal antibodies of the IgG and IgM classes as well as by Congo red assay in the presence of several agro-industrial waste products such as milk permeate, waste coffee grounds, orange peels and rice husks. Subsequently, these β-glucans were purified by using gel filtration and ion-exchange chromatography. FTIR analysis of several β-glucans was carried out to investigate their structural properties. The adsorption of β-glucans on microtiter plates was dependent on the temperature as well as on the time period of immobilization for ELISA. These mAbs can be used in a competitive ELISA for detection and quantification of β-glucans from basidiomycete mushrooms. Full article

A key function of naturally occurring antibodies is to control pathologically altered cells, such as those with aberrant glycosylation. Age-related diminution in the pool of B cells producing these immunoglobulins is linked to impaired anti-tumor immunity. In this study, the levels of antibodies against tumor-associated carbohydrate antigens (TACAs)—common in gastric cancer (GC) and other malignancies—were analyzed in 235 treatment-naïve GC patients (stages I–IV) and 76 healthy donors using a printed glycan array (PGA). We found that anti-glycan IgM levels, but not IgG, reduced with age in both patients and donors. Crucially, IgM levels against most glycans were significantly lower in the GC cohort compared with healthy donors, a trend that remained after age adjustment. Furthermore, an immunohistochemical analysis revealed that human anti-GalNAcα (Tn) antibodies—a well-characterized TACA in gastrointestinal cancers—bound to tumor cells and exhibited perinuclear and membrane staining in non-tumor surface cells within the same organ. These data support the hypothesis that gastric cancer patients have reduced levels of anti-glycan IgMs, which are responsible for the early recognition of transformed cells. This specific immunodeficiency may contribute to a permissive environment for tumor development. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with uncertain etiology. Chronic viral infection, including Epstein–Barr virus (EBV), has been implicated as a potential driver of repetitive epithelial injury and dysregulated repair. We sought to evaluate and define the breadth versus specificity of EBV-directed humoral immunity in IPF. We performed proteome-scale serological profiling using an EBV protein microarray (202 proteins) representing all proteins expressed by the EBV proteome (type I and II) on plasma samples from 32 patients with confirmed IPF (87.5% male; mean age 60.9 years) and 15 healthy disease-free controls (40% male; mean age 57.9 years). Per-sample global EBV IgG means were higher in IPF than controls (Welch p = 0.005), and the difference persisted after sex adjustment (p = 0.012). Although no single antigen met a stringent FDR significance threshold, 10 EBV antigen-specific antibody responses showed nominal elevation in IPF, with 2 remaining nominally significant after sex adjustment and 5 additional antibody responses reaching significance only in linear regression models. Overall, these results support the concept that IPF is associated with a diffuse elevation of EBV-directed humoral responses rather than antigen-specific dominance, consistent with ongoing, low-level viral reactivation. The presence of an EBV-negative subgroup within the IPF cohort underscores etiological heterogeneity within IPF. Full article

Background: Feto-maternal hemorrhages (FMHs) due to placenta disruption and bleeding from fetal maternal circulation can lead to life-threatening fetal anemia. These hemorrhages are more often of small volume and remain unreported. Sensitization to fetal red blood cell (RBC) antigens can occur during pregnancy, at delivery, or after invasive procedures. The sensitized mother produces IgG antibodies (abs) that cross the placenta and cause the hemolysis of fetal RBCs, release of hemoglobin, and increased levels of unconjugated bilirubin in the fetus or neonate. The result is hemolytic disease of the fetus and newborn (HDFN). Methods: In this study, we aim to provide a structured overview of RBC alloimmunization in pregnancy. A literature search was conducted using PubMed. English articles published from January 2010 to October 2025 were selected by the authors. The contributing manuscripts focused on managing RBC alloimmunization in pregnancy, FMH screening and quantification, antenatal and postnatal testing, Rh immune globulin (Rh Ig or Anti-D) prophylaxis, and national registry data. Results: Frequencies of RBC abs vary among American, Caucasian, and Asian populations because of genetic diversity, different antibody detection and antibody identification methods, and FMH tests. More specifically, the erythrocyte rosette is a simple screening test for FMH. A positive rosette must be quantified by the Kleihauer–Betke (KB) or flow cytometry (FC). The KB results may be overestimated or underestimated. The advantages of FC include high accuracy, specificity, and repeatability. Ultimately, anti-D prophylaxis protocol varies from country to country. Conclusion: Maternal alloimmunization is an uncommon and highly variable event. Although introducing anti-D prophylaxis has decreased the Rh immunization rate, it is still an unmet medical need. In brief, mitigation strategies for RBC alloimmunization risk include accurate maternal and neonatal testing at different time points, adequate Rh immune globulin prophylaxis in D-negative pregnant women, preventing sensitizing events, adopting a conservative transfusion policy, and upfront ABO and Rh (C/c, E/e) and Kell matching in females under 50 years of age. Full article