Search Results (25,855)

Antimicrobial peptides (AMPs) have re-emerged as promising anti-infective agents, particularly against multidrug-resistant bacteria; however, their therapeutic development remains constrained by proteolytic degradation, host cell toxicity, and rapid systemic clearance. Rather than focusing solely on sequence discovery, recent efforts have shifted toward structural and supramolecular modification strategies aimed at improving stability, selectivity, and pharmacological performance. This review critically analyzes intramolecular modifications—including phosphorylation, glycosylation, acetylation, methylation, and backbone cyclization—that modulate peptide conformation and resistance to enzymatic degradation. In parallel, extramolecular approaches such as PEGylation, lipidation, and conjugation to antibiotics, siderophores, or antibodies are examined in the context of enhanced targeting and prolonged bioavailability. Particular emphasis is placed on localized delivery systems, including hydrogels, polymeric films, and nanofibrous scaffolds, which enable spatially controlled administration and mitigate systemic exposure. By integrating evidence from ex vivo and in vivo infection models, this work delineates the translational potential and remaining bottlenecks of chemically engineered AMP platforms for skin and soft tissue infections. Full article

Traditional cancer therapies such as surgery, chemotherapy, and antibody-based treatments often face significant barriers, including systemic toxicity, a lack of selectivity, and the emergence of drug resistance. These issues demand innovative and targeted solutions. Peptide-based therapeutics have gained prominence for their ability to disrupt cancer pathways and facilitate targeted drug delivery, offering structural flexibility, precise targeting, and low immunogenicity with minimal effects on healthy tissues. Concurrently, aptamers, which are structured nucleic acid molecules capable of high-affinity molecular recognition, are being developed as both direct therapeutic agents and as targeting ligands for the improved delivery of anticancer drugs. Combining peptide and aptamer technologies with engineered exosomes provides a modular drug delivery system that enhances targeting specificity, stability, and the ability to cross complex biological barriers such as the blood–brain barrier. The emergence of peptide-decorated, aptamer-decorated exosomes represents a new frontier in precision oncology, promising highly selective, biocompatible, and tunable cancer therapies. Further advances are required to overcome challenges in pharmacokinetics, scalable production, and regulatory compliance, but ongoing bioengineering and nanotechnology research continues to accelerate the translation of these innovative strategies toward improved cancer diagnostics and treatment outcomes. This review discusses the synergistic integration of peptides and aptamers with exosome-based delivery systems, highlighting their current applications and future possibilities. Full article

Inborn errors of immunity (IEIs) encompass a heterogeneous group of more than 550 genetic conditions with variable ages of onset. A significant proportion of IEI arises from genetic variants that may not yet be fully elucidated or recorded in existing genomic databases. Molecular diagnoses are achieved in approximately 15–35% of IEI cases, yet in only 9–20% of individuals with predominant antibody deficiencies, particularly in adult cohorts. We aimed to evaluate whole genome sequencing (WGS) diagnostic yield in adults suspected to have IEI. Clinical assessments of the patients were carried out at tertiary medical institutions in Timisoara and Bucharest, Romania. The study cohort included a consecutive series of 21 adult patients (aged 19–60 years) with IEI phenotype, who underwent genetic analysis, using WGS as the first diagnostic approach. A definitive molecular diagnosis was confirmed in only 9.5% (2/21) of the participants, in LRBA and BTK genes. Variants of uncertain significance (VUS) were detected in three patients (13.6%) in TNFRSF13B, COPA, GATA2 genes. For about half of the cohort the onset of the disease was noted in childhood. WGS as a first-line diagnostic strategy in a cohort of adults with IEI yielded a low diagnostic rate. There were significant delays in genetic diagnosis, as half of the cohort experienced childhood-onset symptoms. Results suggest that adult IEI diagnosis remains challenging, necessitating functional studies and longitudinal re-evaluation of genomic data. Full article

Gestational diabetes mellitus (GDM) is a prevalent metabolic disorder associated with adverse maternal and fetal outcomes. However, current diagnostic strategies have a limited capacity to identify women at risk early in pregnancy. In this longitudinal prospective pilot study, 200 pregnant Mexican women were recruited at 11–14 weeks and underwent follow-up throughout pregnancy. Of these, 34 women (19 with GDM and 15 with normal glucose tolerance [NGT]) completed follow-up and were included in the final analyses. Most withdrawals were due to logistical constraints, although the reduced final sample size should be considered when interpreting generalizability. Nine serum proteins (ADIPOQ, AFM, FABP4, IGFBP-5, PAPP-A, PAPP-A2, RBP4, RETN, SHBG) were measured simultaneously using an antibody array and subsequently validated by ELISA. FABP4 showed the greatest increase in the first trimester (4.9-fold, p = 0.0105) and the highest apparent discriminative performance (AUC = 0.91), which declined in the second and third trimesters. Exploratory, hypothesis-generating multivariable analyses suggested a stronger association when FABP4 was combined with gravidity and serum triglycerides (AUC up to 0.97). Overall, FABP4 emerged as a promising candidate biomarker for early GDM detection in Mexican women; however, these findings are preliminary and require validation in larger, independent cohorts to support early risk stratification. Full article

Background and Objectives: Metaplastic breast carcinoma (MBC) is a rare, aggressive malignancy that is often resistant to conventional chemotherapy and characterized by a triple-negative phenotype. While immune checkpoint inhibition shows promise, the prognostic significance and distribution of programmed death-ligand 1 (PD-L1) expression within the heterogeneous architecture of MBC remain poorly understood. This study aimed to evaluate PD-L1 expression and the density of tumor-infiltrating lymphocytes (TILs) to clarify their roles in patient stratification and overall survival (OS). Materials and Methods: We retrospectively analyzed 48 MBC cases diagnosed between 2010 and 2025. PD-L1 expression was quantified using the Combined Positive Score (CPS) with the 22C3 antibody clone across diverse histological components. The density of stromal TIL density was assessed following internationally standardized guidelines. Clinical outcomes and clinicopathological parameters, including metastasis, lymphovascular invasion (LVI), and histological subtype, were correlated with biomarker status using Kaplan–Meier survival analysis and Cox proportional hazards regression models. Results: PD-L1 positivity (CPS ≥1) was identified in 72.9% of cases, one of the highest rates documented in literature. Notably, an inverse relationship was observed with PD-L1-negative tumors, which exhibited significantly higher rates of distant metastasis (46.2% vs. 17.1%; p = 0.039). Multivariate analysis confirmed that low density of TILs (HR = 9.66; p = 0.016), metastasis (HR = 4.40; p = 0.023), and the presence of LVI (HR = 3.84; p = 0.047) were strong independent predictors of mortality. While PD-L1 status alone did not directly dictate overall survival, mean overall survival was markedly reduced in the low TILs cohort (32.2 months) compared to the high TILs group (114.2 months). Conclusions: The high prevalence of PD-L1 expression supports routine screening for immunotherapy eligibility in MBC. Our findings suggest that PD-L1-negative cases represent a high-risk biological subset driven by alternative immune evasion mechanisms. Integrating TIL density with conventional pathological parameters provides a more robust prognostic framework, enabling personalized therapeutic strategies for this challenging malignancy. Full article

Physical integration between endosymbiotic algae and host mitochondria is a recurring feature across photosynthetic symbioses, yet the structural nature of this association has remained unresolved. In the ciliate Paramecium bursaria, each endosymbiotic Chlorella cell is enclosed by a perialgal vacuole (PV) membrane consistently surrounded by host mitochondria, suggesting a conserved architecture for metabolic interaction. Although transmission electron microscopy has shown close membrane apposition, it has remained unclear whether this reflects incidental proximity or a reinforced adhesion. Here, we provide direct evidence that the PV membrane and host mitochondrial membrane form a stable physical association. Using discontinuous Percoll centrifugation, we isolated intact units in which Chlorella and mitochondria co-sedimented, indicating that their association withstands mechanical disruption. By fluorescently labeling the PV and mitochondrial membranes with BODIPY FL C₅-ceramide (BC₅C), together with a mitochondria-specific monoclonal antibody and DAPI, we visualized the PV membrane under light microscopy and demonstrated that the mitochondrial–PV membrane complex persists after homogenization and centrifugation. As expected from the membrane-insertion behavior of BC₅C, this fluorescent labeling revealed that the PV–mitochondrial membrane association is structurally reinforced rather than incidental, providing a mechanistic framework for understanding how Chlorella cells are stably positioned beneath the host cortex. Full article

Background and Objectives: Alloantibodies directed against human platelet antigens and human leukocyte antigens are implicated in several immune-mediated platelet disorders, including platelet transfusion refractoriness, post-transfusion purpura and fetal and neonatal alloimmune thrombocytopenia. Reliable and simultaneous detection of these antibodies is essential for accurate diagnosis and appropriate clinical management. The aim of this study was to determine the prevalence and specificity spectrum of anti-HLA and anti-HPA alloantibodies in patients with suspected immune-mediated platelet disorders using a multiplex bead-based assay, and to evaluate its diagnostic utility in a Serbian cohort. Materials and Methods: A bead-based glycoprotein-specific antibody detection assay was performed using monoclonal antibodies specific for platelet glycoproteins and HLA class I molecules, separately coupled to Luminex microbeads. Serum samples were collected from 259 patients, including 234 patients with thrombocytopenia, 11 with neonatal alloimmune thrombocytopenia, and 14 with suspected platelet transfusion refractoriness. All samples were tested using the PakLx Luminex assay, and results were interpreted with MatchIt! Antibody software. Results: Of the 259 tested samples, 72 (27.8%) were positive for HLA and/or platelet-specific antibodies. Among the positive samples, 29.2% contained HLA class I antibodies, 45.8% contained platelet-specific antibodies, and 25% showed combined HLA and platelet antibody positivity. The most frequently detected platelet-specific antibodies were directed against GPIIb/IIIa (HPA-1, -3, -4) and GPIa/IIa (HPA-5). Conclusions: This first analysis of platelet alloantibodies in a Serbian cohort demonstrates a high prevalence of antibody positivity in patients with neonatal alloimmune thrombocytopenia and platelet transfusion refractoriness, with anti-HPA-1a as the predominant specificity. The significant association between clinical presentation and antibody profile underscores the need for targeted diagnostic testing. Multiplex bead-based technology provides comprehensive alloantibody detection, facilitating optimized transfusion management in immune-mediated platelet disorders. Full article

Intestinal infections caused by Salmonella enterica serovar Typhi (S. Typhi) remain a global health concern, making preventive strategies and diagnostic tools essential. This study aimed to identify mimotope peptides of the Vi antigen using phage display and assess their recognition by rabbit and 46 human sera, as well as their potential for diagnosis and immunogen design. Rabbits were immunized with the Vi antigen (AgVi) from S. Typhi ATCC 6539, and sera-derived IgG was used for phage biopanning. DNA sequences from selected phagotopes were synthesized as Salmonella mimotope peptides (SMPs), either linear or KLH-conjugated. Their reactivity was tested with ELISAs against AgVi and SMPs, using both rabbit sera and 46 human serum samples. Ten phagotopes were identified, with a consensus motif (D/G–A/V–x–P–x–x–G–x–x–x–x–x), suggesting α-helix structures. Immunization with KLH-conjugated peptides generated specific antibodies, particularly SMPVi/5 and SMPVi/10, which recognized AgVi and their respective peptides. Competitive inhibition assays confirmed that SMPVi/5 reduced the anti-AgVi binding in a dose-dependent manner. In human sera, AgVi recognition occurred in 52% of samples, while SMPVi/5 and SMPVi/10 were recognized in 45%. Overall, SMPVi/5 demonstrated immunogenicity and functional mimicry, supporting its use as a synthetic reagent for serological assays and as a candidate for immunogen design. Full article

Neurofilament light chain (NfL) is a promising biomarker of axonal injury across acute and chronic neurodegeneration, which can improve drug discovery and disease monitoring models. Traditional in vivo animal models cannot fully mimic human pathophysiology of neurodegenerative diseases (NDDs), but in vitro models based on human cells solve this problem, reducing the time and cost of drug testing. We developed an electrochemical immunosensor for NfL detection in cell culture media to monitor acute neuronal injury in in vitro models. The biosensor was designed in two configurations: the label-free system, which directly detects NfL in the sample via the antibody–antigen interaction, and the sandwich configuration, which incorporates two additional antibodies. Detection was examined using electrochemical techniques, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). The sensor demonstrated a detection limit of 3–9 pg mL⁻¹, and a dynamic working range spanning from 10 up to 10⁷ pg mL⁻¹. Importantly, NfL was successfully detected in physiological media collected from cultured neurons that were differentiated from the long-term human neuroepithelial-like stem cells. This discovery highlights the platform’s applicability for in vitro neurodegenerative models. The immunosensor offers a sensitive, scalable, and cost-effective alternative for neurodegeneration detection in drug testing applications. Full article

Objectives: This study aimed to investigated the role of Giardia extracellular vesicles (EVs) in intercellular communication and to evaluated their potential as vaccine candidates. Methods: The immunomodulatory effects of Giardia EVs were assessed in mouse macrophages and human monocyte-derived dendritic cells (Mo-DCs), with a particular focus on key inflammatory signaling pathways. In vivo immunogenicity was evaluated following EV administration, and the antigenic composition of EV cargo was characterized by proteomic analysis. Results: Giardia EVs activated pro-inflammatory signaling pathways in mouse macrphages, including SAPK/JNK, ERK1/2, and NF-κB. This activation was associated with IκB-α degradation and nuclear translocation of p65. Furthermore, EV stimulation significantly upregulated the expression of pro-inflammatory genes, including Il1β, Il6, Il4, Ptgs2, Nos2, and Tnf, with log₂ fold changes ranging from 3.9 to 15.8. Consistently, EVs increased iNOS protein expression (28–45%) and nitrite production (9.6–12.3-fold). In human Mo-DCs, Giardia EVs promoted cellular maturation, as evidenced by increased expression of MHC-II, CD80, and CD86, and enhanced T-cell proliferation with a Th1-skewed profile. In vivo immunization induced antigen-specific antibody responses, with IgG subclass distribution indicative of a balanced Th1/Th2 response. Proteomic analysis identified immunoreactive EV-associated proteins, including elongation factor 1-alpha, α-7.3 giardin, tubulin, and variant surface proteins (VSPs), which are well-established antigens in Giardia infection, with prominent bands observed at approximately 22 kDa and 50 kDa. Conclusions: Collectively, these findings demonstrate that Giardia EVs modulate innate immune responses in vitro, elicit antigen-specific humoral immunity in vivo, and contain conserved immunogenic proteins. These properties support their potential as a promising cell-free vaccine platform against giardiasis. Full article

Background/Objectives: Sporotrichosis is an emerging zoonotic subcutaneous fungal infection with limited therapeutic options, highlighting the need for improved immunomodulatory strategies. CTLA-4 is an inhibitory immune checkpoint that negatively regulates T-cell activation. In this study, we evaluated whether a CTLA-4 antisense oligonucleotide (CTLA-4 ASO) is associated with enhanced immune responses to an adjuvanted recombinant Sporothrix sp. enolase antigen (rSsEno) formulation. Methods: CTLA-4 ASO uptake, cytotoxicity, and gene-silencing activity were assessed in murine splenocytes in vitro. BALB/c mice were immunized with rSsEno formulated with Montanide Gel 01, either alone or in combination with 5 µg CTLA-4 ASO. Antigen-specific serum antibody responses were quantified by ELISA. Splenocytes from immunized mice were restimulated with enolase, and cytokine production (IFN-γ, IL-2, IL-17, and TNF-α) was measured using Cytometric Bead Array (CBA). Results: CTLA-4 ASO was efficiently internalized by splenocytes and was associated with reduced expression of CTLA-4 without detectable cytotoxicity in vitro. Mice receiving the ASO-supplemented formulation developed significantly higher anti-enolase antibody titers compared to those immunized with adjuvant alone. Upon antigen restimulation, splenocytes from ASO-treated mice produced higher levels of IFN-γ, IL-2, TNF-α, and IL-17, consistent with an enhanced recall response characterized by a mixed Th1/Th17 cytokine profile. Conclusions: CTLA-4 ASO was associated with an enhanced recall response characterized by a mixed Th1/Th17 cytokine profile. These findings suggest a potential immunomodulatory effect of CTLA-4 targeting. Further studies incorporating dose optimization, infection challenge models, and appropriate sequence controls are required to determine the specificity and relevance of these effects for protective immunity against sporotrichosis. Full article

Background and Aim: Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by immune dysregulation. Environmental factors, including infectious agents, have been proposed to influence disease activity in inflammatory bowel disease. Although Borrelia burgdorferi has been shown to exert complex immunomodulatory effects on host immune responses, its seroprevalence and potential association with disease activity in patients with ulcerative colitis have not been systematically investigated. This study aimed to evaluate the seroprevalence of Borrelia burgdorferi IgG antibodies in patients with ulcerative colitis and to assess the relationship between seropositivity and laboratory markers of disease activity. Methods: In this retrospective observational study, 100 patients with ulcerative colitis (59 males, 41 females; mean age 48.5 ± 17 years) who underwent Borrelia burgdorferi IgG serological testing due to musculoskeletal or neurological symptoms suggestive of possible Lyme disease between October 2020 and October 2024 were included. Demographic characteristics, hematological and biochemical parameters, and inflammatory markers were compared between seropositive and seronegative groups. Due to the retrospective design, validated clinical disease activity indices were not consistently available; therefore, disease activity was indirectly assessed using laboratory inflammatory markers. Results: Among patients with ulcerative colitis, 22% were seropositive for Borrelia burgdorferi IgG. Seropositive patients had significantly lower uric acid, alkaline phosphatase, and C-reactive protein levels compared to seronegative patients (p = 0.001, p = 0.023, and p = 0.020, respectively). Free T4 levels were significantly higher in the seropositive group (p = 0.049). In terms of erythrocyte indices, mean corpuscular volume and mean corpuscular hemoglobin were significantly higher, while RDW-CV values were significantly lower in seropositive patients (all p < 0.05). Conclusion:Borrelia burgdorferi IgG seropositivity in patients with ulcerative colitis was associated with lower laboratory markers of systemic inflammation and a more stable hematological profile. Although causality cannot be established, these findings may suggest a potential association between prior Borrelia exposure and a distinct inflammatory phenotype in UC; however, this relationship should be interpreted with caution. Further prospective and mechanistic studies are warranted to clarify the potential immunological interactions between environmental microbial exposure and inflammatory bowel disease activity. Full article

Background/Objectives: Autoimmune thyroiditis affects physical and cognitive development in children. Therefore, early detection can prevent symptoms that could lead to lifelong changes. Autoimmune thyroiditis can frequently accompany type 1 diabetes (T1DM) and celiac disease (CD). The goal in this study is to evaluate its usability as a screening method by assessing thyroid elasticity in children with negative thyroid autoantibodies and T1DM or CD. Methods: This cross-sectional, case–control, single-center study was conducted with children who had applied to the Pediatrics outpatient clinic of Kayseri City Education and Research Hospital (Turkey). The study included three groups of cases (T1DM, CD and control). The value of the shear wave elastography (SWE) color map was recorded in kPa. Comparisons between two independent groups were conducted using either Student’s t-test or the Mann–Whitney U-test, while categorical variables were analyzed with the Chi-square test. A correlation analysis was conducted to evaluate the relationship between the variables. Results: The study cohort comprised 185 children, of whom 71 had T1DM, 54 had CD, and 60 constituted the healthy control group. The participants ranged in age from 4 to 17.9 years, with a mean age of 11.4 ± 3.8 years. The gender distribution did not differ significantly between the groups. Anti-thyroid peroxidase (TPOAb) levels did not differ significantly between the groups (p = 0.894). Thyroid volume or standard deviation score did not differ significantly between the groups. Corresponding SWE values in the T1DM, CD and control groups were 7.7 (6.0–9.3), 5.9 (5.2–7.9) versus 7.1 (6.0–9.6), respectively (p = 0.002). Correlations were significantly associated between SWE scores and anti-thyroglobulin (TgAb), thyroid volume, mean hemoglobin A1c (HbA1c), and time elapsed from a diagnosis of CD. Conclusions: The SWE scores were observed to be higher in children with T1DM compared to those with CD. Full article

Background/Objectives: Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrheal illness worldwide, resulting in approximately 380,000 deaths annually, with significant morbidity in children and travelers to endemic regions. ETEC infection begins with the attachment of the bacterium to the small intestine via filamentous colonization factors (CF), followed by the production of heat-labile (LT) and heat-stable (ST) toxins that induce watery diarrhea. Targeting CF to prevent ETEC attachment is challenging due to strain heterogeneity. Methods: In previous studies, we developed a class-switched human monoclonal antibody, 68–90, expressed as secretory IgA (SIgA) in rice for cost-effective and stable storage. Rice-produced SIgA exhibited comparable binding efficiency to CfaE, a component of CF, compared to CHO-produced SIgA in vitro. Results: In this work, we showed that oral administration of 68–90 SIgA to Aotus nancymaae did not alter gut microbiome distribution or show signs of systemic exposure. Conclusions: These findings suggest that oral delivery of ETEC-specific SIgA is safe and does not disrupt the gut microbial population, highlighting its potential as an effective and targeted therapeutic strategy. Full article

Background: With the evolving paradigm of vaccine development, microcapsules have attracted considerable research interest as particulate adjuvants over the past decades. However, the rational engineering design of microcapsule-based composite adjuvant systems to elicit robust immune responses remains a significant challenge. Methods: This study developed polylactic acid (PLA) microcapsules with spatiotemporally coupled delivery and immunopotentiator properties. The resulting formulations were assessed for humoral and cellular immune responses in mice. Results: We prepared uniform-sized microcapsules (MC) and formulated them with monophosphoryl lipid A (MPLA) as a composite component (MPLA@MC), with hydrodynamic diameters of 4.58 μm and 4.12 μm, respectively. Such composite adjuvants, when loaded with ovalbumin (OVA) to form OVA@MC and OVA&MPLA@MC, promoted cellular uptake and activation, exhibiting preferred lysosomal escape advantages. For in vivo experiments, microcapsule-based vaccines elevated serum levels of IgG antibody, and OVA&MPLA@MC induced Th1-biased antibody responses. Specifically, OVA&MPLA@MC also elicited strong cellular immune responses compared to other vaccines, as evidenced by increased secretion of Interferon-γ (IFN-γ) in mouse splenocytes and Granzyme B (Gzmb) in T cells. Mechanistically, muscle tissues at the injection site showed that microcapsule-based vaccines enhanced the recruitment for phagocytosis. Meanwhile, bulk RNA sequencing (RNA-seq) confirmed extensive activation of immune responses and related signaling pathways. Conclusions: This rationally designed composite strategy for spatiotemporally coupled delivery serves as a potent platform for orchestrating synergistic immune responses, opening up new avenues for the development of effective therapeutic and anti-infectious vaccines. Full article