Search Results (69)

Background/Objectives: Messenger RNA (mRNA) vaccine technology has shown great potential in the prevention of infectious diseases and treatment of cancers, but its full potential is limited by non-specific delivery mediated by the current lipid nanoparticle (LNP) platform. Methods: Here, we developed a dendritic cell (DC)-targeting LNP incorporated with an ultra-high-affinity CLEC9A-specific nanobody that facilitates enhanced DC uptake but reduced liver accumulation. We assessed the therapeutic efficacy of nanobody-functionalized lipid nanoparticles (Nb-LNPs) in a mouse Lewis lung carcinoma (LLC) model, alongside an evaluation of T cell-mediated immune responses and dendritic cell activation, facilitated by the delivery of mRNA-based neoantigen vaccines. Results: Compared with the use of an unfunctionalized LNP, personalized mRNA cancer vaccines encapsulated with this Nb-LNP demonstrated not only superior anti-tumor effects but also a favorable bio-safety profile in a mouse Lewis lung carcinoma model. The mRNA Nb-LNP neoantigen vaccines also induced substantially higher levels of DC maturation and more potent antigen-specific T cell responses, in particular CD4⁺ T cell responses, which are critical for initiation of anti-tumor immunity and immune memory. Conclusions: Taken together, these results suggest that precision-engineered LNPs conjugated with a CLEC9A-specific antibody or nanobody could be a promising platform for delivering mRNA vaccines specifically to dendritic cells, improving their prophylactic or therapeutic effects. Full article

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, largely due to late-stage diagnosis and limited therapeutic efficacy. The carbohydrate antigen 19-9 (CA19-9) is the most widely used serum biomarker in the management of PDAC. While CA19-9 has significant limitations as a screening or diagnostic tool, including low sensitivity for early-stage disease and a lack of expression in the Lewis antigen-negative population, its value in the post-diagnostic setting is well established. This review examines the production and clearance dynamics of CA19-9. It critically evaluates how these factors impact its role as a biomarker for prognosis, assessment of resectability, and real-time monitoring of therapeutic response and recurrence in patients with PDAC. We explore how the relatively short half-life and correlation with tumor burden make CA19-9 a dynamic tool for tracking disease progression and treatment efficacy, often providing insights that precede radiographic changes. This review concludes that, despite its limitations, CA19-9 remains an important, cost-effective, and widely accessible biomarker for the longitudinal management of patients with established pancreatic cancer. Its dynamic changes allow continuous real-time disease monitoring providing critical information for clinical decision-making. Full article

Background: Pancreatic cancer (PC) is one of the cancers with poor prognosis. Although carbohydrate antigen (CA) 19-9 is currently the most specific and sensitive biomarker for the diagnosis of PC and, therefore, the most frequently used, approximately 34% of PC patients may have a Lewis antigen-negative phenotype and secrete little, if any, CA19-9. Therefore, effective alternative diagnostic methods for PC is required. Methods: In this study, we examined whether differentially expressed proteins in the blood of PC patients could be identified by global shotgun proteomics analysis using an in vitro cell line sample. Results: We identified 142 candidate proteins with differential expression in PC cells. A semiquantitative method and bioinformatic analysis led to a total of 14 candidate proteins that could potentially be detected in blood. Validation studies revealed that the expression of fibulin-1 was lower in PC cells than in normal pancreatic ductal cells. Moreover, in vivo fibulin-1 expression was significantly lower in serum from PC patients than in healthy individuals. Conclusions: These findings suggest that lower serum levels of fibulin-1 may be a novel biomarker for the detection of PC. Full article

Post-translational modifications (PTMs) are critically important for protein structure and function, with glycosylation being one of the most common forms of PTM. The gastric pathogen Helicobacter pylori has a general glycosylation system, which performs complex glycosylation of lipopolysaccharide, flagella proteins, and outer membrane proteins (OMPs). One of the best-described OMPs of H. pylori is the blood group binding adhesin (BabA), which interacts with the Lewis histo-blood group antigen, Lewis b. The 3D structure for BabA has been determined, and the ligand specifically described. Although BabA is reported to be a glycoprotein, there are limited data examining the effects of glycosylation on the structure and function of this protein. This study examined the folding and thermostability of non-glycosylated recombinant BabA and used computational approaches to predict the effect of glycosylation on the protein, with a focus on its possible heterologous expression in mammalian cells. Three potential O-linked and three potential N-linked glycosylation sites were predicted. Furthermore, the effect of glycan shielding on the solvent-accessible surface area of BabA was examined. Molecular dynamics simulations highlighted local indicators, including root mean square fluctuation and the number of protein-glycan contacts that were affected by glycosylation. Taken together, the findings support a role of glycans in surface shielding and promoting local stabilization in specific areas of the BabA protein. This study helps to strengthen the understanding of the importance of glycosylation and the role it plays in the structure, function, and stability of H. pylori proteins. Full article

Background: The biosynthesis of Lewis (Le) antigens depends on the FUT3 gene, encoding an α(1,3/4)-fucosyltransferase. Individuals lacking functional FUT3 exhibit a Le(a–b–) phenotype, regardless of secretor status. Methods: This study determined the prevalence of FUT3 single nucleotide variants (SNVs) in Thai blood donors and characterised genotype and allele distributions. We also examined the association between FUT3 variants and the presence of Le antibodies to better understand variability in immune responses. A total of 112 blood donors were recruited, comprising 52 non-responders and 60 responders for Le antibody detection. The FUT3 coding sequence was amplified by polymerase chain reaction and directly sequenced to identify single nucleotide variants (SNVs) and haplotypes. Results: Associations between FUT3 SNVs, haplotypes, and Le antibody responsiveness were subsequently analysed. Thirteen FUT3 SNVs were identified, with c.59T>G (rs28362459) present in all Le(a–b–) cases. The FUT3*01N.17.03 (le^59,1067) haplotype was most common (0.634) and showed the strongest association with Le antibody responsiveness (adjusted OR = 3.052, 95% CI: 1.683–5.534, p < 0.0001). Differences in antibody types, isotypes, and the FUT3*01N.17.03 genotype between groups were not statistically significant. Conclusions: This first study characterises FUT3 variations in Le(a–b–) Thai blood donors and identifies FUT3*01N.17.03 as associated with Le antibody responsiveness, highlighting its relevance for population-specific genetic diagnostics in transfusion medicine. Full article

Glycans on the surface of all immune cells are the product of diverse post-translational modifications (glycosylation) that affect almost all proteins and possess enormous structural heterogeneity. Their bioinformational content is decoded by glycan-binding proteins (lectins, GBPs), such as C-type lectins, including selectins, galectins, and Siglecs. Glycans located on the surface of immune cells are involved in many immunological processes through interactions with GBPs. Lectins recognize changes in the glycan epitopes; distinguish among host (self), microbial (non-self), and tumor (modified self) antigens; and consequently regulate immune responses. Understanding GBP–glycan interactions accelerates the development of glycan-targeted therapeutics in severe diseases, including inflammatory and autoimmune diseases and cancer. This review will discuss N- and O-glycosylations and glycosyltransferases involved in the biosynthesis of carbohydrate epitopes and address how interactions between glycan epitopes and GBPs are crucial in immune responses. The pivotal role of the glycan antigen tetrasaccharide sialyl Lewis x in mediating immune and tumor cell trafficking into the extravascular site will be discussed. Next, the role of glycans in modulating bacterial, fungal, viral, and parasitic infections and cancer will be surveyed. Finally, the role of glycosylation in antibodies and carbohydrate vaccines will be analyzed. Full article

Group A rotavirus continues to be a leading global etiological agent of severe gastroenteritis in young children under 5 years of age. The replication of this virus in the host is associated with the occurrence of Lewis antigens and the secretor condition. Moreover, histo-blood group antigens (HBGAs) act as attachment factors to the outer viral protein of VP4 for rotavirus. Therefore, in this study, we employed a metabolomic approach to reveal potential signature metabolic molecules and metabolic pathways specific to rotavirus P[8] strain infection (VP4 genotype), which is associated with the expression of HBGA combined secretor and Lewis (Le) phenotypes, specifically secretor/Le^(a+b+). Further integration of the achieved metabolomics results with lipidomic and proteomics metadata analyses was performed. Saliva samples were collected from children diagnosed as negative or positive for rotavirus P[8] strain infection (VP4 genotype), which is associated with the HBGA combined secretor/Le^(a+b+). A total of 22 signature metabolic molecules that were downregulated include butyrate, putrescine, lactic acid, and 7 analytes. The upregulated metabolic molecule was 2,3-Butanediol. Significant pathway alterations were also specifically observed in various metabolism processes, including galactose and butanoate metabolisms. Butyrate played a significant role in viral infection and was revealed to exhibit different reactions with glycerolipids, glycerophospholipids, sphingolipids, sterol lipids, and fatty acyls. Moreover, butyrate might interact with protein receptors of free fatty acid receptor 2 (FFAR2) and free fatty acid receptor 3 (FFAR3). The revealed metabolic pathways and molecule might provide fundamental insight into the status of rotavirus P[8] strain infection for monitoring its effects on humans. Full article

Background: Mucin-1 (MUC1) is a glycoprotein that is hypoglycosylated and overexpressed in most adenocarcinomas, making it a promising target for cancer vaccines. Our group previously demonstrated that C3 (OPSS)-liposomes enhance antigen uptake by antigen-presenting cells (APCs) via the complement C3 pathway and, when combined with toll-like receptor (TLR) agonists, reduce tumor growth in murine cancer models. Methods: In the present study, we evaluate the immunogenicity of MUC1 peptide vaccines encapsulated in C3-liposomes, with and without TLR agonists, using MUC1-tolerant transgenic mice challenged with Lewis lung carcinoma (LLC.MUC1) cells. To assess vaccine effectiveness, tumor volumes were measured, and flow cytometry and ELISA and ELISPOT assays were used to assess the immune response. Results: Both male and female C57BL/6 transgenic mice vaccinated with MUC1 C3-liposomes developed significantly smaller tumors than those vaccinated with free MUC1 peptide or PBS. Notably, a sex-dependent response emerged in mice vaccinated with MUC1 C3-liposomes with TLR agonists (TLR4, TLR7/8, and TLR9); male mice exhibited greater tumor suppression than females. Flow cytometry analysis revealed that female mice had significantly higher levels of CD11b⁺, LY6C⁺, and LY6G⁺ MDSC cells, suggesting a potential mechanism for the sex difference. Additionally, MUC1 C3-liposome vaccination elicited robust adaptive immune responses, including significantly higher levels of IFN-γ-producing T cells and MUC1-specific IgG antibodies compared to non-encapsulated MUC1 or TLR adjuvant-only formulations. Conclusions: These findings underscore the potential of C3-liposome-based antigen vaccines to enhance anti-tumor immunity and highlight the impact of sex differences in vaccine efficacy. Full article

Galectins are β-galactoside-binding animal lectins involved in various biological functions, such as host defense. Galectin-2 and -3 are members of the galectin family that are expressed in the stomach, including the gastric mucosa and surface mucous cells. Galectin-3 exhibits aggregation and bactericidal activity against Helicobacter pylori in a β-galactoside-dependent manner. We previously reported that galectin-2 has the same activity under neutral pH conditions. In this study, the H. pylori aggregation activity of galectin-2 was examined under weakly acidic conditions, in which H. pylori survived. Galectin-2 agglutinated H. pylori even at pH 6.0, but not at pH 5.0, correlating with its structural stability, as determined using circular dichroism. Additionally, galectin-2 binding to the lipopolysaccharide (LPS) of H. pylori cultured under weakly acidic conditions was investigated using affinity chromatography and Western blotting. Galectin-2 could bind to H. pylori LPS containing H type I, a Lewis antigen, in a β-galactoside-dependent manner. In contrast, galectin-3 was structurally more stable than galectin-2 under acidic conditions and bound to H. pylori LPS containing H type I and Lewis X. In conclusion, galectin-2 and -3 might function cooperatively in the defense against H. pylori in the stomach under different pH conditions. Full article

Oligodeoxynucleotides (ODNs) containing unmethylated cytosine–phosphate–guanosine (CpG) motifs are readily recognized by Toll-like receptor 9 on immune cells, trigger an immunomodulatory cascade, induce a Th1 -biased immune milieu, and have great potential as an adjuvant in cancer vaccines. In this study, a green one-step synthesis process was adopted to prepare an amino-rich metal–organic nanoplatform (FN). The synthesized FN nanoplatform can simultaneously and effectively load model tumor antigens (OVA)/autologous tumor antigens (dLLC) and immunostimulatory CpG ODNs with an unmodified PD backbone and a guanine quadruplex structure to obtain various cancer vaccines. The FN nanoplatform and immunostimulatory CpG ODNs generate synergistic effects to enhance the immunogenicity of different antigens and inhibit the growth of established and distant tumors in both the murine E.G7-OVA lymphoma model and the murine Lewis lung carcinoma model. In the E.G7-OVA lymphoma model, vaccination efficiently increases the CD4⁺, CD8⁺, and tetramer⁺CD8⁺ T cell populations in the spleens. In the Lewis lung carcinoma model, vaccination efficiently increases the CD3⁺CD4⁺ and CD3⁺CD8⁺ T cell populations in the spleens and CD3⁺CD8⁺, CD3⁻CD8⁺, and CD11b⁺CD80⁺ cell populations in the tumors, suggesting the alteration of tumor microenvironments from cold to hot tumors. Full article

Cancer vaccines have emerged as a potent strategy to improve cancer immunity, with or without the combination of checkpoint blockade. In our investigation, liposomal formulations containing synthetic long peptides and α-Galactosylceramide, along with a DC-SIGN-targeting ligand, Lewis Y (Le^Y), were studied for their anti-tumor potential. The formulated liposomes boosted with anti-CD40 adjuvant demonstrated robust invariant natural killer (iNKT), CD4⁺, and CD8⁺ T-cell activation in vivo. The incorporation of Le^Y facilitated the targeting of antigen-presenting cells expressing DC-SIGN in vitro and in vivo. Surprisingly, mice vaccinated with Le^Y-modified liposomes exhibited comparable tumor reduction and survival rates to those treated with untargeted counterparts despite a decrease in antigen-specific CD8⁺ T-cell responses. These results suggest that impaired induction of antigen-specific CD8⁺ T-cells via DC-SIGN targeting does not compromise anti-tumor potential, hinting at alternative immune activation routes beyond CD8⁺ T-cell activation. Full article

The ABO blood groups, Lewis antigens, and secretor systems are important components of transfusion medicine. These interconnected systems have been also shown to be associated with differing susceptibility to bacterial and viral infections, likely as the result of selection over the course of evolution and the constant tug of war between humans and infectious microbes. This comprehensive narrative review aimed to explore the literature and to present the current state of knowledge on reported associations of the ABO, Lewis, and secretor blood groups with SARS-CoV-2 infection and COVID-19 severity. Our main finding was that the A blood group may be associated with increased susceptibility to SARS-CoV-2 infection, and possibly also with increased disease severity and overall mortality. The proposed pathophysiological pathways explaining this potential association include antibody-mediated mechanisms and increased thrombotic risk amongst blood group A individuals, in addition to altered inflammatory cytokine expression profiles. Preliminary evidence does not support the association between ABO blood groups and COVID-19 vaccine response, or the risk of developing long COVID. Even though the emergency state of the pandemic is over, further research is needed especially in this area since tens of millions of people worldwide suffer from lingering COVID-19 symptoms. Full article

Background: CA 19-9 is a commonly assessed tumor marker, considered characteristic of pancreatic ductal adenocarcinoma (PDAC) and biliary tract cancers; however, the positive predictive value of CA 19.9 is too low, and the usage of CA 19.9 as a screening tool in the healthy population remains controversial. Methods: The presented case illustrates a reversed diagnosis of highly elevated serum CA 19-9 levels in a 54-year-old female complaining of pain in the epigastric region, shortly after COVID-19 vaccination. Laboratory tests showed a significantly elevated level of the CA 19-9 marker (>12,000 U/mL, reference value: <37 U/mL) with normal pancreatic enzyme activity. The patient underwent imaging examination, which showed no abnormalities, except for increased pancreatic dimension and areas of fluid signal in the pancreas in magnetic resonance imaging (MRI), which may correspond to autoimmune pancreatitis (AIP). The patient remains asymptomatic with a recommendation for a follow-up MRI in 12 months. Results: A literature review conducted revealed multi-causal CA 19-9 increases above 1000 U/mL, including non-cancerous diseases of the lung, pancreas, liver, ovary, kidney, and others. The median concentration of CA 19-9 regardless of the cause of disease was 2810 U/mL (IQR ± 6895). The median CA 19-9 values in men and women were 3500 (IQR ± 10,050) and 2455 (IQR ± 3927), respectively, and differ significantly between the compared groups (p < 0.05). There was no difference between CA 19-9 values and the categorized cause of the increase. Conclusions: Conducting differential diagnosis, it should not be forgotten that most international guidelines recommend the use of CA 19-9 only in conjunction with pathology of pancreas in radiological imaging; however, even such a combination can point the diagnostic pathway in the wrong direction. A highly elevated CA 19-9 level, typically associated with PDAC, may be the result of benign disease including AIP related to COVID-19 vaccination. Full article

Semen prostatic acid phosphatase (PAP) has been proposed as an endogenous ligand for dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN), which plays a critical immuno-modulating role in maintaining homeostasis in the female reproductive tracts. In the current study, we assumed that semen PAP bears a set of fucosylated and mannosylated glycans, which may mediate the efficient binding of PAP to DC-SIGN. To investigate this hypothesis, we developed ELISA assays using Galanthus nivalis and Lotus tetragonolobus lectins capable of binding mannose-containing glycans or LewisX and LewisY motifs, respectively. In our assay with Galanthus nivalis, we detected that the relative reactivity of PAP mannose-presenting glycans in the normozoospermic idiopathic group was significantly higher than in the asthenozoospermic, oligozoospermic and oligoasthenozoospermic groups. Simultaneously, we observed slight differences in the relative reactivities of PAP glycans with Lotus tetragonolobus lectin among groups of patients with abnormal semen parameters. Subsequently, we examined whether DC-SIGN interacts with seminal plasma PAP glycans, and we detected a significantly higher relative reactivity in the normozoospermic group compared to the oligozoospermic group. Finally, we concluded that the significantly aberrant abundance of mannosylated functional groups of PAP among patients with semen disorders can suggest that PAP may thereby be engaged in modulating the immune response and promoting a tolerogenic response to male antigens in the female reproductive system. Full article

Live-attenuated, oral rotavirus vaccines have significantly reduced rotavirus-associated diarrhoea morbidity and infant mortality. However, vaccine immunogenicity is diminished in low-income countries. We investigated whether maternal and infant intrinsic susceptibility to rotavirus infection via histo-blood group antigen (HBGA) profiles influenced rotavirus (ROTARIX^®) vaccine-induced responses in Zambia. We studied 135 mother–infant pairs under a rotavirus vaccine clinical trial, with infants aged 6 to 12 weeks at pre-vaccination up to 12 months old. We determined maternal and infant ABO/H, Lewis, and secretor HBGA phenotypes, and infant FUT2 HBGA genotypes. Vaccine immunogenicity was measured as anti-rotavirus IgA antibody titres. Overall, 34 (31.3%) children were seroconverted at 14 weeks, and no statistically significant difference in seroconversion was observed across the various HBGA profiles in early infant life. We also observed a statistically significant difference in rotavirus-IgA titres across infant HBGA profiles at 12 months, though no statistically significant difference was observed between the study arms. There was no association between maternal HBGA profiles and infant vaccine immunogenicity. Overall, infant HBGAs were associated with RV vaccine immunogenicity at 12 months as opposed to in early infant life. Further investigation into the low efficacy of ROTARIX^® and appropriate intervention is key to unlocking the full vaccine benefits for U5 children. Full article