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Aims: Ficolin 3 (FCN3) has the highest complement-activating capacity through the lectin pathway and is synthesized mainly in the liver and lung. Yet, its potential molecular mechanism in hepatocarcinogenesis is not fully understood., Materials and Methods: The expression of FCN3 in hepatocellular carcinoma (HCC) tumor and non-tumor tissues was analyzed by RT-qPCR, Western blotting and immunofluorescence staining assays. Lentivector-mediated ectopic overexpression was performed to explore the role of FCN3 in vitro and in vivo. Whether FCN3 inhibited HCC cell growth and survival via complement pathway was determined with immunocytochemical staining for C3b, membrane attack complex (MAC) formation and complement killing assay using recombinant FCN3 (rFCN3) in combination with human serum with or without heat inactivation, and with C6 blocking antibody., Key Findings: The transcript and protein of FCN3 were found to be remarkably down-regulated in HCC tumor tissues. FCN3 expression was found to be associated with better survival of HCC patients. Restoration of FCN3 expression significantly inhibited proliferation, migration and anchorage independent growth of HCC cell lines, and xenograft tumor growth. FCN3 expression induced apoptosis of HCC cells. C3 and MAC formation was stimulated by FCN3 overexpression or rFCN3 treatment. rFCN3 enhanced human serum-induced complement activation and cell death. C6 blocking antibody significantly attenuated complement-mediated cell death and restored the growth of FCN3-overexpressing HCC cells., Significance: FCN3 has a malignant suppressor role in HCC cells. Our study provides new insights into the molecular mechanisms that drive HCC progression and potential therapeutic targets for treating HCC., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Developing countries continuously face challenges to get rid of amoebiasis, a protozoan disease caused by Entamoeba histolytica. Every year around 900 million people get affected by amoebiasis, among them only 10 % of people show the symptoms of the disease while 90 % of people do not show any symptoms but still, serve as carriers of the disease. Asymptomatic persons carry cysts of Entamoeba in their fecal matter, which is carried by house flies to contaminate the food and water. Entamoeba histolytica is a very successful pathogen because it has very well-developed virulence factors that function in infection to host as well as in overcoming the host's immune response. However, researchers have very little information about the clear relationship between virulence factors and the virulence of Entamoeba histolytica, through various research, researchers have been able to identify key pathogenic factors that are crucial to the pathogenesis of amoebiasis and have provided valuable insights into the development of the disease. The objective of this review is to underscore various virulence factors (Monosaccharides, Gal/GalNAc lectin, extracellular vesicles, cysteine proteases, amoeba-pores, and actin microfilament) involved in pathogenesis which may be helpful for designing of future drug or therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Innate immune responses such as phagocytosis are critically linked to the generation of adaptive immune responses against the neoantigens in cancer and the efferocytosis that is essential for homeostasis in diseases characterized by lung injury, inflammation, and remodeling as in chronic obstructive pulmonary disease (COPD). Chitinase 3-like-1 (CHI3L1) is induced in many cancers where it inhibits adaptive immune responses by stimulating immune checkpoint molecules (ICPs) and portends a poor prognosis. CHI3L1 is also induced in COPD where it regulates epithelial cell death. In this study, we demonstrate that pulmonary melanoma metastasis inhibits macrophage phagocytosis by stimulating the CD47-SIRPα and CD24-Siglec10 phagocytosis checkpoint pathways while inhibiting macrophage "eat me" signals from calreticulin and HMGB1. We also demonstrate that these effects on macrophage phagocytosis are associated with CHI3L1 stimulation of the SHP-1 and SHP-2 phosphatases and inhibition of the accumulation and phosphorylation of cytoskeleton-regulating nonmuscle myosin IIa. This inhibition of innate immune responses such as phagocytosis provides a mechanistic explanation for the ability of CHI3L1 to stimulate ICPs and inhibit adaptive immune responses in cancer and diseases such as COPD. The ability of CHI3L1 to simultaneously inhibit innate immune responses, stimulate ICPs, inhibit T cell costimulation, and regulate a number of other oncogenic and inflammation pathways suggests that CHI3L1-targeted therapeutics are promising interventions in cancer, COPD, and other disorders., (Copyright © 2024 by The American Association of Immunologists, Inc.)

Mycoplasma pneumoniae and Mycoplasma genitalium are two emerging bacterial pathogens that colonize the human respiratory and urogenital epithelia, respectively. Both pathogens express cell surface cytoadhesins that play a crucial role in the interaction with the host, mediating the attachment to sialylated glycan receptors and triggering infection. The design of competitive binding inhibitors of Mycoplasma cytoadhesins has potential to disrupt these interactions and lessen bacterial pathogenesis. To this end, we report here molecular insights into the adhesion mechanisms of M. pneumoniae and M. genitalium, which are largely mediated by sialylated glycans on the host cell surface. In detail, a combination of Nuclear Magnetic Resonance (NMR) spectroscopy, fluorescence analysis and computational studies allowed us to explore the recognition by the cytoadhesins P40/P90 in M. pneumoniae and P110 in M. genitalium of sialylated N- and O-glycans. We reveal that, unlike other bacterial adhesins, which are characterized by a wide binding pocket, Mycoplasma cytoadhesins principally accommodate the sialic acid residue, in a similar manner to mammalian Siglecs. These findings represent crucial insight into the future development of novel compounds to counteract Mycoplasma infections by inhibiting bacterial adherence to host tissues., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Cancer immunotherapy has revolutionized the treatment landscape by harnessing the power of the immune system to combat malignancies. Two of the most promising players in this field are cluster of differentiation 24 (CD24) and sialic acid-binding Ig-like lectin 10 (Siglec-10), and both of them play pivotal roles in modulating immune responses. CD24, a cell surface glycoprotein, emerges as a convincing fundamental signal transducer for therapeutic intervention, given its significant implication in the processes related to tumour progression and immunogenic evasion. Additionally, the immunomodulatory functions of Siglec-10, a prominent member within the Siglec family of immune receptors, have recently become a crucial point of interest, particularly in the context of the tumour microenvironment. Hence, the intricate interplay of both CD24 and Siglec-10 assumes a critical role in fostering tumour growth, facilitating metastasis and also orchestrating immune evasion. Recent studies have found multiple evidences supporting the therapeutic potential of targeting CD24 in cancer treatment. Siglec-10, on the other hand, exhibits immunosuppressive properties that contribute to immune tolerance within the tumour microenvironment. Therefore, we delve into the complex mechanisms through which Siglec-10 modulates immune responses and facilitates immune escape in cancer. Siglec-10 also acts as a viable target for cancer immunotherapy and presents novel avenues for the development of therapeutic interventions. Furthermore, we examine the synergy between CD24 and Siglec-10 in shaping the immunosuppressive tumour microenvironment and discuss the implications for combination therapies. Therefore, understanding the roles of CD24 and Siglec-10 in cancer immunotherapy opens exciting possibilities for the development of novel therapeutics., (© 2024 John Wiley & Sons Ltd.)

The structural dynamics of the interactions between defensins or lysozymes and various saccharide chains that are covalently linked to lipids or proteins were analyzed in relation to the sub-molecular architecture of the carbohydrate binding sites of lectins. Using tissue materials from rare and endangered domestic animals as well as from dogs it was possible to compare these results with data obtained from a human glioblastoma tissue. The binding mechanisms were analyzed on a cellular and a sub-molecular size level using biophysical techniques (e.g. NMR, AFM, MS) which are supported by molecular modeling tools. This leads to characteristic structural patterns being helpful to understand glyco-biochemical pathways in which galectins, defensins or lysozymes are involved. Carbohydrate chains have a distinct impact on cell differentiation, cell migration and immunological processes. The absence or the presence of sialic acids and the conformational dynamics in glycans are often correlated with zoonoses such as influenza- and coronavirus-infections. Receptor-sensitive glycomimetics could be a solution. The new findings concerning the function of galectin-3 in the nucleus in relation to differentiation processes can be understood when the binding specificity of neuroleptic molecules as well as the interactions between proteins and nucleic acids are describable on a sub-molecular size level., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Because of the composition and structural complexity of crustacean shells, their color change mechanism during thermal processing remains unclear. This study identified and characterized two intrinsic protein components, hemocyanin (Lv-Hc) and β-1,3-glucan-binding protein (Lv-BGBP) from Litopenaeus vannamei shrimp shells by a combination of ion-exchange chromatography, gel filtration, and mass spectrometry. It was found that a mixture of Lv-Hc, a gray protein, and Lv-BGBP (which is a natural astaxanthin-binding protein with a red color) is responsible for the brown color of fresh shrimp shells. Upon heating to 100 °C, the mixture of these proteins turned red, mimicking the color change observed in cooked shrimp shells. This transition is attributed to the extremely high thermal stability of Lv-BGBP, which has the ability to protect astaxanthin from thermal induced degradation. These findings provide significant insights into the molecular mechanism governing shrimp shell coloration, advancing our understanding of crustacean biochemistry.

Extracellular vesicles (EVs) harbor abundant glycans that mediate various functions, such as intercellular communication and disease advancement, which play significant roles in disease progression. However, the presence of EV heterogeneity in body fluids and the complex nature of the glycan structures have posed challenges for the detection of EV glycans. In this study, we provide a streamlined method integrated, me mbrane- s pecific s eparation with lectin-induced ag gr e gation strategy (MESSAGE), for multiplexed profiling of EV glycans. By leveraging a rationally designed lectin-induced aggregation strategy, the expression of EV glycans is converted to size-based signals. With the assistance learning machine algorithms, the MESSAGE strategy with high sensitivity, specificity, and simplicity can be used for early cancer diagnosis and classification, as well as monitoring cancer metastasis via 20 μL plasma sample within 2 h. Furthermore, our platform holds promise for advancing the field of EV-based liquid biopsy for clinical applications, opening new possibilities for the profiling of EV glycan signatures in various disease states.

Background: Ficolins (FCNs) are a family of proteins, comprising FCN1, FCN2 and FCN3, and integral to the immune system which have been implicated in the onset and progression of tumors. Despite their recognized roles, a comprehensive analysis of FCNs in lung cancer remains elusive., Methods: We employed a variety of bioinformatics tools, including UCSC, SangerBox, Ualcan, cBioPortal, String, Metascape, GeneMANIA, TIDE, CTD, and CAMP databases to investigate the differential expression, diagnostic and prognostic significance, genetic alterations, functional enrichment, immune infiltration, and potential immunotherapeutic implications of FCN1, FCN2, and FCN3 in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). Additionally, RT-qPCR and immunohistochemistry were utilized to validate the expressions of FCNs at the mRNA and protein levels in LUSC and LUAD., Results: Our comprehensive bioinformatic analysis, supported by RT-qPCR and immunohistochemistry, revealed that the expressions of FCN1, FCN2 and FCN3 were consistently downregulated in both LUSC and LUAD tumor tissues. FCNs demonstrated significant diagnostic potential for LUSC and LUAD, with the area under the receiver operating characteristic curve (AUC) for FCN1 and FCN3 exceeding 0.90. Furthermore, FCN2 and FCN3 showed a strong negative correlation with overall survival (OS) in LUSC, whereas FCN1 and FCN2 were positively correlated with OS in LUAD, suggesting their prognostic value in lung cancer. Gene enrichment analysis indicated that FCNs were predominantly associated with the complement system and complement activation pathways. Immune infiltration analysis further revealed a significant positive correlation between FCNs and the presence of neutrophils and resting mast cells. Our analysis of immunotherapy outcomes revealed a significant disparity in the immunophenoscore (IPS) among lung cancer patients treated with immune checkpoint inhibitors (ICIs), distinguishing those with high FCN expression from those with low FCN expression. Additionally, we identified small molecule compounds related to FCNs and drugs pertinent to LUSC and LUAD., Conclusion: FCNs held promise as diagnostic and prognostic biomarkers for LUSC and LUAD. This study also elucidated the relationship of FCNs with the tumor microenvironment, offering novel insights into the immunotherapeutic landscape for LUSC and LUAD., (© 2024. The Author(s).)

O-Linked β- N -acetylglucosamine (O-GlcNAc) modification (i.e., O-GlcNAcylation) on proteins plays critical roles in the regulation of diverse biological processes. However, protein O-GlcNAcylation analysis, especially at a large scale, has been a challenge. So far, a number of enrichment materials and methods have been developed for site-specific O-GlcNAc proteomics in different biological settings. Despite the presence of multiple methods, their performance for the O-GlcNAc proteomics is largely unclear. In this work, by using the lysates of PANC-1 cells (a pancreatic cancer cell line), we provided a head-to-head comparison of three affinity enrichment methods and materials (i.e., antibody, lectin AANL6, and an OGA mutant) for site-specific O-GlcNAc proteomics. The enriched peptides were analyzed by HCD product-dependent EThcD (i.e., HCD-pd-EThcD) mass spectrometry. The resulting data files were processed by three different data analysis packages (i.e., Sequest HT, Byonic, and FragPipe). Our data suggest that each method captures a subpopulation of the O-GlcNAc proteins. Besides the enrichment methods, we also observe complementarity between the different data analysis tools. Thus, combining different approaches holds promise for enhanced coverage of O-GlcNAc proteomics.

This comprehensive review meticulously compiles data on an array of lectins and their interactions with different cancer types through specific glycans. Crucially, it establishes the link between aberrant glycosylation and cancer types. This repository of lectin-defined glycan signatures, assumes paramount importance in the realm of cancer and its dynamic nature. Cancer, known for its remarkable heterogeneity and individualized behaviour, can be better understood through these glycan signatures. The current review discusses the important lectins and their carbohydrate specificities, especially recognizing glycans of cancer origin. The review also addresses the key aspects of differentially expressed glycans on normal and cancerous cell surfaces. Specific cancer types highlighted in this review include breast cancer, colon cancer, glioblastoma, cervical cancer, lung cancer, liver cancer, and leukaemia. The glycan profiles unveiled through this review hold the key to tailor-made treatment and precise diagnostics. It opens up avenues to explore the potential of targeting glycosyltransferases and glycosidases linked with cancer advancement and metastasis. Armed with knowledge about specific glycan expressions, researchers can design targeted therapies to modulate glycan profiles, potentially hampering the advance of this relentless disease., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

In order to discriminate between detrimental, commensal, and beneficial microbes, plants rely on polysaccharides such as β-glucans, which are integral components of microbial and plant cell walls. The conversion of cell wall-associated β-glucan polymers into a specific outcome that affects plant-microbe interactions is mediated by hydrolytic and non-hydrolytic β-glucan-binding proteins. These proteins play crucial roles during microbial colonization: they influence the composition and resilience of host and microbial cell walls, regulate the homeostasis of apoplastic concentrations of β-glucan oligomers, and mediate β-glucan perception and signaling. This review outlines the dual roles of β-glucans and their binding proteins in plant immunity and symbiosis, highlighting recent discoveries on the role of β-glucan-binding proteins as modulators of immunity and as symbiosis receptors involved in the fine-tuning of microbial accommodation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Invertebrate lectins exhibit structural diversity and play crucial roles in the innate immune responses by recognizing and eliminating pathogens. In the present study, a novel lectin containing a Gal&#95;Lectin, a CUB and a transmembrane domain was identified from the Pacific oyster Crassostrea gigas (defined as CgGal-CUB). CgGal-CUB mRNA was detectable in all the examined tissues with the highest expression in adductor muscle (11.00-fold of that in haemocytes, p < 0.05). The expression level of CgGal-CUB mRNA in haemocytes was significantly up-regulated at 3, 24, 48 and 72 h (8.37-fold, 12.13-fold, 4.28-fold and 10.14-fold of that in the control group, respectively) after Vibrio splendidus stimulation. The recombinant CgGal-CUB (rCgGal-CUB) displayed binding capability to Mannan (MAN), peptidoglycan (PGN), D-(+)-Galactose and L-Rhamnose monohydrate, as well as Gram-negative bacteria (Escherichia coli, V. splendidus and Vibrio anguillarum), Gram-positive bacteria (Micrococcus luteus, Staphylococcus aureus, and Bacillus sybtilis) and fungus (Pichia pastoris). rCgGal-CUB was also able to agglutinate V. splendidus, and inhibit V. splendidus growth. Furthermore, rCgGal-CUB exhibited the activities of enhancing the haemocyte phagocytosis towards V. splendidus, and the phagocytosis rate of haemocytes was descended in blockage assay with CgGal-CUB antibody. These results suggested that CgGal-CUB served as a pattern recognition receptor to bind various PAMPs and bacteria, and enhanced the haemocyte phagocytosis towards V. splendidus., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Multivalency is a fundamental principle in nature that leads to high-affinity intermolecular recognition through multiple cooperative interactions that overcome the weak binding of individual constituents. For example, multivalency plays a critical role in lectin-carbohydrate interactions that participate in many essential biological processes. Designing high-affinity multivalent glycoconjugates that engage lectins results in systems with the potential to disrupt these biological processes, offering promising applications in therapeutic design and bioengineering. Here, a versatile and tunable synthetic platform for the synthesis of metallosupramolecular glycoassemblies is presented that leverages subcomponent self-assembly, which employs metal ion templates to generate complex supramolecular architectures from simple precursors in one pot. Through ligand design, this approach provides precise control over molecular parameters such as size, shape, flexibility, valency, and charge, which afforded a diverse family of well-defined hybrid glyconanoassemblies. Evaluation of these complexes as multivalent binders to Concanavalin A (Con A) by isothermal titration calorimetry (ITC) demonstrates the optimal saccharide tether length and the effect of electrostatics on protein affinity, revealing insights into the impact of synthetic design on molecular recognition. The presented studies offer an enhanced understanding of structure-function relationships governing lectin-saccharide interactions at the molecular level and guide a systematic approach towards optimizing glyconanoassembly binding parameters., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The mesothelium is a non-adhesive protective surface that lines the serosal cavities and organs within the body. The glycocalyx is a complex structure that coats the outer layer of the mesothelium. However, due to the limitations of conventional fixation techniques, studies on glycans are limited. In this study, lectin staining of frozen tissues was performed to investigate the diversity of glycans in the glycocalyx of mesothelial cells in mice. Datura stramonium lectin (DSL), which recognizes lactosamine and binds to Galectin-3 and -1, was broadly bound to the mesothelial cells of the visceral and parietal peritoneum but not to the pancreas, liver, intestine, or heart. Furthermore, human mesothelial cells in the omentum and parietal peritoneum were positive for DSL. Erythrina cristagalli lectin binding was specific to mesothelial cells in the parietal peritoneum, that is, the pleura, diaphragm, and peritoneum. Intriguingly, surface sialylation, the key element in reducing peritoneal dissemination and implantation, and promoting ascites formation by ovarian carcinoma cells, was much higher in the parietal peritoneum than in the omentum. These findings revealed slight differences in the glycans of mesothelial cells of different organs, which may be related to clinical diseases. These results also suggest that there may be differences in the functions of parietal and visceral mesothelial cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

In mammals, siglec7, an integral component of the siglecs, is principally found on the surface of natural killer (NK) cells, macrophages, and monocytes, where it interacts with various pathogens to perform immunological regulatory activities. Nonetheless, the immune defense and mechanism of siglec7 in early vertebrates remain unknown. In this study, we identified siglec7 from Oreochromis niloticus (OnSiglec7) and revealed its immune functions. Specifically, OnSiglec7 was abundantly expressed in immune-related tissues of healthy tilapia and its transcription level was strongly activated after being challenged with A. hydrophila, S. agalactiae, and Poly: IC. Meanwhile, OnSiglec7 protein was purified and analyzed, which could recognize multiple pathogens through binding and agglutinating activity. Moreover, OnSiglec7-positive cells were mainly distributed in non-specific cytotoxic cells (NCC) of tilapia HKLs and showed cell membrane localization. Furthermore, OnSiglec7 blockage affected multiple innate immune responses (inflammation, apoptosis, and pyroptosis process) by regulating the activation of MAPK, NF-κB, TLR, and JAK-STAT pathways. Finally, OnSiglec7 blockage also greatly enhanced the cytotoxic effect of tilapia NCC. Summarily, this study uncovers immune functions and mechanisms of siglec7 in primitive vertebrates, thereby enhancing our understanding of the systemic evolution and ancient functions of other siglecs within the host's innate immune system (to our knowledge)., Competing Interests: Declaration of competing interest The authors declare that there were no financial or commercial connections which could be perceived as a conflict of interest during the research., (Copyright © 2024. Published by Elsevier B.V.)

Glycan recognition by lectins mediates important biological events. This Tutorial Review aims to introduce lectin-ligand interactions and show how these molecular recognition events inspire innovations such as: (i) glycomimetic ligands; (ii) multivalent ligand agonists/antagonists; (iii) ligands for precision delivery of therapies to cells, where therapies include vaccines, siRNA and LYTACs (iv) development of diagnostics. A small number of case studies are selected to demonstrate principles for development of new ligands for applications inspired by knowledge of natural glycan ligand structure and function.

This study characterized the binding mechanisms of the lectin cMoL (from Moringa oleifera seeds) to carbohydrates using spectroscopy and molecular dynamics (MD). The interaction with carbohydrates was studied by evaluating lectin fluorescence emission after titration with glucose or galactose (2.0-11 mM). The Stern-Volmer constant (Ksv), binding constant (Ka), Gibbs free energy (∆G), and Hill coefficient were calculated. After the urea-induced denaturation of cMoL, evaluations were performed using fluorescence spectroscopy, circular dichroism (CD), and hemagglutinating activity (HA) evaluations. The MD simulations were performed using the Amber 20 package. The decrease in Ksv revealed that cMoL interacts with carbohydrates via a static mechanism. The cMoL bound carbohydrates spontaneously (ΔG < 0) and presented a Ka on the order of 10 2 , with high selectivity for glucose. Protein-ligand complexes were stabilized by hydrogen bonds and hydrophobic interactions. The Hill parameter (h~2) indicated that the binding occurs through the cMoL dimer. The loss of HA at urea concentrations at which the fluorescence and CD spectra indicated protein monomerization confirmed these results. The MD simulations revealed that glucose bound to the large cavity formed between the monomers. In conclusion, the biotechnological application of cMoL lectin requires specific methods or media to improve its dimeric protein structure.

Intelectin-1 (ITLN1; also Omentin-1, OMNT1) is secreted by adipose tissue (AT) and plays an important role in glucose metabolism regulation, with links to obesity-associated diseases. ITLN1 activity so far has rarely been investigated using RNA-sequencing and in larger cohorts. We evaluated ITLN1 expression among three clinical cohorts of the Leipzig Obesity BioBank-a cross-sectional cohort comprising of 1480 people, a cohort of people with metabolically healthy or unhealthy obesity (31 insulin-sensitive, 42 insulin-resistant individuals with obesity), and a longitudinal two-step bariatric surgery cohort (n = 65). We hypothesized that AT ITLN1 expression is associated with serum omentin-1, clinical parameters associated with obesity, and with weight loss after bariatric surgery. We also investigated the correlation of AT ITLN1 expression with genes related to inflammatory response, lipid metabolism, obesity, and regulation of energy balance. Likewise, we inspected gene group expression and metabolic pathways associated with ITLN1 expression using gene set enrichment and gene correlation analysis. We show that ITLN1 expression differs in VAT and SAT, and should therefore be analyzed separately. Furthermore, ITLN1 expression increases with VAT tissue mass, but is negatively affected by AT tissue dysfunction among individuals with unhealthy obesity, corroborated by interplay with genes related to tissue inflammation. Gene set enrichment and gene correlation analysis of ITLN1 expression suggest that AT ITLN1 expression is related to local inflammatory processes in AT, but also in processes such as regulation of appetite, energy balance, and maintenance of body weight., (© 2024. The Author(s).)

The cyst wall of the eye pathogen Acanthamoeba castellanii contains cellulose and has ectocyst and endocyst layers connected by conical ostioles. Cyst walls contain families of lectins that localize to the ectocyst layer (Jonah) or the endocyst layer and ostioles (Luke and Leo). How lectins and an abundant laccase bind cellulose and why proteins go to locations in the wall are not known and are the focus of the studies here. Structural predictions identified β-jelly-roll folds (BJRFs) of Luke and sets of four disulfide knots (4DKs) of Leo, each of which contains linear arrays of aromatic amino acids, also present in carbohydrate-binding modules of bacterial and plant endocellulases. Ala mutations showed that these aromatics are necessary for cellulose binding and proper localization of Luke and Leo in the Acanthamoeba cyst wall. BJRFs of Luke, 4DKs of Leo, a single β-helical fold (BHF) of Jonah, and a copper oxidase domain of the laccase each bind to glycopolymers in both layers of deproteinated cyst walls. Promoter swaps showed that ectocyst localization does not just correlate with but is caused by early encystation-specific expression, while localization in the endocyst layer and ostioles is caused by later expression. Evolutionary studies showed distinct modes of assembly of duplicated domains in Luke, Leo, and Jonah lectins and suggested Jonah BHFs originated from bacteria, Luke BJRFs share common ancestry with slime molds, while 4DKs of Leo are unique to Acanthamoeba .IMPORTANCE Acanthamoebae is the only human parasite with cellulose in its cyst wall and conical ostioles that connect its inner and outer layers. Cyst walls are important virulence factors because they make Acanthamoebae resistant to surface disinfectants, hand sanitizers, contact lens sterilizers, and antibiotics applied to the eye. The goal here was to understand better how proteins are targeted to specific locations in the cyst wall. To this end, we identified three new proteins in the outer layer of the cyst wall, which may be targets for diagnostic antibodies in corneal scrapings. We used structural predictions and mutated proteins to show linear arrays of aromatic amino acids of two unrelated wall proteins are necessary for binding cellulose and proper wall localization. We showed early expression during encystation causes proteins to localize to the outer layer, while later expression causes proteins to localize to the inner layer and the ostioles., Competing Interests: The authors declare no conflict of interest.

Lectin-based approaches remain a valuable tool for analyzing glycosylation, especially when detecting cancer-related changes. Certain glycans function as platforms for cell communication, signal transduction, and adhesion. Therefore, the functions of glycans are important considerations for clinical aspects, such as cancer, infection, and immunity. Considering that the three-dimensional structure and multivalency of glycans are important factors for their function, their binding characteristics toward lectins provide vital information. Glycans and lectins are inextricably linked, and studies on lectins have also led to research on the roles of glycans. The applications of lectins are not limited to analysis but can also be used as drug delivery tools. Moreover, mammalian lectins are potential therapeutic targets because certain lectins change their expression in cancer, and lectin regulation subsequently regulates several molecules with glycans. Herein, we review lectin-based approaches for analyzing the role of glycans and their clinical applications in diseases, as well as our recent results.

Bacterial biofilm formation and attachment to hosts are mediated by carbohydrate-binding lectins, exopolysaccharides, and their interactions in the extracellular matrix (ECM). During tomato infection Ralstonia pseudosolanacearum (Rps) GMI1000 highly expresses three lectins: LecM, LecF, and LecX. The latter two are uncharacterized. We evaluated the roles in bacterial wilt disease of LecF, a fucose-binding lectin, LecX, a xylose-binding lectin, and the Rps exopolysaccharide EPS I. Interestingly, single and double lectin mutants attached to tomato roots better and formed more biofilm under static conditions in vitro. Consistent with this finding, static bacterial aggregation was suppressed by heterologous expression of lecFGMI1000 and lecXGMI1000 in other Ralstonia strains that naturally lack these lectins. Crude ECM from a ΔlecF/X double mutant was more adhesive than the wild-type ECM, and LecF and LecX increased Rps attachment to ECM. The enhanced adhesiveness of the ΔlecF/X ECM could explain the double mutant's hyper-attachment in static conditions. Unexpectedly, mutating lectins decreased Rps attachment and biofilm viscosity under shear stress, which this pathogen experiences in plant xylem. LecF, LecX, and EPS I were all essential for biofilm development in xylem fluid flowing through cellulose-coated microfluidic channels. These results suggest that under shear stress, LecF and LecX increase Rps attachment by interacting with the ECM and plant cell wall components like cellulose. In static conditions such as on root surfaces and in clogged xylem vessels, the same lectins suppress attachment to facilitate pathogen dispersal. Thus, Rps lectins have a dual biological function that depends on the physical environment., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Carter et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Importance: Porcine epidemic diarrhea virus (PEDV) binds to particular cell surface receptors to penetrate cells. The virus specifically identifies certain carbohydrate structures present on the surface of the cell to facilitate the binding process. Nevertheless, the influence of viral infections on specific alterations of glycoconjugates in the small intestines remains unexplored., Objective: This work aimed to examine the alterations in glycoconjugates in the small intestines of piglets naturally infected with PEDV using lectin histochemistry., Methods: Six piglets including three PEDV-infected and three non-infected piglets were evaluated. Small intestinal samples were histopathologically examined, and lectin histochemistry was performed., Results: Piglets infected with PEDV had significant histological abnormalities in their small intestines, such as pronounced villous atrophy, varying degrees of villous fusion, and diverse mucosal alterations. Specific regions of the duodenum, jejunum, and ileum showed discernible variations in glycoconjugate distribution, as determined by lectin histochemistry. Compared with the controls, the PEDV-infected piglets showed significant changes in N-acetylglucosamine- and galactose-binding lectins (particularly wheat germ agglutinin and Arachis hypogaea (peanut) agglutinin) in multiple intestinal regions., Conclusions and Relevance: These findings can enhance understanding of how viruses such as PEDV impact the glycoconjugate composition of the small intestines and emphasize the potential connection between the pathogenesis of PEDV and glycoconjugate., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Korean Society of Veterinary Science.)

Chemical communication through olfaction is crucial for fish behaviours, mediating in socio-sexual behaviours as reproduction. Turbot, a flatfish with significant aquaculture production, possesses a well-developed olfactory system from early developmental stages. After metamorphosis, flatfish acquire their characteristic bilateral asymmetry with an ocular side facing the open water column, housing the dorsal olfactory rosette, and a blind side in contact with the sea bottom where the ventral rosette is located. This study aimed to address the existing gap in specific histological, ultrastructural, lectin-histochemical and immunohistochemical studies of the turbot olfactory rosettes and olfactory bulbs. We examined microdissected olfactory organs of adult turbots and premetamorphic larvae by using routine histological staining techniques, and a wide array of lectins and primary antibodies against G-proteins and calcium-binding proteins. We observed no discernible structural variations in the olfactory epithelium between rosettes, except for the dorsal rosette being larger in size compared to the ventral rosette. Additionally, the use of transmission electron microscopy significantly improved the characterization of the adult olfactory epithelium, exhibiting high cell density, small cell size, and a wide diversity of cell types. Moreover, specific immunopositivity in sensory and non-sensory cells provided us of essential information regarding their olfactory roles. The results obtained significantly enriched the scarce morphological and neurochemical information available on the turbot olfactory system, revealing a highly complex olfactory epithelium with distinct features compared to other teleost species, especially with regard to olfactory cell distribution and immunolabelling patterns., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aberrant glycosylation recently emerged as an unmissable hallmark of cancer progression in many cancers. In melanoma, there is growing evidence that the tumour 'glycocode' plays a major role in promoting cell proliferation, invasion, migration, but also dictates the nature of the immune infiltrate, which strongly affects immune cell function, and clinical outcome. Aberrant glycosylation patterns dismantle anti-tumour defence through interactions with lectins on immune cells, which are crucial to shape anti-tumour immunity but also to trigger immune evasion. The glycan/lectin axis represents a new immune subversion pathway that is exploited by melanoma to hijack immune cells and escape from immune control. In this review, we describe the glycosylation features of melanoma tumour cells, and further gather findings related to the role of glycosylation in melanoma tumour progression, deciphering in detail its impact on immunity. We also depict glycan-based strategies aiming at restoring a functional anti-tumour response in melanoma patients. Glycans/lectins emerge as key immune checkpoints with promising translational properties. Exploitation of these pathways could reshape potent anti-tumour immunity while impeding immunosuppressive circuits triggered by aberrant tumour glycosylation patterns, holding great promise for cancer therapy., (© 2024 The Authors. Immunology published by John Wiley & Sons Ltd.)

Glycans are carbohydrates present in every organism that bind to specific molecules such as lectins, a diverse group of proteins. Glycans are vital to cell proliferation and protein trafficking. In addition, embryogenesis is a critical phase in the development of marine organisms. This study investigated the effects of chilling and cryoprotective agents (CPAs) on glycans in the embryos of Stenopus hispidus. The glycan profiles of embryos of S. hispidus at the heartbeat stage were analyzed using lectin arrays. The results of analyses revealed that mannose was the most abundant glycan in the S. hispidus embryos; mannose is crucial to cell proliferation, providing the energy required for embryonic growth. Additionally, the results reveled that chilling altered the content of several glycans, including fucose and Gla-GlcNAc. Chilling may promote monosaccharide accumulation, facilitating osmotic regulation of cells and signal molecules to aid S. hispidus embryos in adapting to cold conditions. Changes were also observed in the lectins NPA, orysata, PALa, ASA, discoidin II, discoidin I, UDA, PA-IIL, and PHA-P after the samples were treated with different CPAs. DMSO may minimize cell damage during exposure to chilling by preserving cell structures, membrane properties, and functions. The present study is the first to investigate the profiles and functions of glycans in shrimp embryos subjected to low-temperature injuries. This study enhances the understanding of cell reproduction during embryogenesis and provides valuable information for the study of glycans in embryos., Competing Interests: Declaration of competing interest I declare that the authors have no competing interests as defined by the journal, or other interests that might be perceived to influence the results and/or discussion reported in this paper., (Copyright © 2024 Society for Cryobiology. Published by Elsevier Inc. All rights reserved.)

Glycosylation is a ubiquitous cellular or microenvironment-specific post-translational modification that occurs on the surface of normal cells and tumor cells. Tumor cell-associated glycosylation is involved in hematogenous metastasis. A wide variety of tumors undergo aberrant glycosylation to interact with platelets. As platelets have many opportunities to engage circulating tumor cells, they represent an important avenue into understanding the role glycosylation plays in tumor metastasis. Platelet involvement in tumor metastasis is evidenced by observations that platelets protect tumor cells from damaging shear forces and immune system attack, aid metastasis through the endothelium at specific sites, and facilitate tumor survival and colonization. During platelet-tumor-cell interactions, many opportunities for glycan-ligand binding emerge. This review integrates the latest information about glycans, their ligands, and how they mediate platelet-tumor interactions. We also discuss adaptive changes that tumors undergo upon glycan-lectin binding and the impact glycans have on targeted therapeutic strategies for treating tumors in clinical settings.

Glycan-binding specificity was studied for Jacalin, RCA 120, SBA, PHA-L, PHA-E, WGA, UEA, AAL, LTL, LEL, SNA, DSA, LCA, MAH and Con A, lectins widely used in histochemistry. Oligosaccharide- and polysaccharide-based glycan arrays were applied. Expected specificity was confirmed for only 6 of the 15 lectins and the glycan binding profiles of some lectins were dramatically broader than generally accepted. WGA, LEL and DSA known as chitooligosaccharide-specific, were unexpectedly polyreactive, binding to other glycans with the same affinity as to chitobiose, ABH antigens and oligolactosamines (unsubstituted and sialylated). SBA, in addition to expected binding to glycans with terminal GalNAcα, also had high affinity for the GM1 ganglioside. MAH demonstrated much higher affinity to a variety of sulfated glycans compared to Neu5Acα2-3Galβ1-3GalNAcα. Contrary to the common view, LCA demonstrated the maximum binding to (GlcNAcβ1-2Manα1) 2 -3,6-Manβ1-4GlcNAcβ1-4GlcNAc N-glycan, while it had no interaction with corresponding Gal or Neu5Ac terminated versions. This observed polyreactivity of some lectins casts doubt on their use in accurately determining the presence of a specific glycan structure by histochemical studies. However, comparisons of sera from healthy and diseased individuals with help of a lectin array can easily establish differences in glycosylation patterns and presumptive glycan identities, which can later be clarified using more accurate methods of structural analysis., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Human sialic acid-binding immunoglobulin-like lectins (Siglecs) are expressed on subsets of immune cells. Siglec-8 is an immune inhibitory Siglec on eosinophils and mast cells, which are effectors in allergic disorders including eosinophilic esophagitis. Inhibition occurs when Siglec-8 is crosslinked by multivalent Siglec ligands in target tissues. Previously we discovered a high-affinity Siglec-8 sialoglycan ligand on human airways composed of terminally sialylated keratan sulfate chains carried on a single protein, DMBT1. Here we extend that approach to another allergic inflammatory target tissue, human esophagus. Lectin overlay histochemistry revealed that Siglec-8 ligands are expressed predominantly by esophageal submucosal glands, and are densely packed in submucosal ducts leading to the lumen. Expression is tissue-specific; esophageal glands express Siglec-8 ligand whereas nearby gastric glands do not. Extraction and resolution by gel electrophoresis revealed a single predominant human esophageal Siglec-8 ligand migrating at >2 MDa. Purification by size exclusion and affinity chromatography, followed by proteomic mass spectrometry, revealed the protein carrier to be MUC5B. Whereas all human esophageal submucosal cells express MUC5B, only a portion convert it to Siglec-8 ligand by adding terminally sialylated keratan sulfate chains. We refer to this as MUC5B S8L. Material from the esophageal lumen of live subjects revealed MUC5B S8L species ranging from ~1-4 MDa. We conclude that MUC5B in the human esophagus is a protein canvas on which Siglec-8 binding sialylated keratan sulfate chains are post-translationally added. These data expand understanding of Siglec-8 ligands and may help us understand their roles in allergic immune regulation., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The occurrence of chronic inflammation resulting from infection with human papillomaviruses is an important factor in the development of cervical cancer (CC); thus, deciphering the crosstalk between the tumor microenvironment and innate immune cells during the establishment of immune tolerance is vital for identifying potential treatment strategies., Methods: Single-cell RNA sequencing data and primary tumor samples from patients with CC were used to evaluate the functional role of Siglec-10 on dendritic cells (DCs). Patient-derived tumor fragment platforms were used to examine the ability of Siglec-10 blockade to reinvigorate DC-mediate T-cell activation and tumor clearance., Results: Here, we demonstrated that Siglec-10 is a prominent inhibitory checkpoint for DCs infiltrated in CC. CC epithelial cells use their aberrant surface sialylated structures to induce the transformation of conventional DCs into phenotypes characterized by low immunogenicity and high immunotolerance. Additionally, Siglec-10 + DCs suppress the function of adaptive T cells via galectin-9 signaling to strengthen the immunosuppressive CC microenvironment. Disturbance of Siglec-10 signaling restored the DC-mediated tumoricidal response and increased adaptive T cells sensitivity to programmed cell death protein 1 inhibition., Conclusion: Our study confirms the checkpoint role of Siglec-10 on DCs and proposes that targeting Siglec-10 may be a promising avenue for immunotherapy against CC., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Glycan profile comparisons are one of the most tedious analytical exercises for establishing compliance with recombinant therapeutic protein batches. Based on its intensive research, the FDA has confirmed that lectin array binding with fluorescent monitoring is the fastest and most reliable method for profile comparisons. Using a database of over 150 biological products expressed in nine diverse mammalian cell systems, the FDA immobilized 74 lectins to study their binding using fluorescently labeled glycoproteins. The FDA identified nine distinct lectins from a custom-designed lectin microarray: rPhoSL, rOTH3, RCA120, rMan2, MAL&#95;I, rPSL1a, PHAE, rMOA, and PHALs, which detect core fucose, terminal GlcNAc, terminal β-galactose, high mannose, α-2,3-linked sialic acids, α-2,6-linked sialic acids, bisecting GlcNAc, terminal α-galactose, and triantennary structures, respectively. This method can be used for screening and routine testing and to monitor batch-to-batch variability of therapeutic proteins, including establishing analytical similarity as a crucial part of biosimilar development.

Leishmaniases, caused by Leishmania parasites, are widespread and pose significant health risks globally. Visceral leishmaniasis (VL) is particularly prevalent in Brazil, with high morbidity and mortality rates. Traditional treatments, such as pentavalent antimonials, have limitations due to toxicity and resistance. Therefore, exploring new compounds like lectins is crucial. Concanavalin A (ConA) has shown promise in inhibiting Leishmania growth. This study aimed to evaluate its leishmanicidal effect on L. infantum promastigotes and understand its mechanism of action. In vitro tests demonstrated inhibition of promastigote growth when treated with ConA, with IC 50 values ranging from 3 to 5 μM over 24-72 h. This study suggests that ConA interacts with L. infantum glycans. Additionally, ConA caused damage to the membrane integrity of parasites and induced ROS production, contributing to parasite death. Scanning electron microscopy confirmed morphological alterations in treated promastigotes. ConA combined with the amphotericin B (AmB) showed synergistic effects, reducing the required dose of AmB, and potentially mitigating its toxicity. ConA demonstrated no cytotoxic effects on macrophages, instead stimulating their proliferation. These findings reinforce that lectin exhibits promising leishmanicidal activity against L. infantum promastigotes, making ConA a potential candidate for leishmaniasis treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Weak binding of carbohydrates with protein receptors possesses serious drawbacks in the advancement of therapeutics; however, the development of strategies for multipoint interactions between carbohydrates and protein can overcome these challenges. One such method is developed in this work where glycopolymer- grafted silica nanoparticles with a large number of carbohydrate units are prepared for the interactions with multiple binding sites of the protein. First, a glycomonomer, β-d-galactose-hydroxyethyl methacrylate (β-GEMA), was synthesized in a two-step process by coupling β-d-galactose pentaacetate and hydroxyethyl methacrylate (HEMA), followed by deacetylation for the preparation of poly(β-GEMA) glycopolymers (GPs). Further, the poly(β-GEMA) chains were grafted onto the silica nanoparticle (SiNP) surface by utilizing the " grafting - from " strategy of surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization to prepare p(β-GEMA)-grafted SiNPs (GNPs). Five different chain lengths ranging from 10 to 40 kDa of the GPs and the GNPs were prepared, and various characterization techniques confirmed the formation of GPs and grafting of the GPs on the SiNP surface. The particle size of GNPs and the number of GPs grafted on the SiNP surface showed a strong dependence on the chain length of the GPs. Further, the GNPs were subjected to a binding study with β-galactose-specific protein peanut agglutinin (PNA). A much stronger binding in the case of GNPs was observed with an association constant ∼320 times and ∼53 times than that of the monomeric methyl-β-d-galactopyranoside and the GPs, respectively. Additionally, the binding of the PNA with GNPs and GPs was also studied with varying chain lengths to understand the effects of the chain length on the binding affinity. A clear increase in binding constants was observed in the case of GNPs with increasing chain length of grafted GPs, attributed to the enhanced enthalpic and entropic contributions. This work holds its uniqueness in these improved interactions between carbohydrates and proteins, which can be used for carbohydrate-based targeted therapeutics.

Background: Tuberculosis (TB), predominantly caused by Mycobacterium tuberculosis (MTB) infection, remains a prominent global health challenge. Macrophages are the frontline defense against MTB, relying on autophagy for intracellular bacterial clearance. However, MTB can combat and evade autophagy, and it influences macrophage polarization, facilitating immune evasion and promoting infection. We previously found that heparin-binding hemagglutinin (HBHA) inhibits autophagy in A549 cells; however, its role in macrophage autophagy and polarization remains unclear., Methods: Bacterial cultures, cell cultures, Western blotting, immunofluorescence, macrophage infection assays, siRNA knockdown, and enzyme-linked immunosorbent assay were used to investigate HBHA's impact on macrophages and its relevance in Mycobacterium infection., Results: HBHA inhibited macrophage autophagy. Expression of recombinant HBHA in Mycobacterium smegmatis (rMS-HBHA) inhibited autophagy, promoting bacterial survival within macrophages. Conversely, HBHA knockout in the Mycobacterium bovis bacillus Calmette-Guérin (BCG) mutant (BCG-ΔHBHA) activated autophagy and reduced bacterial survival. Mechanistic investigations revealed that HBHA may inhibit macrophage autophagy through the Toll-like receptor 4-dependent PI3K-AKT-mTOR signaling pathway. Furthermore, HBHA induced macrophage M2 polarization., Conclusions: Mycobacterium may exploit HBHA to suppress the antimicrobial immune response in macrophages, facilitating intracellular survival and immune evasion through autophagy inhibition and M2 polarization induction. Our findings may help identify novel therapeutic targets and develop more effective treatments against MTB infection., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Gliomas are the most common primary intracranial tumors, known for their high invasiveness and destructiveness. Sialic acid-binding immunoglobulin-like lectin 7 (SIGLEC7) is present in various immune cells, especially macrophages, and significantly affects immune homeostasis and cancer cell response. However, research on the role and prognostic impact of SIGLEC7 in glioma patients is currently limited., Methods: We utilized transcriptomic data from 702 glioma patients in The Cancer Genome Atlas (TCGA) and 693 glioma patients in the Chinese Glioma Genome Atlas (CGGA), along with clinical samples we collected, to comprehensively investigate the impact of SIGLEC7 on glioma expression patterns, biological functions, and prognostic value. We focused on its role in glioma-related immune responses and immune cell infiltration and analyzed its expression at the single-cell level. Finally, we validated the role of SIGLEC7 in gliomas through tissue and cell experiments., Results: SIGLEC7 expression was significantly increased in glioma patients with malignant characteristics. Survival analysis indicated that glioma patients with high SIGLEC7 expression had significantly lower survival rates. Gene function analysis revealed that SIGLEC7 is primarily involved in immune and inflammatory responses and is strongly negatively correlated with tumor-associated immune regulation. Additionally, the expression of most immune checkpoints was positively correlated with SIGLEC7, and immune cell infiltration analysis clearly demonstrated a significant positive correlation between SIGLEC7 expression and M2 macrophage infiltration levels. Single-cell analysis, along with tissue and cell experiments, confirmed that SIGLEC7 enhances macrophage polarization towards the M2 phenotype, thereby promoting glioma invasiveness through the immunosuppressive effects of M2 macrophages. Cox regression analysis and the establishment of survival prediction models indicated that high SIGLEC7 expression is an unfavorable prognostic factor for glioma patients., Discussion: High SIGLEC7 expression predicts poor prognosis in glioma patients and is closely associated with M2 macrophages in the tumor environment. In the future, SIGLEC7 may become a promising target for glioma immunotherapy., Competing Interests: Author PW, YC, ZH and XH are employed by the company Beijing Yihua Biotechnology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 An, Ren, Yuan, Qiu, Wang, Cheng, He, Han, Li and An.)

Recruiting circulating cells based on interactions between surface receptors and corresponding ligands holds promise for capturing cells with specific adhesive properties. Our study investigates the adhesion of skin cells to specific lectins, particularly focusing on advancements in lectin-based biosensors with diagnostic potential. We explore whether we can successfully capture normal skin (melanocytes and keratinocytes) and melanoma (WM35, WM115, WM266-4) cells in a low-shear flow environment by coating surfaces with lectins. Specifically, we coated surfaces with Dolichos biflorus (DBA) and Maackia Amurensis (MAL) lectins, which were used to detect and capture specific skin cells from the flow of cell mixture. Alterations in glycan expression (confirmed by fluorescent microscopy) demonstrated that DBA binds predominantly to normal skin cells, while MAL interacts strongly with melanoma cells. Assessing adhesion under static and dynamic low-shear stress conditions (up to 30 mPa) underscores the reliability of DBA and MAL as markers for discriminating specific cell type. Melanocytes and keratinocytes adhere to DBA-coated surfaces, while melanoma cells prefer MAL-coated surfaces. A comprehensive analysis encompassing cell shape, cytoskeleton, and focal adhesions shows the independence of our approach from the inherent characteristics of cells, thus demonstrating its robustness. Our results carry practical implications for lectin-biosensor designs, emphasizing the significance of glycan-based discrimination of pathologically altered cells. Combined with microfluidics, it demonstrates the value of cell adhesion as a discriminant of cancer-related changes, with potential applications spanning diagnostics, therapeutic interventions, and advanced biomedical technologies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Neisserial adhesin A (NadA) is a meningococcal surface protein included as recombinant antigen in 4CMenB, a protein-based vaccine able to induce protective immune responses against Neisseria meningitidis serogroup B (MenB). Although NadA is involved in the adhesion/invasion of epithelial cells and human myeloid cells, its function in meningococcal physiology is still poorly understood. To clarify the role played by NadA in the host-pathogen interaction, we sought to identify its cellular receptors. We screened a protein microarray encompassing 2,846 human and 297 mouse surface/secreted recombinant proteins using recombinant NadA as probe. Efficient NadA binding was revealed on the paired sialic acid-binding immunoglobulin-type lectins receptors 5 and 14 (Siglec-5 and Siglec-14), but not on Siglec-9 therein used as control. The interaction was confirmed by biochemical tools with the determination of the K D value in the order of nanomolar and the identification of the NadA binding site by hydrogen-deuterium exchange coupled to mass spectrometry. The N-terminal domain of the Siglec-5 that recognizes the sialic acid was identified as the NadA binding domain. Intriguingly, exogenously added recombinant soluble Siglecs, including Siglec-9, were found to decorate N. meningitidis surface in a NadA-dependent manner. However, Siglec-5 and Siglec-14 transiently expressed in CHO-K1 cells endorsed NadA binding and increased N. meningitidis adhesion/invasion while Siglec-9 did not. Taken together, Siglec-5 and Siglec-14 satisfy all features of NadA receptors suggesting a possible role of NadA in the acute meningococcal infection.IMPORTANCEBacteria have developed several strategies for cell colonization and immune evasion. Knowledge of the host and pathogen factors involved in these mechanisms is crucial to build efficacious countermoves. Neisserial adhesin A (NadA) is a meningococcal surface protein included in the anti-meningococcus B vaccine 4CMenB, which mediates adhesion to and invasion of epithelial cells. Although NadA has been shown to bind to other cell types, like myeloid and endothelial cells, it still remains orphan of a defined host receptor. We have identified two strong NadA interactors, Siglec-5 and Siglec-14, which are mainly expressed on myeloid cells. This showcases that NadA is an additional and key player among the Neisseria meningitidis factors targeting immune cells. We thus provide novel insights on the strategies exploited by N. meningitidis during the infection process, which can progress to a severe illness and death., Competing Interests: V.V., S.U.L., W.P., E.B., K.S., V.M., N.N., and D.M. are employees of GSK. R.R., V.M., K.S., and D.M. report ownership of GSK shares and/or restricted GSK shares. M.M. is an employee of the University of Naples Federico II with a consultancy contract with GSK.

Background: Exosomes, as emerging biomarkers in liquid biopsies in recent years, offer profound insights into cancer diagnostics due to their unique molecular signatures. The glycosylation profiles of exosomes have emerged as potential biomarkers, offering a novel and less invasive method for cancer diagnosis and monitoring. Colorectal cancer (CRC) represents a substantial global health challenge and burden. Thus there is a great need for the aberrant glycosylation patterns on the surface of CRC cell-derived exosomes, proposing them as potential biomarkers for tumor characterization., Results: The interactions of 27 lectins with exosomes from three CRC cell lines (SW480, SW620, HCT116) and one normal colon epithelial cell line (NCM460) have been analyzed by the lectin microarray. The result indicates that Ulex Europaeus Agglutinin I (UEA-I) exhibits high affinity and specificity towards exosomes derived from SW480 cells. The expression of glycosylation related genes within cells has been analyzed by high-throughput quantitative polymerase chain reaction (HT-qPCR). The experimental result of HT-qPCR is consistent with that of lectin microarray. Moreover, the limit of detection (LOD) of UEA-I microarray is calculated to be as low as 2.7 × 10 5 extracellular vehicles (EVs) mL -1 (three times standard deviation (3σ) of blank sample). The UEA-I microarray has been successfully utilized to dynamically monitor the progression of tumors in mice-bearing SW480 CRC subtype, applicable in tumor sizes ranging from 2 mm to 20 mm in diameter., Significance: The results reveal that glycan expression pattern of exosome is linked to specific CRC subtypes, and regulated by glycosyltransferase and glycosidase genes of mother cells. Our findings illuminate the potential of glycosylation molecules on the surface of exosomes as reliable biomarkers for diagnosis of tumor at early stage and monitoring of cancer progression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The aim of the present study was to determine the effects of the adipokines progranulin and omentin on the basic functions of feline ovarian cells. For this purpose, we investigated the effects of the addition of progranulin and omentin (0, 0.1, 1, or 10 ng/ml) on the proliferation (accumulation of PCNA and cyclin B1), apoptosis (accumulation of Bax and caspase 3) and progesterone release of cultured feline ovarian granulosa cells by quantitative immunocytochemistry and enzyme-linked immunosorbent assays (ELISAs). Both progranulin and omentin increased cell proliferation and decreased apoptosis. Both progranulin and omentin promoted progesterone release. The present findings demonstrate that the adipokines progranulin and omentin can directly regulate basic feline ovarian cell functions., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Glycosylation, a crucial posttranslational modification, plays a significant role in numerous physiological and pathological processes. Lectin microarrays, which leverage the high specificity of lectins for sugar binding, are ideally suited for profiling the glycan spectra of diverse and complex biological samples. In this review, we explore the evolution of lectin detection technologies, as well as the applications and challenges of lectin microarrays in analyzing the glycome profiles of various clinical samples, including serum, saliva, tissues, sperm, and urine. This review not only emphasizes significant advancements in the high-throughput analysis of polysaccharides but also provides insight into the potential of lectin microarrays for diagnosing and managing diseases such as tumors, autoimmune diseases, and chronic inflammation. We aim to provide a clear, concise, and comprehensive overview of the use of lectin microarrays in clinical settings, thereby assisting researchers in conducting clinical studies in glycobiology.

Lectins are proteins that bind specifically and reversibly to carbohydrates, and some of them have significant anti-tumor activities. Compared to those of lectins from land plants, there are far fewer studies on algal lectins, despite of the high biodiversity of algae. However, canonical strategies based on chromatographic feature-oriented screening cannot satisfy the requirement for algal lectin discovery. In this study, prospecting for novel OAAH family lectins throughout 358 genomes of red algae and cyanobacteria was conducted. Then 35 candidate lectins and 1843 of their simulated mutated forms were virtually screened based on predicted binding specificities to characteristic carbohydrates on cancer cells inferred by a deep learning model. A new lectin, named Siye, was discovered in Kappaphycus alvarezii genome and further verified on different cancer cells. Without causing agglutination of erythrocytes, Siye showed significant cytotoxicity to four human cancer cell lines (IC 50 values ranging from 0.11 to 3.95 μg/mL), including breast adenocarcinoma HCC1937, lung carcinoma A549, liver cancer HepG2 and romyelocytic leukemia HL60. And the cytotoxicity was induced through promoting apoptosis by regulating the caspase and the p53 pathway within 24 h. This study testifies the feasibility and efficiency of the genome mining guided by evolutionary theory and artificial intelligence in the discovery of algal lectins., Competing Interests: Declaration of competing interest All authors have read and agreed to the published version of the manuscript. All the authors have declared that no competing interests exist and approved it for publication., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Klebsiella pneumoniae is an opportunistic bacterium that frequently colonizes the nasopharynx and gastrointestinal tract and can also cause severe infections when invading other tissues, particularly in immunocompromised individuals. Moreover, K. pneumoniae variants exhibiting a hypermucoviscous (HMV) phenotype are usually associated with hypervirulent strains that can produce invasive infections even in immunocompetent individuals. Major carbohydrate structures displayed on the K. pneumoniae surface are the polysaccharide capsule and the lipopolysaccharide, which presents an O-polysaccharide chain in its outermost part. Various capsular and O-chain structures have been described. Of note, production of a thick capsule is frequently observed in HMV variants. Here we examined the surface sugar epitopes of a collection of HMV and non-HMV K. pneumoniae clinical isolates and their recognition by several Siglecs and galectins, two lectin families of the innate immune system, using bacteria microarrays as main tool. No significant differences among isolates in sialic acid content or recognition by Siglecs were observed. In contrast, analysis of the binding of model lectins with diverse carbohydrate-binding specificities revealed striking differences in the recognition by galactose- and mannose-specific lectins, which correlated with the binding or lack of binding of galectins and pointed to the O-chain as the plausible ligand. Fluorescence microscopy and microarray analyses of galectin-9 binding to entire cells and outer membranes of two representative HMV isolates supported the bacteria microarray results. In addition, Western blot analysis of the binding of galectin-9 to outer membranes unveiled protein bands recognized by this galectin, and fingerprint analysis of these bands identified several proteins containing potential O -glycosylation sites, thus broadening the spectrum of possible galectin ligands on the K. pneumoniae surface. Moreover, Siglecs and galectins apparently target different structures on K. pneumoniae surfaces, thereby behaving as non-redundant complementary tools of the innate immune system., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Campanero-Rhodes, Martí, Hernández-Ortiz, Cubero, Ereño-Orbea, Ardá, Jiménez-Barbero, Ardanuy and Solís.)

Human lectins are integral to maintaining microbial homeostasis on the skin, in the blood, and at mucosal barriers. These proteins can recognize microbial glycans and inform the host about its microbial status. In accordance with their roles, their production can vary with tissue type. They also can have unique structural and biochemical properties, and they can influence microbial colonization at sites proximal and distal to their tissue of origin. In line with their classification as innate immune proteins, soluble lectins have long been studied in the context of acute infectious disease, but only recently have we begun to appreciate their roles in maintaining commensal microbial communities (i.e., the human microbiota). This review provides an overview of soluble lectins that operate at host-microbe interfaces, their glycan recognition properties, and their roles in physiological and pathological mechanisms.

Aquaporins (AQPs) are important for water transport in the gastrointestinal tract. Changes in their expression and/or localization could cause in disorders and be used as therapeutic targets. Aquaporin-4 (AQP4) is expressed predominantly on the basolateral membrane of the parietal cells in the corpus of the murine gastric glands. Although the secretion of gastric juice is not affected in AQP4-deficient knockout, we evaluated by light microscopy whether the lack of AQP4 affects the glycopatterns of secreting gastric cells. Wild type (WT) and AQP4-deficient knockout mice (KO) were fed a standard diet ad libitum before sacrifice. Segments of stomach corpus were collected, fixed in buffered formalin, and embedded in paraffin wax. Sections, 5-μm thick, were analyzed by histochemical methods (Periodic acid-Schiff, Alcian Blue pH 2.5), and binding of lectins specific to GalNAc (SBA, DBA), Gal (PNA) GlcNAc (WGA, GSAII) mannose and/or glucose (ConA), and fucose (UEA-I, AAA, LTA). Immunohistochemical methods such as anti-Muc6 for neck cells and anti- β- H + /K + -ATPase for parietal cells were also performed. Compared to WT mice, in the mucous cells of KO lower amounts of glycans with galactosyl/galactosaminylated, glycosyl/glycosaminylated, and fucosylated residues were observed; lower fucosylation resulted also in the parietal cells. The observed differences of KO in respect to WT could lead to severer pathological conditions. RESEARCH HIGHLIGHTS: Glycopatterns in gastric glands were compared between wild type (WT) and AQP4-deficient knockout (KO) mice by histochemical and lectin-binding methods. In the mucous cells of KO lower amounts of glycans with galactosyl/galactosaminylated, glycosyl/glycosaminylated and fucosylated residues were observed. In the parietal cells lower fucosylation also resulted. AQP4-deficiency affects glycosylation and could result in altered functionality and pathological conditions., (© 2024 Wiley Periodicals LLC.)

Competing Interests: Conflict of interest statement. None declared.

Multivalent lectin-glycan interactions (MLGIs) are pivotal for viral infections and immune regulation. Their structural and biophysical data are thus highly valuable, not only for understanding their basic mechanisms but also for designing potent glycoconjugate therapeutics against target MLGIs. However, such information for some important MGLIs remains poorly understood, greatly limiting research progress. We have recently developed densely glycosylated nanoparticles, e.g. , ∼4 nm quantum dots (QDs) or ∼5 nm gold nanoparticles (GNPs), as mechanistic probes for MLGIs. Using two important model lectin viral receptors, DC-SIGN and DC-SIGNR, we have shown that these probes can not only offer sensitive fluorescence assays for quantifying MLGI affinities, but also reveal key structural information ( e.g. , binding site orientation and binding mode) useful for MLGI targeting. However, the small sizes of the previous scaffolds may not be optimal for maximising MLGI affinity and targeting specificity. Herein, using α-manno-α-1,2-biose (DiMan) functionalised GNP (GNP-DiMan) probes, we have systematically studied how GNP scaffold size ( e.g. , 5, 13, and 27 nm) and glycan density ( e.g. , 100, 75, 50 and 25%) determine their MLGI affinities, thermodynamics, and antiviral properties. We have developed a new GNP fluorescence quenching assay format to minimise the possible interference of GNP's strong inner filter effect in MLGI affinity quantification, revealing that increasing the GNP size is highly beneficial for enhancing MLGI affinity. We have further determined the MLGI thermodynamics by combining temperature-dependent affinity and Van't Hoff analyses, revealing that GNP-DiMan-DC-SIGN/R binding is enthalpy driven with favourable binding Gibbs free energy changes (Δ G °) being enhanced with increasing GNP size. Finally, we show that increasing the GNP size significantly enhances their antiviral potency. Notably, the DiMan coated 27 nm GNP potently and robustly blocks both DC-SIGN and DC-SIGNR mediated pseudo-Ebola virus cellular entry with an EC 50 of ∼23 and ∼49 pM, respectively, making it the most potent glycoconjugate inhibitor against DC-SIGN/R-mediated Ebola cellular infections. Our results have established GNP-glycans as a new tool for quantifying MLGI biophysical parameters and revealed that increasing the GNP scaffold size significantly enhances their MLGI affinities and antiviral potencies.

Osteoporosis is characterized by an imbalance between osteoclast-mediated bone resorption and osteoblast-related bone formation, particularly increased osteoclastogenesis. However, the mechanisms by which epigenetic factors regulate osteoclast precursor differentiation during osteoclastogenesis remain poorly understood. Here, we show that the specific knockout of the chromatin remodeling factor Arid1a in bone marrow-derived macrophages (BMDMs) results in increased bone mass. The loss of Arid1a in BMDM inhibits cell-cell fusion and maturation of osteoclast precursors, thereby suppressing osteoclast differentiation. Mechanistically, Arid1a increases the chromatin access in the gene promoter region of sialic acid-binding Ig-like lectin 15 (Siglec15) by transcription factor Jun/Fos, which results in the upregulation of Siglec15 and promotion of osteoclast differentiation. However, the loss of Arid1a reprograms the chromatin structure to restrict Siglec15 expression in osteoclast precursors, thereby inhibiting BMDM differentiation into mature osteoclasts. Deleting Arid1a after ovariectomy (a model for postmenopausal bone loss) alleviated bone loss and maintained bone mass. In summary, epigenetic reprogramming mediated by Arid1a loss suppresses osteoclast differentiation and may serve as a promising therapeutic strategy for treating bone loss diseases., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society for Bone and Mineral Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Preeclampsia, especially early-onset preeclampsia (EO-PE), is a pregnancy complication that has serious consequences for the health of both the mother and the fetus. Although abnormal placentation due to mitochondrial dysfunction is speculated to contribute to the development of EO-PE, the underlying mechanisms have yet to be fully elucidated., Methods: The expression and localization of Siglec-6 in the placenta from normal pregnancies, preterm birth and EO-PE patients were examined by RT-qPCR, Western blot and IHC. Transwell assays were performed to evaluate the effect of Siglec-6 on trophoblast cell migration and invasion. Seahorse experiments were conducted to assess the impact of disrupting Siglec-6 expression on mitochondrial function. Co-IP assay was used to examine the interaction of Siglec-6 with SHP1/SHP2. RNA-seq was employed to investigate the mechanism by which Siglec-6 inhibits mitochondrial function in trophoblast cells., Results: The expression of Siglec-6 in extravillous trophoblasts is increased in placental tissues from EO-PE patients. Siglec-6 inhibits trophoblast cell migration and invasion and impairs mitochondrial function. Mechanismly, Siglec-6 inhibits the activation of NF-κB by recruiting SHP1/SHP2, leading to increased expression of GPR20. Notably, the importance of GPR20 function downstream of Siglec-6 in trophoblasts is supported by the observation that GPR20 downregulation rescues defects caused by Siglec-6 overexpression. Finally, overexpression of Siglec-6 in the placenta induces a preeclampsia-like phenotype in a pregnant mouse model., Conclusions: This study indicates that the regulatory pathway Siglec-6/GPR20 has a crucial role in regulating trophoblast mitochondrial function, and we suggest that Siglec-6 and GPR20 could serve as potential markers and targets for the clinical diagnosis and therapy of EO-PE., (© 2024. The Author(s).)

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis, with clinical outcomes ranging from asymptomatic infections to severe invasive diseases. The innate immune system, particularly macrophages, is of paramount importance in resisting the invasion of host tissues and organs by the trophozoites of E. histolytica . Parasite-derived pathogenic factors, such as lectins, play a pivotal role in the promotion of macrophage polarization phenotypes that have undergone alteration. Nevertheless, the precise mechanisms by which E. histolytica modulates immune polarization remain largely unknown. The current study focused on the immunomodulatory effects of the Igl-C fragment of E. histolytica Gal/GalNAc lectin on macrophage polarization. These results demonstrated that Igl-C could induce the secretion of IL-1β, IL-6, and other cytokines, activating a mixed M1/M2 polarization state. M1 polarization of macrophages occurs in the early stages and gradually transitions to M2 polarization in the later stages, which may contribute to the persistence of the infection. Igl-C induces the macrophage M1 phenotype and causes the release of immune effector molecules, including iNOS and cytokines, by activating the NF-κB p65 and JAK-STAT1 transcription factor signaling pathways. Furthermore, Igl-C supports the macrophage M2 phenotype via JAK-STAT3 and IL-4-STAT6 pathways, which activate arginase expression in later stages, contributing to the tissue regeneration and persistence of the parasite. The involvement of distinct signaling pathways in mediating this response highlights the complex interplay between the parasite and the host immune system. These findings enhance our understanding of the Igl-C-mediated pathogenic mechanisms during E. histolytica infection., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Dong, Zhang, Li, Zhang, Cheng and Feng.)

Carcinomas are common in humans but rare among closely related "great apes." Plausible explanations, including human-specific genomic alterations affecting the biology of sialic acids, are proposed, but causality remains unproven. Here, an integrated evolutionary genetics-phenome-transcriptome approach studied the role of SIGLEC12 gene (encoding Siglec-XII) in epithelial transformation and cancer. Exogenous expression of the protein in cell lines and genetically engineered mice recapitulated approximately 30% of the human population in whom the protein is expressed in a form that cannot bind ligand because of a fixed, homozygous, human-universal missense mutation. Siglec-XII-null cells/mice recapitulated the remaining approximately 70% of the human population in whom an additional polymorphic frameshift mutation eliminates the entire protein. Siglec-XII expression drove several pro-oncogenic phenotypes in cell lines and increased tumor burden in mice challenged with chemical carcinogen and inflammation. Transcriptomic studies yielded a 29-gene signature of Siglec-XII-positive disease and when used as a computational tool for navigating human data sets, pinpointed with surprising precision that SIGLEC12 expression (model) recapitulates a very specific type of colorectal carcinomas (disease) that is associated with mismatch-repair defects and inflammation, disproportionately affects European Americans, and carries a favorable prognosis. They revealed a hitherto-unknown evolutionary genetic mechanism for an ethnic/environmental predisposition of carcinogenesis.