Decoding the multifaceted roles of galectins in self-defense.

In this review, we aim to explore the multifaceted roles of galectins in host defense from a broader perspective, particularly regarding their functions when host integrity is compromised. Numerous comprehensive reviews on galectin functions in immunity have already been published. For researchers new to the field, this wealth of information may create an impression of galectins as proteins involved in a wide array of biological processes.

Preparation of Glycan Arrays Using Glycopeptides Derived From Biomaterials.

In general, viruses recognize host cell surface glycans, but the measurement of virus-host cell glycan interaction is not widely operated. This is not only because commercially available, structure-defined glycans are limited, but also because such interactions, if any, between viruses and isolated glycans are relatively weak, and thus, difficult to detect by conventional methods, e.g.

Transformation of Agrocybe cylindracea Galectin into αGalNAc-Specific Lectin.

A multi-specific fungal galectin from the mushroom Agrocybe cylindracea (ACG) binds a broad range of β-galactosides, as well as their derivative GalNAcα1-3Gal. Site-directed mutagenesis of the hydrophilic residues His, Asn, Arg, and Glu, involved in carbohydrate recognition, abolished the binding affinity of the derived mutants to β-galactosides, whereas only N46A caused increased affinity to GalNAcα1-3Gal-containing oligosaccharides and loss of β-galactoside-binding activity. Detailed structural analysis revealed that Pro45, the preceding residue of Asn46 of the wild-type ACG, takes the cis imide conformation to tether Asn46 onto a loop region to make new hydrogen bonds with β-galactosides and to compensate for the lack of evolutionarily conserved Asn.

Distinguishing functional exosomes and other extracellular vesicles as a nucleic acid cargo by the anion-exchange method.

The development of a new large-scale purification protocol is required for research on the reliable bioactivity and drug discovery of extracellular vesicles (EVs). To address this issue, herein, we propose an effective method for preparing high-performance exosomes (EXOs) by using an anion-exchange method. Cytotoxic T-lymphocyte (CTL) EVs from 4 L of culture supernatant through a 220 nm cut-off filter are divided into two populations at a deproteinization rate of over 99.

Development of Urinary Diagnostic Biomarker for IgA Nephropathy by Lectin Microarray.

Introduction: The pathogenic roles of aberrantly glycosylated IgA1 have been reported. However, it is unexplored whether the profiling of urinary glycans contributes to the diagnosis of IgAN.

Methods: We conducted a retrospective study enrolling 493 patients who underwent renal biopsy at Okayama University Hospital between December 2010 and September 2017.

DCIR and its ligand asialo-biantennary N-glycan regulate DC function and osteoclastogenesis.

Dendritic cell immunoreceptor (DCIR) is a C-type lectin receptor with a carbohydrate recognition domain and an immunoreceptor tyrosine-based inhibitory motif. Previously, we showed that Dcir-/- mice spontaneously develop autoimmune enthesitis and sialadenitis, and also develop metabolic bone abnormalities. However, the ligands for DCIR functionality remain to be elucidated.

Total Synthesis of Acaulide and Acaulone A.

Acaulide and acaulone A, which contain 14-membered macrodiolides, were isolated from a culture of sp. H-JQSF. The antiosteoporosis activity of acaulide is expected to contribute to drug discovery research for an aging society.

A technique for removing tumourigenic pluripotent stem cells using rBC2LCN lectin.

Introduction: Tumourigenesis attributed to residual undifferentiated cells in a graft is considered to be a significant issue in cell therapy using human pluripotent stem cells. To ensure the safety of regenerative medicine derived from pluripotent stem cells, residual undifferentiated cells must be eliminated in the manufacturing process. We previously described the lectin probe rBC2LCN, which binds harmlessly and specifically to the cell surface of human pluripotent stem cells.

Preparation and Detection of Glycan-Binding Activity of Influenza Virus.

We describe a method to detect influenza virus using an evanescent-field-activated fluorescence scanner type glycan array and ELISA system. Neoglycoprotein was prepared by combination of organic chemistry and biomaterial preparation. These ligands were spotted on a glass plate or plastic well to make a glycan array and ELISA plate.

Glycan Binding Profiling of Jacalin-Related Lectins from the Pearl Shell.

We determined the primary structures of jacalin-related lectins termed PPL3s (PPL3A, 3B, and 3C, which are dimers consisting of sequence variants α + α, α + β, β + β, respectively) and PPL4, which is heterodimer consisting of α + β subunits, isolated from mantle secretory fluid of (Mabe) pearl shell. Their carbohydrate-binding properties were analyzed, in addition to that of PPL2A, which was previously reported as a matrix protein. PPL3s and PPL4 shared only 35-50% homology to PPL2A, respectively; they exhibited significantly different carbohydrate-binding specificities based on the multiple glycan binding profiling data sets from frontal affinity chromatography analysis.

Lectin engineering: the possible and the actual.

Lectins are a widespread group of sugar-binding proteins occurring in all types of organisms including animals, plants, bacteria, fungi and even viruses. According to a recent report, there are more than 50 lectin scaffolds (∼Pfam), for which three-dimensional structures are known and sugar-binding functions have been confirmed in the literature, which far exceeds our view in the twentieth century (Fujimoto 2014 , 579-606 (doi:10.1007/978-1-4939-1292-6_46)).

N-glycan structures of human alveoli provide insight into influenza A virus infection and pathogenesis.

Unlabelled: The rapidly evolvable influenza A virus has caused pandemics linked to millions of deaths in the past century. Influenza A viruses are categorized by H (hemagglutinin; HA) and N (neuraminidase; NA) proteins expressed on the viral envelope surface. Analyses of past pandemics suggest that the HA gene segment comes from a nonhuman virus, which is then introduced into an immunologically naïve human population with potentially devastating consequences.

Fucose-specific lectin of Aspergillus fumigatus: binding properties and effects on immune response stimulation.

Aspergillus fumigatus is the major causative fungus of aspergillosis, and many studies have explored the relationship between A. fumigatus and pathogenicity. In the current study, we focused on a fucose-specific lectin, FleA, as a novel molecule which related to the pathogenicity of A.

Development of a Sensitive Microarray Platform for the Ranking of Galectin Inhibitors: Identification of a Selective Galectin-3 Inhibitor.

Glycan microarrays are useful tools for lectin glycan profiling. The use of a glycan microarray based on evanescent-field fluorescence detection was herein further extended to the screening of lectin inhibitors in competitive experiments. The efficacy of this approach was tested with 2/3'-mono- and 2,3'-diaromatic type II lactosamine derivatives and galectins as targets and was validated by comparison with fluorescence anisotropy proposed as an orthogonal protein interaction measurement technique.

A Novel Therapeutic Strategy for Pancreatic Cancer: Targeting Cell Surface Glycan Using rBC2LC-N Lectin-Drug Conjugate (LDC).

Various cancers, including pancreatic ductal adenocarcinoma (PDAC), remain intractable even with costly tumor-targeting antibody drugs. Because the outermost coatings of cancer cells are composed of cell-specific glycan layers (glycocalyx), lectins, proteins with glycan-binding potential, were evaluated for possible use as drug carriers in PDAC treatment. A human PDAC cell line with well-to-moderately differentiated properties (Capan-1) was subjected to lectin microarray analysis to identify specific lectin-glycan pairs.

Lectin microarray analysis of isolated polysaccharides from Sasa veitchii.

We report lectin microarray profile of the polysaccharide fraction derived from Sasa veitchii leaf that exhibits anti-influenza activity. This fraction showed higher reactivities with lectins known as binders to oligo-mannose, fucose, or galactose. Our findings along with previously reported monosaccharide components suggest that the polysaccharide can be cross-reactive with cell surface receptors involved in immune system, thereby exerting anti-influenza activity.

Sugar-Binding Profiles of Chitin-Binding Lectins from the Hevein Family: A Comprehensive Study.

Chitin-binding lectins form the hevein family in plants, which are defined by the presence of single or multiple structurally conserved GlcNAc (N-acetylglucosamine)-binding domains. Although they have been used as probes for chito-oligosaccharides, their detailed specificities remain to be investigated. In this study, we analyzed six chitin-binding lectins, DSA, LEL, PWM, STL, UDA, and WGA, by quantitative frontal affinity chromatography.

Engineering of recombinant Wisteria floribunda agglutinin specifically binding to GalNAcβ1,4GlcNAc (LacdiNAc).

Wisteria floribunda agglutinin (WFA) is a useful probe for distinguishing glycan structural alterations in diseases such as intrahepatic bile duct carcinoma and hepatic fibrosis; however, the gene encoding WFA has not been identified. Here, we identified the gene encoding WFA, and recombinant WFA (rWFA) was expressed in Escherichia coli and purified. The natural complementary DNA sequence obtained from wisteria seeds contained an open reading frame of 861 nucleotides encoding a WFA precursor, which included a hydrophobic signal peptide at the N-terminus, a propeptide at the C-terminus and a single cysteine (Cys) residue for dimer formation.

Isolation of Rice Bran Lectins and Characterization of Their Unique Behavior in Caco-2 Cells.

Rice bran lectins, named as RBA1 and RBA2, were isolated from in two chromatography steps: affinity chromatography and cation-exchange chromatography. RBA1 was found to be composed of a covalently linked heterodimer of 20- and 12-kDa subunits, and RBA2 was a noncovalently linked dimer of 12-kDa subunits. Both RBA1 and RBA2 bound to desialylated complex glycoproteins such as fetuin, α1-acid glycoprotein, and transferrin, and agalactosylated complex glycoproteins such as agalacto fetuin, agalacto-α1-acid glycoprotein, and agalacto-transferrin, in addition to chitooligosacchrides.

Carbohydrate recognition by the rhamnose-binding lectin SUL-I with a novel three-domain structure isolated from the venom of globiferous pedicellariae of the flower sea urchin Toxopneustes pileolus.

The globiferous pedicellariae of the venomous sea urchin Toxopneustes pileolus contains several biologically active proteins. We have cloned the cDNA of one of the toxin components, SUL-I, which is a rhamnose-binding lectin (RBL) that acts as a mitogen through binding to carbohydrate chains on target cells. Recombinant SUL-I (rSUL-I) was produced in Escherichia coli cells, and its carbohydrate-binding specificity was examined with the glycoconjugate microarray analysis, which suggested that potential target carbohydrate structures are galactose-terminated N-glycans.

Development of a practical sandwich assay to detect human pluripotent stem cells using cell culture media.

Human pluripotent stem cells are considered to be ideal cell sources for regenerative medicine, but their clinical and industrial application is hindered by their tumorigenic potential. Previously we have identified a pluripotent stem cell-specific lectin rBC2LCN recognizing podocalyxin as a cell surface ligand. More recently, podocalyxin was found to be a soluble ligand of rBC2LCN that is secreted specifically from human pluripotent stem cells into cell culture media.

Carbohydrate-binding domain of the POMGnT1 stem region modulates O-mannosylation sites of α-dystroglycan.

The dystrophin glycoprotein complex, which connects the cell membrane to the basement membrane, is essential for a variety of biological events, including maintenance of muscle integrity. An O-mannose-type GalNAc-β1,3-GlcNAc-β1,4-(phosphate-6)-Man structure of α-dystroglycan (α-DG), a subunit of the complex that is anchored to the cell membrane, interacts directly with laminin in the basement membrane. Reduced glycosylation of α-DG is linked to some types of inherited muscular dystrophy; consistent with this relationship, many disease-related mutations have been detected in genes involved in O-mannosyl glycan synthesis.

Identification, Characterization, and X-ray Crystallographic Analysis of a Novel Type of Mannose-Specific Lectin CGL1 from the Pacific Oyster Crassostrea gigas.

A novel mannose-specific lectin, named CGL1 (15.5 kDa), was isolated from the oyster Crassostrea gigas. Characterization of CGL1 involved isothermal titration calorimetry (ITC), glycoconjugate microarray, and frontal affinity chromatography (FAC).

Structural and quantitative evidence of α2-6-sialylated N-glycans as markers of the differentiation potential of human mesenchymal stem cells.

Human somatic stem cells such as mesenchymal stem cells (hMSCs) have the capacity to differentiate into mesenchymal tissue lineages and to alter immune regulatory functions. As such, they hold promise for use in stem cell-based therapies. However, no method is currently available to evaluate the actual differentiation capacity of hMSCs prior to cell transplantation.