302 results found
Makrydaki E, Donini R, Krueger A, et al., 2024, Immobilized enzyme cascade for targeted glycosylation, Nature Chemical Biology, ISSN: 1552-4450
Glycosylation is a critical post-translational protein modification that affects folding, half-life and functionality. Glycosylation is a non-templated and heterogeneous process because of the promiscuity of the enzymes involved. We describe a platform for sequential glycosylation reactions for tailored sugar structures (SUGAR-TARGET) that allows bespoke, controlled N-linked glycosylation in vitro enabled by immobilized enzymes produced with a one-step immobilization/purification method. We reconstruct a reaction cascade mimicking a glycosylation pathway where promiscuity naturally exists to humanize a range of proteins derived from different cellular systems, yielding near-homogeneous glycoforms. Immobilized β-1,4-galactosyltransferase is used to enhance the galactosylation profile of three IgGs, yielding 80.2-96.3% terminal galactosylation. Enzyme recycling is demonstrated for a reaction time greater than 80 h. The platform is easy to implement, modular and reusable and can therefore produce homogeneous glycan structures derived from various hosts for functional and clinical evaluation.
Sammon D, Krueger A, Busse-Wicher M, et al., 2023, Molecular mechanism of decision-making in glycosaminoglycan biosynthesis, Nature Communications, Vol: 14, ISSN: 2041-1723
Two major glycosaminoglycan types, heparan sulfate (HS) and chondroitin sulfate (CS), control many aspects of development and physiology in a type-specific manner. HS and CS are attached to core proteins via a common linker tetrasaccharide, but differ in their polymer backbones. How core proteins are specifically modified with HS or CS has been an enduring mystery. By reconstituting glycosaminoglycan biosynthesis in vitro, we establish that the CS-initiating N-acetylgalactosaminyltransferase CSGALNACT2 modifies all glycopeptide substrates equally, whereas the HS-initiating N-acetylglucosaminyltransferase EXTL3 is selective. Structure-function analysis reveals that acidic residues in the glycopeptide substrate and a basic exosite in EXTL3 are critical for specifying HS biosynthesis. Linker phosphorylation by the xylose kinase FAM20B accelerates linker synthesis and initiation of both HS and CS, but has no effect on the subsequent polymerisation of the backbone. Our results demonstrate that modification with CS occurs by default and must be overridden by EXTL3 to produce HS.
Kikuchi C, Antonopoulos A, Wang S, et al., 2023, Glyco-engineered MDCK cells display preferred receptors of H3N2 influenza absent in eggs used for vaccines, Nature Communications, Vol: 14, ISSN: 2041-1723
Evolution of human H3N2 influenza viruses driven by immune selection has narrowed the receptor specificity of the hemagglutinin (HA) to a restricted subset of human-type (Neu5Acα2-6 Gal) glycan receptors that have extended poly-LacNAc (Galβ1-4GlcNAc) repeats. This altered specificity has presented challenges for hemagglutination assays, growth in laboratory hosts, and vaccine production in eggs. To assess the impact of extended glycan receptors on virus binding, infection, and growth, we have engineered N-glycan extended (NExt) cell lines by overexpressing β3-Ν-acetylglucosaminyltransferase 2 in MDCK, SIAT, and hCK cell lines. Of these, SIAT-NExt cells exhibit markedly increased binding of H3 HAs and susceptibility to infection by recent H3N2 virus strains, but without impacting final virus titers. Glycome analysis of these cell lines and allantoic and amniotic egg membranes provide insights into the importance of extended glycan receptors for growth of recent H3N2 viruses and relevance to their production for cell- and egg-based vaccines.
Gimeno-Molina B, Bayar E, Mountain K, et al., 2023, The role of cervical neutrophils in cervicovaginal inflammation in women at high-risk of delivering preterm, 12th International Workshop Reunion Island Reproductive Immunology, Immunological tolerance and Immunology of preeclampsia, Publisher: ELSEVIER IRELAND LTD, Pages: 31-31, ISSN: 0165-0378
Mountain K, MacIntyre D, Chan D, et al., 2023, ABO blood group antigens and preterm birth risk, 12th International Workshop Reunion Island Reproductive Immunology, Immunological tolerance and Immunology of preeclampsia, Publisher: ELSEVIER IRELAND LTD, Pages: 37-37, ISSN: 0165-0378
Xie Y, Zhao F, Freitag N, et al., 2023, Maternal-derived galectin-1 shapes the placenta niche through Sda terminal glycosylation: implication for preeclampsia, PNAS Nexus, Vol: 2, ISSN: 2752-6542
Placental abnormalities cause impaired fetal growth and poor pregnancy outcome (e.g. preeclampsia [PE]) with long-lasting consequences for the mother and offspring. The molecular dialogue between the maternal niche and the developing placenta is critical for the function of this organ. Galectin-1 (gal-1), a highly expressed glycan-binding protein at the maternal–fetal interface, orchestrates the maternal adaptation to pregnancy and placenta development. Down-regulation or deficiency of gal-1 during pregnancy is associated with the development of PE; however, the maternal- and placental-derived gal-1 contributions to the disease onset are largely unknown. We demonstrate that lack of gal-1 imposes a risk for PE development in a niche-specific manner, and this is accompanied by a placental dysfunction highly influenced by the absence of maternal-derived gal-1. Notably, differential placental glycosylation through the Sda-capped N-glycans dominates the invasive trophoblast capacity triggered by maternal-derived gal-1. Our findings show that gal-1 derived from the maternal niche is essential for healthy placenta development and indicate that impairment of the gal-1 signaling pathway within the maternal niche could be a molecular cause for maternal cardiovascular maladaptation during pregnancy.
Huang Z, Lai PF, Cocker ATH, et al., 2023, Roles of N-linked glycosylation and glycan-binding proteins in placentation: trophoblast infiltration, immunomodulation, angiogenesis, and pathophysiology, Biochemical Society Transactions, Vol: 51, Pages: 639-653, ISSN: 0300-5127
Protein N-linked glycosylation is a structurally diverse post-translational modification that stores biological information in a larger order of magnitude than other post-translational modifications such as phosphorylation, ubiquitination and acetylation. This gives N-glycosylated proteins a diverse range of properties and allows glyco-codes (glycan-related information) to be deciphered by glycan-binding proteins (GBPs). The intervillous space of the placenta is richly populated with membrane-bound and secreted glycoproteins. Evidence exists to suggest that altering the structural nature of their N-glycans can impact several trophoblast functions, which include those related to interactions with decidual cells. This review summarizes trophoblast-related activities influenced by N-glycan-GBP recognition, exploring how different subtypes of trophoblasts actively adapt to characteristics of the decidualized endometrium through cell-specific expression of N-glycosylated proteins, and how these cells receive decidua-derived signals via N-glycan-GBP interactions. We highlight work on how changes in N-glycosylation relates to the success of trophoblast infiltration, interactions of immunomodulators, and uterine angiogenesis. We also discuss studies that suggest aberrant N-glycosylation of trophoblasts may contribute to the pathogenesis of pregnancy complications (e.g. pre-eclampsia, early spontaneous miscarriages and hydatidiform mole). We propose that a more in-depth understanding of how N-glycosylation shapes trophoblast phenotype during early pregnancy has the potential to improve our approach to predicting, diagnosing and alleviating poor maternal/fetal outcomes associated with placental dysfunction.
Kotidis P, Donini R, Arnsdorf J, et al., 2023, CHOGlycoNET: comprehensive glycosylation reaction network for CHO cells, Metabolic Engineering, Vol: 76, Pages: 87-96, ISSN: 1096-7176
Chinese hamster ovary (CHO) cells are extensively used for the production of glycoprotein therapeutics proteins, for which N-linked glycans are a critical quality attribute due to their influence on activity and immunogenicity. Manipulation of protein glycosylation is commonly achieved through cell or process engineering, which are often guided by mathematical models. However, each study considers a unique glycosylation reaction network that is tailored around the cell line and product at hand. Herein, we use 200 glycan datasets for both recombinantly produced and native proteins from different CHO cell lines to reconstruct a comprehensive reaction network, CHOGlycoNET, based on the individual minimal reaction networks describing each dataset. CHOGlycoNET is used to investigate the distribution of mannosidase and glycosyltransferase enzymes in the Golgi apparatus and identify key network reactions using machine learning and dimensionality reduction techniques. CHOGlycoNET can be used for accelerating glycomodel development and predicting the effect of glycoengineering strategies. Finally, CHOGlycoNET is wrapped in a SBML file to be used as a standalone model or in combination with CHO cell genome scale models.
Chakraborty A, Perez M, Carroll JD, et al., 2023, Hypoxia Controls the Glycome Signature and Galectin-8-Ligand Axis to Promote Protumorigenic Properties of Metastatic Melanoma., J Invest Dermatol, Vol: 143, Pages: 456-469.e8
The prognosis for patients with metastatic melanoma (MM) involving distant organs is grim, and treatment resistance is potentiated by tumor-initiating cells (TICs) that thrive under hypoxia. MM cells, including TICs, express a unique glycome featuring i-linear poly-N-acetyllactosamines through the loss of I-branching enzyme, β1,6 N-acetylglucosaminyltransferase 2. Whether hypoxia instructs MM TIC development by modulating the glycome signature remains unknown. In this study, we explored hypoxia-dependent alterations in MM glycome‒associated genes and found that β1,6 N-acetylglucosaminyltransferase 2 was downregulated and a galectin (Gal)-8-ligand axis, involving both extracellular and cell-intrinsic Gal-8, was induced. Low β1,6 N-acetylglucosaminyltransferase 2 levels correlated with poor patient outcomes, and patient serum samples were elevated for Gal-8. Depressed β1,6 N-acetylglucosaminyltransferase 2 in MM cells upregulated TIC marker, NGFR/CD271, whereas loss of MM cell‒intrinsic Gal-8 markedly lowered NGFR and reduced TIC activity in vivo. Extracellular Gal-8 bound preferentially to i-linear poly-N-acetyllactosamines on N-glycans of the TIC marker and prometastatic molecule CD44, among other receptors, and activated prosurvival factor protein kinase B. This study reveals the importance of hypoxia governing the MM glycome by enforcing i-linear poly-N-acetyllactosamine and Gal-8 expression. This mechanistic investigation also uncovers glycome-dependent regulation of pro-MM factor, NGFR, implicating i-linear poly-N-acetyllactosamine and Gal-8 as biomarkers and therapeutic targets of MM.
Yung HW, Zhao X, Glover L, et al., 2023, Perturbation of placental protein glycosylation by endoplasmic reticulum stress promotes maladaptation of maternal hepatic glucose metabolism, iScience, Vol: 26, ISSN: 2589-0042
Placental hormones orchestrate maternal metabolic adaptations to support pregnancy. We hypothesized that placental ER stress, which characterizes early-onset pre-eclampsia (ePE), compromises glycosylation, reducing hormone bioactivity and these maladaptations predispose the mother to metabolic disease in later life. We demonstrate ER stress reduces the complexity and sialylation of trophoblast protein N-glycosylation, while aberrant glycosylation of vascular endothelial growth factor reduced its bioactivity. ER stress alters the expression of 66 of the 146 genes annotated with “protein glycosylation” and reduces the expression of sialyltransferases. Using mouse placental explants, we show ER stress promotes the secretion of mis-glycosylated glycoproteins. Pregnant mice carrying placentas with junctional zone-specific ER stress have reduced blood glucose, anomalous hepatic glucose metabolism, increased cellular stress and elevated DNA methyltransferase 3A. Using pregnancy-specific glycoproteins as a readout, we also demonstrate aberrant glycosylation of placental proteins in women with ePE, thus providing a mechanistic link between ePE and subsequent maternal metabolic disorders.
Cioce A, Calle B, Rizou T, et al., 2022, Cell-specific bioorthogonal tagging of glycoproteins, Nature Communications, Vol: 13, Pages: 1-18, ISSN: 2041-1723
Altered glycoprotein expression is an undisputed corollary of cancer development. Understanding these alterations is paramount but hampered by limitations underlying cellular model systems. For instance, the intricate interactions between tumour and host cannot be adequately recapitulated in monoculture of tumour-derived cell lines. More complex co-culture models usually rely on sorting procedures for proteome analyses and rarely capture the details of protein glycosylation. Here, we report a strategy termed Bio-Orthogonal Cell line-specific Tagging of Glycoproteins (BOCTAG). Cells are equipped by transfection with an artificial biosynthetic pathway that transforms bioorthogonally tagged sugars into the corresponding nucleotide-sugars. Only transfected cells incorporate bioorthogonal tags into glycoproteins in the presence of non-transfected cells. We employ BOCTAG as an imaging technique and to annotate cell-specific glycosylation sites in mass spectrometry-glycoproteomics. We demonstrate application in co-culture and mouse models, allowing for profiling of the glycoproteome as an important modulator of cellular function.
Wu G, Grassi P, MacIntyre D, et al., 2022, N-Glycosylation of cervicovaginal fluid reflects microbial community, immune activity, and pregnancy status, Scientific Reports, Vol: 12, Pages: 1-14, ISSN: 2045-2322
Human cervicovaginal fluid (CVF) is a complex, functionally important and glycan rich biological fluid, fundamental in mediating physiological events associated with reproductive health. Using a comprehensive glycomic strategy we reveal an extremely rich and complex N-glycome in CVF of pregnant and non-pregnant women, abundant in paucimannose and highmannose glycans, complex glycans with 2-4 N-Acetyllactosamine (LacNAc) antennae, and Poly-LacNAc glycans decorated with fucosylation and sialylation. N-glycosylation variations were observed to differ in relation to pregnancy status, microbial composition, immune activation, and pregnancy outcome. Compared to CVF from women experiencing term birth, CVF from women who subsequently experienced preterm birth showed lower sialylation, which correlated to the presence of a diverse microbiome, and higher fucosylation, which correlated positively to pro-inflammatory cytokine concentration. This study is the first step towards better understanding the role of cervicovaginal glycans in reproductive health, their contribution to the mechanism of microbial driven preterm birth, and their potential forpreventative therapy.
Mohammed NBB, Antonopoulos A, Dell A, et al., 2022, The pleiotropic role of galectin-3 in melanoma progression: Unraveling the enigma, Advances in Cancer Research, ISSN: 0065-230X
Melanoma is a highly aggressive skin cancer with poor outcomes associated with distant metastasis. Intrinsic properties of melanoma cells alongside the crosstalk between melanoma cells and surrounding microenvironment determine the tumor behavior. Galectin-3 (Gal-3), a ß-galactoside-binding lectin, has emerged as a major effector in cancer progression, including melanoma behavior. Data from melanoma models and patient studies reveal that Gal-3 expression is dysregulated, both intracellularly and extracellularly, throughout the stages of melanoma progression. This review summarizes the most recent data and hypotheses on Gal-3 and its tumor-modulating functions, highlighting its role in driving melanoma growth, invasion, and metastatic colonization. It also provides insight into potential Gal-3-targeted strategies for melanoma diagnosis and treatment.
Cao H, Mathur A, Robertson C, et al., 2022, Measurement of erythrocyte membrane mannoses to assess splenic function, British Journal of Haematology, Vol: 198, Pages: 155-164, ISSN: 0007-1048
Red blood cells (RBCs) lose plasma membrane in the spleen as they age, but the cells and molecules involved are yet to be identified. Sickle cell disease and infection by Plasmodium falciparum cause oxidative stress that induces aggregates of cross-linked proteins with N-linked high-mannose glycans (HMGs). These glycans can be recognised by mannose-binding lectins, including the mannose receptor (CD206), expressed on macrophages and specialised phagocytic endothelial cells in the spleen to mediate the extravascular haemolysis characteristic of these diseases. We postulated this system might also mediate removal of molecules and membrane in healthy individuals. Surface expression of HMGs on RBCs from patients who had previously undergone splenectomy was therefore assessed: high levels were indeed observable as large membrane aggregates. Glycomic analysis by mass spectrometry identified a mixture of Man5-9GlcNAc2 structures. HMG levels correlated well with manual pit counts (r = 0.75–0.85). To assess further whether HMGs might act as a splenic reticuloendothelial function test, we measured levels on RBCs from patients with potential functional hyposplenism, some of whom exhibited high levels that may indicate risk of complications.
Marbiah M, Kotidis P, Donini R, et al., 2022, Rapid antibody glycoengineering in Chinese hamster ovary cells., Journal of Visualized Experiments, Vol: 184, Pages: 1-19, ISSN: 1940-087X
Recombinant monoclonal antibodies bind specific molecular targets and, subsequently, induce an immune response or inhibit the binding of other ligands. However, monoclonal antibody functionality and half-life may be reduced by the type and distribution of host-specific glycosylation. Attempts to produce superior antibodies have inspired the development of genetically modified producer cells that synthesize glyco-optimized antibodies. Glycoengineering typically requires the generation of a stable knockout or knockin cell line using methods such as clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9. Monoclonal antibodies produced by engineered cells are then characterized using mass spectrometric methods to determine if the desired glycoprofile has been obtained. This strategy is time-consuming, technically challenging, and requires specialists. Therefore, an alternative strategy that utilizes streamlined protocols for genetic glycoengineering and glycan detection may assist endeavors toward optimal antibodies. In this proof-of-concept study, an IgG-producing Chinese hamster ovary cell served as an ideal host to optimize glycoengineering. Short interfering RNA targeting the Fut8 gene was delivered to Chinese hamster ovary cells, and the resulting changes in FUT8 protein expression were quantified. The results indicate that knockdown by this method was efficient, leading to a ~60% reduction in FUT8. Complementary analysis of the antibody glycoprofile was performed using a rapid yet highly sensitive technique: capillary gel electrophoresis and laser-induced fluorescence detection. All knockdown experiments showed an increase in afucosylated glycans; however, the greatest shift achieved in this study was ~20%. This protocol simplifies glycoengineering efforts by harnessing in silico design tools, commercially synthesized gene targeting reagents, and rapid quantification assays that do not require extensive prior experience. As such, t
Mountain K, MacIntyre D, Chan D, et al., 2022, Blood group antigens influence host-microbe interactions and risk of early preterm birth, Publisher: WILEY, Pages: 55-56, ISSN: 1470-0328
Duncombe L, Howells L, Haughey A, et al., 2022, The tip of brucella O-Polysaccharide is a potent epitope in response to brucellosis infection and enables short synthetic antigens to be superior diagnostic reagents, Microorganisms, Vol: 10, Pages: 1-19, ISSN: 2076-2607
Brucellosis is a global disease and the world’s most prevalent zoonosis. All cases in livestock and most cases in humans are caused by members of the genus Brucella that possess a surface O-polysaccharide (OPS) comprised of a rare monosaccharide 4-deoxy-4-formamido-D-mannopyranose assembled with α1,2 and α1,3 linkages. The OPS of the bacterium is the basis for serodiagnostic tests for brucellosis. Bacteria that also contain the same rare monosaccharide can induce antibodies that cross-react in serological tests. In previous work we established that synthetic oligosaccharides, representing elements of the Brucella A and M polysaccharide structures, were excellent antigens to explore the antibody response in the context of infection, immunisation and cross reaction. These studies suggested the existence of antibodies that are specific to the tip of the Brucella OPS. Sera from naturally and experimentally Brucella abortus-infected cattle as well as from cattle experimentally infected with the cross-reactive bacterium Yersinia enterocolitica O:9 and field sera that cross react in conventional serological assays were studied here with an expanded panel of synthetic antigens. The addition of chemical features to synthetic antigens that block antibody binding to the tip of the OPS dramatically reduced their polyclonal antibody binding capability providing conclusive evidence that the OPS tip (non-reducing end) is a potent epitope. Selected short oligosaccharides, including those that were exclusively α1,2 linked, also demonstrated superior specificity when evaluated with cross reactive sera compared to native smooth lipopolysaccharide (sLPS) antigen and capped native OPS. This surprising discovery suggests that the OPS tip epitope, even though common to both Brucella and Y. enterocolitica O:9, has more specific diagnostic properties than the linear portion of the native antigens. This finding opens the way to the development of improved serological
Kundu S, Lee Y, Sykes L, et al., 2022, The Effect of Secretor Status and the Vaginal Microbiome on Birth Outcome, Publisher: SPRINGER HEIDELBERG, Pages: 197-197, ISSN: 1933-7191
Edwards E, Livanos M, Krueger A, et al., 2022, Strategies to control therapeutic antibody glycosylation during bioprocessing: synthesis and separation., Biotechnology and Bioengineering, Vol: 119, ISSN: 0006-3592
Glycosylation can be a critical quality attribute (CQA) in biologic manufacturing. In particular, it has implications on the half-life, immunogenicity and pharmacokinetics of therapeutic monoclonal antibodies (mAbs) and must be closely monitored throughout drug development and manufacturing. To address this, advances have been made primarily in upstream processing, including mammalian cell line engineering to yield more predictably glycosylated mAbs, and the addition of media supplements during fermentation to manipulate the metabolic pathways involved in glycosylation. A more robust approach would be a conjoined upstream-downstream processing strategy. This could include implementing novel downstream technologies, such as the use of Fc gamma-based affinity ligands for the separation of mAb glycovariants. This review highlights the importance of controlling therapeutic antibody glycosylation patterns, the challenges faced in terms of glycosylation during mAb biosimilar development, current efforts both upstream and downstream to control glycosylation and their limitations, and the need for research in the downstream space in order to establish holistic and consistent manufacturing processes for the production of antibody therapies. This article is protected by copyright. All rights reserved.
Kawahara R, Chernykh A, Alagesan K, et al., 2022, Author Correction: Community evaluation of glycoproteomics informatics solutions reveals high-performance search strategies for serum glycopeptide analysis, Nature Methods, Vol: 19, Pages: 130-130, ISSN: 1548-7091
Peswani AR, Narkpuk J, Krueger A, et al., 2022, Novel constructs and 1-step chromatography protocols for the production of Porcine Circovirus 2d (PCV2d) and Circovirus 3 (PCV3) subunit vaccine candidates, FOOD AND BIOPRODUCTS PROCESSING, Vol: 131, Pages: 125-135, ISSN: 0960-3085
Kotidis P, Marbiah M, Donini R, et al., 2022, Rapid Antibody Glycoengineering in CHO Cells Via RNA Interference and CGE-LIF <i>N</i>-Glycomics, GLYCOSYLATION, Pages: 147-167, ISSN: 1064-3745
Chakraborty A, Perez M, Mohammed NBB, et al., 2021, hypoxia controls the glycobiological signature and related pro-tumorigenic properties of metastatic melanomas, Publisher: OXFORD UNIV PRESS INC, Pages: 1683-1684, ISSN: 0959-6658
Butta NV, Haslam SM, Dell A, et al., 2021, Glycomic Characterization of Platelets from Patients with Immune Thrombocytopenia, 63rd Annual Meeting and Exposition of the American-Society-of-Hematology (ASH), Publisher: AMER SOC HEMATOLOGY, ISSN: 0006-4971
Kawahara R, Chernykh A, Alagesan K, et al., 2021, Community evaluation of glycoproteomics informatics solutions reveals high-performance search strategies for serum glycopeptide analysis, NATURE METHODS, Vol: 18, Pages: 1304-+, ISSN: 1548-7091
Ezeabikwa B, Mondal N, Antonopoulos A, et al., 2021, Major differences in glycosylation and Fucosyltransferase expression in low-grade versus high-grade bladder cancer cell lines., Glycobiology, Vol: 31, Pages: 1444-1463, ISSN: 0959-6658
Bladder cancer is the ninth most frequently diagnosed cancer worldwide, and there is a need to develop new biomarkers for staging and prognosis of this disease. Here we report that cell lines derived from low-grade and high-grade bladder cancers exhibit major differences in expression of glycans in surface glycoproteins. We analyzed protein glycosylation in three low-grade bladder cancer cell lines RT4 (grade-1-2), 5637 (grade-2), and SW780 (grade-1), and three high-grade bladder cancer cell lines J82COT (grade-3), T24 (grade-3), and TCCSUP (grade-4), with primary bladder epithelial cells, A/T/N, serving as a normal bladder cell control. Using a variety of approaches including flow cytometry, immunofluorescence, glycomics, and gene expression analysis, we observed that the low-grade bladder cancer cell lines RT4, 5637, and SW780 express high levels of the fucosylated Lewis x (Lex) antigen (CD15) (Galβ1-4(Fucα1-3) GlcNAcβ1-R), while normal bladder epithelial A/T/N cells lack Lex expression. T24 and TCCSUP cells also lack Lex, whereas J82COT cells express low levels of Lex. Glycomics analyses revealed other major differences in fucosylation and sialylation of N-glycans between these cell types. O-glycans are highly differentiated, as RT4 cells synthesize core 2-based O-glycans that are lacking in the T24 cells. These differences in glycan expression correlated with differences in RNA expression levels of their cognate glycosyltransferases, including α1-3/4-fucosyltransferase genes. These major differences in glycan structures and gene expression profiles between low- and high-grade bladder cancer cells suggest that glycans and glycosyltransferases are candidate biomarkers for grading bladder cancers.
Baksmeier C, Blundell P, Steckel J, et al., 2021, Modified recombinant human IgG1-Fc is superior to natural IVIG at inhibiting immune-mediated demyelination., Immunology, Vol: 464, Pages: 90-105, ISSN: 0019-2805
Intravenous immunoglobulin (IVIG) is an established treatment for numerous autoimmune conditions. Although Fc fragments derived from IVIG have shown efficacy in controlling immune thrombocytopenia (ITP) in children, the mechanisms of action are unclear and controversial. The aim of this study is to dissect IVIG effector mechanisms using further adapted Fc fragments on demyelination in an ex vivo model of the central nervous system (CNS)-immune interface. Using organotypic cerebellar slice cultures (OSC) from transgenic mice we induced extensive immune-mediated demyelination and oligodendrocyte loss with an antibody specific for myelin oligodendrocyte glycoprotein (MOG) and complement. Protective effects of adapted Fc fragments were assessed by live imaging of GFP expression, immunohistochemistry and confocal microscopy. Cysteine and glycan adapted Fc fragments protected OSC from demyelination in a dose-dependent manner where equimolar concentrations of either IVIG or control Fc were ineffective. The protective effects of the adapted Fc fragments are partly attributed to interference with complement-mediated oligodendroglia damage. Transcriptome analysis ruled out signatures associated with inflammatory or innate immune responses. Taken together our findings show that recombinant biomimetics can be made that are at least two hundred-fold more effective than IVIG in controlling demyelination by anti-MOG antibodies.
Chakraborty A, Perez M, Mohammed NBB, et al., 2021, Hypoxia-mediated downregulation of GCNT2/I-antigen in metastatic melanoma accelerates disease progression and mortality., Annual Meeting of the American-Association-for-Cancer-Research (AACR), Publisher: AMER ASSOC CANCER RESEARCH, ISSN: 0008-5472
Bonnardel F, Haslam SM, Dell A, et al., 2021, Proteome-wide prediction of bacterial carbohydrate-binding proteins as a tool for understanding commensal and pathogen colonisation of the vaginal microbiome, npj Biofilms and Microbiomes, Vol: 7, Pages: 1-10, ISSN: 2055-5008
Bacteria use carbohydrate-binding proteins (CBPs), such as lectins and carbohydrate-binding modules (CBMs), to anchor to specific sugars on host surfaces. CBPs in the gut microbiome are well studied, but their roles in the vagina microbiome and involvement in sexually transmitted infections, cervical cancer and preterm birth are largely unknown. We established a classification system for lectins and designed Hidden Markov Model (HMM) profiles for data mining of bacterial genomes, resulting in identification of >100,000 predicted bacterial lectins available at unilectin.eu/bacteria. Genome screening of 90 isolates from 21 vaginal bacterial species shows that those associated with infection and inflammation produce a larger CBPs repertoire, thus enabling them to potentially bind a wider array of glycans in the vagina. Both the number of predicted bacterial CBPs and their specificities correlated with pathogenicity. This study provides new insights into potential mechanisms of colonisation by commensals and potential pathogens of the reproductive tract that underpin health and disease states.
Ng BG, Sosicka P, Fenaille F, et al., 2021, A mutation in <i>SLC37A4</i> causes a dominantly inherited congenital disorder of glycosylation characterized by liver dysfunction, AMERICAN JOURNAL OF HUMAN GENETICS, Vol: 108, Pages: 1040-1052, ISSN: 0002-9297
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