Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic and persistent inflammation of the joints. Around 50-80% of the RA patients harbour either one or multiple types... Show moreRheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic and persistent inflammation of the joints. Around 50-80% of the RA patients harbour either one or multiple types of autoantibodies, under which also Anti-Citrullinated Protein Antibodies (ACPA). ACPA are highly specific for RA and are strongly associated with the severity of arthritis. The studies described in this thesis aim to explore the structure and biological function of ACPA and the B cells producing these ACPA.The studies highlight the importance of the synovial environment for the survival of ACPA B cells. Moreover, we demonstrate that the variable region of ACPA-IgG differs from that of ACPA-IgM by the introduction of glycans, and that glycans in the constant part of antibodies can be modulated by influences from the micro-environment. This may affect the biological functions of the antibodies. Furthermore, we show that ACPA can bind to so-called Fc gamma receptor I on immune cells which could be a potential effector mechanisms of ACPA. These findings demonstrate that the structure and environment of ACPA play an important role in the ACPA immune response and provide multiple arguments for the active contribution of ACPA in the chronic inflammation of RA. Show less
This Thesis focuses on the design and synthesis of ADP-ribosylated compounds that can be applied in biological studies.The limitations of the contemporary methods of chemical ADP-ribosylation and a... Show moreThis Thesis focuses on the design and synthesis of ADP-ribosylated compounds that can be applied in biological studies.The limitations of the contemporary methods of chemical ADP-ribosylation and a relative scarcity of the well-defined synthetic ADP-ribosylated derivative was an incentive to undertake synthetic studies to further advance the methodologies in the bioorganic chemistry of ADP-ribosylated molecules. This Thesis aims specifically at the developing of new and improved synthetic methodologies and to synthesize advanced mono- or oligo-ADP-ribosylated biomolecules. The target compounds that are described in this Thesis are not only represent a synthetic challenge but also have great value in biology for a better understanding of ADP-ribosylation. Show less
Wang, L.; Overkleeft, H.S.; Marel, G.A. van der; Codee, J.D.C. 2019
Pre‐activation based glycosylations have become a very powerful tool in the assembly of oligosaccharides and the use of nucleophilic additives allows for the in situ generation of reactive... Show morePre‐activation based glycosylations have become a very powerful tool in the assembly of oligosaccharides and the use of nucleophilic additives allows for the in situ generation of reactive intermediates with tailored reactivity. We here use a glycosylation strategy that is based on the use of per‐benzylated imidate building blocks for the fully stereoselective construction of a spacer equipped Aspergillus fumigatus α‐1,3‐octaglucan. We have used the trimethylsilyl iodide (TMSI)‐triphenylphosphine oxide (Ph3P=O) for the stereoselective installation of an azidopropanol spacer and triflic acid (TfOH)‐dimethyl formamide (DMF) enabled glycosylations for the coupling reactions with the secondary glucosyl C‐3‐alcohols. An operationally simple in situ activation coupling procedure is introduced and used for the final glycosylation events towards the octasaccharide. Show less
The aim of this thesis is to explore the glycosylation of PSA as well as to study if alterations can be observed between patients with indolent and malignant PCa. For this purpose the powerful... Show moreThe aim of this thesis is to explore the glycosylation of PSA as well as to study if alterations can be observed between patients with indolent and malignant PCa. For this purpose the powerful analytical platform CE-ESI-MS(/MS) was explored with a special focus on the analysis of glycans and glycopeptides (Chapter 1). The first section of the thesis describes the different method developments implemented for the analysis of PSA with CE-ESI-MS. Namely, Chapter 2 describes that CE-ESI-MS enables to separate glycopeptides with differently linked sialic acids without any additional sample treatment, Chapter 3 shows that an introduction of a dopant enriched nitrogen gas improves the limit of detection (sensitivity) of glycopeptides and Chapter 4 introduces a novel labeling procedure of total plasma N-glycome with the hydrazide Girard’s reagent P. Chapter 5 describes the development of a PSA Glycomics Assay which allows the capture of intact PSA from patients’ urine followed by analysis with the optimized CE-ESI-MS platform (Chapters 2 and 3). Finally, Chapter 6 offers a general discussion about future developments, the potential of PSA glycosylation in the clinical setting, showing the relevance of our results and how these may contribute to further clinical applications towards personalized medicine. Show less
Glycosylation of immunoglobulins is suspected to play a key role in the regulation of the immune system. In this thesis, mass spectrometry-based glycoproteomics methods were used to characterize... Show moreGlycosylation of immunoglobulins is suspected to play a key role in the regulation of the immune system. In this thesis, mass spectrometry-based glycoproteomics methods were used to characterize the glycosylation of various immunoglobulins. In Chapter 2 we describe the development of a glycoproteomics method to analyze IgE glycosylation. In Chapter 3 we reported partial O-glycosylation of IgG3. In addition to structural glycosylation research, we also analyzed antibody glycosylation in population cohorts. In Chapter 4 and Chapter 5, IgG Fc glycopeptide analysis was performed on blood samples using LC-MS(/MS). In a cohort of 76 ANCA vasculitis patients, low galactosylation and sialylation of IgG was associated with a higher chance of future relapse. Furthermore, in the approximately 1800 participants of the Leiden Longevity study (LLS), low galactosylation and sialylation of IgG, together with high fucosylation, showed association with markers of inflammation. We hope that the novel data presented in this thesis may contribute to the elucidation of the role of antibody glycosylation in the immune system, of which the understanding is currently still very limited. Show less
The post-translational modification of proteins known as adenosine diphosphate ribosylation (ADPr) is involved in a wide variety of important biological processes and is also associated with... Show moreThe post-translational modification of proteins known as adenosine diphosphate ribosylation (ADPr) is involved in a wide variety of important biological processes and is also associated with carcinogenesis and the process of aging. Therefore, a better understanding of the biology of ADP-ribosylation is crucial for the development of novel therapeutics. To facilitate this research, the availability of well-defined fragments of mono- and poly-ADP-ribose is essential. This Thesis describes the development of new synthetic methodologies to achieve this and the successful synthesis of well-defined ADP-ribosylated biomolecules. Show less
Kemna, M.J.; Plomp, R.; Paassen, P. van; Koeleman, C.A.M.; Jansen, B.C.; Damoiseaux, J.G.M.C.; ... ; Wuhrer, M. 2017
Glycan modifications of proteins and lipids form an integral part of the cell’s outermost layer and an array of ligands, adding a high degree of complexity to the cellular phenotype. While... Show more Glycan modifications of proteins and lipids form an integral part of the cell’s outermost layer and an array of ligands, adding a high degree of complexity to the cellular phenotype. While this complexity is an analytical challenge, it also offers a wide range of opportunities for biomarkers and treatment targets. This thesis deals with the analysis of colorectal cancer (CRC)-associated glycomic changes. Current knowledge on CRC-associated glycan changes and their biological role have been reviewed in Chapter 1. In Chapters 2, 3, and 6, we developed novel, high-end methodologies for the glycomic analysis of tissues and cell lines to be able to expand our knowledge on cancer glycomics and to overcome some limitations of current techniques. By applying these new methods, this thesis also covers the characterization of changes in glycosylation in CRC tissues as well as cell lines, thereby contributing to the understanding of CRC biology while identifying cancer-specific signatures underlying CRC development. These signatures can be further explored as potential markers to improve patient care. Additionally, in Chapter 5, we extended our research to pancreatic duct adenocarcinoma and characterized the N-glycome of PDAC cells with different metastatic potential and of a normal pancreatic duct cell line. Show less
The glycosylation, the reaction which forms a bond between sugar molecules (the donor and the acceptor), is the central reaction in carbohydrate chemistry. Despite tremendous advances in... Show more The glycosylation, the reaction which forms a bond between sugar molecules (the donor and the acceptor), is the central reaction in carbohydrate chemistry. Despite tremendous advances in the past decades, however, the glycosylation reaction remains relatively poorly understood. Especially the formation of 1,2-cis glycosidic linkages remains a significant challenge. This thesis describes an investigation of the influence of reactivity and selectivity of several classes of carbohydrate donors and –acceptors on the selectivity in glycosylation reactions. Special emphasis was placed on the influence of protecting groups on the donor, and nucleophilicity of the acceptor, two major factors that play a tremendous role in the outcome of a glycosylation reaction. The obtained knowledge has been applied in the synthesis of complex carbohydrate molecules, native to pathogens such as Staphylococcus aureus, of which antibiotic-resistant forms such as MRSA present significant danger in hospitals, and the parasite Schistosoma mansoni, causative agent of the neglected tropical disease schistosomiasis. The synthesis of these molecules can play a part in the development of vaccines targeted against these pathogens. Show less
Volbeda, A.G.; Reintjens, N.R.M.; Overkleeft, H.S.; Marel, G.A. van der; Codée, J.D.C. 2016
General significance: Present work opens a new way for parallel determination of glycosylation changes of both IgG and IgM antibodies by use of high-throughput methods, and their future use as... Show moreGeneral significance: Present work opens a new way for parallel determination of glycosylation changes of both IgG and IgM antibodies by use of high-throughput methods, and their future use as biomarkers for disease diagnosis and prognosis. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc. (C) 2016 Elsevier B.V. All rights reserved. Show less
Wuhrer, M.; Selman, M.H.J.; McDonnell, L.A.; Kumpfel, T.; Derfuss, T.; Khademi, M.; ... ; Krumbholz, M. 2015
Bioconjugates are involved in many biological processes. Glycoconjugates can bind to lectin receptors based on their specific carbohydrate structure. The mannose receptor, a C-type lectin, makes an... Show moreBioconjugates are involved in many biological processes. Glycoconjugates can bind to lectin receptors based on their specific carbohydrate structure. The mannose receptor, a C-type lectin, makes an interesting target to induce selective uptake by dendritic cells and macrophages. This thesis focus on the design and synthesis glycoconjugates linked with oligomannosides and artificial mannose clusters as homing device for the mannose receptor and other mannose binding lectins. Show less
Dall'Olio, F.; Vanhooren, V.; Chen, C.C.; Slagboom, P.E.; Wuhrer, M.; Franceschi, C. 2013
