| 1. |
- Bagdonaite, I., et al.
(författare)
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A Strategy for O-Glycoproteomics of Enveloped Viruses-the O-Glycoproteome of Herpes Simplex Virus Type 1
- 2015
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Ingår i: Plos Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Glycosylation of viral envelope proteins is important for infectivity and interaction with host immunity, however, our current knowledge of the functions of glycosylation is largely limited to N-glycosylation because it is difficult to predict and identify site-specific O-glycosylation. Here, we present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1) as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B were previously implicated in virus attachment to immune cells. We show that HSV-1 infection distorts the secretory pathway and that infected cells accumulate glycoproteins with truncated O-glycans, nonetheless retaining the ability to elongate most of the surface glycans. With the use of precise gene editing, we further demonstrate that elongated O-glycans are essential for HSV-1 in human HaCaT keratinocytes, where HSV-1 produced markedly lower viral titers in HaCaT with abrogated O-glycans compared to the isogenic counterpart with normal O-glycans. The roles of O-linked glycosylation for viral entry, formation, secretion, and immune recognition are poorly understood, and the O-glycoproteomics strategy presented here now opens for unbiased discovery on all enveloped viruses.
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| 2. |
- Bagdonaite, I., et al.
(författare)
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Global Mapping of O-Glycosylation of Varicella Zoster Virus, Human Cytomegalovirus, and Epstein-Barr Virus
- 2016
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 291:23, s. 12014-12028
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Tidskriftsartikel (refereegranskat)abstract
- Herpesviruses are among the most complex and widespread viruses, infection and propagation of which depend on envelope proteins. These proteins serve as mediators of cell entry as well as modulators of the immune response and are attractive vaccine targets. Although envelope proteins are known to carry glycans, little is known about the distribution, nature, and functions of these modifications. This is particularly true for O-glycans; thus we have recently developed a "bottom up" mass spectrometry-based technique for mapping O-glycosylation sites on herpes simplex virus type 1. We found wide distribution of O-glycans on herpes simplex virus type 1 glycoproteins and demonstrated that elongated O-glycans were essential for the propagation of the virus. Here, we applied our proteome-wide discovery platform for mapping O-glycosites on representative and clinically significant members of the herpesvirus family: varicella zoster virus, human cytomegalovirus, and Epstein-Barr virus. We identified a large number of O-glycosites distributed on most envelope proteins in all viruses and further demonstrated conserved patterns of O-glycans on distinct homologous proteins. Because glycosylation is highly dependent on the host cell, we tested varicella zoster virus-infected cell lysates and clinically isolated virus and found evidence of consistent O-glycosites. These results present a comprehensive view of herpesvirus O-glycosylation and point to the widespread occurrence of O-glycans in regions of envelope proteins important for virus entry, formation, and recognition by the host immune system. This knowledge enables dissection of specific functional roles of individual glycosites and, moreover, provides a framework for design of glycoprotein vaccines with representative glycosylation.
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| 3. |
- Bagdonaite, Ieva, et al.
(författare)
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Glycoengineered keratinocyte library reveals essential functions of specific glycans for all stages of HSV-1 infection
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Viral and host glycans represent an understudied aspect of host-pathogen interactions, despite potential implications for treatment of viral infections. This is due to lack of easily accessible tools for analyzing glycan function in a meaningful context. Here we generate a glycoengineered keratinocyte library delineating human glycosylation pathways to uncover roles of specific glycans at different stages of herpes simplex virus type 1 (HSV-1) infectious cycle. We show the importance of cellular glycosaminoglycans and glycosphingolipids for HSV-1 attachment, N-glycans for entry and spread, and O-glycans for propagation. While altered virion surface structures have minimal effects on the early interactions with wild type cells, mutation of specific O-glycosylation sites affects glycoprotein surface expression and function. In conclusion, the data demonstrates the importance of specific glycans in a clinically relevant human model of HSV-1 infection and highlights the utility of genetic engineering to elucidate the roles of specific viral and cellular carbohydrate structures.
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| 4. |
- Iversen, M. B., et al.
(författare)
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An innate antiviral pathway acting before interferons at epithelial surfaces
- 2016
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Ingår i: Nature Immunology. - : Springer Science and Business Media LLC. - 1529-2908 .- 1529-2916. ; 17:2, s. 150-158
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal surfaces are exposed to environmental substances and represent a major portal of entry for microorganisms. The innate immune system is responsible for early defense against infections and it is believed that the interferons (IFNs) constitute the first line of defense against viruses. Here we identify an innate antiviral pathway that works at epithelial surfaces before the IFNs. The pathway is activated independently of known innate sensors of viral infections through a mechanism dependent on viral O-linked glycans, which induce CXCR3 chemokines and stimulate antiviral activity in a manner dependent on neutrophils. This study therefore identifies a previously unknown layer of antiviral defense that exerts its action on epithelial surfaces before the classical IFN response is operative.
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| 5. |
- Rumjantseva, Viktoria, 1978, et al.
(författare)
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Dual roles for hepatic lectin receptors in the clearance of chilled platelets.
- 2009
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Ingår i: Nature medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 15:11, s. 1273-80
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Tidskriftsartikel (refereegranskat)abstract
- Rapid chilling causes glycoprotein-Ib (GPIb) receptors to cluster on blood platelets. Hepatic macrophage beta(2) integrin binding to beta-N-acetylglucosamine (beta-GlcNAc) residues in the clusters leads to rapid clearance of acutely chilled platelets after transfusion. Although capping the beta-GlcNAc moieties by galactosylation prevents clearance of short-term-cooled platelets, this strategy is ineffective after prolonged refrigeration. We report here that prolonged refrigeration increased the density and concentration of exposed galactose residues on platelets such that hepatocytes, through Ashwell-Morell receptor binding, become increasingly involved in platelet removal. Macrophages rapidly removed a large fraction of transfused platelets independent of their storage conditions. With prolonged platelet chilling, hepatocyte-dependent clearance further diminishes platelet recovery and survival after transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold.
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| 6. |
- Nielsen, Mathias Ingemann, et al.
(författare)
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Galectin binding to cells and glycoproteins with genetically modified glycosylation reveals galectin–glycan specificities in a natural context
- 2018
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 293:52, s. 20249-20262
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Tidskriftsartikel (refereegranskat)abstract
- Galectins compose a protein family defined by a conserved sequence motif conferring affinity for -galactose– containing glycans. Moreover, galectins gain higher affinity and fine-tune specificity by glycan interactions at sites adjacent to their -galactoside– binding site, as revealed by extensive testing against panels of purified glycans. However, in cells, galectins bind glycans on glycoproteins and glycolipids in the context of other cellular components, such as at the cell surface. Because of difficulties in characterizing natural cellular environments, we currently lack a detailed understanding of galectin-binding specificities in the cellular context. To address this challenge, we used a panel of genetically stable glycosylation mutated CHO cells that express defined glycans to evaluate the binding affinities of 10 different carbohydrate-recognition domains in galectins to N-glycans and mucin-type O-glycans. Using flow cytometry, we measured the cell-surface binding of the galectins. Moreover, we used fluorescence anisotropy to determine the galectin affinities to recombinant erythropoietin used as a reporter glycoprotein produced by the glycoengineered cells and to synthetic N-glycans with defined branch structures. We found that all galectins, apart from galectin-8N, require complex N-glycans for high-affinity binding. Galectin-8N targeted both N- and O-linked glycans with high affinity, preferring 2,3-sialylated N-acetyllactosamine (LacNAc) structures. Furthermore, we found that 2,3-sialylation suppresses high-affinity binding of select galectins, including galectin-2, -3, -4N, and -7. Structural modeling provided a basis for interpreting the observed binding preferences. These results underscore the power of a glycoengineered platform to dissect the glycan-binding specificities of carbohydrate-binding proteins.
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| 7. |
- Olofsson, Sigvard, 1948, et al.
(författare)
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Viral O-GalNAc peptide epitopes: a novel potential target in viral envelope glycoproteins.
- 2016
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Ingår i: Reviews in medical virology. - : Wiley. - 1099-1654 .- 1052-9276. ; 26:1, s. 34-48
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Tidskriftsartikel (refereegranskat)abstract
- Viral envelope glycoproteins are major targets for antibodies that bind to and inactivate viral particles. The capacity of a viral vaccine to induce virus-neutralizing antibodies is often used as a marker for vaccine efficacy. Yet the number of known neutralization target epitopes is restricted owing to various viral escape mechanisms. We expand the range of possible viral glycoprotein targets, by presenting a previously unknown type of viral glycoprotein epitope based on a short peptide stretch modified with small O-linked glycans. Besides being immunologically active, these epitopes have a high potential for antigenic variation. Thus, sera from patients infected with EBV develop individual IgG responses addressing the different possible glycopeptide glycoforms of one short peptide backbone that reflect individual variations in the course of virus infection. In contrast, in HSV type 2 meningitis patients, CSF antibodies are focussed to only one single glycoform peptide of a major viral glycoprotein. Thus, dependent on the viral disease, the serological response may be variable or constant with respect to the number of targeted peptide glycoforms. Mapping of these epitopes relies on a novel three-step procedure that identifies any reactive viral O-glycosyl peptide epitope with respect to (i) relevant peptide sequence, (ii) the reactive glycoform out of several possible glycopeptide isomers of that peptide sequence, and (iii) possibly tolerated carbohydrate or peptide structural variations at glycosylation sites. In conclusion, the viral O-glycosyl peptide epitopes may be of relevance for development of subunit vaccines and for improved serodiagnosis of viral diseases.
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| 8. |
- Rudjord-Levann, Asha M., et al.
(författare)
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Galectin-1 induces a tumor-associated macrophage phenotype and upregulates indoleamine 2,3-dioxygenase-1
- 2023
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Ingår i: iScience. - 2589-0042. ; 26:7
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Tidskriftsartikel (refereegranskat)abstract
- Galectins are a group of carbohydrate-binding proteins with a presumed immunomodulatory role and an elusive function on antigen-presenting cells. Here we analyzed the expression of galectin-1 and found upregulation of galectin-1 in the extracellular matrix across multiple tumors. Performing an in-depth and dynamic proteomic and phosphoproteomic analysis of human macrophages stimulated with galectin-1, we show that galectin-1 induces a tumor-associated macrophage phenotype with increased expression of key immune checkpoint protein programmed cell death 1 ligand 1 (PD-L1/CD274) and immunomodulator indoleamine 2,3-dioxygenase-1 (IDO1). Galectin-1 induced IDO1 and its active metabolite kynurenine in a dose-dependent manner through JAK/STAT signaling. In a 3D organotypic tissue model system equipped with genetically engineered tumorigenic epithelial cells, we analyzed the cellular source of galectin-1 in the extracellular matrix and found that galectin-1 is derived from epithelial and stromal cells. Our results highlight the potential of targeting galectin-1 in immunotherapeutic treatment of human cancers.
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| 9. |
- Wandall, Rasmus H., et al.
(författare)
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Hiring and learning strategies in prosecution services
- 2021
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Ingår i: The Oxford Handbook of Prosecutors and Prosecution. - : Oxford University Press. - 9780190905422 ; , s. 207-226
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Bokkapitel (refereegranskat)abstract
- The chapter provides a comparative overview of current hiring and learning strategies in prosecution services. It draws on empirical examples from all parts of the world. Specifically, the chapter compares the hiring of chief prosecutors and frontline prosecutors, it compares how learning is organized and carried out, and it describes and discusses the most significant individual methods of learning currently applied by prosecution services. The comparison shows some level of convergence of techniques and strategies. However, prosecution services continue to vary significantly in how they organize and carry out hiring and in how prosecutors learn. To some degree these variations reflect different levels of professionalization and legal accountability, but they also reflect the markedly different ideals, roles, and functions that drive prosecution services in different societies and legal cultures. These differences make for very different conditions under which new and better ways of hiring and learning can be implemented with a view to ensure qualified and legitimate prosecution services.
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| 10. |
- Wandall, Rasmus H., et al.
(författare)
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The public prosecution service and the structuring of sentencing - the nordic case of Denmark
- 2019
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Ingår i: The Evolving Role of the Public Prosecutor : Challenges and Innovations - Challenges and Innovations. - New York, NY: Routledge, 2019. | Series: Directions and developments in criminal justice and law; 3 : Routledge. - 9781138606791 - 9780429884955 ; , s. 60-73
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Bokkapitel (refereegranskat)abstract
- This chapter contributes an original description of a very different structuring arrangement of sentencing institutionalized through the Danish prosecution service since the 1990s. The prosecution service has attained a new and bigger role and new techniques add significantly to the structuring of sentencing. The techniques of structuring sentencing are: preparatory works to statutory amendments, prosecution guidelines and prosecution driven court practice database. The public prosecution service is at the very centre of the dramatic increase in structuring of sentencing. The legal tradition outlines four ways in which the prosecution service institutionalizes the described techniques of structuring sentencing: By taking part in the drafting of preparatory works to statutory amendments, By using its quasi-judicial role to presenting facts and law to the judicial courts, By controlling knowledge on normal sentencing levels through its hierarchical organizational structure and By following up on judicial sentencing practice on behalf of the legislature.
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