1
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Dinesen A, Andersen VL, Elkhashab M, Pilati D, Bech P, Fuchs E, Samuelsen TR, Winther A, Cai Y, Märcher A, Wall A, Omer M, Nielsen JS, Chudasama V, Baker JR, Gothelf KV, Wengel J, Kjems J, Howard KA. An Albumin-Holliday Junction Biomolecular Modular Design for Programmable Multifunctionality and Prolonged Circulation. Bioconjug Chem 2024; 35:214-222. [PMID: 38231391 PMCID: PMC10886128 DOI: 10.1021/acs.bioconjchem.3c00491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/22/2023] [Accepted: 12/22/2023] [Indexed: 01/18/2024]
Abstract
Combinatorial properties such as long-circulation and site- and cell-specific engagement need to be built into the design of advanced drug delivery systems to maximize drug payload efficacy. This work introduces a four-stranded oligonucleotide Holliday Junction (HJ) motif bearing functional moieties covalently conjugated to recombinant human albumin (rHA) to give a "plug-and-play" rHA-HJ multifunctional biomolecular assembly with extended circulation. Electrophoretic gel-shift assays show successful functionalization and purity of the individual high-performance liquid chromatography-purified modules as well as efficient assembly of the rHA-HJ construct. Inclusion of an epidermal growth factor receptor (EGFR)-targeting nanobody module facilitates specific binding to EGFR-expressing cells resulting in approximately 150-fold increased fluorescence intensity determined by flow cytometric analysis compared to assemblies absent of nanobody inclusion. A cellular recycling assay demonstrated retained albumin-neonatal Fc receptor (FcRn) binding affinity and accompanying FcRn-driven cellular recycling. This translated to a 4-fold circulatory half-life extension (2.2 and 0.55 h, for the rHA-HJ and HJ, respectively) in a double transgenic humanized FcRn/albumin mouse. This work introduces a novel biomolecular albumin-nucleic acid construct with extended circulatory half-life and programmable multifunctionality due to its modular design.
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Affiliation(s)
- Anders Dinesen
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Veronica L. Andersen
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Marwa Elkhashab
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Diego Pilati
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Pernille Bech
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Elisabeth Fuchs
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Torbjørn R. Samuelsen
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Alexander Winther
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Yunpeng Cai
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Anders Märcher
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Archie Wall
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | - Marjan Omer
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Jesper S. Nielsen
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Vijay Chudasama
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | - James R. Baker
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | - Kurt V. Gothelf
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jesper Wengel
- Nucleic
Acid Center, Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Jørgen Kjems
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
| | - Kenneth A. Howard
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Molecular Biology and
Genetics, Aarhus University, DK-8000 Aarhus
C, Denmark
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2
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Teodori L, Omer M, Kjems J. RNA nanostructures for targeted drug delivery and imaging. RNA Biol 2024; 21:1-19. [PMID: 38555519 PMCID: PMC10984137 DOI: 10.1080/15476286.2024.2328440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2024] [Indexed: 04/02/2024] Open
Abstract
The RNA molecule plays a pivotal role in many biological processes by relaying genetic information, regulating gene expression, and serving as molecular machines and catalyzers. This inherent versatility of RNA has fueled significant advancements in the field of RNA nanotechnology, driving the engineering of complex nanoscale architectures toward biomedical applications, including targeted drug delivery and bioimaging. RNA polymers, serving as building blocks, offer programmability and predictability of Watson-Crick base pairing, as well as non-canonical base pairing, for the construction of nanostructures with high precision and stoichiometry. Leveraging the ease of chemical modifications to protect the RNA from degradation, researchers have developed highly functional and biocompatible RNA architectures and integrated them into preclinical studies for the delivery of payloads and imaging agents. This review offers an educational introduction to the use of RNA as a biopolymer in the design of multifunctional nanostructures applied to targeted delivery in vivo, summarizing physical and biological barriers along with strategies to overcome them. Furthermore, we highlight the most recent progress in the development of both small and larger RNA nanostructures, with a particular focus on imaging reagents and targeted cancer therapeutics in pre-clinical models and provide insights into the prospects of this rapidly evolving field.
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Affiliation(s)
- Laura Teodori
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus, Denmark
- Center for RNA Therapeutics towards Metabolic Diseases (RNA-META), Aarhus University, Aarhus, Denmark
| | - Marjan Omer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus, Denmark
| | - Jørgen Kjems
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus, Denmark
- Center for RNA Therapeutics towards Metabolic Diseases (RNA-META), Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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3
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Catapano C, Rahm JV, Omer M, Teodori L, Kjems J, Dietz MS, Heilemann M. Biased activation of the receptor tyrosine kinase HER2. Cell Mol Life Sci 2023; 80:158. [PMID: 37208479 DOI: 10.1007/s00018-023-04806-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/20/2023] [Accepted: 05/11/2023] [Indexed: 05/21/2023]
Abstract
HER2 belongs to the ErbB sub-family of receptor tyrosine kinases and regulates cellular proliferation and growth. Different from other ErbB receptors, HER2 has no known ligand. Activation occurs through heterodimerization with other ErbB receptors and their cognate ligands. This suggests several possible activation paths of HER2 with ligand-specific, differential response, which has so far remained unexplored. Using single-molecule tracking and the diffusion profile of HER2 as a proxy for activity, we measured the activation strength and temporal profile in live cells. We found that HER2 is strongly activated by EGFR-targeting ligands EGF and TGFα, yet with a distinguishable temporal fingerprint. The HER4-targeting ligands EREG and NRGβ1 showed weaker activation of HER2, a preference for EREG, and a delayed response to NRGβ1. Our results indicate a selective ligand response of HER2 that may serve as a regulatory element. Our experimental approach is easily transferable to other membrane receptors targeted by multiple ligands.
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Affiliation(s)
- Claudia Catapano
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-Von-Laue-Str. 7, 60438, Frankfurt, Germany
| | - Johanna V Rahm
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-Von-Laue-Str. 7, 60438, Frankfurt, Germany
| | - Marjan Omer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Laura Teodori
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Jørgen Kjems
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Marina S Dietz
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-Von-Laue-Str. 7, 60438, Frankfurt, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-Von-Laue-Str. 7, 60438, Frankfurt, Germany.
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4
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Ferapontov A, Omer M, Baudrexel I, Nielsen JS, Dupont DM, Juul-Madsen K, Steen P, Eklund AS, Thiel S, Vorup-Jensen T, Jungmann R, Kjems J, Degn SE. Antigen footprint governs activation of the B cell receptor. Nat Commun 2023; 14:976. [PMID: 36813795 PMCID: PMC9947222 DOI: 10.1038/s41467-023-36672-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/10/2023] [Indexed: 02/24/2023] Open
Abstract
Antigen binding by B cell receptors (BCR) on cognate B cells elicits a response that eventually leads to production of antibodies. However, it is unclear what the distribution of BCRs is on the naïve B cell and how antigen binding triggers the first step in BCR signaling. Using DNA-PAINT super-resolution microscopy, we find that most BCRs are present as monomers, dimers, or loosely associated clusters on resting B cells, with a nearest-neighbor inter-Fab distance of 20-30 nm. We leverage a Holliday junction nanoscaffold to engineer monodisperse model antigens with precision-controlled affinity and valency, and find that the antigen exerts agonistic effects on the BCR as a function of increasing affinity and avidity. Monovalent macromolecular antigens can activate the BCR at high concentrations, whereas micromolecular antigens cannot, demonstrating that antigen binding does not directly drive activation. Based on this, we propose a BCR activation model determined by the antigen footprint.
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Affiliation(s)
- Alexey Ferapontov
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark
| | - Marjan Omer
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Isabelle Baudrexel
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jesper Sejrup Nielsen
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Daniel Miotto Dupont
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | | | - Philipp Steen
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Munich, Germany
| | - Alexandra S Eklund
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark
| | | | - Ralf Jungmann
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Max Planck Institute of Biochemistry, Martinsried, Germany.,Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Munich, Germany
| | - Jørgen Kjems
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
| | - Søren Egedal Degn
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark. .,Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus C, Denmark.
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5
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Popov V, Andreescu M, Patrinoiu O, Popescu M, Omer M, Mihai F, Ofiteru G, Despan C, Constantin O, Pirvu C, Grigorie A, Rus A, Badoiu Niculae MD, Badea A, Iliescu L. P1601: THE ASSESSMENT OF PREDICTIVE ROLE OF PROTEIN C AND S FOR CRITICAL FORM OF COVID-19. Hemasphere 2022. [PMCID: PMC9430941 DOI: 10.1097/01.hs9.0000849260.73241.b6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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6
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Teodori L, Omer M, Märcher A, K. Skaanning M, L. Andersen V, S. Nielsen J, Oldenburg E, Lin Y, V. Gothelf K, Kjems J. Site-specific nanobody-oligonucleotide conjugation for super-resolution imaging. J Biol Methods 2022; 9:e159. [PMID: 35510035 PMCID: PMC9058258 DOI: 10.14440/jbm.2022.381] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/17/2021] [Accepted: 12/24/2021] [Indexed: 12/02/2022] Open
Abstract
Camelid single-domain antibody fragments, also called nanobodies, constitute a class of binders that are small in size (~15 kDa) and possess antigen-binding properties similar to their antibody counterparts. Facile production of recombinant nanobodies in several microorganisms has made this class of binders attractive within the field of molecular imaging. Particularly, their use in super-resolution microscopy has improved the spatial resolution of molecular targets due to a smaller linkage error. In single-molecule localization microscopy techniques, the effective spatial resolution can be further enhanced by site-specific fluorescent labeling of nanobodies owing to a more homogeneous protein-to-fluorophore stoichiometry, reduced background staining and a known distance between dye and epitope. Here, we present a protocol for site-specific bioconjugation of DNA oligonucleotides to three distinct nanobodies expressed with an N- or C-terminal unnatural amino acid, 4-azido-L-phenylalanine (pAzF). Using copper-free click chemistry, the nanobody-oligonucleotide conjugation reactions were efficient and yielded highly pure bioconjugates. Target binding was retained in the bioconjugates, as demonstrated by bio-layer interferometry binding assays and the super-resolution microscopy technique, DNA points accumulation for imaging in nanoscale topography (PAINT). This method for site-specific protein-oligonucleotide conjugation can be further extended for applications within drug delivery and molecular targeting where site-specificity and stoichiometric control are required.
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7
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Omer M, Amir-Khalili A, Sojoudi A, Thao Le T, A Cook S, Faye Toh D, Bryant J, Chin C, Miguel Paiva J, Fung K, Aung N, Y Khanji M, Rauseo E, Cooper J, E Petersen S. Assessing automated CMR contouring algorithms using systematic contour quality scoring analysis. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeaa356.434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): SmartHeart EPSRC programme grant (www.nihr.ac.uk), London Medical Imaging and AI Centre for Value-Based Healthcare
Background
Quality measures for machine learning algorithms include clinical measures such as end-diastolic (ED) and end-systolic (ES) volume, volumetric overlaps such as Dice similarity coefficient and surface distances such as Hausdorff distance. These measures capture differences between manually drawn and automated contours but fail to capture the trust of a clinician to an automatically generated contour.
Purpose
We propose to directly capture clinicians’ trust in a systematic way. We display manual and automated contours sequentially in random order and ask the clinicians to score the contour quality. We then perform statistical analysis for both sources of contours and stratify results based on contour type.
Data
The data selected for this experiment came from the National Health Center Singapore. It constitutes CMR scans from 313 patients with diverse pathologies including: healthy, dilated cardiomyopathy (DCM), hypertension (HTN), hypertrophic cardiomyopathy (HCM), ischemic heart disease (IHD), left ventricular non-compaction (LVNC), and myocarditis. Each study contains a short axis (SAX) stack, with ED and ES phases manually annotated. Automated contours are generated for each SAX image for which manual annotation is available. For this, a machine learning algorithm trained at Circle Cardiovascular Imaging Inc. is applied and the resulting predictions are saved to be displayed in the contour quality scoring (CQS) application.
Methods: The CQS application displays manual and automated contours in a random order and presents the user an option to assign a contour quality score
1: Unacceptable, 2: Bad, 3: Fair, 4: Good. The UK Biobank standard operating procedure is used for assessing the quality of the contoured images. Quality scores are assigned based on how the contour affects clinical outcomes. However, as images are presented independent of spatiotemporal context, contour quality is assessed based on how well the area of the delineated structure is approximated. Consequently, small contours and small deviations are rarely assigned a quality score of less than 2, as they are not clinically relevant. Special attention is given to the RV-endo contours as often, mostly in basal images, two separate contours appear. In such cases, a score of 3 is given if the two disjoint contours sufficiently encompass the underlying anatomy; otherwise they are scored as 2 or 1.
Results
A total of 50991 quality scores (24208 manual and 26783 automated) are generated by five expert raters. The mean score for all manual and automated contours are 3.77 ± 0.48 and 3.77 ± 0.52, respectively. The breakdown of mean quality scores by contour type is included in Fig. 1a while the distribution of quality scores for various raters are shown in Fig. 1b.
Conclusion
We proposed a method of comparing the quality of manual versus automated contouring methods. Results suggest similar statistics in quality scores for both sources of contours.
Abstract Figure 1
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Affiliation(s)
- M Omer
- Circle Cardiovascular Imaging Inc., Calgary, Canada
| | | | - A Sojoudi
- Circle Cardiovascular Imaging Inc., Calgary, Canada
| | - T Thao Le
- National Heart Centre Singapore, Singapore, Singapore
| | - S A Cook
- National Heart Centre Singapore, Singapore, Singapore
| | - D Faye Toh
- National Heart Centre Singapore, Singapore, Singapore
| | - J Bryant
- National Heart Centre Singapore, Singapore, Singapore
| | - C Chin
- National Heart Centre Singapore, Singapore, Singapore
| | | | - K Fung
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - N Aung
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - M Y Khanji
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - E Rauseo
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - J Cooper
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - S E Petersen
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
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8
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Ferapontov A, Omer M, Nielsen J, Thiel S, Kjems J, Degn SE. Molecular requirements for B cell receptor engagement and activation. The Journal of Immunology 2020. [DOI: 10.4049/jimmunol.204.supp.217.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
B cells are a central component of the adaptive branch of the immune system, responsible for humoral immunity through production of antibodies. Antigen engagement of the B cell receptor (BCR) is the first step in B cell activation; yet despite its recognized importance, the exact mechanism of BCR activation remains controversial. A central point of contention has been whether monovalent antigen is capable of activating the BCR or not. To address this question, we leveraged the B1-8hi knock-in BCR model, in which λ light-chain positive B cells display intermediate and high affinity binding to the haptens NP ((4-hydroxy-3-nitrophenyl)acetyl) and NIP ((4-hydroxy-3-iodo-5-nitrophenyl)acetyl), respectively, and combined this with a recently developed nucleic acid based scaffolding technology (Holliday junctions [HJs]) to prepare defined mono-, di- and trivalent displays of NP and NIP. Using confocal imaging, flow and imaging cytometry, as well as calcium-flux analyses, we find that HJs carrying 2 or 3 copies of either NP or NIP can bind and activate B1-8hi B cells across a wide range of concentrations, whereas HJs carrying a single NP require high concentrations for any measurable activity. Most interestingly, HJs carrying a single NIP are able to bind B1-8hi B cells at low concentrations, approaching equimolar stoichiometry, but despite measurable BCR engagement do not elicit activation. Our results may reconcile previous contradictory reports regarding monovalent antigen activation, by providing a framework for understanding complex interaction effects of antigen affinity, valency and concentration.
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9
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Alarfaj R, Aljihani S, Alzayer M, Johani SA, Balkhy H, Yassin A, Omer M, AlKhulaifi M, Alghoribi M, Halwani M. The Inhibitory activity of Tobramycin and Liposomal-Tobramycin-N-Acetylcysteine formulations Against Uropathogenic Escherichia coli (UPEC) Biofilms. J Infect Public Health 2020. [DOI: 10.1016/j.jiph.2020.01.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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10
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Abdalla AS, Salih A, Chicken W, Idaewor P, Elamass M, Omer M, Eldruki S, Comez T, Barron M, Asaad A. Ki-67 expression impact on lympho-vascular invasion presence in early breast cancer. Eur J Surg Oncol 2019. [DOI: 10.1016/j.ejso.2018.10.166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Apaydin A, Kocaelli H, Omer M. Management of self-inflicted gunshot (pellet) wounds of the jaws with Le fort I osteotomy followed by implant insertion and prosthetic rehabilitation. Int J Oral Maxillofac Surg 2015. [DOI: 10.1016/j.ijom.2015.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Montes VN, Subramanian S, Goodspeed L, Wang SA, Omer M, Bobik A, Teshigawara K, Nishibori M, Chait A. Anti-HMGB1 antibody reduces weight gain in mice fed a high-fat diet. Nutr Diabetes 2015; 5:e161. [PMID: 26075638 PMCID: PMC4491852 DOI: 10.1038/nutd.2015.11] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/05/2015] [Accepted: 04/22/2015] [Indexed: 01/19/2023] Open
Abstract
Insulin resistance in obesity is believed to be propagated by adipose tissue and liver inflammation. HMGB1 is a multifunctional protein that is pro-inflammatory when released from cells. It has been previously demonstrated that anti-HMGB1 antibody reduces atherosclerotic lesion pro-inflammatory cells and progression of atherosclerosis in a mouse model. To test the potential beneficial role of blocking HMGB1 in adipose tissue and liver inflammation in mice fed an obesogenic diet, we administered anti-HMGB1 antibody to C57Bl/6 mice fed a high (60%)-fat diet. The mice were treated with weekly injections of an anti-HMGB1 antibody or anti-KLH antibody (isotype control) for 16 weeks. Mice that received the anti-HMGB1 antibody gained less weight than the control-treated animals. Anti-HMGB1 treatment also reduced hepatic expression of TNF-alpha and MCP-1, molecules that promote inflammation. However, adipose tissue inflammation, as measured by gene expression analyses and immunohistochemistry, did not differ between the two groups. There also were no differences in glucose or insulin tolerance between the two groups. When feeding mice a high-fat diet, these data suggest that HMGB1 may have a crucial role in weight gain and liver inflammation.
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Affiliation(s)
- V N Montes
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - S Subramanian
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - L Goodspeed
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - S A Wang
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - M Omer
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - A Bobik
- BakerIDI Heart and Diabetes Institute, Melbourne, Australia
| | - K Teshigawara
- Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - M Nishibori
- Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - A Chait
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
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13
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Abstract
In this paper, we present a case review of a 58-year-old female who presented to our emergency department with pyrexia, dyspnoea, dehydration and pain in her left breast six months following coronary artery bypass grafting (CABG). Although her sternotomy wound had healed well, examination revealed fluctuance of the whole precordium and left breast. She underwent antibiotic treatment and subsequent surgical debridement, followed by the application of vacuum-assisted dressings. Surgical reconstruction was deemed unsuitable and therefore the patient continued to be managed with vacuum dressings followed by routine dressings to allow the wound to heal by secondary intention. The patient was discharged three months after initial presentation in a good condition. The wound had completely healed four months later.
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Affiliation(s)
- A Mustafa
- Specialist Cardiothoracic Surgeon, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| | - C Carr
- Cardiothoracic Surgeon, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| | - S Alkhafagi
- Specialist Cardiothoracic Surgeon,Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| | - N Mughal
- Clinical Associate, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| | - M Omer
- Clinical Associate, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| | - A Alkhulaifi
- Chairman of Cardiothoracic Surgery, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
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14
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Omer M. O717 Establishment of a gynecological laparoscopy unit in Omdurman Maternity Hospital, Sudan - challenges and outcome. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61090-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Salman M, Omer M. O819 Implementation of health systems in reducing maternal mortality. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61192-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Dobinson KF, Harrington MA, Omer M, Rowe RC. Molecular Characterization of Vegetative Compatibility Group 4A and 4B Isolates of Verticillium dahliae Associated with Potato Early Dying. Plant Dis 2000; 84:1241-1245. [PMID: 30832175 DOI: 10.1094/pdis.2000.84.11.1241] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Forty isolates of Verticillium dahliae, collected from potato seed tubers and potato plants from various regions in North America and previously assigned to vegetative compatibility groups (VCGs) 4A or 4B, were characterized using molecular markers. The VCG 4A isolates were previously shown to be a highly virulent pathotype of potato and to interact synergistically with the root-lesion nematode Pratylenchus penetrans to cause potato early dying. All but one of the VCG 4A isolates characterized in this study lacked the subspecies-specific repetitive DNA sequence E18 and could be differentiated from the remaining isolates by restriction fragment length polymorphisms (RFLPs) in the nuclear rDNA and Trp1 loci. The E18 RFLP patterns of several VCG 4B isolates from Maine and New York were highly similar to those of VCG 4B isolates previously collected from potato and tomato fields in Ontario. The data presented here suggest that the molecular markers will be useful for the detection and classification of isolates of V. dahliae associated with potato early dying.
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Affiliation(s)
- K F Dobinson
- Agriculture and Agri-Food Canada, London, ON, Canada N5V 4T3
| | - M A Harrington
- Department of Plant Sciences, University of Western Ontario, London, ON, Canada N6A 5B7
| | - M Omer
- Department of Plant Pathology, Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691
| | - R C Rowe
- Department of Plant Pathology, Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691
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