1
|
Su J, Harati Taji Z, Kosinska AD, Ates Oz E, Xie Z, Bielytskyi P, Shein M, Hagen P, Esmaeili S, Steiger K, Protzer U, Schütz AK. Introducing adjuvant-loaded particulate hepatitis B core antigen as an alternative therapeutic hepatitis B vaccine component. JHEP Rep 2024; 6:100997. [PMID: 38425450 PMCID: PMC10904195 DOI: 10.1016/j.jhepr.2023.100997] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/27/2023] [Accepted: 12/19/2023] [Indexed: 03/02/2024] Open
Abstract
Background & Aims Particulate hepatitis B core antigen (HBcoreAg) is a potent immunogen used as a vaccine carrier platform. HBcoreAg produced in E. coli encapsidates random bacterial RNA (bRNA). Using the heterologous protein-prime, viral-vector-boost therapeutic hepatitis B vaccine TherVacB, we compared the properties of different HBcoreAg forms. We explored how the content of HBcoreAg modulates antigen stability, immunogenicity, and antiviral efficacy. Methods bRNA was removed from HBcoreAg by capsid disassembly, followed by reassembly in the absence or presence of specific nucleic acid-based adjuvants poly I:C or CpG. The morphology and structure of empty, bRNA-containing and adjuvant-loaded HBcoreAg were monitored by electron microscopy and nuclear magnetic resonance spectroscopy. Empty, bRNA-containing or adjuvant-loaded HBcoreAg were applied together with HBsAg and with or without nucleic acid-based external adjuvants within the TherVacB regimen in both wild-type and HBV-carrier mice. Results While HBcoreAg retained its structure upon bRNA removal, its stability and immunogenicity decreased significantly. Loading HBcoreAg with nucleic acid-based adjuvants re-established stability of the capsid-like antigen. Immunization with poly I:C- or CpG-loaded HBcoreAg induced high antibody titers against co-administered HBsAg. When applied within the TherVacB regimen, they activated vigorous HBcoreAg- and HBsAg-specific T-cell responses in wild-type and HBV-carrier mice, requiring a significantly lower dose of adjuvant compared to externally added adjuvant. Finally, immunization with adjuvant-loaded HBcoreAg mixed with HBsAg led to long-term control of persistent HBV replication in the HBV-carrier mice. Conclusion Adjuvant-loaded HBcoreAg retained capsid integrity and stability, was as immunogenic in vivo as externally adjuvanted HBcoreAg, requiring lower adjuvant levels, and supported immunity against co-administered, non-adjuvanted HBsAg. Thus, adjuvant-loaded HBcoreAg represents a promising novel platform for vaccine development. Impact and implications Hepatitis B core antigen (HBcoreAg) recapitulates the capsid of the HBV that hosts the viral genome. Produced recombinantly, it is not infectious but emerges as a potent immunogen in vaccine development. In this preclinical study, we show that loading HBcoreAg with defined nucleic-acid-based adjuvants on the one hand stabilizes the HBcoreAg with standardized capsid content and, on the other hand, efficiently promotes the immunity of HBcoreAg and a co-administered antigen, allowing for reduced adjuvant doses. Therefore, adjuvant-loaded HBcoreAg not only serves as an encouraging option for therapeutic hepatitis B vaccines, but could also act as an efficient adjuvant delivery system for other types of vaccine.
Collapse
Affiliation(s)
- Jinpeng Su
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
- German Center for Infection Research (DZIF), Munich partner site, Germany
| | - Zahra Harati Taji
- Ludwig Maximilians University of Munich, 81377, Munich, Germany
- Bavarian NMR Center, Technical University of Munich, 85748, Garching, Germany
- Institute of Structural Biology, Helmholtz Munich, 85764, Neuherberg, Germany
| | - Anna D. Kosinska
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
- German Center for Infection Research (DZIF), Munich partner site, Germany
| | - Edanur Ates Oz
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
| | - Zhe Xie
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
| | - Pavlo Bielytskyi
- Bavarian NMR Center, Technical University of Munich, 85748, Garching, Germany
- Institute of Structural Biology, Helmholtz Munich, 85764, Neuherberg, Germany
| | - Mikhail Shein
- Ludwig Maximilians University of Munich, 81377, Munich, Germany
- Bavarian NMR Center, Technical University of Munich, 85748, Garching, Germany
- Institute of Structural Biology, Helmholtz Munich, 85764, Neuherberg, Germany
| | - Philipp Hagen
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
| | - Shohreh Esmaeili
- Ludwig Maximilians University of Munich, 81377, Munich, Germany
- Bavarian NMR Center, Technical University of Munich, 85748, Garching, Germany
- Institute of Structural Biology, Helmholtz Munich, 85764, Neuherberg, Germany
| | - Katja Steiger
- Comparative Experimental Pathology, Institute of Pathology, School of Medicine and Health, Technical University Munich, 81675, Munich, Germany
| | - Ulrike Protzer
- Institute of Virology, Technical University of Munich / Helmholtz Munich, 81675, Munich, Germany
- German Center for Infection Research (DZIF), Munich partner site, Germany
| | - Anne K. Schütz
- Ludwig Maximilians University of Munich, 81377, Munich, Germany
- Bavarian NMR Center, Technical University of Munich, 85748, Garching, Germany
- Institute of Structural Biology, Helmholtz Munich, 85764, Neuherberg, Germany
| |
Collapse
|
2
|
Szántó JK, Dietschreit JCB, Shein M, Schütz AK, Ochsenfeld C. Systematic QM/MM Study for Predicting 31P NMR Chemical Shifts of Adenosine Nucleotides in Solution and Stages of ATP Hydrolysis in a Protein Environment. J Chem Theory Comput 2024; 20:2433-2444. [PMID: 38497488 DOI: 10.1021/acs.jctc.3c01280] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
NMR (nuclear magnetic resonance) spectroscopy allows for important atomistic insights into the structure and dynamics of biological macromolecules; however, reliable assignments of experimental spectra are often difficult. Herein, quantum mechanical/molecular mechanical (QM/MM) calculations can provide crucial support. A major problem for the simulations is that experimental NMR signals are time-averaged over much longer time scales, and since computed chemical shifts are highly sensitive to local changes in the electronic and structural environment, sufficiently large averages over representative structural ensembles are essential. This entails high computational demands for reliable simulations. For NMR measurements in biological systems, a nucleus of major interest is 31P since it is both highly present (e.g., in nucleic acids) and easily observable. The focus of our present study is to develop a robust and computationally cost-efficient framework for simulating 31P NMR chemical shifts of nucleotides. We apply this scheme to study the different stages of the ATP hydrolysis reaction catalyzed by p97. Our methodology is based on MM molecular dynamics (MM-MD) sampling, followed by QM/MM structure optimizations and NMR calculations. Overall, our study is one of the most comprehensive QM-based 31P studies in a protein environment and the first to provide computed NMR chemical shifts for multiple nucleotide states in a protein environment. This study sheds light on a process that is challenging to probe experimentally and aims to bridge the gap between measured and calculated NMR spectroscopic properties.
Collapse
Affiliation(s)
- Judit Katalin Szántó
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, D-81377 München, Germany
| | - Johannes C B Dietschreit
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, D-81377 München, Germany
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Mikhail Shein
- Department of Chemistry, University of Munich (LMU), Butenandtstr. 5-13, D-81377 München, Germany
| | - Anne K Schütz
- Department of Chemistry, University of Munich (LMU), Butenandtstr. 5-13, D-81377 München, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, D-81377 München, Germany
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| |
Collapse
|
3
|
Shein M, Hitzenberger M, Cheng TC, Rout SR, Leitl KD, Sato Y, Zacharias M, Sakata E, Schütz AK. Characterizing ATP processing by the AAA+ protein p97 at the atomic level. Nat Chem 2024; 16:363-372. [PMID: 38326645 PMCID: PMC10914628 DOI: 10.1038/s41557-024-01440-0] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
The human enzyme p97 regulates various cellular pathways by unfolding hundreds of protein substrates in an ATP-dependent manner, making it an essential component of protein homeostasis and an impactful pharmacological target. The hexameric complex undergoes substantial conformational changes throughout its catalytic cycle. Here we elucidate the molecular motions that occur at the active site in the temporal window immediately before and after ATP hydrolysis by merging cryo-EM, NMR spectroscopy and molecular dynamics simulations. p97 populates a metastable reaction intermediate, the ADP·Pi state, which is poised between hydrolysis and product release. Detailed snapshots reveal that the active site is finely tuned to trap and eventually discharge the cleaved phosphate. Signalling pathways originating at the active site coordinate the action of the hexamer subunits and couple hydrolysis with allosteric conformational changes. Our multidisciplinary approach enables a glimpse into the sophisticated spatial and temporal orchestration of ATP handling by a prototype AAA+ protein.
Collapse
Affiliation(s)
- Mikhail Shein
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany
- Bavarian NMR Center, Technical University of Munich, Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Manuel Hitzenberger
- Physics Department and Center of Protein Assemblies, Technical University of Munich, Garching, Germany.
| | - Tat Cheung Cheng
- Institute for Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany
| | - Smruti R Rout
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany
- Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen, Germany
| | - Kira D Leitl
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany
- Bavarian NMR Center, Technical University of Munich, Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Yusuke Sato
- Center for Research on Green Sustainable Chemistry, Graduate School of Engineering, Tottori University, Tottori, Japan
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Martin Zacharias
- Physics Department and Center of Protein Assemblies, Technical University of Munich, Garching, Germany.
| | - Eri Sakata
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany.
- Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen, Germany.
| | - Anne K Schütz
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany.
- Bavarian NMR Center, Technical University of Munich, Garching, Germany.
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.
| |
Collapse
|
4
|
Harati Taji Z, Bielytskyi P, Shein M, Sani MA, Seitz S, Schütz AK. Transient RNA Interactions Leave a Covalent Imprint on a Viral Capsid Protein. J Am Chem Soc 2022; 144:8536-8550. [PMID: 35512333 PMCID: PMC9121876 DOI: 10.1021/jacs.1c12439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The hepatitis B virus (HBV) is the leading cause of persistent liver infections. Its DNA-based genome is synthesized through reverse transcription of an RNA template inside the assembled capsid shell. In addition to the structured assembly domain, the capsid protein harbors a C-terminal extension that mediates both the enclosure of RNA during capsid assembly and the nuclear entry of the capsid during infection. The arginine-rich motifs within this extension, though common to many viruses, have largely escaped atomic-scale investigation. Here, we leverage solution and solid-state nuclear magnetic resonance spectroscopy at ambient and cryogenic temperatures, under dynamic nuclear polarization signal enhancement, to investigate the organization of the genome within the capsid. Transient interactions with phosphate groups of the RNA backbone confine the arginine-rich motifs to the interior capsid space. While no secondary structure is induced in the C-terminal extension, interactions with RNA counteract the formation of a disulfide bond, which covalently tethers this peptide arm onto the inner capsid surface. Electrostatic and covalent contributions thus compete in the spatial regulation of capsid architecture. This disulfide switch represents a coupling mechanism between the structured assembly domain of the capsid and the enclosed nucleic acids. In particular, it enables the redox-dependent regulation of the exposure of the C-terminal extension on the capsid surface, which is required for nuclear uptake of the capsid. Phylogenetic analysis of capsid proteins from hepadnaviruses points toward a function of this switch in the persistence of HBV infections.
Collapse
Affiliation(s)
- Zahra Harati Taji
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Pavlo Bielytskyi
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Mikhail Shein
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Stefan Seitz
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg 69120, Germany.,Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Anne K Schütz
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| |
Collapse
|
5
|
Albanese M, Chen YFA, Hüls C, Gärtner K, Tagawa T, Mejias-Perez E, Keppler OT, Göbel C, Zeidler R, Shein M, Schütz AK, Hammerschmidt W. MicroRNAs are minor constituents of extracellular vesicles that are rarely delivered to target cells. PLoS Genet 2021; 17:e1009951. [PMID: 34871319 PMCID: PMC8675925 DOI: 10.1371/journal.pgen.1009951] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 12/16/2021] [Accepted: 11/16/2021] [Indexed: 12/14/2022] Open
Abstract
Mammalian cells release different types of vesicles, collectively termed extracellular vesicles (EVs). EVs contain cellular microRNAs (miRNAs) with an apparent potential to deliver their miRNA cargo to recipient cells to affect the stability of individual mRNAs and the cells’ transcriptome. The extent to which miRNAs are exported via the EV route and whether they contribute to cell-cell communication are controversial. To address these issues, we defined multiple properties of EVs and analyzed their capacity to deliver packaged miRNAs into target cells to exert biological functions. We applied well-defined approaches to produce and characterize purified EVs with or without specific viral miRNAs. We found that only a small fraction of EVs carried miRNAs. EVs readily bound to different target cell types, but EVs did not fuse detectably with cellular membranes to deliver their cargo. We engineered EVs to be fusogenic and document their capacity to deliver functional messenger RNAs. Engineered fusogenic EVs, however, did not detectably alter the functionality of cells exposed to miRNA-carrying EVs. These results suggest that EV-borne miRNAs do not act as effectors of cell-to-cell communication. The majority of metazoan cells release vesicles of different types and origins, such as exosomes and microvesicles, now collectively termed extracellular vesicles (EVs). EVs have gained much attention because they contain microRNAs (miRNAs) and thus could regulate their specific mRNA targets in recipient or acceptor cells that take up EVs. Using a novel fusion assay with superior sensitivity and specificity, we revisited this claim but found no convincing evidence for an efficient functional uptake of EVs in many different cell lines and primary human blood cells. Even EVs engineered to fuse and deliver their miRNA cargo to recipient cells had no measurable effect on target mRNAs in very carefully controlled, quantitative experiments. Our negative results clearly indicate that EVs do not act as vehicles for miRNA-based cell-to-cell communication.
Collapse
Affiliation(s)
- Manuel Albanese
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- Max von Pettenkofer Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
- * E-mail: (MA); (WH)
| | - Yen-Fu Adam Chen
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Corinna Hüls
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Kathrin Gärtner
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Takanobu Tagawa
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Ernesto Mejias-Perez
- Max von Pettenkofer Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Oliver T. Keppler
- Max von Pettenkofer Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Christine Göbel
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
| | - Reinhard Zeidler
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
- Department of Otorhinolaryngology, Klinikum der Universität München, Munich, Germany
| | - Mikhail Shein
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching, Germany
| | - Anne K. Schütz
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Hammerschmidt
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany
- German Centre for Infection Research (DZIF), Partner site Munich, Germany
- * E-mail: (MA); (WH)
| |
Collapse
|
6
|
Jung S, Jacobs KFK, Shein M, Schütz AK, Mohr F, Stadler H, Stadler D, Lucko AM, Altstetter SM, Wilsch F, Deng L, Protzer U. Efficient and reproducible depletion of hepatitis B virus from plasma derived extracellular vesicles. J Extracell Vesicles 2020; 10:e12040. [PMID: 33363711 PMCID: PMC7754750 DOI: 10.1002/jev2.12040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 09/24/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
Extracellular vesicles (EVs) are emerging fundamental players in viral infections by shuttling viral components, mediating immune responses and likely the spread of the virus. However, the obstacles involved in purifying EVs and removing contaminating viral particles in a reliable and effective manner bottlenecks the full potential for the development of clinical and diagnostic treatment options targeting EV. Because of the similarities in size, density, membrane composition and mode of biogenesis of EVs and virions there are no standardized approaches for virus-removal from EV preparations yet. Functional EV studies also require EV samples that are devoid of antibody contaminants. Consequently, the study of EVs in virology needs reliable and effective protocols to purify EVs and remove contaminating antibodies and viral particles. Here, we established a protocol for EV purification from hepatitis B virus (HBV)-containing plasma by a combination of size-exclusion chromatography and affinity-based purification. After purification, EV samples were free of virus-sized particles, HBV surface antigen, HBV core antigen, antibodies or infectious material. Viral genomic contamination was also decreased following purification. By using appropriate antibodies and size parameters, this protocol could potentially be applied to purification of EVs from other viral samples. In summary, we established a fast, reproducible and robust approach for the removal of HBV from EV preparations. Looking forward to the point of purifying EVs from clinical samples, this method should enable studies shedding light on the underlying mechanisms of EVs in viral infections and their diagnostic and prognostic potential.
Collapse
Affiliation(s)
- Stephanie Jung
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
| | | | - Mikhail Shein
- Bavarian NMR Center, Department of ChemistryTechnical University of MunichGarchingGermany
| | - Anne Kathrin Schütz
- Bavarian NMR Center, Department of ChemistryTechnical University of MunichGarchingGermany
| | | | | | - Daniela Stadler
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
| | - Aaron Michael Lucko
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
| | | | - Florian Wilsch
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
| | - Li Deng
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
| | - Ulrike Protzer
- Institute of VirologySchool of MedicineHelmholtz Zentrum München/Technical University of MunichGarchingGermany
- German Center for Infection Research (DZIF)Munich partner siteGarchingGermany
| |
Collapse
|
7
|
Rydzek S, Shein M, Bielytskyi P, Schütz AK. Observation of a Transient Reaction Intermediate Illuminates the Mechanochemical Cycle of the AAA-ATPase p97. J Am Chem Soc 2020; 142:14472-14480. [DOI: 10.1021/jacs.0c03180] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Simon Rydzek
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany
| | - Mikhail Shein
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany
| | - Pavlo Bielytskyi
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany
| | - Anne K. Schütz
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| |
Collapse
|
8
|
Shein M, Jeschke G. Comparison of Free Radical Levels in the Aerosol from Conventional Cigarettes, Electronic Cigarettes, and Heat-Not-Burn Tobacco Products. Chem Res Toxicol 2019; 32:1289-1298. [PMID: 30932480 PMCID: PMC6584902 DOI: 10.1021/acs.chemrestox.9b00085] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Indexed: 11/28/2022]
Abstract
Aerosols from electronic cigarettes and heat-not-burn tobacco products have been found to contain lower levels of almost all compounds from the list of Harmful and Potentially Harmful Constituents known to be present in tobacco products and tobacco smoke than smoke from conventional cigarettes. Free radicals, which also pose potential health risks, are not considered in this list, and their levels in the different product types have not yet been compared under standardized conditions. We compared the type and quantity of free radicals in mainstream aerosol of 3R4F research cigarettes, two types of electronic cigarettes, and a heat-not-burn tobacco product. Free radicals and NO in the gas phases were separately spin trapped and quantified by electron paramagnetic resonance (EPR) spectroscopy by using a smoking machine for aerosol generation and a flow-through cell to enhance reproducibility of the quantification. Particulate matter was separated by a Cambridge filter and extracted, and persistent radicals were quantified by EPR spectroscopy. Levels of organic radicals for electronic cigarettes and the heat-not-burn product, as measured with the PBN spin trap, did not exceed 1% of the level observed for conventional cigarettes and were close to the radical level observed in air blanks. The radicals found in the smoke of conventional cigarettes were oxygen centered, most probably alkoxy radicals, whereas a signal for carbon-centered radicals near the detection limit was observed in aerosol from the heat-not-burn product and electronic cigarettes. The NO level in aerosol produced by electronic cigarettes was below our detection limit, whereas for the heat-not-burn product, it reached about 7% of the level observed for whole smoke from 3R4F cigarettes. Persistent radicals in particulate matter could be quantified only for 3R4F cigarettes. Aerosols from vaping and heat-not-burn tobacco products have much lower free radical levels than cigarette smoke, however, the toxicological implications of this finding are as yet unknown.
Collapse
Affiliation(s)
| | - Gunnar Jeschke
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| |
Collapse
|
9
|
Esat K, David G, Poulkas T, Shein M, Signorell R. Phase transition dynamics of single optically trapped aqueous potassium carbonate particles. Phys Chem Chem Phys 2018; 20:11598-11607. [DOI: 10.1039/c8cp00599k] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study reveals that complex multiple processes occur during efflorescence and deliquescence in unsupported, submicron sized particles.
Collapse
Affiliation(s)
- Kıvanç Esat
- Laboratory of Physical Chemistry
- ETH Zürich
- Zürich
- Switzerland
| | - Grégory David
- Laboratory of Physical Chemistry
- ETH Zürich
- Zürich
- Switzerland
| | | | - Mikhail Shein
- Laboratory of Physical Chemistry
- ETH Zürich
- Zürich
- Switzerland
| | - Ruth Signorell
- Laboratory of Physical Chemistry
- ETH Zürich
- Zürich
- Switzerland
| |
Collapse
|
10
|
Shein M. [The concept of microhistory: accident and treatment of a girl from Lacandon]. Bol Soc Mex Hist Filos Med 2001; 13:87-97. [PMID: 11638199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
|
11
|
Shein M. Management of prescribing. J Ky Med Assoc 1993; 91:513-5. [PMID: 8270849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
12
|
Abstract
An Arab family is reported in which the proband and two affected sibs had bilateral rhizomelia of the humerus and other skeletal, craniofacial and cardiac abnormalities. Since all three affected sibs died during early childhood, this may be a lethal condition. We believe this constellation of findings which has not been previously described represents a new syndrome, most probably transmitted as an autosomal recessive disorder.
Collapse
|
13
|
Abstract
A young girl with compensated Hashimoto thyroiditis suffered from progressive encephalopathy while euthyroid. Seizures and mental abnormalities responded excellently to corticosteroids only, supporting the view that encephalopathy could be the clinical manifestation of autoimmune cerebral vasculitis.
Collapse
|
14
|
Shein M, Pick S. [Gilbert's disease]. Bol Med Hosp Infant Mex 1980; 37:1255-65. [PMID: 7470272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
An extensive review of Gilbert's disease (unconjugated, non-hemolytic hyperbilirubinemia) is made with incidence not exactly determined, but it is a disease linked to hereditary factors. Two types of the disease, together with the controversy existing as to their pathogenesis are discussed. The clinical picture and all laboratory studies carried out to reach a diagnosis are reviewed. Also, the histopathology and treatment are briefly described. Two cases of this disease in the same family are presented.
Collapse
|
15
|
Lisker R, Pérez Briceño R, Sosa R, Shein M. [Hereditary and epidemiological aspects of erythrocyte glucose-6-phosphate dehydrogenase deficiency in Mexico]. GAC MED MEX 1976; 111:454-8. [PMID: 964538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
|