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Puri A, Ibrahim F, O'Reilly Beringhs A, Isemann C, Zakrevsky P, Whittenburg A, Hargrove D, Kanai T, Dillard RS, de Val N, Nantz MH, Lu X, Shapiro BA. Stealth oxime ether lipid vesicles promote delivery of functional DsiRNA in human lung cancer A549 tumor bearing mouse xenografts. Nanomedicine 2022; 44:102572. [PMID: 35671983 PMCID: PMC9427711 DOI: 10.1016/j.nano.2022.102572] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/15/2022] [Accepted: 05/24/2022] [Indexed: 11/29/2022]
Abstract
We previously reported that hydroxylated oxime ether lipids (OELs) efficiently deliver functional Dicer substrate siRNAs (DsiRNAs) in cells. Here, we explored in vivo utility of these OELs, using OEL4 as a prototype and report that surface modification of the OEL4 formulations was essential for their in vivo applications. These surface-modified OEL4 formulations were developed by inclusion of various PEGylated lipids. The vesicle stability and gene knock-down were dependent on the PEG chain length. OEL4 containing DSPE-PEG350 and DSPE-PEG1000 (surprisingly not DSPE2000) promoted gene silencing in cells. In vivo studies demonstrated that OEL4 vesicles formulated using 3 mol% DSPE-PEG350 accumulate in human lung cancer (A549-luc2) xenografts in mice and exhibit a significant increase in tumor to liver ratios. These vesicles also showed a statistically significant reduction of luciferase signal in tumors compared to untreated mice. Taken together, the scalable OEL4:DSPE-PEG350 formulation serves as a novel candidate for delivery of RNAi therapeutics.
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Affiliation(s)
- Anu Puri
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America.
| | - Faisal Ibrahim
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America; Department of Chemistry, University of Louisville, Louisville, KY, United States of America
| | | | - Camryn Isemann
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America
| | - Paul Zakrevsky
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America
| | - Abigail Whittenburg
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America
| | - Derek Hargrove
- School of Pharmacy, University of Connecticut, Storrs, CT, United States of America
| | - Tapan Kanai
- Centre for Molecular Microscopy, FNLCR, Leidos Biomedical Research, Inc., Frederick, MD, United States of America
| | - Rebecca S Dillard
- Centre for Molecular Microscopy, FNLCR, Leidos Biomedical Research, Inc., Frederick, MD, United States of America
| | - Natalia de Val
- Centre for Molecular Microscopy, FNLCR, Leidos Biomedical Research, Inc., Frederick, MD, United States of America
| | - Michael H Nantz
- Department of Chemistry, University of Louisville, Louisville, KY, United States of America
| | - Xiuling Lu
- School of Pharmacy, University of Connecticut, Storrs, CT, United States of America
| | - Bruce A Shapiro
- RNA Structure and Design Section, RNA Biology Laboratory, NCI-NIH, Frederick, MD, United States of America.
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Abstract
In this chapter, we present an overview of a standard protocol to achieve structure determination at high resolution by Single Particle Analysis cryogenic Electron Microscopy using apoferritin as a standard sample. The purified apoferritin is applied to a glow-discharged support and then flash frozen in liquid ethane. The prepared grids are loaded into the electron microscope and checked for particle spreading and ice thickness. The microscope alignments are performed and the data collection session is setup for an overnight data collection. The collected movies containing two-dimensional images of the apoferritin sample are then processed to obtain a high-resolution three-dimensional reconstruction.
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Affiliation(s)
- Christoph A Diebolder
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Rebecca S Dillard
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Ludovic Renault
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands.
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3
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Andrés G, Charro D, Matamoros T, Dillard RS, Abrescia NGA. The cryo-EM structure of African swine fever virus unravels a unique architecture comprising two icosahedral protein capsids and two lipoprotein membranes. J Biol Chem 2020; 295:1-12. [PMID: 31649031 PMCID: PMC6952596 DOI: 10.1074/jbc.ac119.011196] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [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: 09/24/2019] [Revised: 10/22/2019] [Indexed: 11/06/2022] Open
Abstract
African swine fever virus (ASFV) is a complex nucleocytoplasmic large DNA virus (NCLDV) that causes a devastating swine disease currently present in many countries of Africa, Europe, and Asia. Despite intense research efforts, relevant gaps in the architecture of the infectious virus particle remain. Here, we used single-particle cryo-EM to analyze the three-dimensional structure of the mature ASFV particle. Our results show that the ASFV virion, with a radial diameter of ∼2,080 Å, encloses a genome-containing nucleoid surrounded by two distinct icosahedral protein capsids and two lipoprotein membranes. The outer capsid forms a hexagonal lattice (triangulation number T = 277) composed of 8,280 copies of the double jelly-roll major capsid protein (MCP) p72, arranged in trimers displaying a pseudo-hexameric morphology, and of 60 copies of a penton protein at the vertices. The inner protein layer, organized as a T = 19 capsid, confines the core shell, and it is composed of the mature products derived from the ASFV polyproteins pp220 and pp62. Also, an icosahedral membrane lies between the two protein layers, whereas a pleomorphic envelope wraps the outer capsid. This high-level organization confers to ASFV a unique architecture among the NCLDVs that likely reflects the complexity of its infection process and may help explain current challenges in controlling it.
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Affiliation(s)
- German Andrés
- Centro de Biología Molecular Severo Ochoa, CSIC and Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Diego Charro
- Molecular Recognition and Host-Pathogen Interactions Programme, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Spain
| | - Tania Matamoros
- Centro de Biología Molecular Severo Ochoa, CSIC and Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rebecca S Dillard
- NeCEN, Institute of Biology Leiden, Leiden University, 2333_CC Leiden, Netherlands
| | - Nicola G A Abrescia
- Molecular Recognition and Host-Pathogen Interactions Programme, CIC bioGUNE, CIBERehd, Bizkaia Technology Park, 48160 Derio, Spain; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.
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4
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Dillard RS, Hampton CM, Strauss JD, Ke Z, Altomara D, Guerrero-Ferreira RC, Kiss G, Wright ER. Biological Applications at the Cutting Edge of Cryo-Electron Microscopy. Microsc Microanal 2018; 24:406-419. [PMID: 30175702 PMCID: PMC6265046 DOI: 10.1017/s1431927618012382] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cryo-electron microscopy (cryo-EM) is a powerful tool for macromolecular to near-atomic resolution structure determination in the biological sciences. The specimen is maintained in a near-native environment within a thin film of vitreous ice and imaged in a transmission electron microscope. The images can then be processed by a number of computational methods to produce three-dimensional information. Recent advances in sample preparation, imaging, and data processing have led to tremendous growth in the field of cryo-EM by providing higher resolution structures and the ability to investigate macromolecules within the context of the cell. Here, we review developments in sample preparation methods and substrates, detectors, phase plates, and cryo-correlative light and electron microscopy that have contributed to this expansion. We also have included specific biological applications.
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Affiliation(s)
- Rebecca S Dillard
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Cheri M Hampton
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Joshua D Strauss
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Zunlong Ke
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Deanna Altomara
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Ricardo C Guerrero-Ferreira
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Gabriella Kiss
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
| | - Elizabeth R Wright
- 1Division of Pediatric Infectious Diseases,Emory University School of Medicine,Children's Healthcare of Atlanta,Atlanta,GA 30322,USA
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5
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Ke Z, Strauss JD, Hampton CM, Brindley MA, Dillard RS, Leon F, Lamb KM, Plemper RK, Wright ER. Promotion of virus assembly and organization by the measles virus matrix protein. Nat Commun 2018; 9:1736. [PMID: 29712906 PMCID: PMC5928126 DOI: 10.1038/s41467-018-04058-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 03/29/2018] [Indexed: 12/05/2022] Open
Abstract
Measles virus (MeV) remains a major human pathogen, but there are presently no licensed antivirals to treat MeV or other paramyxoviruses. Here, we use cryo-electron tomography (cryo-ET) to elucidate the principles governing paramyxovirus assembly in MeV-infected human cells. The three-dimensional (3D) arrangement of the MeV structural proteins including the surface glycoproteins (F and H), matrix protein (M), and the ribonucleoprotein complex (RNP) are characterized at stages of virus assembly and budding, and in released virus particles. The M protein is observed as an organized two-dimensional (2D) paracrystalline array associated with the membrane. A two-layered F–M lattice is revealed suggesting that interactions between F and M may coordinate processes essential for MeV assembly. The RNP complex remains associated with and in close proximity to the M lattice. In this model, the M lattice facilitates the well-ordered incorporation and concentration of the surface glycoproteins and the RNP at sites of virus assembly. Virus assembly is technically challenging to study. Here the authors use cryo-electron tomography of measles virus-infected human cells to determine native-state virus structure and they locate well-ordered M lattices that organize viral glycoproteins, RNP, and drive assembly.
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Affiliation(s)
- Zunlong Ke
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Joshua D Strauss
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Cheri M Hampton
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Melinda A Brindley
- Department of Infectious Diseases, Department of Population Health and Center for Vaccines and Immunology, University of Georgia, Athens, GA, 30602, USA.,Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA
| | - Rebecca S Dillard
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Fredrick Leon
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Kristen M Lamb
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA.
| | - Elizabeth R Wright
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA. .,Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, GA, 30322, USA.
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6
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Ellison CK, Kan J, Dillard RS, Kysela DT, Ducret A, Berne C, Hampton CM, Ke Z, Wright ER, Biais N, Dalia AB, Brun YV. Obstruction of pilus retraction stimulates bacterial surface sensing. Science 2018; 358:535-538. [PMID: 29074778 DOI: 10.1126/science.aan5706] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/17/2017] [Accepted: 09/19/2017] [Indexed: 01/27/2023]
Abstract
It is critical for bacteria to recognize surface contact and initiate physiological changes required for surface-associated lifestyles. Ubiquitous microbial appendages called pili are involved in sensing surfaces and facilitating downstream behaviors, but the mechanism by which pili mediate surface sensing has been unclear. We visualized Caulobacter crescentus pili undergoing dynamic cycles of extension and retraction. Within seconds of surface contact, these cycles ceased, which coincided with synthesis of the adhesive holdfast required for attachment. Physically blocking pili imposed resistance to pilus retraction, which was sufficient to stimulate holdfast synthesis without surface contact. Thus, to sense surfaces, bacteria use the resistance on retracting, surface-bound pili that occurs upon surface contact.
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Affiliation(s)
- Courtney K Ellison
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Jingbo Kan
- Biology Department, CUNY Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, USA.,Graduate Center of CUNY, 365 5th Avenue, New York, NY 10016, USA
| | - Rebecca S Dillard
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
| | - David T Kysela
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Adrien Ducret
- Molecular Microbiology and Structural Biochemistry, Université Lyon 1, CNRS, UMR 5086, 7 passage du Vercors, 69367 Lyon Cedex 07, France
| | - Cecile Berne
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Cheri M Hampton
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
| | - Zunlong Ke
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA.,School of Biology, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA
| | - Elizabeth R Wright
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
| | - Nicolas Biais
- Biology Department, CUNY Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, USA.,Graduate Center of CUNY, 365 5th Avenue, New York, NY 10016, USA
| | - Ankur B Dalia
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Yves V Brun
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA.
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7
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Gigante AM, Hampton CM, Dillard RS, Gil F, Catalão MJ, Moniz-Pereira J, Wright ER, Pimentel M. The Ms6 Mycolyl-Arabinogalactan Esterase LysB is Essential for an Efficient Mycobacteriophage-Induced Lysis. Viruses 2017; 9:v9110343. [PMID: 29149017 PMCID: PMC5707550 DOI: 10.3390/v9110343] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [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: 10/17/2017] [Revised: 11/10/2017] [Accepted: 11/14/2017] [Indexed: 01/21/2023] Open
Abstract
All dsDNA phages encode two proteins involved in host lysis, an endolysin and a holin that target the peptidoglycan and cytoplasmic membrane, respectively. Bacteriophages that infect Gram-negative bacteria encode additional proteins, the spanins, involved in disruption of the outer membrane. Recently, a gene located in the lytic cassette was identified in the genomes of mycobacteriophages, which encodes a protein (LysB) with mycolyl-arabinogalactan esterase activity. Taking in consideration the complex mycobacterial cell envelope that mycobacteriophages encounter during their life cycle, it is valuable to evaluate the role of these proteins in lysis. In the present work, we constructed an Ms6 mutant defective on lysB and showed that Ms6 LysB has an important role in lysis. In the absence of LysB, lysis still occurs but the newly synthesized phage particles are deficiently released to the environment. Using cryo-electron microscopy and tomography to register the changes in the lysis phenotype, we show that at 150 min post-adsorption, mycobacteria cells are incompletely lysed and phage particles are retained inside the cell, while cells infected with Ms6wt are completely lysed. Our results confirm that Ms6 LysB is necessary for an efficient lysis of Mycobacterium smegmatis, acting, similarly to spanins, in the third step of the lysis process.
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Affiliation(s)
- Adriano M Gigante
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal.
| | - Cheri M Hampton
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA.
| | - Rebecca S Dillard
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA.
| | - Filipa Gil
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal.
| | - Maria João Catalão
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal.
| | - José Moniz-Pereira
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal.
| | - Elizabeth R Wright
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA.
| | - Madalena Pimentel
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal.
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8
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Magnotti EL, Hughes SA, Dillard RS, Wang S, Hough L, Karumbamkandathil A, Lian T, Wall JS, Zuo X, Wright ER, Conticello VP. Self-Assembly of an α-Helical Peptide into a Crystalline Two-Dimensional Nanoporous Framework. J Am Chem Soc 2016; 138:16274-16282. [PMID: 27936625 PMCID: PMC5739522 DOI: 10.1021/jacs.6b06592] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [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] [Indexed: 12/18/2022]
Abstract
Sequence-specific peptides have been demonstrated to self-assemble into structurally defined nanoscale objects including nanofibers, nanotubes, and nanosheets. The latter structures display significant promise for the construction of hybrid materials for functional devices due to their extended planar geometry. Realization of this objective necessitates the ability to control the structural features of the resultant assemblies through the peptide sequence. The design of a amphiphilic peptide, 3FD-IL, is described that comprises two repeats of a canonical 18 amino acid sequence associated with straight α-helical structures. Peptide 3FD-IL displays 3-fold screw symmetry in a helical conformation and self-assembles into nanosheets based on hexagonal packing of helices. Biophysical evidence from TEM, cryo-TEM, SAXS, AFM, and STEM measurements on the 3FD-IL nanosheets support a structural model based on a honeycomb lattice, in which the length of the peptide determines the thickness of the nanosheet and the packing of helices defines the presence of nanoscale channels that permeate the sheet. The honeycomb structure can be rationalized on the basis of geometrical packing frustration in which the channels occupy defect sites that define a periodic superlattice. The resultant 2D materials may have potential as materials for nanoscale transport and controlled release applications.
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Affiliation(s)
| | - Spencer A. Hughes
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Rebecca S. Dillard
- Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia 30322, United States
| | - Shengyuan Wang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Lillian Hough
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | | | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joseph S. Wall
- Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973, United States
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Elizabeth R. Wright
- Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia 30322, United States
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9
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Hampton CM, Strauss JD, Ke Z, Dillard RS, Hammonds JE, Alonas E, Desai TM, Marin M, Storms RE, Leon F, Melikyan GB, Santangelo PJ, Spearman PW, Wright ER. Correlated fluorescence microscopy and cryo-electron tomography of virus-infected or transfected mammalian cells. Nat Protoc 2016; 12:150-167. [PMID: 27977021 DOI: 10.1038/nprot.2016.168] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [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
Correlative light and electron microscopy (CLEM) combines spatiotemporal information from fluorescence light microscopy (fLM) with high-resolution structural data from cryo-electron tomography (cryo-ET). These technologies provide opportunities to bridge knowledge gaps between cell and structural biology. Here we describe our protocol for correlated cryo-fLM, cryo-electron microscopy (cryo-EM), and cryo-ET (i.e., cryo-CLEM) of virus-infected or transfected mammalian cells. Mammalian-derived cells are cultured on EM substrates, using optimized conditions that ensure that the cells are spread thinly across the substrate and are not physically disrupted. The cells are then screened by fLM and vitrified before acquisition of cryo-fLM and cryo-ET images, which is followed by data processing. A complete session from grid preparation through data collection and processing takes 5-15 d for an individual experienced in cryo-EM.
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Affiliation(s)
- Cheri M Hampton
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Joshua D Strauss
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Zunlong Ke
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Rebecca S Dillard
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Jason E Hammonds
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Eric Alonas
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Tanay M Desai
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Mariana Marin
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Rachel E Storms
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Fredrick Leon
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Gregory B Melikyan
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Philip J Santangelo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Paul W Spearman
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Elizabeth R Wright
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA.,Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia, USA
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10
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Mitchell AJ, Gray WD, Schroeder M, Yi H, Taylor JV, Dillard RS, Ke Z, Wright ER, Stephens D, Roback JD, Searles CD. Pleomorphic Structures in Human Blood Are Red Blood Cell-Derived Microparticles, Not Bacteria. PLoS One 2016; 11:e0163582. [PMID: 27760197 PMCID: PMC5070825 DOI: 10.1371/journal.pone.0163582] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 11/24/2015] [Accepted: 09/12/2016] [Indexed: 12/01/2022] Open
Abstract
Background Red blood cell (RBC) transfusions are a common, life-saving therapy for many patients, but they have also been associated with poor clinical outcomes. We identified unusual, pleomorphic structures in human RBC transfusion units by negative-stain electron microscopy that appeared identical to those previously reported to be bacteria in healthy human blood samples. The presence of viable, replicating bacteria in stored blood could explain poor outcomes in transfusion recipients and have major implications for transfusion medicine. Here, we investigated the possibility that these structures were bacteria. Results Flow cytometry, miRNA analysis, protein analysis, and additional electron microscopy studies strongly indicated that the pleomorphic structures in the supernatant of stored RBCs were RBC-derived microparticles (RMPs). Bacterial 16S rDNA PCR amplified from these samples were sequenced and was found to be highly similar to species that are known to commonly contaminate laboratory reagents. Conclusions These studies suggest that pleomorphic structures identified in human blood are RMPs and not bacteria, and they provide an example in which laboratory contaminants may can mislead investigators.
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Affiliation(s)
- Adam J. Mitchell
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Warren D. Gray
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Max Schroeder
- Division of Infectious Disease, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Hong Yi
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia, United States of America
| | - Jeannette V. Taylor
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia, United States of America
| | - Rebecca S. Dillard
- Division of Infectious Disease, Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - Zunlong Ke
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Elizabeth R. Wright
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Disease, Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - David Stephens
- Division of Infectious Disease, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - John D. Roback
- Center for Transfusion and Cellular Therapy, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Charles D. Searles
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
- Section of Cardiology, Atlanta VA Medical Center, Decatur, Georgia, United States of America
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Yi H, Strauss JD, Ke Z, Alonas E, Dillard RS, Hampton CM, Lamb KM, Hammonds JE, Santangelo PJ, Spearman PW, Wright ER. Native immunogold labeling of cell surface proteins and viral glycoproteins for cryo-electron microscopy and cryo-electron tomography applications. J Histochem Cytochem 2015; 63:780-92. [PMID: 26069287 DOI: 10.1369/0022155415593323] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/29/2015] [Indexed: 11/22/2022] Open
Abstract
Numerous methods have been developed for immunogold labeling of thick, cryo-preserved biological specimens. However, most of the methods are permutations of chemical fixation and sample sectioning, which select and isolate the immunolabeled region of interest. We describe a method for combining immunogold labeling with cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET) of the surface proteins of intact mammalian cells or the surface glycoproteins of assembling and budding viruses in the context of virus-infected mammalian cells cultured on EM grids. In this method, the cells were maintained in culture media at physiologically relevant temperatures while sequentially incubated with the primary and secondary antibodies. Subsequently, the immunogold-labeled specimens were vitrified and observed under cryo-conditions in the transmission electron microscope. Cryo-EM and cryo-ET examination of the immunogold-labeled cells revealed the association of immunogold particles with the target antigens. Additionally, the cellular structure was unaltered by pre-immunolabeling chemical fixation and retained well-preserved plasma membranes, cytoskeletal elements, and macromolecular complexes. We think this technique will be of interest to cell biologists for cryo-EM and conventional studies of native cells and pathogen-infected cells.
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Affiliation(s)
- Hong Yi
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia (HY, ERW)
| | - Joshua D Strauss
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Zunlong Ke
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia (ZK)
| | - Eric Alonas
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia (EA, PJS)
| | - Rebecca S Dillard
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Cheri M Hampton
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Kristen M Lamb
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Jason E Hammonds
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Philip J Santangelo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia (EA, PJS)
| | - Paul W Spearman
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
| | - Elizabeth R Wright
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, Georgia (HY, ERW),Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia (JDS, RSD, CMH, KML, JEH, PWS, ERW)
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