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Nolan JP. The evolution of spectral flow cytometry. Cytometry A 2022; 101:812-817. [PMID: 35567367 DOI: 10.1002/cyto.a.24566] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 01/27/2023]
Abstract
This special issue of Cytometry marks the transition of spectral flow cytometry from an emerging technology into a transformative force that will shape the fields of cytometry and single-cell analysis for some time to come. Tracing its roots to the earliest years of flow cytometry, spectral flow cytometry has evolved from the domain of individual researchers pushing the limits of hardware, reagents, and software to the mainstream, where it is being harnessed and adapted to meet the analytical challenges presented by modern biomedical research. In particular, the current form of spectral flow technology has arisen to address the needs of multiparameter immunophenotyping of immune cells in basic and translational research, and much of the current instrumentation and software reflects the needs of those applications. Yet, the possibilities enabled by high-resolution analysis of the spectral properties of optical absorbance, scatter, and emission have only begun to be exploited. In this brief review, the author highlights the origins and early milestones of single-cell spectral analysis, assesses the current state of instrumentation and software, and speculates as to future directions of spectral flow cytometry technology and applications.
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Affiliation(s)
- John P Nolan
- Scintillon Institute, San Diego, California, USA
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2
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Henderson J, Havranek O, Ma MCJ, Herman V, Kupcova K, Chrbolkova T, Pacheco-Blanco M, Wang Z, Comer JM, Zal T, Davis RE. Detecting Förster resonance energy transfer in living cells by conventional and spectral flow cytometry. Cytometry A 2022; 101:818-834. [PMID: 34128311 DOI: 10.1002/cyto.a.24472] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 05/31/2021] [Accepted: 06/07/2021] [Indexed: 01/27/2023]
Abstract
Assays based on Förster resonance energy transfer (FRET) can be used to study many processes in cell biology. Although this is most often done with microscopy for fluorescence detection, we report two ways to measure FRET in living cells by flow cytometry. Using a conventional flow cytometer and the "3-cube method" for intensity-based calculation of FRET efficiency, we measured the enzymatic activity of specific kinases in cells expressing a genetically-encoded reporter. For both AKT and protein kinase A, the method measured kinase activity in time-course, dose-response, and kinetic assays. Using the Cytek Aurora spectral flow cytometer, which applies linear unmixing to emission measured in multiple wavelength ranges, FRET from the same reporters was measured with greater single-cell precision, in real time and in the presence of other fluorophores. Results from gene-knockout studies suggested that spectral flow cytometry might enable the sorting of cells on the basis of FRET. The methods we present provide convenient and flexible options for using FRET with flow cytometry in studies of cell biology.
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Affiliation(s)
- Jared Henderson
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
| | - Ondrej Havranek
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA.,BIOCEV, First Faculty of Medicine, Charles University, Vestec, Czech Republic.,Department of Hematology, Charles University and General University Hospital, Prague, Czech Republic
| | - Man Chun John Ma
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
| | - Vaclav Herman
- BIOCEV, First Faculty of Medicine, Charles University, Vestec, Czech Republic.,Department of Hematology, Charles University and General University Hospital, Prague, Czech Republic
| | - Kristyna Kupcova
- BIOCEV, First Faculty of Medicine, Charles University, Vestec, Czech Republic
| | - Tereza Chrbolkova
- BIOCEV, First Faculty of Medicine, Charles University, Vestec, Czech Republic
| | | | - Zhiqiang Wang
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
| | - Justin M Comer
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
| | - Tomasz Zal
- Department of Leukemia, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
| | - Richard Eric Davis
- Department of Lymphoma and Myeloma, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA.,Department of Translational Molecular Pathology, The University of Texas-MD Anderson Cancer Center, Houston, Texas, USA
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Lim J, Petersen M, Bunz M, Simon C, Schindler M. Flow cytometry based-FRET: basics, novel developments and future perspectives. Cell Mol Life Sci 2022; 79:217. [PMID: 35352201 PMCID: PMC8964568 DOI: 10.1007/s00018-022-04232-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/07/2022] [Indexed: 12/29/2022]
Abstract
Förster resonance energy transfer (FRET) is a widespread technology used to analyze and quantify protein interactions in multiple settings. While FRET is traditionally measured by microscopy, flow cytometry based-FRET is becoming popular within the last decade and more commonly used. Flow cytometry based-FRET offers the possibility to assess FRET in a short time-frame in a high number of cells thereby allowing stringent and statistically robust quantification of FRET in multiple samples. Furthermore, established, simple and easy to implement gating strategies facilitate the adaptation of flow cytometry based-FRET measurements to most common flow cytometers. We here summarize the basics of flow cytometry based-FRET, highlight recent novel developments in this field and emphasize on exciting future perspectives.
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Affiliation(s)
- JiaWen Lim
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Moritz Petersen
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Maximilian Bunz
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Claudia Simon
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Michael Schindler
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.
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Yang XA, Zweifach A. Temperature-Dependent Expression of a CFP-YFP FRET Diacylglycerol Sensor Enables Multiple-Read Screening for Compounds That Affect C1 Domains. SLAS DISCOVERY 2019; 24:682-692. [PMID: 30802416 DOI: 10.1177/2472555219830086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intramolecular CFP-YFP fluorescence resonance energy transfer (FRET) sensors expressed in cells are powerful research tools but have seen relatively little use in screening. We exploited the discovery that the expression of a CFP-YFP FRET diacylglycerol sensor (DAGR) increases over time when cells are incubated at room temperature to assess requirements for robust measurements using a Molecular Devices Spectramax i3x fluorescence plate reader. Expression levels resulting in YFP fluorescence >10-fold higher than untransfected cells and phorbol ester-stimulated FRET ratio changes of 60% or more were required to consistently give robust Z' > 0.5. As a means of confirming that these conditions are suitable for screening, we developed a novel multiple-read protocol to assay the NCI's Mechanistic Set III for agonists and antagonists of C1 domain activation. Sixteen compounds prevented C1 domain translocation. However, none blocked phorbol ester-stimulated protein kinase C (PKC) activity assessed using a phospho-specific antibody-six actually stimulated PKC activity. Cytometry, which produces higher Z' for a given FRET ratio change, might have been a better approach for discovering antagonists, as it would have allowed lower phorbol ester concentrations to be used. We conclude that CFP-YFP FRET measured in a Spectramax i3x plate reader can be used for screening under the conditions we defined. Our strategy of varying expression level and FRET ratio could be useful to others for determining conditions needed for robust cell-based intramolecular CFP-YFP FRET measurements on their instrumentation.
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Affiliation(s)
- Xiuyi Alexander Yang
- 1 Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT, USA
| | - Adam Zweifach
- 1 Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT, USA
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Soleja N, Manzoor O, Khan I, Ahmad A, Mohsin M. Role of green fluorescent proteins and their variants in development of FRET-based sensors. J Biosci 2018. [DOI: 10.1007/s12038-018-9783-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Ding M, Edwards BS. High-Throughput Flow Cytometry in Drug Discovery. SLAS DISCOVERY 2018; 23:599-602. [DOI: 10.1177/2472555218778250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Mei Ding
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Mölndal, Sweden
| | - Bruce S. Edwards
- Department of Pathology, Center for Molecular Discovery, University of New Mexico, Albuquerque, NM, USA
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Voyton CM, Morris MT, Ackroyd PC, Morris JC, Christensen KA. FRET Flow Cytometry-Based High Throughput Screening Assay To Identify Disrupters of Glucose Levels in Trypanosoma brucei. ACS Infect Dis 2018; 4:1058-1066. [PMID: 29741365 DOI: 10.1021/acsinfecdis.8b00058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trypanosoma brucei, which causes human African typanosomiasis (HAT), derives cellular ATP from glucose metabolism while in the mammalian host. Targeting glucose uptake or regulation in the parasite has been proposed as a potential therapeutic strategy. However, few methods have been described to identify and characterize potential inhibitors of glucose uptake and regulation. Here, we report development of a screening assay that identifies small molecule disrupters of glucose levels in the cytosol and glycosomes. Using an endogenously expressed fluorescent protein glucose sensor expressed in cytosol or glycosomes, we monitored intracellular glucose depletion in the different cellular compartments. Two glucose level disrupters were identified, one of which only exhibited inhibition of glycosomal glucose and did not affect cytosolic levels. In addition to inhibiting glucose uptake with relatively high potency (EC50 = 700 nM), the compound also showed modest bloodstream form parasite killing activity. Expanding this assay will allow for identification of candidate compounds that disrupt parasite glucose metabolism.
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Affiliation(s)
- Charles M. Voyton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
| | | | - P. Christine Ackroyd
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
| | | | - Kenneth A. Christensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
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Zhao Z, Rajagopalan R, Zweifach A. A Novel Multiple-Read Screen for Metabolically Active Compounds Based on a Genetically Encoded FRET Sensor for ATP. SLAS DISCOVERY 2018; 23:907-918. [PMID: 29898642 DOI: 10.1177/2472555218780636] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Both glycolysis and mitochondrial energetics are targets of interest for developing antiproliferative cancer therapeutics. We developed a novel multiple-read assay based on long-term expression in K562 cells of a genetically encoded intramolecular Förster resonance energy transfer sensor for adenosine triphosphate (ATP). The assay, conducted in a fluorescent plate reader, can identify compounds that inhibit oxidative phosphorylation-dependent ATP production, glycolysis, or both after short-term treatment. We screened a National Cancer Institute (NCI) compound library, identifying inhibitors of oxidative phosphorylation-dependent ATP production and glycolysis. Three glycolysis inhibitors blocked hexokinase activity, demonstrating that our assay can serve as the initial step in a workflow to identify compounds that inhibit glycolysis via a defined desired mechanism. Finally, upon reviewing the literature, we found surprisingly little evidence that inhibiting glycolysis with small molecules is antiproliferative. Using NCI data on proliferation of K562 cells, we found that inhibitors of oxidative phosphorylation-dependent ATP production were no more antiproliferative than the overall library, whereas all glycolysis inhibitors were in the top third of most effective antiproliferative compounds. Our results thus present a powerful new way to screen for compounds that affect cellular metabolism and also provide important support for the idea that blocking glycosis is antiproliferative.
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Affiliation(s)
- Ziyan Zhao
- 1 Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Rahul Rajagopalan
- 1 Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Adam Zweifach
- 1 Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
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Ding M, Clark R, Bardelle C, Backmark A, Norris T, Williams W, Wigglesworth M, Howes R. Application of High-Throughput Flow Cytometry in Early Drug Discovery: An AstraZeneca Perspective. SLAS DISCOVERY 2018; 23:719-731. [PMID: 29787326 DOI: 10.1177/2472555218775074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Flow cytometry is a powerful tool providing multiparametric analysis of single cells or particles. The introduction of faster plate-based sampling technologies on flow cytometers has transformed the technology into one that has become attractive for higher throughput drug discovery screening. This article describes AstraZeneca's perspectives on the deployment and application of high-throughput flow cytometry (HTFC) platforms for small-molecule high-throughput screening (HTS), structure-activity relationship (SAR) and phenotypic screening, and antibody screening. We describe the overarching HTFC workflow, including the associated automation and data analysis, along with a high-level overview of our HTFC assay portfolio. We go on to discuss the practical challenges encountered and solutions adopted in the course of our deployment of HTFC, as well as future enhancements and expansion of the technology to new areas of drug discovery.
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Affiliation(s)
- Mei Ding
- 1 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Roger Clark
- 2 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | | | - Anna Backmark
- 1 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Tyrrell Norris
- 1 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Wendy Williams
- 4 Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
| | - Mark Wigglesworth
- 3 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Macclesfield, UK
| | - Rob Howes
- 1 Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
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