scholarly journals Versatile phenotype-activated cell sorting

2020 ◽  
Vol 6 (43) ◽  
pp. eabb7438
Author(s):  
Jihwan Lee ◽  
Zhuohe Liu ◽  
Peter H. Suzuki ◽  
John F. Ahrens ◽  
Shujuan Lai ◽  
...  
Keyword(s):  
High Throughput ◽  
Cell Sorting ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Human Cells ◽  
Target Cells ◽  
Temporal Properties ◽  
Single Target ◽  
New Variant ◽  
Improved Methods

Unraveling the genetic and epigenetic determinants of phenotypes is critical for understanding and re-engineering biology and would benefit from improved methods to separate cells based on phenotypes. Here, we report SPOTlight, a versatile high-throughput technique to isolate individual yeast or human cells with unique spatiotemporal profiles from heterogeneous populations. SPOTlight relies on imaging visual phenotypes by microscopy, precise optical tagging of single target cells, and retrieval of tagged cells by fluorescence-activated cell sorting. To illustrate SPOTlight’s ability to screen cells based on temporal properties, we chose to develop a photostable yellow fluorescent protein for extended imaging experiments. We screened 3 million cells expressing mutagenesis libraries and identified a bright new variant, mGold, that is the most photostable yellow fluorescent protein reported to date. We anticipate that the versatility of SPOTlight will facilitate its deployment to decipher the rules of life, understand diseases, and engineer new molecules and cells.

scholarly journals The CRISPR/Cas9 Minipig—A Transgenic Minipig to Produce Specific Mutations in Designated Tissues

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3024
Author(s):  
Martin Fogtmann Berthelsen ◽  
Maria Riedel ◽  
Huiqiang Cai ◽  
Søren H. Skaarup ◽  
Aage K. O. Alstrup ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Somatic Cells ◽  
Genetic Alterations ◽  
Lung Epithelial Cells ◽  
Target Cells ◽  
Multiple Gene ◽  
Conditional Expression ◽  
Gene Alterations

The generation of large transgenic animals is impeded by complex cloning, long maturation and gastrulation times. An introduction of multiple gene alterations increases the complexity. We have cloned a transgenic Cas9 minipig to introduce multiple mutations by CRISPR in somatic cells. Transgenic Cas9 pigs were generated by somatic cell nuclear transfer and were backcrossed to Göttingen Minipigs for two generations. Cas9 expression was controlled by FlpO-mediated recombination and was visualized by translation from red to yellow fluorescent protein. In vitro analyses in primary fibroblasts, keratinocytes and lung epithelial cells confirmed the genetic alterations executed by the viral delivery of single guide RNAs (sgRNA) to the target cells. Moreover, multiple gene alterations could be introduced simultaneously in a cell by viral delivery of sgRNAs. Cells with loss of TP53, PTEN and gain-of-function mutation in KRASG12D showed increased proliferation, confirming a transformation of the primary cells. An in vivo activation of Cas9 expression could be induced by viral delivery to the skin. Overall, we have generated a minipig with conditional expression of Cas9, where multiple gene alterations can be introduced to somatic cells by viral delivery of sgRNA. The development of a transgenic Cas9 minipig facilitates the creation of complex pre-clinical models for cancer research.

scholarly journals High-Throughput Growth Assay for Toxoplasma gondii Using Yellow Fluorescent Protein

2003 ◽  
Vol 47 (1) ◽  
pp. 309-316 ◽  
Author(s):  
Marc-Jan Gubbels ◽  
Catherine Li ◽  
Boris Striepen
Keyword(s):  
Toxoplasma Gondii ◽  
High Throughput ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Host Cells ◽  
Rapid Screening ◽  
Published Data ◽  
Parasite Line ◽  
Wild Type ◽  
Growth Assay

ABSTRACT A high-throughput growth assay for the protozoan parasite Toxoplasma gondii was developed based on a highly fluorescent transgenic parasite line. These parasites are stably transfected with a tandem yellow fluorescent protein (YFP) and are 1,000 times more fluorescent than the wild type. Parasites were inoculated in optical-bottom 384-well culture plates containing a confluent monolayer of host cells, and growth was monitored by using a fluorescence plate reader. The signal was linearly correlated with parasite numbers over a wide array. Direct comparison of the YFP growth assay with the β-galactosidase growth assay by using parasites expressing both reporters demonstrated that the assays' sensitivities were comparable but that the accuracy of the YFP assay was higher, especially at higher numbers of parasites per well. Determination of the 50%-inhibitory concentrations of three known growth-inhibiting drugs (cytochalasin D, pyrimethamine, and clindamycin) resulted in values comparable to published data. The delayed parasite death kinetics of clindamycin could be measured without modification of the assay, making this assay very versatile. Additionally, the temperature-dependent effect of pyrimethamine was assayed in both wild-type and engineered drug-resistant parasites. Lastly, the development of mycophenolic acid resistance after transfection of a resistance gene in T. gondii was followed. In conclusion, the YFP growth assay limits pipetting steps to a minimum, is highly versatile and amendable to automation, and should enable rapid screening of compounds to fulfill the need for more efficient and less toxic antiparasitic drugs.

scholarly journals Microfluidics-based selection of red-fluorescent proteins with decreased rates of photobleaching

2015 ◽  
Vol 7 (2) ◽  
pp. 263-273 ◽  
Author(s):  
Kevin M. Dean ◽  
Jennifer L. Lubbeck ◽  
Lloyd M. Davis ◽  
Chola K. Regmi ◽  
Prem P. Chapagain ◽  
...  
Keyword(s):  
High Throughput ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Microfluidic Platform ◽  
Red Fluorescent Proteins ◽  
New Variant ◽  
Selection Of

We use a high-throughput microfluidic platform that sorts cells on the basis of fluorescent protein photostability to identify a new variant with improved photon output.

scholarly journals Development and utilization of human decidualization reporter cell line uncovers new modulators of female fertility

2019 ◽  
Vol 116 (39) ◽  
pp. 19541-19551
Author(s):  
Meade Haller ◽  
Yan Yin ◽  
Liang Ma
Keyword(s):  
Cell Line ◽  
High Throughput ◽  
High Throughput Screening ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Patient Specific ◽  
Reporter Cell Line ◽  
Reporter Cell ◽  
A Genome ◽  
Decidual Cells

Failure of embryo implantation accounts for a significant percentage of female infertility. Exquisitely coordinated molecular programs govern the interaction between the competent blastocyst and the receptive uterus. Decidualization, the rapid proliferation and differentiation of endometrial stromal cells into decidual cells, is required for implantation. Decidualization defects can cause poor placentation, intrauterine growth restriction, and early parturition leading to preterm birth. Decidualization has not yet been systematically studied at the genetic level due to the lack of a suitable high-throughput screening tool. Herein we describe the generation of an immortalized human endometrial stromal cell line that uses yellow fluorescent protein under the control of the prolactin promoter as a quantifiable visual readout of the decidualization response (hESC-PRLY cells). Using this cell line, we performed a genome-wide siRNA library screen, as well as a screen of 910 small molecules, to identify more than 4,000 previously unrecognized genetic and chemical modulators of decidualization. Ontology analysis revealed several groups of decidualization modulators, including many previously unappreciated transcription factors, sensory receptors, growth factors, and kinases. Expression studies of hits revealed that the majority of decidualization modulators are acutely sensitive to ovarian hormone exposure. Gradient treatment of exogenous factors was used to identify EC50 values of small-molecule hits, as well as verify several growth factor hits identified by the siRNA screen. The high-throughput decidualization reporter cell line and the findings described herein will aid in the development of patient-specific treatments for decidualization-based recurrent pregnancy loss, subfertility, and infertility.

scholarly journals pFPL Vectors for High-Throughput Protein Localization in Fungi: Detecting Cytoplasmic Accumulation of Putative Effector Proteins

2015 ◽  
Vol 28 (2) ◽  
pp. 107-121 ◽  
Author(s):  
Xiaoyan Gong ◽  
Oscar Hurtado ◽  
Baohua Wang ◽  
Congqing Wu ◽  
Mihwa Yi ◽  
...  
Keyword(s):  
High Throughput ◽  
Large Scale ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Protein Localization ◽  
Yellow Fluorescent Protein ◽  
Effector Proteins ◽  
Fungal Transformation ◽  
In Planta ◽  
Green Fluorescent

As part of a large-scale project whose goal was to identify candidate effector proteins in Magnaporthe oryzae, we developed a suite of vectors that facilitate high-throughput protein localization experiments in fungi. These vectors utilize Gateway recombinational cloning to place a gene's promoter and coding sequences upstream and in frame with enhanced cyan fluorescent protein, green fluorescent protein (GFP), monomeric red fluorescence protein (mRFP), and yellow fluorescent protein or a nucleus-targeted mCHERRY variant. The respective Gateway cassettes were incorporated into Agrobacterium-based plasmids to allow efficient fungal transformation using hygromycin or geneticin resistance selection. mRFP proved to be more sensitive than the GFP spectral variants for monitoring proteins secreted in planta; and extensive testing showed that Gateway-derived fusion proteins produced localization patterns identical to their “directly fused” counterparts. Use of plasmid for fungal protein localization (pFPL) vectors with two different selectable markers provided a convenient way to label fungal cells with different fluorescent proteins. We demonstrate the utility of the pFPL vectors for identifying candidate effector proteins and we highlight a number of important factors that must be taken into consideration when screening for proteins that are translocated across the host plasma membrane.

scholarly journals Development of a High-Throughput Assay To Measure the Neutralization Capability of Anti-Cytomegalovirus Antibodies

2013 ◽  
Vol 20 (4) ◽  
pp. 540-550 ◽  
Author(s):  
Thomas J. Gardner ◽  
Cynthia Bolovan-Fritts ◽  
Melissa W. Teng ◽  
Veronika Redmann ◽  
Thomas A. Kraus ◽  
...  
Keyword(s):  
Virus Infection ◽  
High Throughput ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Screening Tools ◽  
Surface Glycoprotein ◽  
Immediate Early ◽  
Viral Gene ◽  
Cmv Infection ◽  
High Throughput Assay

ABSTRACTInfection by human cytomegalovirus (CMV) elicits a strong humoral immune response and robust anti-CMV antibody production. Diagnosis of virus infection can be carried out by using a variety of serological assays; however, quantification of serum antibodies against CMV may not present an accurate measure of a patient's ability to control a virus infection. CMV strains that express green fluorescent protein (GFP) fusion proteins can be used as screening tools for evaluating characteristics of CMV infectionin vitro. In this study, we employed a CMV virus strain, AD169, that ectopically expresses a yellow fluorescent protein (YFP) fused to the immediate-early 2 (IE2) protein product (AD169IE2-YFP) to quantify a CMV infection in human cells. We created a high-throughput cell-based assay that requires minimal amounts of material and provides a platform for rapid analysis of the initial phase of virus infection, including virus attachment, fusion, and immediate-early viral gene expression. The AD169IE2-YFPcell infection system was utilized to develop a neutralization assay with a monoclonal antibody against the viral surface glycoprotein gH. The high-throughput assay was extended to measure the neutralization capacity of serum from CMV-positive subjects. These findings describe a sensitive and specific assay for the quantification of a key immunological response that plays a role in limiting CMV dissemination and transmission. Collectively, we have demonstrated that a robust high-throughput infection assay can analyze the early steps of the CMV life cycle and quantify the potency of biological reagents to attenuate a virus infection.

scholarly journals Microclusters of inhibitory killer immunoglobulin–like receptor signaling at natural killer cell immunological synapses

2006 ◽  
Vol 174 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Bebhinn Treanor ◽  
Peter M.P. Lanigan ◽  
Sunil Kumar ◽  
Chris Dunsby ◽  
Ian Munro ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Killer Cell ◽  
Inhibitory Synapses ◽  
Homogeneous Distribution ◽  
Target Cells ◽  
Supramolecular Organization ◽  
Immune Synapse

We report the supramolecular organization of killer Ig–like receptor (KIR) phosphorylation using a technique applicable to imaging phosphorylation of any green fluorescent protein–tagged receptor at an intercellular contact or immune synapse. Specifically, we use fluorescence lifetime imaging (FLIM) to report Förster resonance energy transfer (FRET) between GFP-tagged KIR2DL1 and a Cy3-tagged generic anti-phosphotyrosine monoclonal antibody. Visualization of KIR phosphorylation in natural killer (NK) cells contacting target cells expressing cognate major histocompatibility complex class I proteins revealed that inhibitory signaling is spatially restricted to the immune synapse. This explains how NK cells respond appropriately when simultaneously surveying susceptible and resistant target cells. More surprising, phosphorylated KIR was confined to microclusters within the aggregate of KIR, contrary to an expected homogeneous distribution of KIR signaling across the immune synapse. Also, yellow fluorescent protein–tagged Lck, a kinase important for KIR phosphorylation, accumulated in a multifocal distribution at inhibitory synapses. Spatial confinement of receptor phosphorylation within the immune synapse may be critical to how activating and inhibitory signals are integrated in NK cells.

High-Throughput Flow Cytometry–Based Assay to Identify Apoptosis-Inducing Proteins

2007 ◽  
Vol 12 (4) ◽  
pp. 510-520 ◽  
Author(s):  
Mamatha Sauermann ◽  
Florian Hahne ◽  
Christian Schmidt ◽  
Meher Majety ◽  
Heiko Rosenfelder ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
High Throughput ◽  
Specific Antibody ◽  
Caspase 3 ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Nuclear Fragmentation ◽  
Protein Fluorescence ◽  
Transfected Cells ◽  
High Throughput Assay

After sequencing the human genome, the challenge ahead is to systematically analyze the functions and disease relation of the proteins encoded. Here the authors describe the application of a flow cytometry—based high-throughput assay to screen for apoptosis-activating proteins in transiently transfected cells. The assay is based on the detection of activated caspase-3 with a specific antibody, in cells overexpressing proteins tagged C- or N-terminally with yellow fluorescent protein. Fluorescence intensities are measured using a flow cytometer integrated with a high-throughput autosampler. The applicability of this screen has been tested in a pilot screen with 200 proteins. The candidate proteins were all verified in an independent microscopy-based nuclear fragmentation assay, finally resulting in the identification of 6 apoptosis inducers. ( Journal of Biomolecular Screening 2007:510-520)

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