Abstract
Genome-scale functional genetic screens are used to identify key genetic regulators of a phenotype of interest. However, the identification of genetic modifications that lead to a phenotypic change requires sorting large numbers of cells, which increases operational times and costs and limits cell viability. Here, we introduce immunomagnetic cell sorting facilitated by a microfluidic chip as a rapid and scalable high-throughput method for loss-of-function phenotypic screening using CRISPR–Cas9. We used the method to process an entire genome-wide screen containing more than 108 cells in less than 1 h—considerably surpassing the throughput achieved by fluorescence-activated cell sorting, the gold-standard technique for phenotypic cell sorting—while maintaining high levels of cell viability. We identified modulators of the display of CD47, which is a negative regulator of phagocytosis and an important cell-surface target for immuno-oncology drugs. The top hit of the screen, the glutaminyl cyclase QPCTL, was validated and shown to modify the N-terminal glutamine of CD47. The method presented could bridge the gap between fluorescence-activated cell sorting and less flexible yet higher-throughput systems such as magnetic-activated cell sorting.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
The main data supporting the results in this study are available within the paper and the Supplementary Information. Supplementary Tables 2–4 contain raw read counts, normalized read counts and normalized Z scores for all of the screens. Unprocessed sequencing files are available from the corresponding authors on reasonable request.
Code availability
The ImageJ custom macro used for automated image segmentation is provided in the Supplementary Information.
References
Sharma, S. & Petsalaki, E. Application of CRISPR-Cas9 based genome-wide screening approaches to study cellular signalling mechanisms. Int. J. Mol. Sci. 19, 933 (2018).
Burr, M. L. et al. CMTM6 maintains the expression of PD-L1 and regulates anti-tumour immunity. Nature 549, 101–105 (2017).
Mezzadra, R. et al. Identification of CMTM6 and CMTM4 as PD-L1 protein regulators. Nature 549, 106–110 (2017).
Binek, A. et al. Flow cytometry has a significant impact on the cellular metabolome. J. Proteome Res. 18, 169–181 (2019).
Llufrio, E. M., Wang, L., Naser, F. J. & Patti, G. J. Sorting cells alters their redox state and cellular metabolome. Redox Biol. 16, 381–387 (2018).
Brockmann, M. et al. Genetic wiring maps of single-cell protein states reveal an off-switch for GPCR signalling. Nature 546, 307–311 (2017).
Wroblewska, A. et al. Protein barcodes enable high-dimensional single-cell CRISPR screens. Cell 175, 1141–1155 (2018).
de Groot, R., Lüthi, J., Lindsay, H., Holtackers, R. & Pelkmans, L. Large-scale image-based profiling of single-cell phenotypes in arrayed CRISPR-Cas9 gene perturbation screens. Mol. Syst. Biol. 14, e8064 (2018).
Haney, M. S. et al. Identification of phagocytosis regulators using magnetic genome-wide CRISPR screens. Nat. Genet. 50, 1716–1727 (2018).
Parnas, O. et al. A genome-wide CRISPR screen in primary immune cells to dissect regulatory networks. Cell 162, 675–686 (2015).
Han, X. et al. CRISPR-Cas9 delivery to hard-to-transfect cells via membrane deformation. Sci. Adv. 1, e1500454 (2015).
Han, X. et al. Microfluidic cell deformability assay for rapid and efficient kinase screening with the CRISPR-Cas9 system. Angew. Chem. Int. Edn 55, 8561–8565 (2016).
Aldridge, P. M. et al. Prismatic deflection of live tumor cells and cell clusters. ACS Nano 12, 12692–12700 (2018).
Matlung, H. L., Szilagyi, K., Barclay, N. A. & van den Berg, T. K. The CD47-SIRPα signaling axis as an innate immune checkpoint in cancer. Immunol. Rev. 276, 145–164 (2017).
Weiskopf, K. Cancer immunotherapy targeting the CD47/SIRPα axis. Eur. J. Cancer 76, 100–109 (2017).
Advani, R. et al. CD47 blockade by Hu5F9-G4 and rituximab in non-Hodgkin’s lymphoma. N. Engl. J. Med. 379, 1711–1721 (2018).
Kong, F. et al. CD47: a potential immunotherapy target for eliminating cancer cells. Clin. Transl. Oncol. 18, 1051–1055 (2016).
Seiffert, M. et al. Human signal-regulatory protein is expressed on normal, but not on subsets of leukemic myeloid cells and mediates cellular adhesion involving its counterreceptor CD47. Blood 94, 3633–3643 (1999).
Leclair, P. et al. CD47-ligation induced cell death in T-acute lymphoblastic leukemia. Cell Death Dis. 9, 544 (2018).
Carette, J. E. et al. Ebola virus entry requires the cholesterol transporter Niemann–Pick C1. Nature 477, 340–343 (2011).
Bürckstümmer, T. et al. A reversible gene trap collection empowers haploid genetics in human cells. Nat. Methods 10, 965–971 (2013).
Lee, S.-E. et al. Proteogenomic analysis to identify missing proteins from haploid cell lines. Proteomics 18, e1700386 (2018).
Paulo, J. A. & Gygi, S. P. Isobaric tag-based protein profiling of a nicotine-treated alpha7 nicotinic receptor-null human haploid cell line. Proteomics 18, e1700475 (2018).
Hart, T. et al. High-resolution CRISPR screens reveal fitness genes and genotype-specific cancer liabilities. Cell 163, 1515–1526 (2015).
Hart, T. et al. Evaluation and design of genome-wide CRISPR/SpCas9 knockout screens. G3 (Bethesda) 7, 2719–2727 (2017).
Mair, B. et al. Essential gene profiles for human pluripotent stem cells identify uncharacterized genes and substrate dependencies. Cell Rep. 27, 599–615 (2019).
Colic, M. et al. Identifying chemogenetic interactions from CRISPR knockout screens with drugZ. Genome Med. 11, 52 (2019).
Logtenberg, M. E. W. et al. Glutaminyl cyclase is an enzymatic modifier of the CD47–SIRPα axis and a target for cancer immunotherapy. Nat. Med. 25, 612–619 (2019).
Wu, Z. et al. Identification of glutaminyl cyclase isoenzyme isoQC as a regulator of SIRPα-CD47 axis. Cell Res. 29, 502–505 (2019).
Cynis, H. et al. Isolation of an isoenzyme of human glutaminyl cyclase: retention in the Golgi complex suggests involvement in the protein maturation machinery. J. Mol. Biol. 379, 966–980 (2008).
Stephan, A. et al. Mammalian glutaminyl cyclases and their isoenzymes have identical enzymatic characteristics. FEBS J. 276, 6522–6536 (2009).
Hatherley, D. et al. Paired receptor specificity explained by structures of signal regulatory proteins alone and complexed with CD47. Mol. Cell 31, 266–277 (2008).
Ho, C. C. M. et al. “Velcro” engineering of high affinity CD47 ectodomain as signal regulatory protein α (SIRPα) antagonists that enhance antibody-dependent cellular phagocytosis. J. Biol. Chem. 290, 12650–12663 (2015).
Pozzi, C., Di Pisa, F., Benvenuti, M. & Mangani, S. The structure of the human glutaminyl cyclase-SEN177 complex indicates routes for developing new potent inhibitors as possible agents for the treatment of neurological disorders. J. Biol. Inorg. Chem. 23, 1219–1226 (2018).
Ramsbeck, D. et al. Structure-activity relationships of benzimidazole-based glutaminyl cyclase inhibitors featuring a heteroaryl scaffold. J. Med. Chem. 56, 6613–6625 (2013).
Lues, I. et al. A phase 1 study to evaluate the safety and pharmacokinetics of PQ912, a glutaminyl cyclase inhibitor, in healthy subjects. Alzheimers Dement. 1, 182–195 (2015).
Hoffmann, T. et al. Glutaminyl cyclase inhibitor PQ912 improves cognition in mouse models of Alzheimer’s disease—studies on relation to effective target occupancy. J. Pharmacol. Exp. Ther. 362, 119–130 (2017).
Kumar, A. & Bachhawat, A. K. Pyroglutamic acid: throwing light on a lightly studied metabolite. Curr. Sci. 102, 288–297 (2012).
Kehlen, A. et al. N-terminal pyroglutamate formation in CX3CL1 is essential for its full biologic activity. Biosci. Rep. 37, BSR20170712 (2017).
Cynis, H. et al. The isoenzyme of glutaminyl cyclase is an important regulator of monocyte infiltration under inflammatory conditions. EMBO Mol. Med. 3, 545–558 (2011).
Leonidas, D. D. et al. Refined crystal structures of native human angiogenin and two active site variants: implications for the unique functional properties of an enzyme involved in neovascularisation during tumour growth. J. Mol. Biol. 285, 1209–1233 (1999).
Deuse, T. et al. Hypoimmunogenic derivatives of induced pluripotent stem cells evade immune rejection in fully immunocompetent allogeneic recipients. Nat. Biotechnol. 37, 252–258 (2019).
Stoeckius, M. et al. Simultaneous epitope and transcriptome measurement in single cells. Nat. Methods 14, 865–868 (2017).
Adams, J. D., Kim, U. & Soh, H. T. Multitarget magnetic activated cell sorter. Proc. Natl Acad. Sci. USA 105, 18165–18170 (2008).
Labib, M. et al. Aptamer and antisense-mediated two-dimensional isolation of specific cancer cell subpopulations. J. Am. Chem. Soc. 138, 2476–2479 (2016).
Philpott, D. et al. High-throughput microfluidic cell sorting platform (MICS). Prot. Exch. https://doi.org/10.21203/rs.2.10282/v1 (2019).
Uhlen, M. et al. A pathology atlas of the human cancer transcriptome. Science 357, eaan2507 (2017).
Sasaki, S., Futagi, Y., Kobayashi, M., Ogura, J. & Iseki, K. Functional characterization of 5-oxoproline transport via SLC16A1/MCT1. J. Biol. Chem. 290, 2303–2311 (2015).
Boix, E. et al. Role of the N terminus in RNase A homologues: differences in catalytic activity, ribonuclease inhibitor interaction and cytotoxicity. J. Mol. Biol. 257, 992–1007 (1996).
Liao, Y.-D. et al. The structural integrity exerted by N-terminal pyroglutamate is crucial for the cytotoxicity of frog ribonuclease from Rana pipiens. Nucleic Acids Res. 31, 5247–5255 (2003).
La Mendola, D. et al. Copper binding to naturally occurring, lactam form of angiogenin differs from that to recombinant protein, affecting their activity. Metallomics 8, 118–124 (2016).
Ren, Y. et al. A simple and reliable PDMS and SU-8 irreversible bonding method and its application on a microfluidic-MEA device for neuroscience research. Micromachines 6, 1923–1934 (2015).
Luk, V. N., Mo, G. C. & Wheeler, A. R. Pluronic additives: a solution to sticky problems in digital microfluidics. Langmuir 24, 6382–6389 (2008).
Brinkman, E. K., Chen, T., Amendola, M. & van Steensel, B. Easy quantitative assessment of genome editing by sequence trace decomposition. Nucleic Acids Res. 42, e168 (2014).
Hsiau, T. et al. Inference of CRISPR edits from Sanger trace data. Preprint at bioRxiv https://doi.org/10.1101/251082 (2019).
Nielsen, H. in Protein Function Prediction: Methods in Molecular Biology Vol. 1611 (ed. Kihara, D.) 59–73 (Springer, 2017).
Gogleva, A., Drost, H.-G. & Schornack, S. SecretSanta: flexible pipelines for functional secretome prediction. Bioinformatics 34, 2295–2296 (2018).
Burdukiewicz, M., Sobczyk, P., Chilimoniuk, J., Gagat, P. & Mackiewicz, P. Prediction of signal peptides in proteins from malaria parasites. Int. J. Mol. Sci. 19, 3709 (2018).
Käll, L., Krogh, A. & Sonnhammer, E. L. L. A combined transmembrane topology and signal peptide prediction method. J. Mol. Biol. 338, 1027–1036 (2004).
Fortelny, N., Yang, S., Pavlidis, P., Lange, P. F. & Overall, C. M. Proteome TopFIND 3.0 with TopFINDer and PathFINDer: database and analysis tools for the association of protein termini to pre- and post-translational events. Nucleic Acids Res. 43, D290–D297 (2015).
Acknowledgements
We thank members of the Kelley, Moffat, Angers and C. Boone and B. Andrews laboratories for helpful discussions; K. Chan for TKOv3 library virus preparation; M. Usaj for help with data analysis; P. Mero for administrative assistance; J. Tomic for help with tissue culture; E. Cohen, M. Soste and F. Soares for technical assistance; D. White and J. Warzyszynska for flow cytometry assistance; and staff at the Centre for Applied Genomics (TCAG) at the Hospital for Sick Children (SickKids) for sequencing. This work was supported by grants from the Canadian Institutes for Health Research (to J.M., S.O.K. and S.A.) and the University of Toronto’s Medicine by Design initiative, which receives funding from the Canada First Research Excellence Fund (to S.O.K., J.M. and S.A). J.M. is a Canada Research Chair in Functional Genomics.
Author information
Authors and Affiliations
Contributions
B.M. and P.M.A. performed most of the experiments and analysed data with help from R.S.A., D.P., M.L. and S.N.M. M.Z. and R.S.A. developed the MS assay. A.H.Y.T. helped with screen sequencing and data analysis. B.M., P.M.A., R.S.A., J.M. and S.O.K. wrote the manuscript. B.M., P.M.A., E.H.S., S.A., J.M. and S.O.K. designed the study. S.A., J.M. and S.O.K. supervised the study.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Supplementary Information
Supplementary figures, tables, protocols and codes.
Supplementary Dataset 1
Screen data for MACS.
Supplementary Dataset 2
Screen data for immunomagnetic cell sorting.
Supplementary Dataset 3
Screen data for FACS.
Rights and permissions
About this article
Cite this article
Mair, B., Aldridge, P.M., Atwal, R.S. et al. High-throughput genome-wide phenotypic screening via immunomagnetic cell sorting. Nat Biomed Eng 3, 796–805 (2019). https://doi.org/10.1038/s41551-019-0454-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41551-019-0454-8
This article is cited by
-
Harnessing the power of clustered regularly interspaced short palindromic repeats (CRISPR) based microfluidics for next-generation molecular diagnostics
Molecular Biology Reports (2024)
-
Emerging phagocytosis checkpoints in cancer immunotherapy
Signal Transduction and Targeted Therapy (2023)
-
Identification of druggable regulators of cell secretion via a kinome-wide screen and high-throughput immunomagnetic cell sorting
Nature Biomedical Engineering (2023)
-
Direct electrification of silicon microfluidics for electric field applications
Microsystems & Nanoengineering (2023)
-
A magneto-activated nanoscale cytometry platform for molecular profiling of small extracellular vesicles
Nature Communications (2023)