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Abstract
Single-cell transcriptomic analysis (scRNA-seq) can enable researchers to explore the gene expression patterns of thousands of individual cells simultaneously. Processing the complex data generated by scRNA-seq requires specialized computational tools. This chapter focuses on the analytical aspect of scRNA-seq workflow, with a focus on resolving biological signals from large-scale scRNA-seq data produced by the Drop-Seq platform.
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Affiliation(s)
- Benjamin Babcock
- Department of Medicine, Division of Immunology, Lowance Center for Human Immunology, Emory University School of Medicine, Atlanta, GA, USA.
- Department of Neurology, University of North Carolina Medical School, Chapel Hill, NC, USA.
| | - Daniel Malawsky
- Department of Neurology, University of North Carolina Medical School, Chapel Hill, NC, USA
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
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2
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Abstract
Droplet-based single-cell RNA-seq (scRNA-seq) requires the addition of bar codes that mark the cell and transcript of origin. Cell-specific bar codes, typically added by cDNA elongation on beads, label each transcript derived from an individual cell. Transcript-specific bar codes serve as unique molecular identifiers and allow for the maintenance of transcript proportions after PCR-based amplification of cDNA. This chapter provides methods for generating bar-coded scRNA-seq libraries after droplet encapsulation.
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Affiliation(s)
- Benjamin Babcock
- Department of Medicine, Division of Immunology, Lowance Center for Human Immunology, Emory University School of Medicine, Atlanta, GA, USA.
- Department of Neurology, University of North Carolina Medical School, Chapel Hill, NC, USA.
| | - Seth Weir
- Department of Neurology, University of North Carolina Medical School, Chapel Hill, NC, USA
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3
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Abstract
Single-cell RNA sequencing (scRNA-seq) allows for the transcriptomic profiling of a sample tissue with single-cell resolution. The concept of scRNA-seq builds on traditional, "bulk" RNA-seq by recording and preserving the cellular origin of each transcript throughout library preparation. Here we describe an adaptation of the Drop-Seq method (Macosko et al. Cell 161, 1202-1214, 2015), in which nanoliter-scale droplets are used to physically separate dissociated cells, while a cell-specific DNA barcode is simultaneously introduced. Following barcoding, cDNAs can be mixed and pooled while retaining the identity of the cell of origin. The benefit of the Drop-Seq approach is high throughput from relatively small samples of tissue. The method described here is appropriate for processing an input of as few as 150,000 cells, with a final yield of as many as 5000 single-cell transcripts captured.
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Affiliation(s)
- Benjamin Babcock
- Department of Medicine, Division of Immunology, Lowance Center for Human Immunology, Emory University School of Medicine, Atlanta, GA, USA.
| | - Seth Weir
- Department of Neurology, University of North Carolina Medical School, Chapel Hill, NC, USA
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4
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Swiderska-Syn M, Mir-Pedrol J, Oles A, Babcock B, Martin V, Krieg C, Gershon T, McCrea H, Rodriguez-Blanco J. STEM-26. ASTROCYTIC SOX2+ CELLS RELAY IN NON-CANONICAL GLI SIGNALING TO FACILITATE MEDULLOBLASTOMA RELAPSE. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac209.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Medulloblastoma is the most common malignant pediatric brain tumor. Despite the fair efficacy of current treatment approaches, 30 % of patients with medulloblastoma relapse. Cells expressing the stemness biomarker SRY (sex determining region Y)-box 2 (SOX2) are known to play key roles in sustaining medulloblastoma growth, providing chemo-resistance, and driving tumor relapse. It is therefore critical to elucidate the underlying mechanisms that propagate these cells and ensure therapies to target them. Single cell sequencing analyses revealed the existence of a subset of astrocyte-like SOX2+ cells expressing biomarkers indicative of SHH signaling activation. Intriguingly, such SOX2+ cells were not affected by the upstream SHH inhibitor vismodegib. Using SOX2+ enriched cultures, we observed that astrocyte-like SOX2 cells not only express SHH effectors, but require GLI signaling to proliferate, and that GLI is activated in a non-canonical and MYC dependent manner. Importantly, in vivo inhibition of SHH signaling downstream of SMO depleted the vismodegib resistant SOX2+ cell pool, while reduced the ability of residual medulloblastoma tissues to engraft in vivo. Our data show that in medulloblastoma, a subset of SOX2+ tumor cells rely on non-canonical GLI signaling to propagate, and emphasizes the importance of using therapies that deplete SOX2+ cells to prevent tumor recurrence.
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Affiliation(s)
| | | | - Alexander Oles
- Medical University of South Carolina , Charleston, SC , USA
| | | | | | - Carsten Krieg
- Medical University of South Carolina , Charleston, SC , USA
| | - Timothy Gershon
- University of North Carolina School of Medicine , Chapel Hill, NC , USA
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5
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Ma T, Ryu H, McGregor M, Babcock B, Neidleman J, Xie G, George AF, Frouard J, Murray V, Gill G, Ghosn E, Newell EW, Lee SA, Roan NR. Protracted yet Coordinated Differentiation of Long-Lived SARS-CoV-2-Specific CD8 + T Cells during Convalescence. J Immunol 2021; 207:1344-1356. [PMID: 34389625 PMCID: PMC8763019 DOI: 10.4049/jimmunol.2100465] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/28/2021] [Indexed: 12/31/2022]
Abstract
CD8+ T cells can potentiate long-lived immunity against COVID-19. We screened longitudinally-sampled convalescent human donors against SARS-CoV-2 tetramers and identified a participant with an immunodominant response against residues 322 to 311 of nucleocapsid (Nuc322-331), a peptide conserved in all variants of concern reported to date. We conducted 38-parameter cytometry by time of flight on tetramer-identified Nuc322-331-specific CD8+ T cells and on CD4+ and CD8+ T cells recognizing the entire nucleocapsid and spike proteins, and took 32 serological measurements. We discovered a coordination of the Nuc322-331-specific CD8+ T response with both the CD4+ T cell and Ab pillars of adaptive immunity. Over the approximately six month period of convalescence monitored, we observed a slow and progressive decrease in the activation state and polyfunctionality of Nuc322-331-specific CD8+ T cells, accompanied by an increase in their lymph node-homing and homeostatic proliferation potential. These results suggest that following a typical case of mild COVID-19, SARS-CoV-2-specific CD8+ T cells not only persist but continuously differentiate in a coordinated fashion well into convalescence into a state characteristic of long-lived, self-renewing memory.
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Affiliation(s)
- Tongcui Ma
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Heeju Ryu
- Vaccine and Infectious Disease Division, Fred Hutchison Cancer Research Center, Seattle, WA
| | - Matthew McGregor
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Benjamin Babcock
- Department of Medicine, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA
| | - Jason Neidleman
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Guorui Xie
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Ashley F George
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Julie Frouard
- Gladstone Institutes, San Francisco, CA
- Department of Urology, University of California San Francisco, San Francisco, CA
| | - Victoria Murray
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA; and
| | - Gurjot Gill
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA; and
| | - Eliver Ghosn
- Department of Medicine, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA
- Department of Pediatrics, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA
| | - Evan W Newell
- Vaccine and Infectious Disease Division, Fred Hutchison Cancer Research Center, Seattle, WA
| | - Sulggi A Lee
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA; and
| | - Nadia R Roan
- Gladstone Institutes, San Francisco, CA;
- Department of Urology, University of California San Francisco, San Francisco, CA
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6
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Malawsky DS, Weir SJ, Ocasio JK, Babcock B, Dismuke T, Cleveland AH, Donson AM, Vibhakar R, Wilhelmsen K, Gershon TR. Cryptic developmental events determine medulloblastoma radiosensitivity and cellular heterogeneity without altering transcriptomic profile. Commun Biol 2021; 4:616. [PMID: 34021242 PMCID: PMC8139976 DOI: 10.1038/s42003-021-02099-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 08/17/2020] [Accepted: 04/12/2021] [Indexed: 12/20/2022] Open
Abstract
It is unclear why medulloblastoma patients receiving similar treatments experience different outcomes. Transcriptomic profiling identified subgroups with different prognoses, but in each subgroup, individuals remain at risk of incurable recurrence. To investigate why similar-appearing tumors produce variable outcomes, we analyzed medulloblastomas triggered in transgenic mice by a common driver mutation expressed at different points in brain development. We genetically engineered mice to express oncogenic SmoM2, starting in multipotent glio-neuronal stem cells, or committed neural progenitors. Both groups developed medulloblastomas with similar transcriptomic profiles. We compared medulloblastoma progression, radiosensitivity, and cellular heterogeneity, determined by single-cell transcriptomic analysis (scRNA-seq). Stem cell-triggered medulloblastomas progressed faster, contained more OLIG2-expressing stem-like cells, and consistently showed radioresistance. In contrast, progenitor-triggered MBs progressed slower, down-regulated stem-like cells and were curable with radiation. Progenitor-triggered medulloblastomas also contained more diverse stromal populations, with more Ccr2+ macrophages and fewer Igf1+ microglia, indicating that developmental events affected the subsequent tumor microenvironment. Reduced mTORC1 activity in M-Smo tumors suggests that differential Igf1 contributed to differences in phenotype. Developmental events in tumorigenesis that were obscure in transcriptomic profiles thus remained cryptic determinants of tumor composition and outcome. Precise understanding of medulloblastoma pathogenesis and prognosis requires supplementing transcriptomic/methylomic studies with analyses that resolve cellular heterogeneity.
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Affiliation(s)
- Daniel Shiloh Malawsky
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Seth J Weir
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Jennifer Karin Ocasio
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Benjamin Babcock
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Taylor Dismuke
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Abigail H Cleveland
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Cancer Cell Biology Training Program, University of North Carolina, Chapel Hill, NC, USA
| | - Andrew M Donson
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's, Hospital Colorado, Aurora, CO, USA
| | - Rajeev Vibhakar
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's, Hospital Colorado, Aurora, CO, USA
| | - Kirk Wilhelmsen
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
- Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
- RENCI, Chapel Hill, NC, USA.
| | - Timothy R Gershon
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
- UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
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7
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Ma T, Ryu H, McGregor M, Babcock B, Neidleman J, Xie G, George AF, Frouard J, Murray V, Gill G, Ghosn E, Newell E, Lee S, Roan NR. Protracted yet coordinated differentiation of long-lived SARS-CoV-2-specific CD8+ T cells during COVID-19 convalescence. bioRxiv 2021:2021.04.28.441880. [PMID: 33948597 PMCID: PMC8095211 DOI: 10.1101/2021.04.28.441880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
CD8+ T cells are important antiviral effectors that can potentiate long-lived immunity against COVID-19, but a detailed characterization of these cells has been hampered by technical challenges. We screened 21 well-characterized, longitudinally-sampled convalescent donors that recovered from mild COVID-19 against a collection of SARS-CoV-2 tetramers, and identified one participant with an immunodominant response against Nuc322-331, a peptide that is conserved in all the SARS-CoV-2 variants-of-concern reported to date. We conducted 38-parameter CyTOF phenotyping on tetramer-identified Nuc322-331-specific CD8+ T cells, and on CD4+ and CD8+ T cells recognizing the entire nucleocapsid and spike proteins from SARS-CoV-2, and took 32 serological measurements on longitudinal specimens from this participant. We discovered a coordination of the Nuc322-331-specific CD8+ T response with both the CD4+ T cell and antibody pillars of adaptive immunity. Nuc322-331-specific CD8+ T cells were predominantly central memory T cells, but continually evolved over a ~6-month period of convalescence. We observed a slow and progressive decrease in the activation state and polyfunctionality of the Nuc322-331-specific CD8+ T cells, accompanied by an increase in their lymph-node homing and homeostatic proliferation potential. These results suggest that following a typical case of mild COVID-19, SARS-CoV-2-specific CD8+ T cells not only persist but continuously differentiate in a coordinated fashion well into convalescence, into a state characteristic of long-lived, self-renewing memory.
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Affiliation(s)
- Tongcui Ma
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Heeju Ryu
- Vaccine and Infectious Disease Division Fred Hutchison Cancer Research Center, Seattle, WA, USA
| | - Matthew McGregor
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Benjamin Babcock
- Department of Medicine, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Jason Neidleman
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Guorui Xie
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Ashley F. George
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Julie Frouard
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
| | - Victoria Murray
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA, USA
| | - Gurjot Gill
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA, USA
| | - Eliver Ghosn
- Department of Medicine, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA, USA
- Department of Pediatrics, Lowance Center for Human Immunology, Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Evan Newell
- Vaccine and Infectious Disease Division Fred Hutchison Cancer Research Center, Seattle, WA, USA
| | - Sulggi Lee
- Zuckerberg San Francisco General Hospital and the University of California, San Francisco, CA, USA
| | - Nadia R. Roan
- Gladstone Institutes, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
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8
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Aliverti E, Tilson JL, Filer DL, Babcock B, Colaneri A, Ocasio J, Gershon TR, Wilhelmsen KC, Dunson DB. Projected t-SNE for batch correction. Bioinformatics 2020; 36:3522-3527. [PMID: 32176244 PMCID: PMC7267829 DOI: 10.1093/bioinformatics/btaa189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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] [Received: 11/16/2019] [Revised: 03/02/2020] [Accepted: 03/12/2020] [Indexed: 12/31/2022] Open
Abstract
MOTIVATION Low-dimensional representations of high-dimensional data are routinely employed in biomedical research to visualize, interpret and communicate results from different pipelines. In this article, we propose a novel procedure to directly estimate t-SNE embeddings that are not driven by batch effects. Without correction, interesting structure in the data can be obscured by batch effects. The proposed algorithm can therefore significantly aid visualization of high-dimensional data. RESULTS The proposed methods are based on linear algebra and constrained optimization, leading to efficient algorithms and fast computation in many high-dimensional settings. Results on artificial single-cell transcription profiling data show that the proposed procedure successfully removes multiple batch effects from t-SNE embeddings, while retaining fundamental information on cell types. When applied to single-cell gene expression data to investigate mouse medulloblastoma, the proposed method successfully removes batches related with mice identifiers and the date of the experiment, while preserving clusters of oligodendrocytes, astrocytes, and endothelial cells and microglia, which are expected to lie in the stroma within or adjacent to the tumours. AVAILABILITY AND IMPLEMENTATION Source code implementing the proposed approach is available as an R package at https://github.com/emanuelealiverti/BC_tSNE, including a tutorial to reproduce the simulation studies. CONTACT aliverti@stat.unipd.it.
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Affiliation(s)
- Emanuele Aliverti
- Department of Statistical Sciences, University of Padova, Padova 35121, Italy
| | | | - Dayne L Filer
- RENCI, University of North Carolina, Chapel Hill, NC 27517, USA
- Department of Genetics
| | | | | | | | - Timothy R Gershon
- Department of Neurology
- UNC Neuroscience Center
- Carolina Institute for Developmental Disabilities
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Kirk C Wilhelmsen
- RENCI, University of North Carolina, Chapel Hill, NC 27517, USA
- Department of Genetics
- Department of Neurology
| | - David B Dunson
- Department of Statistical Science, Duke University, Durham, NC 27708, USA
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9
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Ocasio J, Babcock B, Malawsky D, Weir SJ, Loo L, Simon JM, Zylka MJ, Hwang D, Dismuke T, Sokolsky M, Rosen EP, Vibhakar R, Zhang J, Saulnier O, Vladoiu M, El-Hamamy I, Stein LD, Taylor MD, Smith KS, Northcott PA, Colaneri A, Wilhelmsen K, Gershon TR. scRNA-seq in medulloblastoma shows cellular heterogeneity and lineage expansion support resistance to SHH inhibitor therapy. Nat Commun 2019; 10:5829. [PMID: 31863004 PMCID: PMC6925218 DOI: 10.1038/s41467-019-13657-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [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: 04/05/2019] [Accepted: 11/14/2019] [Indexed: 01/23/2023] Open
Abstract
Targeting oncogenic pathways holds promise for brain tumor treatment, but inhibition of Sonic Hedgehog (SHH) signaling has failed in SHH-driven medulloblastoma. Cellular diversity within tumors and reduced lineage commitment can undermine targeted therapy by increasing the probability of treatment-resistant populations. Using single-cell RNA-seq and lineage tracing, we analyzed cellular diversity in medulloblastomas in transgenic, medulloblastoma-prone mice, and responses to the SHH-pathway inhibitor vismodegib. In untreated tumors, we find expected stromal cells and tumor-derived cells showing either a spectrum of neural progenitor-differentiation states or glial and stem cell markers. Vismodegib reduces the proliferative population and increases differentiation. However, specific cell types in vismodegib-treated tumors remain proliferative, showing either persistent SHH-pathway activation or stem cell characteristics. Our data show that even in tumors with a single pathway-activating mutation, diverse mechanisms drive tumor growth. This diversity confers early resistance to targeted inhibitor therapy, demonstrating the need to target multiple pathways simultaneously. Although the hedgehog (HH) pathway is known to be deregulated in medulloblastoma, inhibitors of the pathway have shown disappointing clinical benefit. Using single-cell sequencing in a mouse model of the disease, the authors show that the response to the HH pathway inhibitor vismodegib is cell-type specific.
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Affiliation(s)
- Jennifer Ocasio
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Benjamin Babcock
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Daniel Malawsky
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Seth J Weir
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Lipin Loo
- UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Jeremy M Simon
- UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Mark J Zylka
- UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Duhyeong Hwang
- UNC Eshelman School of Pharmacy, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Taylor Dismuke
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Marina Sokolsky
- UNC Eshelman School of Pharmacy, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Elias P Rosen
- UNC Eshelman School of Pharmacy, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Rajeev Vibhakar
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children's Hospital Colorado, Aurora, CO, USA
| | - Jiao Zhang
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Olivier Saulnier
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Maria Vladoiu
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Ibrahim El-Hamamy
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5G 0A4, Canada.,Program in Computational Biology, Ontario Institute for Cancer Research, Toronto, ON, M5G 0A3, Canada
| | - Lincoln D Stein
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5G 0A4, Canada.,Program in Computational Biology, Ontario Institute for Cancer Research, Toronto, ON, M5G 0A3, Canada
| | - Michael D Taylor
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of Neurosurgery, The Hospital for Sick Children, Toronto, ON, M5S 3E1, Canada
| | - Kyle S Smith
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Paul A Northcott
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alejandro Colaneri
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.,Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Kirk Wilhelmsen
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA. .,Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA. .,Renaissance Computing Institute at UNC (RENCI), Chapel Hill, NC, 27517, USA.
| | - Timothy R Gershon
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA. .,UNC Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA. .,Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA. .,Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.
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10
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Ocasio J, Babcock B, Colaneri A, Taylor M, Wilhelmsen K, Gershon T. MBRS-51. SINGLE CELL TRANSCRIPTOMIC ANALYSIS DEFINES DISCRETE SUBPOPULATIONS IN SHH-DRIVEN MEDULLOBLASTOMAS THAT ARE DIFFERENTIALLY AFFECTED BY VISMODEGIB. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy059.496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jennifer Ocasio
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Benjamin Babcock
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | - Kirk Wilhelmsen
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Timothy Gershon
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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11
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Babcock B, Anderson BW, Papayannopoulos I, Castilleja A, Murray JL, Stifani S, Kudelka AP, Wharton JT, Ioannides CG. Ovarian and breast cytotoxic T lymphocytes can recognize peptides from the amino enhancer of split protein of the Notch complex. Mol Immunol 1998; 35:1121-33. [PMID: 10395201 DOI: 10.1016/s0161-5890(98)00100-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/22/2022]
Abstract
In this study we investigated recognition by ovarian tumor associated lymphocyte (OVTAL), and breast tumor associated lymphocytes (BRTAL), of peptides corresponding to the sequence 125-135 of the Aminoenhancer of split (AES) protein. Three of these peptides designated as G75:AES1/2 (128-135), G60: AES1/2 (127-137) and G61: AES1/2 (125-133) correspond to the wildtype AES sequence, while the fourth G76:GPLTPLPV, AES1/2 (128-135) corresponds to a variant sequence of the peptide G75 with the N-terminal Leu substituted to glycine. These sequences were chosen for study because mass-spectrometric analysis (MS) of a CTL active HPLC peptide fraction eluted from immunoaffinity precipitated HLA-A2 molecule, revealed: (a) the presence of an ion with a mass-to-charge ratio (m/z) of 793 which was more abundant than other ions of similar masses; (b) the tentatively reconstituted sequence of the ion 793 matched the sequence of peptide G76. We found that AES peptides G75 (128-135) and G76 (128-135) (L128G) reconstituted CTL recognition at concentrations ranging between 200-500 nM. These concentrations are lower than concentrations reported to activate effector function of CTL recognizing other epithelial tumor Ag. Furthermore, analysis with cloned CD8+ T cells indicated that G75 and G76 were not cross-reactive specificities, suggesting a key role for the N-terminal residues of the variant peptide in dictating specificities. Since the AES proteins are part of a set of transcriptional repressors encoded by the Enhancer of split [E(spl)] genes, and since these repressors are activated to suppress cell differentiation in response to Notch receptors signalling, the AES peptides may represent a novel class of self-antigens that deserve further consideration as tumor Ag in epithelial cancers.
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Affiliation(s)
- B Babcock
- Department of Gynecologic Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, USA
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Keeley J, Morton B, Babcock B, Castillo P, Fish B, Jerauld E, Johnson B, Landre L, Lum H, Miller C, Parker A, Van Steenwyk G. Dark CO2-fixation and diurnal malic acid fluctuations in the submerged-aquatic Isoetes storkii. Oecologia 1981; 48:332-333. [DOI: 10.1007/bf00346490] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/1980] [Indexed: 11/29/2022]
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Abstract
A 2 channel signal averager based on the KIM-1 microcomputer module is described which can be easily assembled for under $500. Number of samples per pass can be set to 128 or 256 and sample time is variable from 1 msec to 256 msec. Averaged data can be displayed on an oscilloscope, output slowly for use of a chart recorder, or stored on a low cost audio cassette recorder for later analysis. Simply adding additional memory (for less than $100) allows it to be expanded to 8 channels.
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