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Evans EJ, Paul-Eduthan N, Hu J, Gao D, Galbraith M, Espinosa J, DeGregori J. Abstract 1510: Clonal hematopoiesis in Down syndrome and its potential impact on hematopoietic lineages. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-1510] [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: 04/07/2023]
Abstract
Abstract
In cancer-free tissues, somatic mutations accumulate in all of us over time. In most instances, these mutations are inconsequential to cellular fitness or to overall health. However, some mutations can result in a cell having a fitness advantage over its surroundings, enabling proliferation. In the blood, this proliferation - known as clonal hematopoiesis (CH) - is associated with an increased risk of hematologic malignancies, most notably leukemia, and is commonly observed in the elderly. People with Down syndrome (DS) also exhibit CH and have a markedly higher risk of leukemia (up to 400x); therefore, we investigated CH in people with DS to understand how mutations in the blood can lead to disrupted hematopoiesis and lead to varying susceptibility, onset, and severity of hematologic malignancies. To detect CH, I used a rare-mutation detection technique called DuplexSeq to analyze leukocytic genomic DNA from blood draws. This targeted-sequencing tool spans 37 genes implicated in leukemia - including leukemias seen in those with DS - and implements a double-stranded tag to incorporate mutational data from both DNA strands, enabling higher sensitivity than most sequencing methods. We characterized detected mutations using bioinformatic pipelines, various databases, and statistical methods. By comparing CH between people with and without DS, we observe an overrepresentation of protein-altering mutations in people with DS in genes important for hematopoiesis. Notably, people with DS exclusively harbor CH with JAK2 mutations, many of which have been associated with myeloid proliferative neoplasms. Mutations in NPM1 that have been previously seen in cancer are also exclusively observed in people with DS with potential to lead to differentiation block, a hallmark of leukemia. Finally, mutations with the highest variant allele frequency in TET2 are largely observed in people with DS, indicating preferential expansion in the DS context. These fledgling expansions in TET2 may be indicative of modified hematopoietic differentiation. Ongoing work is centered around understanding the consequences of these mutations and how they distinguish phenotypes among people with DS. Using a database for DS research, we are performing multi-omics analyses to understand which biological pathways may be disrupted in the same individuals with CH of interest. Additionally, we will use mouse models of DS to investigate the selective advantage of the observed mutations in the DS context, how they impact differentiation fate, and how cell intrinsic and extrinsic factors can influence clonal expansions. Overall, these studies offer a means by which risk of hematologic malignancies can be monitored by CH with elucidation of potential mechanisms. By characterizing CH, early markers of disrupted hematopoiesis can be established to determine susceptibility of leukemia and be used to monitor those who are most at risk.
Citation Format: Edward J. Evans, Neetha Paul-Eduthan, Junxiao Hu, Dexiang Gao, Matthew Galbraith, Joaquin Espinosa, James DeGregori. Clonal hematopoiesis in Down syndrome and its potential impact on hematopoietic lineages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1510.
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Affiliation(s)
| | | | - Junxiao Hu
- 1University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Dexiang Gao
- 1University of Colorado Anschutz Medical Campus, Aurora, CO
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Hill W, Lim EL, Weeden CE, Lee C, Augustine M, Chen K, Kuan FC, Marongiu F, Evans EJ, Moore DA, Rodrigues FS, Pich O, Bakker B, Cha H, Myers R, van Maldegem F, Boumelha J, Veeriah S, Rowan A, Naceur-Lombardelli C, Karasaki T, Sivakumar M, De S, Caswell DR, Nagano A, Black JRM, Martínez-Ruiz C, Ryu MH, Huff RD, Li S, Favé MJ, Magness A, Suárez-Bonnet A, Priestnall SL, Lüchtenborg M, Lavelle K, Pethick J, Hardy S, McRonald FE, Lin MH, Troccoli CI, Ghosh M, Miller YE, Merrick DT, Keith RL, Al Bakir M, Bailey C, Hill MS, Saal LH, Chen Y, George AM, Abbosh C, Kanu N, Lee SH, McGranahan N, Berg CD, Sasieni P, Houlston R, Turnbull C, Lam S, Awadalla P, Grönroos E, Downward J, Jacks T, Carlsten C, Malanchi I, Hackshaw A, Litchfield K, DeGregori J, Jamal-Hanjani M, Swanton C. Lung adenocarcinoma promotion by air pollutants. Nature 2023; 616:159-167. [PMID: 37020004 PMCID: PMC7614604 DOI: 10.1038/s41586-023-05874-3] [Citation(s) in RCA: 112] [Impact Index Per Article: 112.0] [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: 06/17/2022] [Accepted: 02/21/2023] [Indexed: 04/07/2023]
Abstract
A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development1. Here we propose that environmental particulate matter measuring ≤2.5 μm (PM2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue. Focusing on EGFR-driven lung cancer, which is more common in never-smokers or light smokers, we found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases in four within-country cohorts. Functional mouse models revealed that air pollutants cause an influx of macrophages into the lung and release of interleukin-1β. This process results in a progenitor-like cell state within EGFR mutant lung alveolar type II epithelial cells that fuels tumorigenesis. Ultradeep mutational profiling of histologically normal lung tissue from 295 individuals across 3 clinical cohorts revealed oncogenic EGFR and KRAS driver mutations in 18% and 53% of healthy tissue samples, respectively. These findings collectively support a tumour-promoting role for PM2.5 air pollutants and provide impetus for public health policy initiatives to address air pollution to reduce disease burden.
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Affiliation(s)
- William Hill
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Emilia L Lim
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Clare E Weeden
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Claudia Lee
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Division of Medicine, University College London, London, UK
| | - Marcellus Augustine
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Division of Medicine, University College London, London, UK
- Tumour Immunogenomics and Immunosurveillance Laboratory, University College London Cancer Institute, London, UK
| | - Kezhong Chen
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Department of Thoracic Surgery and Thoracic Oncology Institute, Peking University People's Hospital, Beijing, China
| | - Feng-Che Kuan
- Department of Hematology and Oncology, Chang Gung Memorial Hospital, Chiayi Branch, Chiayi, Taiwan
- Graduate Institute of Clinical Medical Sciences, Chang-Gung University, Taoyuan, Taiwan
| | - Fabio Marongiu
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Edward J Evans
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David A Moore
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Department of Cellular Pathology, University College London Hospitals, London, UK
| | - Felipe S Rodrigues
- Tumour-Host Interaction Laboratory, The Francis Crick Institute, London, UK
| | - Oriol Pich
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Bjorn Bakker
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Hongui Cha
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Renelle Myers
- BC Cancer Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Febe van Maldegem
- Oncogene Biology Laboratory, The Francis Crick Institute, London, UK
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Jesse Boumelha
- Oncogene Biology Laboratory, The Francis Crick Institute, London, UK
| | - Selvaraju Veeriah
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Andrew Rowan
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | | | - Takahiro Karasaki
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Cancer Metastasis Laboratory, University College London Cancer Institute, London, UK
| | - Monica Sivakumar
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Swapnanil De
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Deborah R Caswell
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Ai Nagano
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - James R M Black
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Cancer Genome Evolution Research Group, Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Carlos Martínez-Ruiz
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Cancer Genome Evolution Research Group, Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Min Hyung Ryu
- Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, British Columbia, Canada
| | - Ryan D Huff
- Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, British Columbia, Canada
| | - Shijia Li
- Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, British Columbia, Canada
| | | | - Alastair Magness
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Alejandro Suárez-Bonnet
- Department of Pathobiology and Population Sciences, The Royal Veterinary College, Hatfield, UK
- Experimental Histopathology, The Francis Crick Institute, London, UK
| | - Simon L Priestnall
- Department of Pathobiology and Population Sciences, The Royal Veterinary College, Hatfield, UK
- Experimental Histopathology, The Francis Crick Institute, London, UK
| | - Margreet Lüchtenborg
- National Disease Registration Service (NDRS), NHS England, Leeds, UK
- Centre for Cancer, Society and Public Health, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, London, UK
| | - Katrina Lavelle
- National Disease Registration Service (NDRS), NHS England, Leeds, UK
| | - Joanna Pethick
- National Disease Registration Service (NDRS), NHS England, Leeds, UK
| | - Steven Hardy
- National Disease Registration Service (NDRS), NHS England, Leeds, UK
| | - Fiona E McRonald
- National Disease Registration Service (NDRS), NHS England, Leeds, UK
| | - Meng-Hung Lin
- Health Information and Epidemiology Laboratory, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Clara I Troccoli
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Flagship Biosciences, Boulder, CO, USA
| | - Moumita Ghosh
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - York E Miller
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Veterans Affairs Eastern Colorado Healthcare System, Aurora, CO, USA
| | - Daniel T Merrick
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Robert L Keith
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Veterans Affairs Eastern Colorado Healthcare System, Aurora, CO, USA
| | - Maise Al Bakir
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Chris Bailey
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Mark S Hill
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Lao H Saal
- SAGA Diagnostics, Lund, Sweden
- Division of Oncology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Yilun Chen
- SAGA Diagnostics, Lund, Sweden
- Division of Oncology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Anthony M George
- SAGA Diagnostics, Lund, Sweden
- Division of Oncology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Christopher Abbosh
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Nnennaya Kanu
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Se-Hoon Lee
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Nicholas McGranahan
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Cancer Genome Evolution Research Group, Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | | | - Peter Sasieni
- Comprehensive Cancer Centre, King's College London, London, UK
| | - Richard Houlston
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Clare Turnbull
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Stephen Lam
- BC Cancer Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Philip Awadalla
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Eva Grönroos
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK
| | - Julian Downward
- Oncogene Biology Laboratory, The Francis Crick Institute, London, UK
| | - Tyler Jacks
- David H. Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christopher Carlsten
- Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, British Columbia, Canada
| | - Ilaria Malanchi
- Tumour-Host Interaction Laboratory, The Francis Crick Institute, London, UK
| | - Allan Hackshaw
- Cancer Research UK and UCL Cancer Trials Centre, London, UK
| | - Kevin Litchfield
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Tumour Immunogenomics and Immunosurveillance Laboratory, University College London Cancer Institute, London, UK
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Mariam Jamal-Hanjani
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Cancer Metastasis Laboratory, University College London Cancer Institute, London, UK
- Department of Oncology, University College London Hospitals, London, UK
| | - Charles Swanton
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK.
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK.
- Department of Oncology, University College London Hospitals, London, UK.
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3
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Evans EJ, DeGregori J. Dissecting stepwise mutational impairment of megakaryopoiesis in a model of Down syndrome-associated leukemia. J Clin Invest 2022; 132:161659. [PMID: 35838049 PMCID: PMC9282920 DOI: 10.1172/jci161659] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Individuals with Down syndrome (DS) have more than 100-fold increased risk of acute megakaryoblastic leukemia (AMKL), but its pathogenesis is poorly understood. In this issue of the JCI, Arkoun et al. engineered stepwise DS-AMKL-associated mutations in GATA1, MPL, and SMC3 in human induced pluripotent stem cell (iPSC) clones from individuals with DS to dissect how each mutation affects gene expression control and megakaryocytic differentiation. The authors showed that the mutations cooperatively promote progression from transient myeloproliferative disorder to DS-AMKL. This study highlights the importance of mutation order and context in the perturbations of transcriptional and differentiation pathways involved in the evolution of hematologic malignancies, which will be critical for the development of preventative and therapeutic interventions.
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Affiliation(s)
- Edward J Evans
- Department of Biochemistry and Molecular Genetics and.,Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics and.,Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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DeGregori J, Pham-Danis C, Rozhok AI, Evans EJ, Marongiu F, Scarborough H, Henry CJ. Abstract IA012: Aging, tissue ecology, and the evolution of cancer within us. Cancer Res 2022. [DOI: 10.1158/1538-7445.evodyn22-ia012] [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]
Abstract
Abstract
Why do we get cancer? Why is cancer highly associated with old age? Of course, aging is associated with the accumulation of more mutations, and some of these mutations can contribute to cancer phenotypes. But we now understand that carcinogenesis is much more complex than originally appreciated. In particular, there are tissue environmental forces that both impede and promote cancer evolution. Just as organismal evolution is known to be driven by environmental changes, cellular (somatic) evolution in our bodies is similarly driven by changes in tissue environments, whether caused by the normal process of aging, by lifestyle choices or by extrinsic exposures. Environmental change promotes selection for new phenotypes that are adaptive to the new context. In our tissues, aging or insult-driven alterations in tissues drives selection for adaptive mutations, and some of these mutations can confer malignant phenotypes. We have been using mouse models of cancer initiation, mathematical models of cellular evolution, and analyses of human tissue samples to better understand the evolutionary forces that control somatic cell evolution and thus cancer risk. We have shown that aging and inflammation dependent changes in tissue environments dramatically dictate whether cancer-causing mutations are advantageous to stem cells in our tissues, starting the cells down the path to cancer. Our studies have focused on cancer initiation within the hematopoietic system and the lung. These studies have also uncovered molecular explanations for mutation-driven adaptation to aged and inflammatory tissue environments. In all, these studies indicate that strategies to prevent or treat cancers will need to incorporate interventions that alter tissue microenvironments.
Citation Format: James DeGregori, Catherine Pham-Danis, Andrii I Rozhok, Edward J. Evans, Fabio Marongiu, Hannah Scarborough, Curtis J. Henry. Aging, tissue ecology, and the evolution of cancer within us [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr IA012.
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Evans EJ, DeGregori J. Cells with Cancer-associated Mutations Overtake Our Tissues as We Age. Aging Cancer 2021; 2:82-97. [PMID: 34888527 PMCID: PMC8651076 DOI: 10.1002/aac2.12037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/02/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND To shed light on the earliest events in oncogenesis, there is growing interest in understanding the mutational landscapes of normal tissues across ages. In the last decade, next-generation sequencing of human tissues has revealed a surprising abundance of cells with what would be considered oncogenic mutations. AIMS We performed meta-analysis on previously published sequencing data on normal tissues to categorize mutations based on their presence in cancer and showcase the quantity of cells with cancer-associated mutations in cancer-free individuals. METHODS AND RESULTS We analyzed sequencing data from these studies of normal tissues to determine the prevalence of cells with mutations in three different categories across multiple age groups: 1) mutations in genes designated as drivers, 2) mutations that are in the Cancer Gene Census (CGC), and 3) mutations in the CGC that are considered pathogenic. As we age, the percentage of cells in all three levels increase significantly, reaching over 50% of cells having oncogenic mutations for multiple tissues in the older age groups. The clear enrichment for these mutations, particularly at older ages, likely indicates strong selection for the resulting phenotypes. Combined with an estimation of the number of cells in tissues, we calculate that most older, cancer-free individuals possess at least a 100 billion cells that harbor at least one oncogenic mutation, presumably emanating from a fitness advantage conferred by these mutations that promotes clonal expansion. CONCLUSIONS These studies of normal tissues have highlighted the specific drivers of clonal expansion and how frequently they appear in us. Their high prevalence throughout cancer-free individuals necessitates reconsideration of the oncogenicity of these mutations, which could shape methods of detection, prevention and treatment of cancer, as well as of the potential impact of these mutations on tissue function and our health.
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Affiliation(s)
- Edward J. Evans
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Mullen GM, Evans EJ, Siegert BC, Miller NR, Rosselet BK, Sabzevari I, Brush A, Duan Z, Buddie Mullins C. The interplay between ceria particle size, reducibility, and ethanol oxidation activity of ceria-supported gold catalysts. REACT CHEM ENG 2018. [DOI: 10.1039/c7re00175d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The size of ceria particles influenced the activity of Au/CeO2 catalysts for ethanol oxidation, demonstrating a linear correlation between oxygen storage capacity and catalytic activity.
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Affiliation(s)
- Gregory M. Mullen
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
| | - Edward J. Evans
- Texas Materials Institute
- The University of Texas at Austin
- Austin
- USA
| | - Benjamin C. Siegert
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
| | - Nathan R. Miller
- Department of Geosciences
- Jackson School of Geosciences
- University of Texas at Austin
- Austin
- USA
| | - Benjamin K. Rosselet
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
| | - Iliya Sabzevari
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
| | - Adrianna Brush
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
| | - Zhiyao Duan
- Texas Materials Institute
- The University of Texas at Austin
- Austin
- USA
| | - C. Buddie Mullins
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- Austin
- USA
- Texas Materials Institute
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Lim H, Kim JY, Evans EJ, Rai A, Kim JH, Wygant BR, Mullins CB. Activation of a Nickel-Based Oxygen Evolution Reaction Catalyst on a Hematite Photoanode via Incorporation of Cerium for Photoelectrochemical Water Oxidation. ACS Appl Mater Interfaces 2017; 9:30654-30661. [PMID: 28813595 DOI: 10.1021/acsami.7b08239] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
There has been debate on whether Ni(OH)2 is truly catalytically active for the photo/electrocatalytic oxygen evolution reaction. In this report, we synthesized a Ni(OH)2 cocatalyst on a hematite photoanode and showed that, as has been proposed in other studies, the current density varies as a function of scan rate, which arises due to a photoinduced capacitive charging effect. We discovered that this photoinduced charging of Ni2+/3+ can be overcome by mixing cerium nitrate into the Ni precursor solution. Under illumination, the NiCeOx cocatalyst on a hematite photoanode exhibited an approximately 200 mV cathodic shift in onset potential and a ∼53% enhancement in photocurrent at 1.23 V vs RHE. Material characterization by electrochemical impedance spectroscopy revealed that the Ni species create a p-n junction across the charge space region, which facilitates collection of the photogenerated holes by the cocatalyst layer, and core level X-ray photoelectron spectroscopy showed that Ce incorporated into the Ni-based cocatalyst layer may possibly induce the oxidation of the Ni species. In addition, we observed a reduction in binding energies of Ni after photoelectrochemical water splitting reactions, which suggests that the lattice oxygen of the NiCeOx is consumed in the catalytic cycle, forming oxygen vacancies. The NiCeOx cocatalyst, however, was incapable of passivating the surface recombination centers of the hematite photoanode, as indicated by the unaltered flat-band potential determined with Mott-Schottky analysis.
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Affiliation(s)
- Hyungseob Lim
- Department of Chemistry, McKetta Department of Chemical Engineering, Center for Electrochemistry, and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Jae Young Kim
- Artificial Photosyntehsis Research Group, Korea Research Institute of Chemical Technology , Yusong, Daejeon 305-600, Republic of Korea
| | - Edward J Evans
- Department of Chemistry, McKetta Department of Chemical Engineering, Center for Electrochemistry, and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Amritesh Rai
- Microelectronics Research Center and Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Jun-Hyuk Kim
- Department of Chemistry, McKetta Department of Chemical Engineering, Center for Electrochemistry, and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Bryan R Wygant
- Department of Chemistry, McKetta Department of Chemical Engineering, Center for Electrochemistry, and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States
| | - C Buddie Mullins
- Department of Chemistry, McKetta Department of Chemical Engineering, Center for Electrochemistry, and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States
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Mullen GM, Evans EJ, Sabzevari I, Long BE, Alhazmi K, Chandler BD, Mullins CB. Water Influences the Activity and Selectivity of Ceria-Supported Gold Catalysts for Oxidative Dehydrogenation and Esterification of Ethanol. ACS Catal 2017. [DOI: 10.1021/acscatal.6b02960] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Brittany E. Long
- Department
of Chemistry, Trinity University, San Antonio, Texas 78212, United States
| | | | - Bert D. Chandler
- Department
of Chemistry, Trinity University, San Antonio, Texas 78212, United States
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9
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Abstract
Co-adsorbed H2O enhances the activation of adsorbed O2 on the Pd–Au(111) surface.
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Affiliation(s)
- Sungmin Han
- Department of Chemistry
- Center for Nano and Molecular Science and Technology
- Texas Materials Institute
- Center for Electrochemistry
- University of Texas at Austin
| | - Edward J. Evans
- Department of Chemistry
- Center for Nano and Molecular Science and Technology
- Texas Materials Institute
- Center for Electrochemistry
- University of Texas at Austin
| | - Gregory M. Mullen
- McKetta Department of Chemical Engineering
- Center for Nano and Molecular Science and Technology
- Texas Materials Institute
- Center for Electrochemistry
- University of Texas at Austin
| | - C. Buddie Mullins
- Department of Chemistry
- Center for Nano and Molecular Science and Technology
- Texas Materials Institute
- Center for Electrochemistry
- University of Texas at Austin
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10
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Abstract
Two mathematical models for fibroblast-collagen interaction are proposed which reproduce qualitative features of fibroblast-populated collagen lattice contraction. Both models are force based and model the cells as individual entities with discrete attachment sites; however, the collagen lattice is modelled differently in each model. In the collagen lattice model, the lattice is more interconnected and formed by triangulating nodes to form the fibrous structure. In the collagen fibre model, the nodes are not triangulated, are less interconnected, and the collagen fibres are modelled as a string of nodes. Both models suggest that the overall increase in stress of the lattice as it contracts is not the cause of the reduced rate of contraction, but that the reduced rate of contraction is due to inactivation of the fibroblasts.
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Affiliation(s)
- J C Dallon
- Department of Mathematics, Brigham Young University, Provo, UT 84602-6539, USA
| | - E J Evans
- Department of Mathematics, Brigham Young University, Provo, UT 84602-6539, USA
| | - H Paul Ehrlich
- Division of Plastic Surgery, Hershey Medical Center, Hershey, PA 17033, USA
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11
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Mullen GM, Zhang L, Evans EJ, Yan T, Henkelman G, Mullins CB. Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species. Phys Chem Chem Phys 2015; 17:4730-8. [DOI: 10.1039/c4cp04739g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gold catalysts display high activity and good selectivity for partial oxidation of a number of alcohol species.
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Affiliation(s)
- Gregory M. Mullen
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
| | - Liang Zhang
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | - Edward J. Evans
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | - Ting Yan
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | | | - C. Buddie Mullins
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
- Department of Chemistry
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12
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Yu WY, Zhang L, Mullen GM, Evans EJ, Henkelman G, Mullins CB. Effect of annealing in oxygen on alloy structures of Pd–Au bimetallic model catalysts. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp03515e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Annealing in an oxygen ambient stabilizes Pd atoms on Pd–Au surfaces, resulting in higher oxygen uptake and CO oxidation activity.
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Affiliation(s)
- Wen-Yueh Yu
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
| | - Liang Zhang
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
- Institute for Computational Engineering and Sciences
| | - Gregory M. Mullen
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
| | - Edward J. Evans
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | - Graeme Henkelman
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
- Institute for Computational Engineering and Sciences
| | - C. Buddie Mullins
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
- Department of Chemistry
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13
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Mullen GM, Zhang L, Evans EJ, Yan T, Henkelman G, Mullins CB. Correction: Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species. Phys Chem Chem Phys 2015; 17:9569. [DOI: 10.1039/c5cp90039e] [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: 11/21/2022]
Abstract
Correction for ‘Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species’ by Gregory M. Mullen et al., Phys. Chem. Chem. Phys., 2015, 17, 4730–4738.
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Affiliation(s)
- Gregory M. Mullen
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
| | - Liang Zhang
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | - Edward J. Evans
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | - Ting Yan
- Department of Chemistry
- University of Texas at Austin
- Austin
- USA
| | | | - C. Buddie Mullins
- McKetta Department of Chemical Engineering
- University of Texas at Austin
- Austin
- USA
- Department of Chemistry
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14
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Mullen GM, Zhang L, Evans EJ, Yan T, Henkelman G, Mullins CB. Oxygen and Hydroxyl Species Induce Multiple Reaction Pathways for the Partial Oxidation of Allyl Alcohol on Gold. J Am Chem Soc 2014; 136:6489-98. [DOI: 10.1021/ja502347d] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gregory M. Mullen
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
| | - Liang Zhang
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
| | - Edward J. Evans
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
| | - Ting Yan
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
| | - Graeme Henkelman
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
| | - C. Buddie Mullins
- McKetta Department of Chemical Engineering
and Department of Chemistry, and ‡Center for Nano
and Molecular Science and Technology, Texas Materials Institute, and
Center for Electrochemistry, University of Texas at Austin, Austin, Texas 78712-0231, United States
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15
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Cheng X, Veverka V, Radhakrishnan A, Waters LC, Muskett FW, Morgan SH, Huo J, Yu C, Evans EJ, Leslie AJ, Griffiths M, Stubberfield C, Griffin R, Henry AJ, Jansson A, Ladbury JE, Ikemizu S, Carr MD, Davis SJ. Structure and interactions of the human programmed cell death 1 receptor. J Biol Chem 2013; 288:11771-85. [PMID: 23417675 PMCID: PMC3636866 DOI: 10.1074/jbc.m112.448126] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [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] [Indexed: 01/10/2023] Open
Abstract
PD-1, a receptor expressed by T cells, B cells, and monocytes, is a potent regulator of immune responses and a promising therapeutic target. The structure and interactions of human PD-1 are, however, incompletely characterized. We present the solution nuclear magnetic resonance (NMR)-based structure of the human PD-1 extracellular region and detailed analyses of its interactions with its ligands, PD-L1 and PD-L2. PD-1 has typical immunoglobulin superfamily topology but differs at the edge of the GFCC′ sheet, which is flexible and completely lacks a C″ strand. Changes in PD-1 backbone NMR signals induced by ligand binding suggest that, whereas binding is centered on the GFCC′ sheet, PD-1 is engaged by its two ligands differently and in ways incompletely explained by crystal structures of mouse PD-1·ligand complexes. The affinities of these interactions and that of PD-L1 with the costimulatory protein B7-1, measured using surface plasmon resonance, are significantly weaker than expected. The 3–4-fold greater affinity of PD-L2 versus PD-L1 for human PD-1 is principally due to the 3-fold smaller dissociation rate for PD-L2 binding. Isothermal titration calorimetry revealed that the PD-1/PD-L1 interaction is entropically driven, whereas PD-1/PD-L2 binding has a large enthalpic component. Mathematical simulations based on the biophysical data and quantitative expression data suggest an unexpectedly limited contribution of PD-L2 to PD-1 ligation during interactions of activated T cells with antigen-presenting cells. These findings provide a rigorous structural and biophysical framework for interpreting the important functions of PD-1 and reveal that potent inhibitory signaling can be initiated by weakly interacting receptors.
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Affiliation(s)
- Xiaoxiao Cheng
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
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16
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Kelly AL, Sharpe AG, Nixon JH, Lydiate DJ, Evans EJ. Indistinguishable patterns of recombination resulting from male and female meioses in Brassica napus (oilseed rape). Genome 2012; 40:49-56. [PMID: 18464807 DOI: 10.1139/g97-007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An F1 individual derived from a cross between two distinct lines of spring oilseed rape (Brassica napus) was used to produce a pair of complementary backcross populations, each consisting of 90 individuals. The F1 donated male gametes to the Male population and female gametes to the Female population. Genetic maps were generated from both populations and aligned using 117 common loci to form an integrated genome map of B. napus with 243 RFLP-defined loci. A comparison of the frequency and distribution of crossovers in the two populations of F1 gametes (assayed in the Male and Female populations) detected no differences. The genetic maps derived from the Male and Female populations each consisted of 19 linkage groups spanning 1544 and 1577 cM, respectively. The maps were aligned with other B. napus maps, and all 19 equivalent linkage groups were unambiguously assigned. The genetic size and general organisation of the new maps were comparable with those of pre-existing B. napus maps in most respects, except that the levels of polymorphism in the constituent A and C genomes were unusually similar in the new cross.
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17
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Fernandes RA, Shore DA, Vuong MT, Yu C, Zhu X, Pereira-Lopes S, Brouwer H, Fennelly JA, Jessup CM, Evans EJ, Wilson IA, Davis SJ. T cell receptors are structures capable of initiating signaling in the absence of large conformational rearrangements. J Biol Chem 2012; 287:13324-35. [PMID: 22262845 PMCID: PMC3339974 DOI: 10.1074/jbc.m111.332783] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [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: 12/13/2011] [Revised: 01/10/2012] [Indexed: 12/18/2022] Open
Abstract
Native and non-native ligands of the T cell receptor (TCR), including antibodies, have been proposed to induce signaling in T cells via intra- or intersubunit conformational rearrangements within the extracellular regions of TCR complexes. We have investigated whether any signatures can be found for such postulated structural changes during TCR triggering induced by antibodies, using crystallographic and mutagenesis-based approaches. The crystal structure of murine CD3ε complexed with the mitogenic anti-CD3ε antibody 2C11 enabled the first direct structural comparisons of antibody-liganded and unliganded forms of CD3ε from a single species, which revealed that antibody binding does not induce any substantial rearrangements within CD3ε. Saturation mutagenesis of surface-exposed CD3ε residues, coupled with assays of antibody-induced signaling by the mutated complexes, suggests a new configuration for the complex within which CD3ε is highly exposed and reveals that no large new CD3ε interfaces are required to form during antibody-induced signaling. The TCR complex therefore appears to be a structure that is capable of initiating intracellular signaling in T cells without substantial structural rearrangements within or between the component subunits. Our findings raise the possibility that signaling by native ligands might also be initiated in the absence of large structural rearrangements in the receptor.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- CD3 Complex/chemistry
- CD3 Complex/genetics
- CD3 Complex/immunology
- Crystallography, X-Ray
- Dimerization
- Epitopes, T-Lymphocyte/immunology
- Humans
- Immunoglobulin Fab Fragments/immunology
- Jurkat Cells
- Mice
- Mutagenesis, Site-Directed
- Protein Conformation
- Protein Structure, Tertiary
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction/immunology
- Structure-Activity Relationship
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Affiliation(s)
- Ricardo A. Fernandes
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - David A. Shore
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Mai T. Vuong
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Chao Yu
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Xueyong Zhu
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Selma Pereira-Lopes
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Heather Brouwer
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Janet A. Fennelly
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Claire M. Jessup
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Edward J. Evans
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Ian A. Wilson
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Simon J. Davis
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
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18
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Evans EJ, Adams PD. Expression and Purification of Cdc42 and PBD46. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.973.4] [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: 11/11/2022]
Affiliation(s)
| | - Paul D Adams
- Chemistry and Biochemistry DepartmentUniversity of ArkansasFayettevilleAR
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19
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Yu C, Crispin M, Sonnen AFP, Harvey DJ, Chang VT, Evans EJ, Scanlan CN, Stuart DI, Gilbert RJC, Davis SJ. Use of the α-mannosidase I inhibitor kifunensine allows the crystallization of apo CTLA-4 homodimer produced in long-term cultures of Chinese hamster ovary cells. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:785-9. [PMID: 21795794 PMCID: PMC3144796 DOI: 10.1107/s1744309111017672] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [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: 12/23/2010] [Accepted: 05/10/2011] [Indexed: 02/06/2023]
Abstract
Glycoproteins present problems for structural analysis since they often have to be glycosylated in order to fold correctly and because their chemical and conformational heterogeneity generally inhibits crystallization. It is shown that the α-mannosidase I inhibitor kifunensine, which has previously been used for the purpose of glycoprotein crystallization in short-term (3-5 d) cultures, is apparently stable enough to be used to produce highly endoglycosidase H-sensitive glycoprotein in long-term (3-4 week) cultures of stably transfected Chinese hamster ovary (CHO) cells. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based analysis of the extracellular region of the cytotoxic T-lymphocyte antigen 4 (CTLA-4; CD152) homodimer expressed in long-term CHO cell cultures in the presence of kifunensine revealed that the inhibitor restricted CTLA-4 glycan processing to Man9GlcNAc2 and Man5GlcNAc2 structures. Complex-type glycans were undetectable, suggesting that the inhibitor was active for the entire duration of the cultures. Endoglycosidase treatment of the homodimer yielded protein that readily formed orthorhombic crystals with unit-cell parameters a=43.9, b=51.5, c=102.9 Å and space group P2(1)2(1)2(1) that diffracted to Bragg spacings of 1.8 Å. The results indicate that kifunensine will be effective in most, if not all, transient and long-term mammalian cell-based expression systems.
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Affiliation(s)
- Chao Yu
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, England
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 1QU, England
| | - Andreas F.-P. Sonnen
- Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - David J. Harvey
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 1QU, England
| | - Veronica T. Chang
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, England
| | - Edward J. Evans
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, England
| | - Christopher N. Scanlan
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 1QU, England
| | - David I. Stuart
- Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Robert J. C. Gilbert
- Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, England
| | - Simon J. Davis
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, England
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20
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Evans EJ, Niblick CJ, Taylor AT. Effect of yhiM expression on antibiotic resistance of
E. coli. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.966.1] [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: 11/11/2022]
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21
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Yu C, Sonnen AFP, George R, Dessailly BH, Stagg LJ, Evans EJ, Orengo CA, Stuart DI, Ladbury JE, Ikemizu S, Gilbert RJC, Davis SJ. Rigid-body ligand recognition drives cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptor triggering. J Biol Chem 2010; 286:6685-96. [PMID: 21156796 PMCID: PMC3057841 DOI: 10.1074/jbc.m110.182394] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [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] [Indexed: 11/06/2022] Open
Abstract
The inhibitory T-cell surface-expressed receptor, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), which belongs to the class of cell surface proteins phosphorylated by extrinsic tyrosine kinases that also includes antigen receptors, binds the related ligands, B7-1 and B7-2, expressed on antigen-presenting cells. Conformational changes are commonly invoked to explain ligand-induced "triggering" of this class of receptors. Crystal structures of ligand-bound CTLA-4 have been reported, but not the apo form, precluding analysis of the structural changes accompanying ligand binding. The 1.8-Å resolution structure of an apo human CTLA-4 homodimer emphasizes the shared evolutionary history of the CTLA-4/CD28 subgroup of the immunoglobulin superfamily and the antigen receptors. The ligand-bound and unbound forms of both CTLA-4 and B7-1 are remarkably similar, in marked contrast to B7-2, whose binding to CTLA-4 has elements of induced fit. Isothermal titration calorimetry reveals that ligand binding by CTLA-4 is enthalpically driven and accompanied by unfavorable entropic changes. The similarity of the thermodynamic parameters determined for the interactions of CTLA-4 with B7-1 and B7-2 suggests that the binding is not highly specific, but the conformational changes observed for B7-2 binding suggest some level of selectivity. The new structure establishes that rigid-body ligand interactions are capable of triggering CTLA-4 phosphorylation by extrinsic kinase(s).
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Affiliation(s)
- Chao Yu
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
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22
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Sonnen AFP, Yu C, Evans EJ, Stuart DI, Davis SJ, Gilbert RJ. Domain metastability: a molecular basis for immunoglobulin deposition? J Mol Biol 2010; 399:207-13. [PMID: 20394753 PMCID: PMC2954335 DOI: 10.1016/j.jmb.2010.04.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/31/2010] [Accepted: 04/02/2010] [Indexed: 11/17/2022]
Abstract
We present the crystal structure of an immunoglobulin light-chain-like domain, CTLA-4, as a strand-swapped dimer displaying cis–trans proline isomerisation and native-like hydrogen bonding. We also show that CTLA-4 can form amyloid-like fibres and amorphous deposits explainable by the same strand swapping. Our results suggest a molecular basis for the pathological aggregation of immunoglobulin domains and why amyloid-like fibres are more often composed of homologous rather than heterologous subunits.
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Affiliation(s)
- Andreas F.-P. Sonnen
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
- Corresponding authors. A.F.-P. Sonnen and R.J.C. Gilbert is to be contacted at Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, The University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
| | - Chao Yu
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - Edward J. Evans
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - David I. Stuart
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Simon J. Davis
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - Robert J.C. Gilbert
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
- Corresponding authors. A.F.-P. Sonnen and R.J.C. Gilbert is to be contacted at Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, The University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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23
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Crispin M, Chang VT, Harvey DJ, Dwek RA, Evans EJ, Stuart DI, Jones EY, Lord JM, Spooner RA, Davis SJ. A human embryonic kidney 293T cell line mutated at the Golgi alpha-mannosidase II locus. J Biol Chem 2009; 284:21684-95. [PMID: 19465480 PMCID: PMC2755891 DOI: 10.1074/jbc.m109.006254] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [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: 01/28/2009] [Revised: 04/09/2009] [Indexed: 11/25/2022] Open
Abstract
Disruption of Golgi alpha-mannosidase II activity can result in type II congenital dyserythropoietic anemia and induce lupus-like autoimmunity in mice. Here, we isolated a mutant human embryonic kidney (HEK) 293T cell line called Lec36, which displays sensitivity to ricin that lies between the parental HEK 293T cells, in which the secreted and membrane-expressed proteins are dominated by complex-type glycosylation, and 293S Lec1 cells, which produce only oligomannose-type N-linked glycans. Stem cell marker 19A was transiently expressed in the HEK 293T Lec36 cells and in parental HEK 293T cells with and without the potent Golgi alpha-mannosidase II inhibitor, swainsonine. Negative ion nano-electrospray ionization mass spectra of the 19A N-linked glycans from HEK 293T Lec36 and swainsonine-treated HEK 293T cells were qualitatively indistinguishable and, as shown by collision-induced dissociation spectra, were dominated by hybrid-type glycosylation. Nucleotide sequencing revealed mutations in each allele of MAN2A1, the gene encoding Golgi alpha-mannosidase II: a point mutation that mapped to the active site was found in one allele, and an in-frame deletion of 12 nucleotides was found in the other allele. Expression of the wild type but not the mutant MAN2A1 alleles in Lec36 cells restored processing of the 19A reporter glycoprotein to complex-type glycosylation. The Lec36 cell line will be useful for expressing therapeutic glycoproteins with hybrid-type glycans and as a sensitive host for detecting mutations in human MAN2A1 causing type II congenital dyserythropoietic anemia.
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Affiliation(s)
- Max Crispin
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, and
| | - Veronica T. Chang
- Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford OX3 9DS
| | - David J. Harvey
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, and
| | - Raymond A. Dwek
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, and
| | - Edward J. Evans
- Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford OX3 9DS
| | - David I. Stuart
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN
| | - E. Yvonne Jones
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN
| | - J. Michael Lord
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Robert A. Spooner
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Simon J. Davis
- Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford OX3 9DS
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Evans EJ, Hene L, Vuong M, Abidi HSI, Davis SJ. Transcriptome-based identification of candidate membrane proteins. Methods Mol Biol 2009; 528:37-56. [PMID: 19153683 DOI: 10.1007/978-1-60327-310-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 05/27/2023]
Abstract
A full understanding of leukocyte responses to external stimuli requires knowledge of the full complement of proteins found on their surfaces. Systematic examination of the mammalian cell surfaces at the protein level is hampered by technical difficulties associated with proteomic analysis of so many membrane proteins and the large amounts of starting material required. The use of transcriptomic analyses avoids challenges associated with protein stability and separation and enables the inclusion of an amplification step; thus allowing the use of cell numbers applicable to the study of sub populations of, for example, primary lymphocytes. Here we present a transcriptomic methodology based on Serial Analysis of Gene Expression (SAGE) to recover an essentially complete and quantitative profile of mRNA species in a particular cell. We discuss how, using bioinformatic tools accessible to standard desktop computers, plasma membrane proteins can be identified in silico, from this list. While we describe the use of this approach to characterise the cell surface protein complement of a resting CD8(+) T-cell clone, it is theoretically applicable to any cell surface, where a suitable pure population of cells is available.
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Affiliation(s)
- Edward J Evans
- Nuffield Department of Clinical Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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Abidi SHI, Dong T, Vuong MT, Sreenu VB, Rowland-Jones SL, Evans EJ, Davis SJ. Differential remodeling of a T-cell transcriptome following CD8- versus CD3-induced signaling. Cell Res 2008; 18:641-8. [PMID: 18475290 DOI: 10.1038/cr.2008.56] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
CD8 engagement with class I major histocompatibility antigens greatly enhances T-cell activation, but it is not clear how this is achieved. We address the question of whether or not the antibody-mediated ligation of CD8 alone induces transcriptional remodeling in a T-cell clone, using serial analysis of gene expression. Even though it fails to induce overt phenotypic changes, we find that CD8 ligation profoundly alters transcription in the T-cell clone, at a scale comparable to that induced by antibody-mediated ligation of CD3. The character of the resulting changes is distinct, however, with the net effect of CD8 ligation being substantially inhibitory. We speculate that ligating CD8 induces weak, T-cell receptor (TCR)-mediated inhibitory signals reminiscent of the effects of TCR antagonists. Our results imply that CD8 ligation alone is incapable of activating the T-cell clone because it fails to fully induce NFAT-dependent transcription.
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Affiliation(s)
- S Hussain I Abidi
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
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Hene L, Sreenu VB, Vuong MT, Abidi SHI, Sutton JK, Rowland-Jones SL, Davis SJ, Evans EJ. Deep analysis of cellular transcriptomes - LongSAGE versus classic MPSS. BMC Genomics 2007; 8:333. [PMID: 17892551 PMCID: PMC2104538 DOI: 10.1186/1471-2164-8-333] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [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: 03/09/2007] [Accepted: 09/24/2007] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Deep transcriptome analysis will underpin a large fraction of post-genomic biology. 'Closed' technologies, such as microarray analysis, only detect the set of transcripts chosen for analysis, whereas 'open' e.g. tag-based technologies are capable of identifying all possible transcripts, including those that were previously uncharacterized. Although new technologies are now emerging, at present the major resources for open-type analysis are the many publicly available SAGE (serial analysis of gene expression) and MPSS (massively parallel signature sequencing) libraries. These technologies have never been compared for their utility in the context of deep transcriptome mining. RESULTS We used a single LongSAGE library of 503,431 tags and a "classic" MPSS library of 1,744,173 tags, both prepared from the same T cell-derived RNA sample, to compare the ability of each method to probe, at considerable depth, a human cellular transcriptome. We show that even though LongSAGE is more error-prone than MPSS, our LongSAGE library nevertheless generated 6.3-fold more genome-matching (and therefore likely error-free) tags than the MPSS library. An analysis of a set of 8,132 known genes detectable by both methods, and for which there is no ambiguity about tag matching, shows that MPSS detects only half (54%) the number of transcripts identified by SAGE (3,617 versus 1,955). Analysis of two additional MPSS libraries shows that each library samples a different subset of transcripts, and that in combination the three MPSS libraries (4,274,992 tags in total) still only detect 73% of the genes identified in our test set using SAGE. The fraction of transcripts detected by MPSS is likely to be even lower for uncharacterized transcripts, which tend to be more weakly expressed. The source of the loss of complexity in MPSS libraries compared to SAGE is unclear, but its effects become more severe with each sequencing cycle (i.e. as MPSS tag length increases). CONCLUSION We show that MPSS libraries are significantly less complex than much smaller SAGE libraries, revealing a serious bias in the generation of MPSS data unlikely to have been circumvented by later technological improvements. Our results emphasize the need for the rigorous testing of new expression profiling technologies.
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Affiliation(s)
- Lawrence Hene
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Vattipally B Sreenu
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Mai T Vuong
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - S Hussain I Abidi
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Julian K Sutton
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Sarah L Rowland-Jones
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Simon J Davis
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Edward J Evans
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
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Chang VT, Crispin M, Aricescu AR, Harvey DJ, Nettleship JE, Fennelly JA, Yu C, Boles KS, Evans EJ, Stuart DI, Dwek RA, Jones EY, Owens RJ, Davis SJ. Glycoprotein structural genomics: solving the glycosylation problem. Structure 2007; 15:267-73. [PMID: 17355862 PMCID: PMC1885966 DOI: 10.1016/j.str.2007.01.011] [Citation(s) in RCA: 222] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 01/08/2007] [Accepted: 01/08/2007] [Indexed: 10/29/2022]
Abstract
Glycoproteins present special problems for structural genomic analysis because they often require glycosylation in order to fold correctly, whereas their chemical and conformational heterogeneity generally inhibits crystallization. We show that the "glycosylation problem" can be solved by expressing glycoproteins transiently in mammalian cells in the presence of the N-glycosylation processing inhibitors, kifunensine or swainsonine. This allows the correct folding of the glycoproteins, but leaves them sensitive to enzymes, such as endoglycosidase H, that reduce the N-glycans to single residues, enhancing crystallization. Since the scalability of transient mammalian expression is now comparable to that of bacterial systems, this approach should relieve one of the major bottlenecks in structural genomic analysis.
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Affiliation(s)
- Veronica T. Chang
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Max Crispin
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - A. Radu Aricescu
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - David J. Harvey
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Joanne E. Nettleship
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Janet A. Fennelly
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Chao Yu
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Kent S. Boles
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Edward J. Evans
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - David I. Stuart
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Raymond A. Dwek
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - E. Yvonne Jones
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Raymond J. Owens
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
- Corresponding author
| | - Simon J. Davis
- Nuffield Department of Clinical Medicine and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
- Corresponding author
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Nettleship JE, Aplin R, Aricescu AR, Evans EJ, Davis SJ, Crispin M, Owens RJ. Analysis of variable N-glycosylation site occupancy in glycoproteins by liquid chromatography electrospray ionization mass spectrometry. Anal Biochem 2007; 361:149-51. [PMID: 17178093 DOI: 10.1016/j.ab.2006.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 11/06/2006] [Indexed: 11/18/2022]
Affiliation(s)
- Joanne E Nettleship
- Oxford Protein Production Facility, Wellcome Trust Center for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.
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29
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Evans EJ, Castro MAA, O'Brien R, Kearney A, Walsh H, Sparks LM, Tucknott MG, Davies EA, Carmo AM, van der Merwe PA, Stuart DI, Jones EY, Ladbury JE, Ikemizu S, Davis SJ. Crystal structure and binding properties of the CD2 and CD244 (2B4)-binding protein, CD48. J Biol Chem 2006; 281:29309-20. [PMID: 16803907 DOI: 10.1074/jbc.m601314200] [Citation(s) in RCA: 32] [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] [Indexed: 11/06/2022] Open
Abstract
The structural analysis of surface proteins belonging to the CD2 subset of the immunoglobulin superfamily has yielded important insights into transient cellular interactions. In mice and rats, CD2 and CD244 (2B4), which are expressed predominantly on T cells and natural killer cells, respectively, bind the same, broadly expressed ligand, CD48. Structures of CD2 and CD244 have been solved previously, and we now present the structure of the receptor-binding domain of rat CD48. The receptor-binding surface of CD48 is unusually flat, as in the case of rat CD2, and shares a high degree of electrostatic complementarity with the equivalent surface of CD2. The relatively simple arrangement of charged residues and this flat topology explain why CD48 cross-reacts with CD2 and CD244 and, in rats, with the CD244-related protein, 2B4R. Comparisons of modeled complexes of CD2 and CD48 with the complex of human CD2 and CD58 are suggestive of there being substantial plasticity in the topology of ligand binding by CD2. Thermodynamic analysis of the native CD48-CD2 interaction indicates that binding is driven by equivalent, weak enthalpic and entropic effects, in contrast to the human CD2-CD58 interaction, for which there is a large entropic barrier. Overall, the structural and biophysical comparisons of the CD2 homologues suggest that the evolutionary diversification of interacting cell surface proteins is rapid and constrained only by the requirement that binding remains weak and specific.
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Affiliation(s)
- Edward J Evans
- Nuffield Department of Clinical Medicine, The University of Oxford and MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, United Kingdom
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Evans EJ, Esnouf RM, Manso-Sancho R, Gilbert RJC, James JR, Yu C, Fennelly JA, Vowles C, Hanke T, Walse B, Hünig T, Sørensen P, Stuart DI, Davis SJ. Crystal structure of a soluble CD28-Fab complex. Nat Immunol 2005; 6:271-9. [PMID: 15696168 DOI: 10.1038/ni1170] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Accepted: 01/19/2005] [Indexed: 11/08/2022]
Abstract
Naive T cell activation requires signaling by the T cell receptor and by nonclonotypic cell surface receptors. The most important costimulatory protein is the monovalent homodimer CD28, which interacts with CD80 and CD86 expressed on antigen-presenting cells. Here we present the crystal structure of a soluble form of CD28 in complex with the Fab fragment of a mitogenic antibody. Structural comparisons redefine the evolutionary relationships of CD28-related proteins, antigen receptors and adhesion molecules and account for the distinct ligand-binding and stoichiometric properties of CD28 and the related, inhibitory homodimer CTLA-4. Cryo-electron microscopy-based comparisons of complexes of CD28 with mitogenic and nonmitogenic antibodies place new constraints on models of antibody-induced receptor triggering. This work completes the initial structural characterization of the CD28-CTLA-4-CD80-CD86 signaling system.
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Affiliation(s)
- Edward J Evans
- Nuffield Department of Clinical Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK
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31
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Evans EJ, Hene L, Sparks LM, Dong T, Retiere C, Fennelly JA, Manso-Sancho R, Powell J, Braud VM, Rowland-Jones SL, McMichael AJ, Davis SJ. The T cell surface--how well do we know it? Immunity 2003; 19:213-23. [PMID: 12932355 DOI: 10.1016/s1074-7613(03)00198-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The overall degree of complexity of the T cell surface has been unclear, constraining our understanding of its biology. Using global gene expression analysis, we show that 111 of 374 genes encoding well-characterized leukocyte surface antigens are expressed by a resting cytotoxic T cell. Unexpectedly, of 97 stringently defined, T cell-specific transcripts with unknown functions that we identify, none encode proteins with the modular architecture characteristic of 80% of leukocyte surface antigens. Only two encode proteins with membrane topologies found exclusively in cell surface molecules. Our analysis indicates that the cell type-specific composition of the resting CD8+ T cell surface is now largely defined, providing an insight into the overall compositional complexity of the mammalian cell surface and a framework for formulating systematic models of T cell surface-dependent processes, such as T cell receptor triggering.
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Affiliation(s)
- Edward J Evans
- Nuffield Department of Clinical Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
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Abstract
Considerable progress has been made in characterizing four key sets of interactions controlling antigen responsiveness in T cells, involving the following: the T cell antigen receptor, its coreceptors CD4 and CD8, the costimulatory receptors CD28 and CTLA-4, and the accessory molecule CD2. Complementary work has defined the general biophysical properties of interactions between cell surface molecules. Among the major conclusions are that these interactions are structurally heterogeneous, often reflecting clear-cut functional constraints, and that, although they all interact relatively weakly, hierarchical differences in the stabilities of the signaling complexes formed by these molecules may influence the sequence of steps leading to T cell activation. Here we review these developments and highlight the major challenges remaining as the field moves toward formulating quantitative models of T cell recognition.
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Affiliation(s)
- Simon J Davis
- Nuffield Department of Clinical Medicine, Weatherall Institute of Molecular Medicine, The University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
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Abstract
The CD2 subset of the immunoglobulin superfamily consists of a rapidly expanding family of leukocyte cell surface receptors, at least five of which (CD2, CD48, CD58, CD150, and CD244) are involved in lymphocyte activation as either receptors or ligands. Completion of the draft sequence of the human genome offers the possibility of systematically identifying the full set of proteins and interactions of this important family. Here we describe the identification and characterization of the first new member of the subset, CD2F-10, found exclusively by genome searching.
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Affiliation(s)
- J A Fennelly
- Molecular Sciences Division, Nuffield Department of Clinical Medicine, The University of Oxford, Oxford, OX3 9DU, UK
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35
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Mavaddat N, Mason DW, Atkinson PD, Evans EJ, Gilbert RJ, Stuart DI, Fennelly JA, Barclay AN, Davis SJ, Brown MH. Signaling lymphocytic activation molecule (CDw150) is homophilic but self-associates with very low affinity. J Biol Chem 2000; 275:28100-9. [PMID: 10831600 DOI: 10.1074/jbc.m004117200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signaling lymphocytic activating molecule ((SLAM) CDw150) is a glycoprotein that belongs to the CD2 subset of the immunoglobulin superfamily and is expressed on the surface of activated T- and B-cells. It has been proposed that SLAM is homophilic and required for bidirectional signaling during T- and B-cell activation. Previous work has suggested that the affinity of SLAM self-association might be unusually high, undermining the concept that protein interactions mediating transient cell-cell contacts, such as those involving leukocytes, have to be weak in order that such contacts are readily reversible. Using surface plasmon resonance-based methods and analytical ultracentrifugation (AUC), we confirm that SLAM is homophilic. However, we also establish a new theoretical treatment of surface plasmon resonance-derived homophilic binding data, which indicates that SLAM-SLAM interactions (solution K(d) approximately 200 micrometer) are in fact considerably weaker than most other well characterized protein-protein interactions at the cell surface (solution K(d) approximately 0.4-20 micrometer), a conclusion that is supported by the AUC analysis. Whereas further analysis of the AUC data imply that SLAM could form "head to head" dimers spanning adjacent cells, the very low affinity raises important questions regarding the physiological role and/or properties of such interactions.
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Affiliation(s)
- N Mavaddat
- Sir William Dunn School of Pathology, The University of Oxford, Oxford OX1 3RE, United Kingdom
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36
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Evans EJ, Wickstrom B. Subjective fatigue and self-care in individuals with chronic illness. Medsurg Nurs 1999; 8:363-9. [PMID: 11000775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Fatigue is a serious problem for individuals experiencing chronic illness that can cause difficulties managing self-care activities and achieving quality of life. The applicability of a standardized research instrument for clinical use was explored and shown to have the potential to advance caregivers' understanding of fatigue and its consequences.
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Affiliation(s)
- E J Evans
- Northside Hospital, Atlanta, GA, USA
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37
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Evans PD, Marshall PD, McDonnell B, Richards J, Evans EJ. Radiologic study of the accuracy of a tibial intramedullary cutting guide for knee arthroplasty. J Arthroplasty 1995; 10:43-6. [PMID: 7730829 DOI: 10.1016/s0883-5403(05)80099-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Twenty-one caucasian, adult cadaveric tibiae were prepared as for knee arthroplasty using an intramedullary cutting guide. The instrumentation was used to produce slots in the proximal tibia into which Kirschner wires were placed as radio-opaque markers for subsequent anteroposterior and lateral radiographs. The anatomic axis of the tibia and lines perpendicular to the wire markers were drawn on the radiographs and the angle between the two lines was measured to assess the accuracy of the cuts. Seventy-one percent of the tibial cuts were found to be within 2 degrees of the anatomic axis on the anteroposterior radiograph (mean, 2.1 degrees), while on the lateral radiograph, 81% of the cuts were within 2 degrees (mean, 1.8 degrees). There was a significant tendency to position the bone cuts in varus (P < .05), although this did not correlate with varus or valgus deformity of the bones. There was no consistent tendency to anterior or posterior tilt on the lateral radiograph (P > .05). The results compare favorably with those obtained from a specialist unit using an extramedullary alignment system. The authors conclude that the tibial intramedullary guide can lead to preparation of the proximal tibia for knee arthroplasty as accurately as the conventional extramedullary system.
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Affiliation(s)
- P D Evans
- Department of Orthopaedic Surgery, University of Wales, College of Cardiff, United Kingdom
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Abstract
Fibroblastic cells in vitro were exposed to powders of titanium, titanium-aluminium-vanadium alloy and cobalt-chrome-molybdenum (Co-Cr-Mo) alloy, either in direct contact with the cells or separated from the cells by a microporous membrane. Fine particles of all the materials reduced cell growth when in direct contact with cells, but only the finest particles of Co-Cr-Mo alloy caused cell damage through the microporous membrane. This provides further evidence that there is a mechanism of cell damage in vitro which depends on a direct interaction between cells and particles and is largely independent of the chemical nature of the particle.
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Affiliation(s)
- E J Evans
- Department of Anatomy, University of Wales College of Cardiff, UK
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39
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Islam N, Evans EJ. Influence of lodging and nitrogen rate on the yield and yield attributes of oilseed rape (Brassica napus L.). Theor Appl Genet 1994; 88:530-534. [PMID: 24186106 DOI: 10.1007/bf01240914] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/1993] [Accepted: 08/02/1993] [Indexed: 06/02/2023]
Abstract
The effects of lodging and nitrogen rate were studied in a field trial of oilseed rapeBrassica napus L. Lodging decreased seed yield (16%) compared with a frame-raised crop. Yield decreased because of a significant reduction in each of the yield components coupled with a reduced plant population caused by stem breakage at the ground level. Lodging also reduced the final crop dry weight and harvest index. Seed yield was also lower when 200 kg ha(-1) nitrogen was applied than with 400 kg ha(-1). A general decrease in pod number m(-2), seed nuber pod(-1) and seed weight caused the lower yields. The use of 400 kg ha(-1) of nitrogen changed the contribution of the terminal raceme and individual branches with respect to seed yield. Seed nitrogn content and nitrogen yield increased at the 400 kg ha(-1), lowering both seed oil content and oil yield.
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Affiliation(s)
- N Islam
- Department of Agriculture, The University, NEI 7UR, Newcastle Upon Tyne, UK
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40
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Benjamin M, Ralphs JR, Newell RL, Evans EJ. Loss of the fibrocartilaginous lining of the intertubercular sulcus associated with rupture of the tendon of the long head of biceps brachii. J Anat 1993; 182 ( Pt 2):281-5. [PMID: 8376203 PMCID: PMC1259839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Fibrocartilage lines the intertubercular sulcus of the humerus and protects both the bone and the tendon of the long head of biceps brachii where the tendon passes through the sulcus. It provides a smooth, resilient, lubricated gliding surface on the bone. The fibrocartilage is highly metachromatic and organised into distinct superficial and deep zones. In the superficial zone, the cells are small and the fibres run parallel to the articular surface. In the deep zone, the cells are large and rounded and the coarse bundles of fibres are interwoven. In 6 of the 26 dissecting room cadavers examined the tendons were completely ruptured. In these, the fibrocartilage was replaced by loose connective tissue that resembled the synovium of the tendon sheath. The results suggest that bone fibrocartilage exhibits dynamic behaviour in response to changes in its environment, in the same manner as tendon fibrocartilage.
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Affiliation(s)
- M Benjamin
- Department of Anatomy, University of Wales College of Cardiff, UK
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41
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Abstract
The Seidel locking nail was inserted into the humeri of 20 cadavers. Subsequent dissection showed that the proximal locking screws had damaged the circumflex nerve or biceps tendon in eight of the cases.
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Affiliation(s)
- P D Evans
- Department of Traumatic and Orthopaedic Surgery, University of Wales College of Medicine, Cardiff, UK
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Abstract
To define the anatomical relationships of the nerves to the common arthroscopy portals at the elbow an arthroscope was introduced into 20 cadaver elbows and the positions of the nerves were then determined by dissection. In all cases the posterior interosseous nerve lay close to the radiohumeral joint and to the anterolateral portal. Pronation of the forearm displaced the nerve away from the arthroscope. The median nerve passed consistently within 14 mm of the arthroscope when it was introduced through the anteromedial portal. The branches supplying the superficial forearm flexor muscles were at risk.
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Benjamin M, Newell RL, Evans EJ, Ralphs JR, Pemberton DJ. The structure of the insertions of the tendons of biceps brachii, triceps and brachialis in elderly dissecting room cadavers. J Anat 1992; 180 ( Pt 2):327-32. [PMID: 1506288 PMCID: PMC1259680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The terminal portions of the tendon of brachialis, and the distal tendons of biceps brachii and triceps, were compared by routine histology. All tendons came from elderly dissecting room cadavers. There were pronounced quantitative differences between the 3 tendons in (1) the thickness of the attachment-zone fibrocartilage, (2) the thickness of cortical calcified tissue, and (3) the percentage of bone to marrow. There was significantly more uncalcified fibrocartilage at the attachment of biceps than at the other sites, reflecting greater range of movement of the tendon at this site. The thickness of cortical calcified tissue and the percentage of bone to marrow were significantly greater at the attachment of brachialis than either biceps or triceps. The large quantities of bone at the attachment of brachialis may be related more to the importance of the coronoid process in buttressing the elbow joint than to any special requirement for large amounts of calcified tissue at the tendon attachment. Near its attachment zone, the biceps tendon splits into superficial and deep laminae that are distinct from the macroscopic subdivision of this tendon. It is suggested that the lamination may facilitate the movements of pronation and supination. In support of this, the deep portion of the superficial lamina contained fibrocartilage where it rubbed against the attachment-zone of the deep lamina. In one body, the fibrocartilage of the biceps attachment-zone was subject to degenerative changes, including cell clumping and matrix fissuring.
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Affiliation(s)
- M Benjamin
- Department of Anatomy, University of Wales College of Cardiff, UK
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Benjamin M, Evans EJ, Rao RD, Findlay JA, Pemberton DJ. Quantitative differences in the histology of the attachment zones of the meniscal horns in the knee joint of man. J Anat 1991; 177:127-34. [PMID: 1769887 PMCID: PMC1260420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The attachment zones of the meniscal horns of 7 dissecting room cadavers were examined by routine histology. All the knees were devoid of gross pathological change and no discoid menisci were included. Significant differences are reported in the thickness of the zones of uncalcified fibrocartilage and cortical calcified tissue (calcified fibrocartilage and underlying lamellar bone) and in the percentage of bone:bone marrow. There was a thicker zone of uncalcified fibrocartilage and a greater quantity of calcified tissue at the horns of the lateral than the medial meniscus. The differences in uncalcified fibrocartilage were largely attributable to the posterior horns, but the variations in calcified tissue mainly reflected differences between the anterior horns. It is suggested that the greater mobility of the lateral meniscus and the blending of its anterior horn with the anterior cruciate ligament are important factors accounting for the quantitative differences in the meniscal attachment zones.
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Affiliation(s)
- M Benjamin
- Department of Anatomy, University of Wales College of Cardiff, UK
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Abstract
Finely ground powders of synthetic hydroxyapatite applied to fibroblasts in vitro reduced the total growth rate and mitotic rate of the cells and increased the number of pycnotic cells. The effect was dose related and only occurred with small particles. The small particles appear to either adhere to the cells or are phagocytosed by them and the toxic effect may be physical rather than chemical.
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Affiliation(s)
- E J Evans
- Department of Anatomy, University of Wales College, Cardiff, UK
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Evans EJ, Benjamin M, Pemberton DJ. Variations in the amount of calcified tissue at the attachments of the quadriceps tendon and patellar ligament in man. J Anat 1991; 174:145-51. [PMID: 2032930 PMCID: PMC1256050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Differences are reported in the total calcified tissue/bone marrow ratios and in the total thickness of cortical calcified tissue (lamellar bone and calcified fibrocartilage) between the attachment sites of the quadriceps tendon and the patellar ligament in man. The greatest amount of calcified tissue is at the insertion of the tendon and this is correlated with the larger force that the tendon transmits. It is concluded that differences in maximum force alone can produce a greater density of calcified tissue at ligament or tendon attachments. The similar amounts of calcified tissue at each end of the patellar ligament reflect the identical force that each attachment transmits. At the insertion of the quadriceps tendon and the 'origin' of the patellar ligament, there was more calcified tissue beneath the superficial than the deep parts of the attachment. This suggest that more force is transmitted through some parts of an attachment zone than others.
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Affiliation(s)
- E J Evans
- Department of Anatomy, University of Wales College of Cardiff
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Benjamin M, Evans EJ, Pemberton DJ. Histological studies on the triangular fibrocartilage complex of the wrist. J Anat 1990; 172:59-67. [PMID: 2272909 PMCID: PMC1257203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The triangular fibrocartilage complex of the wrist was serially sectioned for routine histology. Results from eight dissecting room cadavers show that the complex is attached to hyaline cartilage on the radius via its articular disc. In contrast, the dorsal and volar radio-ulnar ligaments attach to the radius via zones of calcified and uncalcified fibrocartilage. The articular disc is thus a wide labrum that provides an articular surface for the ulna and for the carpal bones, and the radio-ulnar ligaments strengthen the attachment of the disc to the radius. Medially, the complex divides into upper and lower laminae. Arching strands of collagen fibres emerge from the upper lamina and pass through a region of highly vascular connective tissue to be attached to the ulna between the articular cartilage on the head and that at the tip of the styloid process. Much of the ulnar attachment is via zones of calcified and uncalcified fibrocartilage which blend with the adjacent articular cartilages. Such an arrangement of tissues prevents undue wear and tear at the ulnar attachment zone during pronation and supination of the forearm. The lower lamina blends with the sheath of extensor carpi ulnaris and the ulnar collateral ligament and allows the whole complex to attach to the carpal and metacarpal bones. The meniscus homologue is a region of dense irregular connective tissue with no independent histological identity.
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Affiliation(s)
- M Benjamin
- Department of Anatomy, University of Wales College of Cardiff
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Evans EJ, Benjamin M, Pemberton DJ. Fibrocartilage in the attachment zones of the quadriceps tendon and patellar ligament of man. J Anat 1990; 171:155-62. [PMID: 2081702 PMCID: PMC1257136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Differences are reported in the quantities and distribution of uncalcified fibrocartilage at the attachment sites of the quadriceps tendon and the patellar ligament. The largest quantity of fibrocartilage was characteristic of the quadriceps tendon. A prominent wedge of fibrocartilage was seen in the proximal part of the tibial attachment of the patellar ligament, though there was no fibrocartilage in the most superficial fibres. Little fibrocartilage was seen at the patellar attachment of the patellar ligament. According to other workers, there is a similar change in angle (about 35 degrees) between the quadriceps insertion (in relation to the patella) and the tibial attachment of the patellar ligament (in relation to the tibia). However, there is virtually no change in angle at the origin of the patellar ligament (relative to the patella). Thus, fibrocartilage is least conspicuous where there is little motility near an attachment site. It is suggested that the larger amount of fibrocartilage in the quadriceps tendon compared with the tibial attachment of the patellar ligament may be related to the greater absolute size (and particularly anterior-posterior thickness) of the tendon compared with the ligament.
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Affiliation(s)
- E J Evans
- Department of Anatomy, University of Wales College of Cardiff
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Benjamin M, Evans EJ. Fibrocartilage. J Anat 1990; 171:1-15. [PMID: 2081696 PMCID: PMC1257123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- M Benjamin
- Department of Anatomy, University of Wales College of Cardiff
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Abstract
Powders of cobalt-chrome-molybdenum alloy were produced by grinding larger particles for 8 h in water, serum or joint fluid. They were administered, in low doses (0.05-0.5 mg/ml) for 1-6 d, to human dermal fibroblasts in vitro. Particles were ground in a biological fluid in order to simulate conditions in an artificial hip joint. Such particles adhered to, or were phagocytosed by, the cells far less than those ground in water. The toxicity of the alloy was linked with a failure of test cells to grow as quickly as the controls - particles ground in water were the most toxic.
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Affiliation(s)
- E J Evans
- Department of Anatomy, University College, Cardiff, Wales
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