1
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Jiu J, Liu H, Li D, Li J, Liu L, Yang W, Yan L, Li S, Zhang J, Li X, Li JJ, Wang B. 3D bioprinting approaches for spinal cord injury repair. Biofabrication 2024; 16:032003. [PMID: 38569491 DOI: 10.1088/1758-5090/ad3a13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 04/03/2024] [Indexed: 04/05/2024]
Abstract
Regenerative healing of spinal cord injury (SCI) poses an ongoing medical challenge by causing persistent neurological impairment and a significant socioeconomic burden. The complexity of spinal cord tissue presents hurdles to successful regeneration following injury, due to the difficulty of forming a biomimetic structure that faithfully replicates native tissue using conventional tissue engineering scaffolds. 3D bioprinting is a rapidly evolving technology with unmatched potential to create 3D biological tissues with complicated and hierarchical structure and composition. With the addition of biological additives such as cells and biomolecules, 3D bioprinting can fabricate preclinical implants, tissue or organ-like constructs, andin vitromodels through precise control over the deposition of biomaterials and other building blocks. This review highlights the characteristics and advantages of 3D bioprinting for scaffold fabrication to enable SCI repair, including bottom-up manufacturing, mechanical customization, and spatial heterogeneity. This review also critically discusses the impact of various fabrication parameters on the efficacy of spinal cord repair using 3D bioprinted scaffolds, including the choice of printing method, scaffold shape, biomaterials, and biological supplements such as cells and growth factors. High-quality preclinical studies are required to accelerate the translation of 3D bioprinting into clinical practice for spinal cord repair. Meanwhile, other technological advances will continue to improve the regenerative capability of bioprinted scaffolds, such as the incorporation of nanoscale biological particles and the development of 4D printing.
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Affiliation(s)
- Jingwei Jiu
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- Department of Orthopaedic Surgery, Shanxi Medical University Second Affiliated Hospital, Taiyuan, People's Republic of China
| | - Haifeng Liu
- Department of Orthopaedic Surgery, Shanxi Medical University Second Affiliated Hospital, Taiyuan, People's Republic of China
| | - Dijun Li
- Department of Orthopaedic Surgery, Shanxi Medical University Second Affiliated Hospital, Taiyuan, People's Republic of China
| | - Jiarong Li
- School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Lu Liu
- School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Wenjie Yang
- School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Lei Yan
- Department of Orthopaedic Surgery, Shanxi Medical University Second Affiliated Hospital, Taiyuan, People's Republic of China
| | - Songyan Li
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Jing Zhang
- Department of Emergency Surgery, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550001, People's Republic of China
| | - Xiaoke Li
- Department of Orthopaedic Surgery, Shanxi Medical University Second Affiliated Hospital, Taiyuan, People's Republic of China
| | - Jiao Jiao Li
- School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Bin Wang
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
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2
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Venter JC, Glass JI, Hutchison CA, Vashee S. Synthetic chromosomes, genomes, viruses, and cells. Cell 2022; 185:2708-2724. [DOI: 10.1016/j.cell.2022.06.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 10/17/2022]
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3
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Hazegh Nikroo A, Lemmens LJM, Wezeman T, Ottmann C, Merkx M, Brunsveld L. Switchable Control of Scaffold Protein Activity via Engineered Phosphoregulated Autoinhibition. ACS Synth Biol 2022; 11:2464-2472. [PMID: 35765959 PMCID: PMC9295147 DOI: 10.1021/acssynbio.2c00122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Scaffold proteins
operate as organizing hubs to enable high-fidelity
signaling, fulfilling crucial roles in the regulation of cellular
processes. Bottom-up construction of controllable scaffolding platforms
is attractive for the implementation of regulatory processes in synthetic
biology. Here, we present a modular and switchable synthetic scaffolding
system, integrating scaffold-mediated signaling with switchable kinase/phosphatase
input control. Phosphorylation-responsive inhibitory peptide motifs
were fused to 14-3-3 proteins to generate dimeric protein scaffolds
with appended regulatory peptide motifs. The availability of the scaffold
for intermolecular partner protein binding could be lowered up to
35-fold upon phosphorylation of the autoinhibition motifs, as demonstrated
using three different kinases. In addition, a hetero-bivalent autoinhibitory
platform design allowed for dual-kinase input regulation of scaffold
activity. Reversibility of the regulatory platform was illustrated
through phosphatase-controlled abrogation of autoinhibition, resulting
in full recovery of 14-3-3 scaffold activity.
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Affiliation(s)
- Arjan Hazegh Nikroo
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
| | - Lenne J M Lemmens
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
| | - Tim Wezeman
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
| | - Christian Ottmann
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
| | - Maarten Merkx
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
| | - Luc Brunsveld
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, Eindhoven, 5612AZ Arizona, The Netherlands
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4
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Grandel NE, Reyes Gamas K, Bennett MR. Control of synthetic microbial consortia in time, space, and composition. Trends Microbiol 2021; 29:1095-1105. [PMID: 33966922 DOI: 10.1016/j.tim.2021.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 02/07/2023]
Abstract
While synthetic microbial systems are becoming increasingly complicated, single-strain systems cannot match the complexity of their multicellular counterparts. Such complexity, however, is much more difficult to control. Recent advances have increased our ability to control temporal, spatial, and community compositional organization, including modular adhesive systems, strain growth relationships, and asymmetric cell division. While these systems generally work independently, combining them into unified systems has proven difficult. Once such unification is proven successful we will unlock a new frontier of synthetic biology and open the door to the creation of synthetic biological systems with true multicellularity.
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Affiliation(s)
- Nicolas E Grandel
- Graduate Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, TX, USA
| | - Kiara Reyes Gamas
- Graduate Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, TX, USA
| | - Matthew R Bennett
- Department of Biosciences, Rice University, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA.
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5
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Abstract
Cells are the basic units of life, and can be mimicked to create artificial analogs enabling the investigation of cellular mechanisms under controlled conditions. Building biomimetic systems ranging from proto-cells to cell-like objects such as compartment membranes can be achieved by collecting biobricks that self-assemble to build simplified models performing specific functions. Hence, scientists can develop and optimize new synthetic cells with biological functions by taking inspiration from nature and exploiting the advantages of synthetic biology. However, the bottom-down approach is not restricted to the basic principles of biological cells, and new mimicry systems can be designed starting with a combination of living and non-living simple molecules to focus on a cellular machinery function. In recent years, microfluidic devices have been well established to engineer bioarchitecture models resembling cell-like structures involving vesicles, compartmentalization, synthetic membranes, and the chip itself as a synthetic cell. This review aims to highlight the role of biological cells and their impact on inspiring the development of biomimetic models. The combination of the principles of synthetic biology with microfluidic technology represents the newly-introduced field of synthetic cells and synthetic membranes that can be further exploited in diagnostic and therapeutic applications.
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6
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Abstract
Engineering biological systems for the production of biofuels and bioproducts holds great potential to transform the bioeconomy, but often requires laborious, time-consuming design-build-test cycles. For decades cell-free systems have offered quick and facile approaches to study enzymes with hopes of informing cellular processes, mainly in the form of purified single-enzyme activity assays. Over the past 20 years, cell-free systems have grown to include multienzymatic systems, both purified and crude. By decoupling cellular growth objectives from enzyme pathway engineering objectives, cell-free systems provide a controllable environment to direct substrates toward a single, desired product. Cell-free approaches are being developed for prototyping and for biomanufacturing. In prototyping applications, the idea is to use cell-free systems to test and optimize biosynthetic pathways before implementation in live cells and scale-up. We present a detailed method for the generation of crude lysates for cell-free pathway prototyping, mix-and-match cell-free metabolic engineering using preenriched lysates, and cell-free protein synthesis driven cell-free metabolic engineering. The cell-free synthetic biology methods described herein are generalizable to any biosynthetic pathway of interest and provide a powerful approach to building pathways in crude lysates for the purpose of prototyping. The foundational principle of the presented approach is that we can construct discrete metabolic pathways through modular assembly of cell-free lysates containing enzyme components produced by overexpression in the lysate chassis strain or by cell-free protein synthesis (in vitro production). Overall, the modular and cell-free nature of our pathway prototyping framework is poised to facilitate multiplexed, automated study of biosynthetic pathways to inform systems-level cellular design.
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Affiliation(s)
- Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, United States; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, United States; Center for Synthetic Biology, Northwestern University, Evanston, IL, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, United States; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, United States; Center for Synthetic Biology, Northwestern University, Evanston, IL, United States; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, United States; Simpson Querrey Institute, Northwestern University, Chicago, IL, United States.
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7
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Rosenthal K, Oehling V, Dusny C, Schmid A. Beyond the bulk: disclosing the life of single microbial cells. FEMS Microbiol Rev 2017; 41:751-780. [PMID: 29029257 PMCID: PMC5812503 DOI: 10.1093/femsre/fux044] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 09/08/2017] [Indexed: 01/08/2023] Open
Abstract
Microbial single cell analysis has led to discoveries that are beyond what can be resolved with population-based studies. It provides a pristine view of the mechanisms that organize cellular physiology, unbiased by population heterogeneity or uncontrollable environmental impacts. A holistic description of cellular functions at the single cell level requires analytical concepts beyond the miniaturization of existing technologies, defined but uncontrolled by the biological system itself. This review provides an overview of the latest advances in single cell technologies and demonstrates their potential. Opportunities and limitations of single cell microbiology are discussed using selected application-related examples.
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Affiliation(s)
- Katrin Rosenthal
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
- Laboratory of Chemical Biotechnology, Department of Biochemical & Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Verena Oehling
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
- Laboratory of Chemical Biotechnology, Department of Biochemical & Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Christian Dusny
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - Andreas Schmid
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
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8
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Cheng JK, Alper HS. Transcriptomics-Guided Design of Synthetic Promoters for a Mammalian System. ACS Synth Biol 2016; 5:1455-1465. [PMID: 27268512 DOI: 10.1021/acssynbio.6b00075] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Despite recent advances in improving titers for therapeutic proteins such as antibodies to the 10 g/L scale, these high yields can only be achieved in select mammalian hosts. Regardless of the host or product, strong promoters are required to obtain high levels of transgene expression. However, the promoters employed to drive this expression are rather limited in variety and are usually either viral-derived or screened empirically during vector design. To begin to move away from viral parts, we employed a more systematic approach to identify and design new synthetic promoters using endogenous elements. To do so, we established a workflow to design these elements by (1) analyzing the transcriptomics profile of a specific cell line under a desired, representative cell culture condition, (2) identifying key genetic motifs using bioinformatics that can be used to rationally construct synthetic promoters, (3) building synthetic promoters using conventional DNA synthesis and molecular biology techniques, and (4) evaluating the performance of these synthetic promoters using model proteins. The resulting promoters perform comparably to the hCMV IE promoter variants tested, but with endogenous components. During this design-build-test cycle we also investigated the underlying design rules for transcription factor binding site arrangement in synthetic promoters. Overall, this approach of using an "omics-guided" workflow for designing synthetic promoters facilitates the construction of high expression vectors for immediate use in current production hosts.
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Affiliation(s)
- Joseph K. Cheng
- Department
of Chemical Engineering, The University of Texas at Austin, 200
E Dean Keeton Street Stop C0400, Austin, Texas 78712, United States
| | - Hal S. Alper
- Department
of Chemical Engineering, The University of Texas at Austin, 200
E Dean Keeton Street Stop C0400, Austin, Texas 78712, United States
- Institute
for Cellular and Molecular Biology The University of Texas at Austin, 2500
Speedway Avenue, Austin, Texas 78712, United States
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9
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Karim AS, Jewett MC. A cell-free framework for rapid biosynthetic pathway prototyping and enzyme discovery. Metab Eng 2016; 36:116-126. [PMID: 26996382 DOI: 10.1016/j.ymben.2016.03.002] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/12/2016] [Accepted: 03/10/2016] [Indexed: 10/22/2022]
Abstract
Speeding up design-build-test (DBT) cycles is a fundamental challenge facing biochemical engineering. To address this challenge, we report a new cell-free protein synthesis driven metabolic engineering (CFPS-ME) framework for rapid biosynthetic pathway prototyping. In our framework, cell-free cocktails for synthesizing target small molecules are assembled in a mix-and-match fashion from crude cell lysates either containing selectively enriched pathway enzymes from heterologous overexpression or directly producing pathway enzymes in lysates by CFPS. As a model, we apply our approach to n-butanol biosynthesis showing that Escherichia coli lysates support a highly active 17-step CoA-dependent n-butanol pathway in vitro. The elevated degree of flexibility in the cell-free environment allows us to manipulate physiochemical conditions, access enzymatic nodes, discover new enzymes, and prototype enzyme sets with linear DNA templates to study pathway performance. We anticipate that CFPS-ME will facilitate efforts to define, manipulate, and understand metabolic pathways for accelerated DBT cycles without the need to reengineer organisms.
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Affiliation(s)
- Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Tech E-136, Evanston, IL 60208, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Tech E-136, Evanston, IL 60208, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA; Simpson Querrey Institute, Northwestern University, Chicago, IL 60611, USA.
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10
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van Roekel HWH, Meijer LHH, Masroor S, Félix Garza ZC, Estévez-Torres A, Rondelez Y, Zagaris A, Peletier MA, Hilbers PAJ, de Greef TFA. Automated design of programmable enzyme-driven DNA circuits. ACS Synth Biol 2015; 4:735-45. [PMID: 25365785 DOI: 10.1021/sb500300d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Molecular programming allows for the bottom-up engineering of biochemical reaction networks in a controlled in vitro setting. These engineered biochemical reaction networks yield important insight in the design principles of biological systems and can potentially enrich molecular diagnostic systems. The DNA polymerase-nickase-exonuclease (PEN) toolbox has recently been used to program oscillatory and bistable biochemical networks using a minimal number of components. Previous work has reported the automatic construction of in silico descriptions of biochemical networks derived from the PEN toolbox, paving the way for generating networks of arbitrary size and complexity in vitro. Here, we report an automated approach that further bridges the gap between an in silico description and in vitro realization. A biochemical network of arbitrary complexity can be globally screened for parameter values that display the desired function and combining this approach with robustness analysis further increases the chance of successful in vitro implementation. Moreover, we present an automated design procedure for generating optimal DNA sequences, exhibiting key characteristics deduced from the in silico analysis. Our in silico method has been tested on a previously reported network, the Oligator, and has also been applied to the design of a reaction network capable of displaying adaptation in one of its components. Finally, we experimentally characterize unproductive sequestration of the exonuclease to phosphorothioate protected ssDNA strands. The strong nonlinearities in the degradation of active components caused by this unintended cross-coupling are shown computationally to have a positive effect on adaptation quality.
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Affiliation(s)
| | | | | | | | - André Estévez-Torres
- Laboratoire
de Photonique et de Nanostructures, CNRS, route de Nozay, 91460 Marcoussis, France
| | - Yannick Rondelez
- LIMMS/CNRS-IIS,
Institute of Industrial Science, University of Tokyo, Komaba 4-6-1
Meguro-ku, Tokyo 153-8505, Japan
| | - Antonios Zagaris
- Department
of Applied Mathematics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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11
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Wells DK, Chuang Y, Knapp LM, Brockmann D, Kath WL, Leonard JN. Spatial and functional heterogeneities shape collective behavior of tumor-immune networks. PLoS Comput Biol 2015; 11:e1004181. [PMID: 25905470 PMCID: PMC4408028 DOI: 10.1371/journal.pcbi.1004181] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 02/06/2015] [Indexed: 12/31/2022] Open
Abstract
Tumor growth involves a dynamic interplay between cancer cells and host cells, which collectively form a tumor microenvironmental network that either suppresses or promotes tumor growth under different conditions. The transition from tumor suppression to tumor promotion is mediated by a tumor-induced shift in the local immune state, and despite the clinical challenge this shift poses, little is known about how such dysfunctional immune states are initiated. Clinical and experimental observations have indicated that differences in both the composition and spatial distribution of different cell types and/or signaling molecules within the tumor microenvironment can strongly impact tumor pathogenesis and ultimately patient prognosis. How such “functional” and “spatial” heterogeneities confer such effects, however, is not known. To investigate these phenomena at a level currently inaccessible by direct observation, we developed a computational model of a nascent metastatic tumor capturing salient features of known tumor-immune interactions that faithfully recapitulates key features of existing experimental observations. Surprisingly, over a wide range of model formulations, we observed that heterogeneity in both spatial organization and cell phenotype drove the emergence of immunosuppressive network states. We determined that this observation is general and robust to parameter choice by developing a systems-level sensitivity analysis technique, and we extended this analysis to generate other parameter-independent, experimentally testable hypotheses. Lastly, we leveraged this model as an in silico test bed to evaluate potential strategies for engineering cell-based therapies to overcome tumor associated immune dysfunction and thereby identified modes of immune modulation predicted to be most effective. Collectively, this work establishes a new integrated framework for investigating and modulating tumor-immune networks and provides insights into how such interactions may shape early stages of tumor formation. Over the course of tumor growth, cancer cells interact with normal cells via processes that are difficult to understand by experiment alone. This challenge is particularly pronounced at early stages of tumor formation, when experimental observation is most limited. Elucidating such interactions could inform both understanding of cancer and clinical practice. To address this need we developed a computational model capturing the current understanding of how individual metastatic tumor cells and immune cells sense and contribute to the tumor environment, which in turn enabled us to investigate the complex, collective behavior of these systems. Surprisingly, we discovered that tumor escape from immune control was enhanced by the existence of small differences (or heterogeneities) in the responses of individual immune cells to their environment, as well as by heterogeneities in the way that cells and the molecules they secrete are arranged in space. These conclusions held true over a range of model formulations, suggesting that this is a general feature of these tumor-immune networks. Finally, we used this model as a test bed to evaluate potential strategies for enhancing immunological control of early tumors, ultimately predicting that specifically modulating tumor-associated immune dysfunction may be more effective than simply enhanced tumor killing.
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Affiliation(s)
- Daniel K. Wells
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois, United States of America
- Northwestern University Physical Sciences-Oncology Center, Evanston, Illinois, United States of America
| | - Yishan Chuang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Louis M. Knapp
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Dirk Brockmann
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois, United States of America
- Northwestern University Physical Sciences-Oncology Center, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, United States of America
- Northwestern Institute on Complex Science, Northwestern University, Evanston, Illinois, United States of America
- Institute for Theoretical Biology, Humboldt University Berlin, Berlin, Germany
| | - William L. Kath
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois, United States of America
- Northwestern University Physical Sciences-Oncology Center, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, United States of America
- Northwestern Institute on Complex Science, Northwestern University, Evanston, Illinois, United States of America
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, United States of America
| | - Joshua N. Leonard
- Northwestern University Physical Sciences-Oncology Center, Evanston, Illinois, United States of America
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, United States of America
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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12
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Liu Y, Fritz BR, Anderson MJ, Schoborg JA, Jewett MC. Characterizing and alleviating substrate limitations for improved in vitro ribosome construction. ACS Synth Biol 2015; 4:454-62. [PMID: 25079899 DOI: 10.1021/sb5002467] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complete cell-free synthesis of ribosomes could make possible minimal cell projects and the construction of variant ribosomes with new functions. Recently, we reported the development of an integrated synthesis, assembly, and translation (iSAT) method for in vitro construction of Escherichia coli ribosomes. iSAT allows simultaneous rRNA synthesis, ribosome assembly, and reporter protein expression as a measure of ribosome activity. Here, we explore causes of iSAT reaction termination to improve efficiency and yields. We discovered that phosphoenolpyruvate (PEP), the secondary energy substrate, and nucleoside triphosphates (NTPs) were rapidly degraded during iSAT reactions. In turn, we observed a significant drop in the adenylate energy charge and termination of protein synthesis. Furthermore, we identified that the accumulation of inorganic phosphate is inhibitory to iSAT. Fed-batch replenishment of PEP and magnesium glutamate (to offset the inhibitory effects of accumulating phosphate by repeated additions of PEP) prior to energy depletion prolonged the reaction duration 2-fold and increased superfolder green fluorescent protein (sfGFP) yield by ~75%. By adopting a semi-continuous method, where passive diffusion enables substrate replenishment and byproduct removal, we prolonged iSAT reaction duration 5-fold and increased sfGFP yield 7-fold to 7.5 ± 0.7 μmol L(-1). This protein yield is the highest ever reported for iSAT reactions. Our results underscore the critical role energy substrates play in iSAT and highlight the importance of understanding metabolic processes that influence substrate depletion for cell-free synthetic biology.
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Affiliation(s)
- Yi Liu
- Interdepartmental Biological Sciences Graduate
Program, ‡Chemistry of Life
Processes Institute, §Department of Chemical and Biological Engineering, ∥Member, Robert H. Lurie Comprehensive
Cancer Center, ⊥Affiliate Member, Institute for Bionanotechnology in Medicine, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Brian R. Fritz
- Interdepartmental Biological Sciences Graduate
Program, ‡Chemistry of Life
Processes Institute, §Department of Chemical and Biological Engineering, ∥Member, Robert H. Lurie Comprehensive
Cancer Center, ⊥Affiliate Member, Institute for Bionanotechnology in Medicine, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Mark J. Anderson
- Interdepartmental Biological Sciences Graduate
Program, ‡Chemistry of Life
Processes Institute, §Department of Chemical and Biological Engineering, ∥Member, Robert H. Lurie Comprehensive
Cancer Center, ⊥Affiliate Member, Institute for Bionanotechnology in Medicine, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Jennifer A. Schoborg
- Interdepartmental Biological Sciences Graduate
Program, ‡Chemistry of Life
Processes Institute, §Department of Chemical and Biological Engineering, ∥Member, Robert H. Lurie Comprehensive
Cancer Center, ⊥Affiliate Member, Institute for Bionanotechnology in Medicine, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael C. Jewett
- Interdepartmental Biological Sciences Graduate
Program, ‡Chemistry of Life
Processes Institute, §Department of Chemical and Biological Engineering, ∥Member, Robert H. Lurie Comprehensive
Cancer Center, ⊥Affiliate Member, Institute for Bionanotechnology in Medicine, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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13
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Chizzolini F, Forlin M, Cecchi D, Mansy SS. Gene position more strongly influences cell-free protein expression from operons than T7 transcriptional promoter strength. ACS Synth Biol 2014; 3:363-71. [PMID: 24283192 DOI: 10.1021/sb4000977] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cell-free transcription-translation of multiple proteins typically exploits genes placed behind strong transcriptional promoters that reside on separate pieces of DNA so that protein levels can be easily controlled by changing DNA template concentration. However, such systems are not amenable to the construction of artificial cells with a synthetic genome. Herein, we evaluated the activity of a series of T7 transcriptional promoters by monitoring the fluorescence arising from a genetically encoded Spinach aptamer. Subsequently the influences of transcriptional promoter strength on fluorescent protein synthesis from one, two, and three gene operons were assessed. It was found that transcriptional promoter strength was more effective at controlling RNA synthesis than protein synthesis in vitro with the PURE system. Conversely, the gene position within the operon strongly influenced protein synthesis but not RNA synthesis.
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Affiliation(s)
- Fabio Chizzolini
- CIBIO, University of Trento, via delle Regole 101, 38123 Mattarello, Italy
| | - Michele Forlin
- CIBIO, University of Trento, via delle Regole 101, 38123 Mattarello, Italy
| | - Dario Cecchi
- CIBIO, University of Trento, via delle Regole 101, 38123 Mattarello, Italy
| | - Sheref S. Mansy
- CIBIO, University of Trento, via delle Regole 101, 38123 Mattarello, Italy
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Dudek RM, Chuang Y, Leonard JN. Engineered cell-based therapies: a vanguard of design-driven medicine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 844:369-91. [PMID: 25480651 DOI: 10.1007/978-1-4939-2095-2_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Engineered cell-based therapies are uniquely capable of performing sophisticated therapeutic functions in vivo, and this strategy is yielding promising clinical benefits for treating cancer. In this review, we discuss key opportunities and challenges for engineering customized cellular functions using cell-based therapy for cancer as a representative case study. We examine the historical development of chimeric antigen receptor (CAR) therapies as an illustration of the engineering design cycle. We also consider the potential roles that the complementary disciplines of systems biology and synthetic biology may play in realizing safe and effective treatments for a broad range of patients and diseases. In particular, we discuss how systems biology may facilitate both fundamental research and clinical translation, and we describe how the emerging field of synthetic biology is providing novel modalities for building customized cellular functions to overcome existing clinical barriers. Together, these approaches provide a powerful set of conceptual and experimental tools for transforming information into understanding, and for translating understanding into novel therapeutics to establish a new framework for design-driven medicine.
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Affiliation(s)
- Rachel M Dudek
- Northwestern University, 2145 Sheridan Road, Technological Institute, Rm. E136, Evanston, IL, 60208-3120, USA,
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15
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Calvert J. Engineering Biology and Society: Reflections on Synthetic Biology. SCIENCE TECHNOLOGY AND SOCIETY 2013. [DOI: 10.1177/0971721813498501] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Synthetic biology, according to some definitions, is the attempt to make biology into an engineering discipline. I ask what is meant by this objective, which seems to have excited and energised many people and encouraged them to start working in the field. I show how synthetic biologists make a point of distinguishing their work from previous genetic ‘engineering’, which is described as bespoke and artisan. I examine synthetic biologists’ accounts of the differences between biology and engineering, which often oppose comprehension to construction. I argue that synthetic biology, like other branches of engineering, aims to meet recognised needs, and to make the world more manipulable and controllable. But there are tensions within the field—some synthetic biologists have reservations about the extent to which biology can be engineered, and ask whether it is necessary to develop a new type of engineering when working with living systems. After exploring these debates, I turn to some of the broader consequences of making biology easier to engineer, particularly the deskilling and democratisation of the technology. I end by arguing that because synthetic biologists are skilled at bringing together both technical and social forces, they are appropriately described as ‘heterogeneous engineers’.
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Affiliation(s)
- Jane Calvert
- Jane Calvert, Science, Technology and Innovation Studies, University of Edinburgh, Old Surgeons’ Hall, Edinburgh, EH1 1LZ, UK
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16
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Kogge W, Richter M. Synthetic biology and its alternatives. Descartes, Kant and the idea of engineering biological machines. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2013; 44:181-189. [PMID: 23623436 DOI: 10.1016/j.shpsc.2013.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The engineering-based approach of synthetic biology is characterized by an assumption that 'engineering by design' enables the construction of 'living machines'. These 'machines', as biological machines, are expected to display certain properties of life, such as adapting to changing environments and acting in a situated way. This paper proposes that a tension exists between the expectations placed on biological artefacts and the notion of producing such systems by means of engineering; this tension makes it seem implausible that biological systems, especially those with properties characteristic of living beings, can in fact be produced using the specific methods of engineering. We do not claim that engineering techniques have nothing to contribute to the biotechnological construction of biological artefacts. However, drawing on Descartes's and Kant's thinking on the relationship between the organism and the machine, we show that it is considerably more plausible to assume that distinctively biological artefacts emerge within a paradigm different from the paradigm of the Cartesian machine that underlies the engineering approach. We close by calling for increased attention to be paid to approaches within molecular biology and chemistry that rest on conceptions different from those of synthetic biology's engineering paradigm.
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Affiliation(s)
- Werner Kogge
- Freie Universität Berlin, Institute of Philosophy, Habelschwerdter Allee 30, 14195 Berlin, Germany.
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17
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Cell-free biology: exploiting the interface between synthetic biology and synthetic chemistry. Curr Opin Biotechnol 2012; 23:672-8. [PMID: 22483202 DOI: 10.1016/j.copbio.2012.02.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 02/16/2012] [Accepted: 02/20/2012] [Indexed: 12/12/2022]
Abstract
Just as synthetic organic chemistry once revolutionized the ability of chemists to build molecules (including those that did not exist in nature) following a basic set of design rules, cell-free synthetic biology is beginning to provide an improved toolbox and faster process for not only harnessing but also expanding the chemistry of life. At the interface between chemistry and biology, research in cell-free synthetic systems is proceeding in two different directions: using synthetic biology for synthetic chemistry and using synthetic chemistry to reprogram or mimic biology. In the coming years, the impact of advances inspired by these approaches will make possible the synthesis of nonbiological polymers having new backbone compositions, new chemical properties, new structures, and new functions.
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18
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Hodgman CE, Jewett MC. Cell-free synthetic biology: thinking outside the cell. Metab Eng 2011; 14:261-9. [PMID: 21946161 DOI: 10.1016/j.ymben.2011.09.002] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/19/2011] [Accepted: 09/09/2011] [Indexed: 01/19/2023]
Abstract
Cell-free synthetic biology is emerging as a powerful approach aimed to understand, harness, and expand the capabilities of natural biological systems without using intact cells. Cell-free systems bypass cell walls and remove genetic regulation to enable direct access to the inner workings of the cell. The unprecedented level of control and freedom of design, relative to in vivo systems, has inspired the rapid development of engineering foundations for cell-free systems in recent years. These efforts have led to programmed circuits, spatially organized pathways, co-activated catalytic ensembles, rational optimization of synthetic multi-enzyme pathways, and linear scalability from the micro-liter to the 100-liter scale. It is now clear that cell-free systems offer a versatile test-bed for understanding why nature's designs work the way they do and also for enabling biosynthetic routes to novel chemicals, sustainable fuels, and new classes of tunable materials. While challenges remain, the emergence of cell-free systems is poised to open the way to novel products that until now have been impractical, if not impossible, to produce by other means.
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Affiliation(s)
- C Eric Hodgman
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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19
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Connecting the virtual world of computers to the real world of medicinal chemistry. Future Med Chem 2011; 3:399-403. [PMID: 21452976 DOI: 10.4155/fmc.11.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Drug discovery involves the simultaneous optimization of chemical and biological properties, usually in a single small molecule, which modulates one of nature's most complex systems: the balance between human health and disease. The increased use of computer-aided methods is having a significant impact on all aspects of the drug-discovery and development process and with improved methods and ever faster computers, computer-aided molecular design will be ever more central to the discovery process.
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