Genome editing technologies to fight infectious diseases

Genome editing by programmable nucleases represents a promising tool that could be exploited to develop new therapeutic strategies to fight infectious diseases. These nucleases, such as zinc-finger nucleases, transcription activator-like effector nucleases, clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein 9 (Cas9) and homing endonucleases, are molecular scissors that can be targeted at predetermined loci in order to modify the genome sequence of an organism. Areas covered: By perturbing genomic DNA at predetermined loci, programmable nucleases can be used as antiviral and antimicrobial treatment. This approach includes targeting of essential viral genes or viral sequences able, once mutated, to inhibit viral replication; repurposing of CRISPR-Cas9 system for lethal self-targeting of bacteria; targeting antibiotic-resistance and virulence genes in bacteria, fungi, and parasites; engineering arthropod vectors to prevent vector-borne infections. Expert commentary: While progress has been done in demonstrating the feasibility of using genome editing as antimicrobial strategy, there are still many hurdles to overcome, such as the risk of off-target mutations, the raising of escape mutants, and the inefficiency of delivery methods, before translating results from preclinical studies into clinical applications

CRISPR as a Driving Force: The Model T of Biotechnology

The CRISPR system for gene editing can break, repair, and replace targeted sections of DNA. Although CRISPR gene editing has important therapeutic potential, it raises several ethical concerns. Some bioethicists worry CRISPR is a prelude to a dystopian future, while others maintain it should not be feared because it is analogous to past biotechnologies. In the scientific literature, CRISPR is often discussed as a revolutionary technology. In this paper we unpack the framing of CRISPR as a revolutionary technology and contrast it with framing it as a value-threatening biotechnology or business-as-usual. By drawing on a comparison between CRISPR and the Ford Model T, we argue CRISPR is revolutionary as a product, process, and as a force for social change. This characterization of CRISPR offers important conceptual clarity to the existing debates surrounding CRISPR. In particular, conceptualizing CRISPR as a revolutionary technology structures regulatory goals with respect to this new technology. Revolutionary technologies have characteristic patterns of implementation, entrenchment, and social impact. As such, early identification of technologies as revolutionary may help construct more nuanced and effective ethical frameworks for public policy

Expanding the CRISPR Toolbox in Zebrafish for Studying Development and Disease

The study of model organisms has revolutionized our understanding of the mechanisms underlying normal development, adult homeostasis, and human disease. Much of what we know about gene function in model organisms (and its application to humans) has come from gene knockouts: the ability to show analogous phenotypes upon gene inactivation in animal models. The zebrafish (Danio rerio) has become a popular model organism for many reasons, including the fact that it is amenable to various forms of genetic manipulation. The RNA-guided CRISPR/Cas9-mediated targeted mutagenesis approaches have provided powerful tools to manipulate the genome toward developing new disease models and understanding the pathophysiology of human diseases. CRISPR-based approaches are being used for the generation of both knockout and knock-in alleles, and also for applications including transcriptional modulation, epigenome editing, live imaging of the genome, and lineage tracing. Currently, substantial effort is being made to improve the specificity of Cas9, and to expand the target coverage of the Cas9 enzymes. Novel types of naturally occurring CRISPR systems [Cas12a (Cpf1); engineered variants of Cas9, such as xCas9 and SpCas9-NG], are being studied and applied to genome editing. Since the majority of pathogenic mutations are single point mutations, development of base editors to convert C:G to T:A or A:T to G:C has further strengthened the CRISPR toolbox. In this review, we provide an overview of the increasing number of novel CRISPR-based tools and approaches, including lineage tracing and base editing

CRISPR/Cas9‐mediated genome editing: from basic research to translational medicine

The recent development of the CRISPR/Cas9 system as an efficient and accessible programmable genome-editing tool has revolutionized basic science research. CRISPR/Cas9 system-based technologies have armed researchers with new powerful tools to unveil the impact of genetics on disease development by enabling the creation of precise cellular and animal models of human diseases. The therapeutic potential of these technologies is tremendous, particularly in gene therapy, in which a patient-specific mutation is genetically corrected in order to treat human diseases that are untreatable with conventional therapies. However, the translation of CRISPR/Cas9 into the clinics will be challenging, since we still need to improve the efficiency, specificity and delivery of this technology. In this review, we focus on several in vitro, in vivo and ex vivo applications of the CRISPR/Cas9 system in human disease-focused research, explore the potential of this technology in translational medicine and discuss some of the major challenges for its future use in patients.Portuguese Foundation for Science and Technology: UID/BIM/04773/2013 1334 Spanish Ministry of Science, Innovation and Universities RTI2018-094629-B-I00 Portuguese Foundation for Science and Technology SFRH/BPD/100434/2014 European Union (EU) 748585 LPCC-NRS/Terry Fox grantsinfo:eu-repo/semantics/publishedVersio

33 - Identification of Proteins that Regulate CRISPR DNA Uptake of Pyrococcus furiosus

The CRISPR-Cas (Clustered Regularly Interspace Short Palindromic Repeats-CRISPR associated) system is a prokaryotic, adaptive immune system used by bacterial and archaeal organism to fight infections by viruses and other harmful invasive DNAs. These prokaryotic CRISPR-Cas immune systems have been exploited as powerful genome editing tools that work many different organisms and cells including humans. The newly developed CRISPR-based technologies are transforming medicine and science and have been used in research applications for developing cures for certain cancers, HIV, hemophilia, etc. The function of the CRISPR-Cas systems follow three basis steps: (1) adaptation (invading DNA is integrated into the host genome at CRISPR locus), (2) crRNA biogenesis (the CRISPR locus creates mature CRISPR RNAs (crRNA)), and (3) invader silencing (mature crRNAs are associated with Cas protein nucleases that silence future foreign invaders). This research focuses on the molecular mechanisms of the first step in the pathway, adaptation. It is known that two proteins, Cas1 and Cas2, are universally conserved among all active CRISPR-Cas systems and are involved in adaptation, specifically the integration of DNA into the CRISPR locus. By using the model organism Pyrococcus furiosus, a hyperthermophilic archaeaon, this research tests potential roles for many candidate proteins that are hypothesized to regulate DNA acquisition and/or modulate the uptake of properly sized and oriented DNA fragments into the CRISPR genome. Identifying proteins that control uptake of DNA and CRISPR loci contribute to CRISPR-Cas systems to aid in the applications it provides, such as its molecular timeline and the genomic editing for diseases

The physicist's guide to one of biotechnology's hottest new topics: CRISPR-Cas

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) constitute a multi-functional, constantly evolving immune system in bacteria and archaea cells. A heritable, molecular memory is generated of phage, plasmids, or other mobile genetic elements that attempt to attack the cell. This memory is used to recognize and interfere with subsequent invasions from the same genetic elements. This versatile prokaryotic tool has also been used to advance applications in biotechnology. Here we review a large body of CRISPR-Cas research to explore themes of evolution and selection, population dynamics, horizontal gene transfer, specific and cross-reactive interactions, cost and regulation, non-immunological CRISPR functions that boost host cell robustness, as well as applicable mechanisms for efficient and specific genetic engineering. We offer future directions that can be addressed by the physics community. Physical understanding of the CRISPR-Cas system will advance uses in biotechnology, such as developing cell lines and animal models, cell labeling and information storage, combatting antibiotic resistance, and human therapeutics.Comment: 75 pages, 15 figures, Physical Biology (2018

The Failure of Federal Biotechnology Regulation

The recent court case and state ballot measures regarding mandatory labels for Genetically Modified Organisms (“GMOs”) suggest the need for a deeper conversation about the federal framework for regulating biotechnology. What is it about GMOs that consumers feel they have the “right to know?” Why has a generation of federal biotechnology regulation failed to satisfy consumer concerns? Are those concerns irrational, or is the regulatory structure inadequate? This Article argues that many consumer concerns underlying the labeling movement raise important scientific and extra- scientific questions that have been apparent since the advent of the technology in the 1980s. Moreover, these concerns persist because the Coordinated Framework for Regulation of Biotechnology has failed to respond to them effectively. The Coordinated Framework was based on statutes that pre-existed the technology and thus poorly fit the unique risks of genetic engineering. Today, genetic engineering is on the verge of a radical shift in technology, a shift that has already begun to burst the seams of those old statutes, leaving agencies with no regulatory authority at all over new products. This Article reviews the evidence behind persistent concerns about GMOs, considers the failures of the Coordinated Framework to address the most valid of those concerns, and canvasses policy questions that Congress must consider to more effectively tailor agency authority to address the risks and to enhance the potential of this rapidly-changing field of technology