1
|
Doerfler AM, Park SH, Assini JM, Youssef A, Saxena L, Yaseen AB, De Giorgi M, Chuecos M, Hurley AE, Li A, Marcovina SM, Bao G, Boffa MB, Koschinsky ML, Lagor WR. LPA disruption with AAV-CRISPR potently lowers plasma apo(a) in transgenic mouse model: A proof-of-concept study. Mol Ther Methods Clin Dev 2022; 27:337-51. [PMID: 36381302 DOI: 10.1016/j.omtm.2022.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
Abstract
Lipoprotein(a) (Lp(a)) represents a unique subclass of circulating lipoprotein particles and consists of an apolipoprotein(a) (apo(a)) molecule covalently bound to apolipoprotein B-100. The metabolism of Lp(a) particles is distinct from that of low-density lipoprotein (LDL) cholesterol, and currently approved lipid-lowering drugs do not provide substantial reductions in Lp(a), a causal risk factor for cardiovascular disease. Somatic genome editing has the potential to be a one-time therapy for individuals with extremely high Lp(a). We generated an LPA transgenic mouse model expressing apo(a) of physiologically relevant size. Adeno-associated virus (AAV) vector delivery of CRISPR-Cas9 was used to disrupt the LPA transgene in the liver. AAV-CRISPR nearly completely eliminated apo(a) from the circulation within a week. We performed genome-wide off-target assays to determine the specificity of CRISPR-Cas9 editing within the context of the human genome. Interestingly, we identified intrachromosomal rearrangements within the LPA cDNA in the transgenic mice as well as in the LPA gene in HEK293T cells, due to the repetitive sequences within LPA itself and neighboring pseudogenes. This proof-of-concept study establishes the feasibility of using CRISPR-Cas9 to disrupt LPA in vivo, and highlights the importance of examining the diverse consequences of CRISPR cutting within repetitive loci and in the genome globally.
Collapse
|
2
|
Abstract
BACKGROUND A first therapeutic target of somatic genome editing (SGE) is sickle cell disease (SCD), the most commonly inherited blood disorders, affecting more than 100,000 individuals in the United States. Advancement of SGE is contingent on patient participation in first in human clinical trials. However, seriously ill patients may be vulnerable to overestimating the benefits of early phase studies while underestimating the risks. Therefore, ensuring potential clinical trial participants are fully informed prior to participating in a SGE clinical trial is critical. Methods: We conducted a mixed-methods study of adults with SCD as well as parents and physicians of individuals with SCD. Participants were asked to complete a genetic literacy survey, watch an educational video about genome editing, complete a two-part survey, and take part in focus group discussions. Focus groups addressed topics on clinical trials, ethics of gene editing, and what is not understood regarding gene editing. All focus groups were audio-recorded, transcribed, and analyzed using conventional content analysis techniques to identify major themes. Results: Our study examined the views of SCD stakeholders regarding what they want and need to know about genome editing to make an informed decision to participate in a SGE clinical trial. Prominent themes included stakeholders' desire to understand treatment side effects, mechanism of action of SGE, trial qualification criteria, and the impact of SGE on quality of life. In addition, some physicians expressed concerns about the extent to which their patients would understand concepts related to SGE; however, individuals with SCD demonstrated higher levels of genetic literacy than estimated by physicians. Conclusions: Designing ethically robust genome editing clinical trials for the SCD population will require, at a minimum, addressing the expressed information needs of the community through culturally sensitive engagement, so that they can make informed decisions to consider participation in clinical trials.
Collapse
Affiliation(s)
- Stacy Desine
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Brittany M. Hollister
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Khadijah E. Abdallah
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Anitra Persaud
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Sara Chandros Hull
- Department of Bioethics, Clinical Center, National Institutes of Health, Bethesda, MD
- Bioethics Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Vence L. Bonham
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| |
Collapse
|
3
|
Li A, Tanner MR, Lee CM, Hurley AE, De Giorgi M, Jarrett KE, Davis TH, Doerfler AM, Bao G, Beeton C, Lagor WR. AAV-CRISPR Gene Editing Is Negated by Pre-existing Immunity to Cas9. Mol Ther 2020; 28:1432-1441. [PMID: 32348718 PMCID: PMC7264438 DOI: 10.1016/j.ymthe.2020.04.017] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [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: 11/20/2019] [Revised: 04/03/2020] [Accepted: 04/15/2020] [Indexed: 02/07/2023] Open
Abstract
Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by an increased proportion of CD8+ T cells in the liver. This cytotoxic T cell response was characterized by hepatocyte apoptosis, loss of recombinant AAV genomes, and complete elimination of genome-edited cells, and was followed by compensatory liver regeneration. Our results raise important efficacy and safety concerns for CRISPR-Cas9-based in vivo genome editing in the liver.
Collapse
Affiliation(s)
- Ang Li
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Mark R Tanner
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ciaran M Lee
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Ayrea E Hurley
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marco De Giorgi
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kelsey E Jarrett
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Timothy H Davis
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Alexandria M Doerfler
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gang Bao
- Department of Bioengineering, Rice University, Houston, TX 77030, USA.
| | - Christine Beeton
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - William R Lagor
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
4
|
Abstract
PURPOSE OF REVIEW The purpose is to review recent progress in applying the CRISPR/Cas9 system to lipid metabolism and therapeutics. RECENT FINDINGS The CRISPR/Cas9 system has been used to generate knockout animals for lipid genes in multiple species. Somatic genome editing with CRISPR/Cas9 can efficiently disrupt genes in adult animals, including a new strategy for generating atherosclerosis. Refinements to the CRISPR/Cas9 system including epigenetic modulators and base editors offer new avenues to manipulate gene expression. The recent report of germline genome editing in humans highlights the promise as well as perils of this technology. SUMMARY CRISPR/Cas9 is a transformative technology that will help advance on our understanding of lipid metabolism and physiology. Somatic genome editing is a particularly promising approach for editing genes in tissues of live organisms, and represents a new means of addressing unmet therapeutic challenges in humans. Educational outreach, public debate, and consideration of ethics and safety must guide the use of genome editing in humans.
Collapse
Affiliation(s)
- Mia Furgurson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | | |
Collapse
|
5
|
Curiel-GarcÍa A, Olive KP. Modeling Pancreatic Cancer through Somatic Editing with AAV. Trends Mol Med 2019; 25:361-362. [PMID: 30878400 DOI: 10.1016/j.molmed.2019.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 02/26/2019] [Indexed: 11/19/2022]
Abstract
Genetically engineered mouse models have revolutionized the study of pancreatic cancer, but have several technical and practical limitations. A new adeno-associated virus (AAV)-driven somatic genome-editing model of pancreatic ductal adenocarcinoma reported by Ideno et al. (Lab. Invest. published online February 6, 2019; https://doi.org/10.1038/s41374-018-0171-z) addresses several of these limitations, achieving rapid and penetrant induction of multiple targeted alterations in the adult murine pancreas.
Collapse
Affiliation(s)
- Alvaro Curiel-GarcÍa
- Department of Medicine, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Kenneth P Olive
- Department of Medicine, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA.
| |
Collapse
|
6
|
Persaud A, Desine S, Blizinsky K, Bonham VL. A CRISPR focus on attitudes and beliefs toward somatic genome editing from stakeholders within the sickle cell disease community. Genet Med 2019; 21:1726-34. [PMID: 30581191 DOI: 10.1038/s41436-018-0409-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 12/05/2018] [Indexed: 11/22/2022] Open
Abstract
Purpose Genome editing holds both tremendous therapeutic promise and significant potential risk. Sickle cell disease (SCD), the most commonly inherited blood disorder, is a frontline candidate for the clinical applications of this tool. However, there is limited knowledge of patient community values and concerns regarding this new technology. This study aims to investigate the perspectives of three key decision-makers (patients, parents, and physicians) toward participation in future CRISPR-mediated somatic genome editing clinical trials. Methods We utilized a mixed-methods approach, involving an educational video tool, two-part survey, and 15 moderated, audio-recorded focus groups, which were conducted in seven U.S. cities. Results Study participants expressed hope that genome editing technology would rechart the course for SCD, but concerns related to involvement burden, uncertainty of clinical outcomes, and equity in access were identified. Major themes emerged from the focus groups: facilitators of, and barriers to, participation in future somatic genome editing clinical trials; information pertinent to the decision-making process; persons from whom participants would seek counsel before making a decision; and recommendations for the research community on meaningful engagement as clinical trials are designed and approved. Conclusion The advent of genome editing has renewed hope for the SCD community, but caution tempers this optimism.
Collapse
|
7
|
Li A, Lee CM, Hurley AE, Jarrett KE, De Giorgi M, Lu W, Balderrama KS, Doerfler AM, Deshmukh H, Ray A, Bao G, Lagor WR. A Self-Deleting AAV-CRISPR System for In Vivo Genome Editing. Mol Ther Methods Clin Dev 2018; 12:111-122. [PMID: 30619914 PMCID: PMC6313841 DOI: 10.1016/j.omtm.2018.11.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 11/29/2018] [Indexed: 12/27/2022]
Abstract
Adeno-associated viral (AAV) vectors packaging the CRISPR-Cas9 system (AAV-CRISPR) can efficiently modify disease-relevant genes in somatic tissues with high efficiency. AAV vectors are a preferred delivery vehicle for tissue-directed gene therapy because of their ability to achieve sustained expression from largely non-integrating episomal genomes. However, for genome editizng applications, permanent expression of non-human proteins such as the bacterially derived Cas9 nuclease is undesirable. Methods are needed to achieve efficient genome editing in vivo, with controlled transient expression of CRISPR-Cas9. Here, we report a self-deleting AAV-CRISPR system that introduces insertion and deletion mutations into AAV episomes. We demonstrate that this system dramatically reduces the level of Staphylococcus aureus Cas9 protein, often greater than 79%, while achieving high rates of on-target editing in the liver. Off-target mutagenesis was not observed for the self-deleting Cas9 guide RNA at any of the predicted potential off-target sites examined. This system is efficient and versatile, as demonstrated by robust knockdown of liver-expressed proteins in vivo. This self-deleting AAV-CRISPR system is an important proof of concept that will help enable translation of liver-directed genome editing in humans.
Collapse
Affiliation(s)
- Ang Li
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Ciaran M Lee
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Ayrea E Hurley
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kelsey E Jarrett
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marco De Giorgi
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weiqi Lu
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Karol S Balderrama
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alexandria M Doerfler
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Anirban Ray
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Gang Bao
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - William R Lagor
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| |
Collapse
|