Researchers at the Delhi-based Institute of Genomics and Integrative Biology (CSIR-IGIB) have discovered a protein variant from a different species of bacteria that can edit the DNA with very high precision. In the tool now commonly used for editing disease-causing mutations in DNA (CRISPR-Cas9), the Cas9 protein behaves like a molecular scissors that cuts the DNA at a specific location and inserts a foreign piece of DNA to correct the mutation that causes the disease.
In addition to binding to the intended target on the DNA, the commonly used Cas9 protein from Strepotococcus pyogenes bacteria (SpCas9) and its engineered derivative tend to potentially bind to DNA at multiple unintended sites thereby leading to unnecessary alterations in the DNA.
The researchers found their new Cas9 protein, which binds and cuts the DNA, was able to correct sickle cell anaemia mutation in patient-derived stem cells. The protein (FnCas9) used by the researchers to edit the DNA is derived from a bacterium Francisella novicida.
The Cas9 protein is supposed to bind to the DNA only when there is a perfect match between the DNA and the protein, thus reducing the chances of the protein binding at non-target sites on the DNA. But even when three mismatches exist between the protein and the DNA, the currently used SpCas9 protein binds and cleaves the DNA. In contrast, the team led by Debojyoti Chakraborty from IGIB found the new FnCas9 protein showed negligible binding when there exists more than one mismatch in the target DNA. The results were published in the journal Proceedings of the National Academy of Sciences (PNAS).
The high specificity of the new FnCas9 protein arises due to reduced affinity to bind to DNA when there is even a single mismatch. And when there is more than one mismatch, complete absence of binding of the protein to the DNA is seen in many cases, says Dr. Chakraborty.
If the Cas9 protein remains bound to DNA at mismatched locations for a long time, there is a possibility that it might cut the DNA at these locations. Also, if it remains bound to DNA, the protein might block the transcription (which is the first step in gene expression) at that location. And if Cas9 is bound at multiple unintended sites then the transcription machinery gets stalled and the expression of genes at these locations might be altered, Dr. Chakraborty explains.
In nature, DNA often gets damaged and is routinely repaired through one of the two pathways. In the case of the homology-directed repair (HDR) pathway, which is relatively less error-prone, matching sequences are used to repair the DNA. The FnCas9 protein was found to increase the HDR repair rate fourfold compared to the widely used SpCas9, says Deepanjan Paul from CSIR-IGIB and one of the first authors of the paper.
The researchers tested the precision of binding and cleavage at the desired sites on the DNA using mouse cell lines (embryonic stem cells and brain cells), human kidney cell lines and induced pluripotent stem cells (iPSc). In the case of human iPS cells, the FnCas9 protein was found to bind to the DNA at the specific site, cut and repair the sickle cell anaemia mutation.
The correction process is the same for any disease-causing mutation and so our FnCas9 protein should theoretically correct any mutation in the DNA. The efficiency might vary, so we must test it for each disorder, says Dr. Chakraborty.
The efficiency of any Cas9 protein delivery as well the ability to correct mutations is generally low in the case of iPS cells. The efficiency of correction is about 1.6%. Though the efficiency to correct mutations is low in iPS cells, the corrected cells can be isolated, multiplied and converted (differentiated) into haematopoietic stem cells. Once differentiated into haematopoietic stem cells, they can be transfused into patients.
Differentiating iPS cells into haematopoietic stem cells is not trivial. Plenty of experimental work is under way to make it efficient for clinical translation, says Dr. Chakraborty.
Recalling how he started working on FnCas9 protein for genome editing, Dr. Chakraborty recalls that he was looking for a Cas9 protein which can target RNA instead of DNA. There was one study that reported that FnCas9 could potentially target viral RNA. We were not able to target RNA using FnCas9 proteins. So we started to investigate whether it can target DNA as well since it was not known if FnCas9 can be used for precise gene correction. We found that not only does it target the DNA but does so with very high specificity, he says.
We are now proceeding for preclinical studies to establish the efficacy of FnCas9 protein for genome-wide binding and targeting using patient-derived cells and mouse models, he says.
You have reached your limit for free articles this month.
Register to The Hindu for free and get unlimited access for 30 days.
Find mobile-friendly version of articles from the day's newspaper in one easy-to-read list.
Enjoy reading our articles without intrusion from advertisements.
A select list of articles that match your interests and tastes.
Move smoothly between articles as our pages load instantly.
A one-stop-shop for seeing the latest updates, and managing your preferences.
We brief you on the latest and most important developments, three times a day.
*Our Digital Subscription plans do not currently include the e-paper ,crossword, iPhone, iPad mobile applications and print. Our plans enhance your reading experience.
- Induced Pluripotent Stem Cell Research Pros And Cons ... - April 2nd, 2020
- Evotec Expands Its IPSC-Based Cell Therapy Platform Evocells Through Licensing Agreement with panCella - Benzinga - April 2nd, 2020
- Citius Signs Option With Novellus To License Novel Stem-Cell Therapy For ARDS - Nasdaq - April 2nd, 2020
- Anti-IL-6 Monoclonal Antibodies as Antiarrhythmic Treatment for HF - The Cardiology Advisor - April 2nd, 2020
- A New NK Cell-based Immunotherapy For Cancer Treatment - Health News Today - March 24th, 2020
- Coriell Institute for Medical Research Awarded $8.6 Million Biobanking Contract from National Institute on Aging - Newswise - March 18th, 2020
- Stem cells to help the heart - Science Magazine - March 12th, 2020
- Induced Pluripotent Stem Cells Market Expected to Witness the Highest Growth 202 - ITResearchBrief.com - March 12th, 2020
- SpaceX Dragon cargo ship, the last to be caught by robot arm, arrives at space station - Space.com - March 11th, 2020
- Notice of Capital and Business Alliance between Heartseed and MEDIPAL HOLDINGS | DNA RNA and Cells | News Channels - PipelineReview.com - March 11th, 2020
- NanoSurface Bio Executes Exclusive License of Heart-on-Chip Technology Launched Into Space - Business Wire - March 9th, 2020
- Eye health: Testing the safety of stem cell therapy for age-related macular degeneration - Open Access Government - March 9th, 2020
- Despite Pro-Life Claims, Stem Cell Therapy Has Very Real Benefits and Should Be Accessible - Patheos - March 6th, 2020
- Little Tissue, Big Mission: Beating Heart Tissues to Ride Aboard The ISS - Newswise - March 4th, 2020
- SpaceX set to launch Falcon 9 rocket and Dragon capsule from Cape Canaveral this week - Florida Today - March 4th, 2020
- SpaceX Targeting March 6 for Launch of its 20th Resupply Mission to International Space Station | - SpaceCoastDaily.com - February 29th, 2020
- The European Bank of Induced Pluripotent Stem Cells: Five Years of Progress - Technology Networks - February 28th, 2020
- New study identifies trigger that turns dormant cancer stem cells into active ones - PR Web - February 26th, 2020
- Induced Pluripotent Stem Cells (iPSCs) Market in 2020: Global Industry Size, Demand, Growth & Development, Trends, Insights and Forecast until... - February 25th, 2020
- Improving shoes, showers, 3D printing: research launching to the Space Station - Space Daily - February 21st, 2020
- Argentinian cultured meat supplier on its 'all-in-one' cell line: 'We offer cells that can grow fast and reduce costs' - FoodNavigator-Latam - February 20th, 2020
- Building a 'doomsday vault' to save the kangaroo and koala from extinction - CNET - February 19th, 2020
- Surge in the Adoption of Stem Cell-Derived Cells to Fuel the Growth of the Stem Cell-Derived Cells Market Through the Assessment Period 2019 2029 -... - February 17th, 2020
- Global Induced Pluripotent Stem Cells Market to Achieve more Profitability Ratio between 2020-2025 - Chronicle 99 - February 16th, 2020
- Cell-based meat in focus: In conversation with Meatable, Finless Foods, New Age Meats - FoodNavigator-USA.com - February 11th, 2020
- Research could be step toward lab-grown eggs and sperm to treat... - ScienceBlog.com - February 10th, 2020
- First dual stem cell therapy jointly developed by City University of Hong Kong brings new hope for cardiac repair - QS WOW News - February 10th, 2020
- Chromatin accessibility analysis reveals regulatory dynamics of developing human retina and hiPSC-derived retinal organoids - Science Advances - February 10th, 2020
- AgeX Therapeutics to Collaborate with University of California, Irvine on Neural Stem Cell Research Program for Huntingtons Disease and Other... - February 4th, 2020
- 2020 Induced Pluripotent Stem Cells (iPSCs) Study: Global Markets, Technologies, Applications and Companies - Yahoo Finance - February 2nd, 2020
- Can Parkinsons be prevented as it stealthily develops? - Big Think - February 2nd, 2020
- Unpicking the proteome in single cells - Science Magazine - February 2nd, 2020
- Kyoto University team gets OK from ministry for plan to transplant iPS-derived cartilage into knee joints - The Japan Times - January 25th, 2020
- The Kyoto University team's plan to transplant iPS cartilage into knee joints is OK - gotech daily - January 25th, 2020
- Get rid of the ache within the nerves discovered with the following pointers, learn - Sahiwal Tv - January 25th, 2020
- Astellas and Adaptimmune team up in CAR-T development - European Biotechnology - January 15th, 2020
- Stem Cell Therapy Market Rising Demand for Digitization in Organizations and Growth till 2027 - Galus Australis - January 15th, 2020
- Allele and Astellas Enter into an Expanded License for the Development of iPSC Lines - Yahoo Finance - January 15th, 2020
- Researchers have managed to bio-print a functional mini-liver in 90 days - FLWL News - January 15th, 2020
- CYTOVIA Therapeutics and the New York Stem Cell Foundation Research Institute enter into a partnership to develop iPSC derived CAR NK Therapeutics -... - January 10th, 2020
- Stem Cells Market Segmentation and Analysis Report, 2025 - Food & Beverage Herald - January 10th, 2020
- Stem Cell Therapy Market Robust Growth Counted to 2025 - Instanews247 - January 10th, 2020
- The Top Biotech Trends We'll Be Watching in 2020 - Singularity Hub - January 10th, 2020
- Induced Pluripotent Stem Cells Market Structure, Industry Inspection, and Forecast 2025 - Filmi Baba - December 28th, 2019
- Top Technical Advances of 2019 - The Scientist - December 24th, 2019
- The next 3D-printing craze? It could be functioning 'mini-livers' - Inverse - December 24th, 2019
- Induced Pluripotent Stem Cells Market: Latest Innovations, Drivers and Industry Key Events 2016 2021 - Market Reports Observer - December 24th, 2019
- Stem Cell-Derived Cells Market Expected to Expand at a Steady CAGR through 2019 2029 - Downey Magazine - December 17th, 2019
- AgeX Therapeutics and Lineage Cell Therapeutics Announce Issuance of U.S. Patent for Method of Generating Induced Pluripotent Stem Cells - Yahoo... - December 11th, 2019
- Patent Granted To Lineage & AgeX - Anti Aging News - December 11th, 2019
- Charles River Announces Strategic Partnership with Bit Bio, Increasing Portfolio of Translational Drug Discovery Technologies - BioSpace - December 11th, 2019
- Fate Therapeutics Presents its First Off-the-shelf, iPSC-derived CAR T-Cell Cancer Immunotherapy Program at ASH Annual Meeting - GlobeNewswire - December 11th, 2019
- Fate Therapeutics Announces New Preclinical Data for FT596 Off-the-Shelf, iPSC-derived CAR NK Cell Cancer Immunotherapy - Benzinga - December 8th, 2019
- Induced Pluripotent Stem Cells Market Assessed To Tell Apart High Growth By Implies In 2018 to 2026 - Wolf Mirror - December 5th, 2019
- Kyoto University Seeking To Use Stem Cells On Knee Treatment - Anti Aging News - December 5th, 2019
- Story of a 15-year old scientist: How it all began - EuroScientist - December 5th, 2019
- Stemonix, Atomwise Team Up on Drug Discovery With MicroOrgans and AI - Xconomy - December 5th, 2019
- Channel in Nerve Cell May be Key in Unlocking Parkinson Disease Therapy - Pharmacy Times - December 3rd, 2019
- First-in-kind Human 3-dimensional Models of Parkinson's Disease and Progressive Multiple Sclerosis Launching to the International Space Station -... - December 3rd, 2019
- Stem Cells Market 2019 Global Growth Analysis and Forecast Report by 2025 - Markets Gazette 24 - November 26th, 2019
- UK animal experiment statistics indicate reluctance to embrace modern tools to advance British labs into the 21st century - Labmate Online - November 10th, 2019
- Human heart cells change during spaceflight, say scientists in study that could have far-reaching effects on c - MEAWW - November 7th, 2019
- Here's Why Fate Therapeutics Dropped as Much as 19.9% Today - Motley Fool - November 7th, 2019
- Space travel may change the human heart - Inverse - November 7th, 2019
- Allogene Therapeutics and Notch Therapeutics Announce Collaboration to Research and Develop Induced Pluripotent Stem Cell (iPSC)-Derived Allogeneic... - November 5th, 2019
- Goldfinch Bio to Present Oral and Poster Presentations at the American Society of Nephrology Kidney Week 2019 Annual Meeting - BioSpace - November 5th, 2019
- MD Anderson and Takeda Team Up on Next-Generation Immuno-Oncology Therapeutics - BioSpace - November 5th, 2019
- Induced Pluripotent Stem Cell Market is expected to witness a strong CAGR of 7.0% from 2018 to 2026 - Zebvo - November 2nd, 2019
- Can organoids, derived from stem cells, be used in disease treatments? - The Hindu - October 26th, 2019
- University team to seek approval for iPS-based heart treatment trial - The Japan Times - October 26th, 2019
- Global Gemcitabine Hydrochloride Market: Segmented By Application And Geography Trends, Growth And Forecasts To 2024 - Health News Office - October 26th, 2019
- Global consortium formed to combat unproven cell banking services - Drug Target Review - October 22nd, 2019
- Bloomberg Philanthropies, Johns Hopkins University School of Medicine, and The New York Stem Cell Foundation Research Institute Announce an... - October 22nd, 2019
- ISCT forms cell and gene therapy sector-wide coalition to combat the rise of unproven commercial cell banking services - PharmiWeb.com - October 21st, 2019
- Mutations Linked to Huntington's Increase Cells' Resistance to Manganese, Study Finds - Huntington's Disease News - October 15th, 2019
- Stem Cells Market : Insights Into the Competitive Scenario of the Market - Online News Guru - October 11th, 2019
- 'Rewind Therapeutics' and Remyelination - SciTech Europa - October 11th, 2019
- Cell Expansion Market is expected to rise at a remarkable CAGR during the Forecast Period 2016 2024 - Space Market Research - October 9th, 2019
- Global Induced Pluripotent Stem Cells Market 2019 Innovative Trends and Insights Research upto 2024 - News Adopt - October 5th, 2019
- New Rett Therapies May Stem From X-chromosome Reactivation Findings - Rett Syndrome News - October 5th, 2019