Breaking News
August 16, 2018 - Promoting HPV Vaccine Doesn’t Prompt Risky Sex by Teens: Study
August 16, 2018 - Treating Rheumatoid Arthritis: Search for a Cure
August 16, 2018 - Research shows in the long run, charcoal toothpaste likely won’t whiten teeth
August 16, 2018 - Seattle Children’s opens new clinic to provide convenient access to pediatric specialty care services
August 16, 2018 - Curious case of the lost contact lens
August 16, 2018 - GN Hearing unveils world’s first Premium-Plus hearing aid
August 16, 2018 - Parental life span linked with increased longevity and health in daughters
August 16, 2018 - Health leaders reveal ten most important medicines in NHS history
August 16, 2018 - Mobile health devices diagnose hidden heart condition in at-risk populations
August 16, 2018 - When it comes to shedding pounds, it pays to think big
August 16, 2018 - Liva Healthcare announces appointment of Thomas Cooke as clinical services manager in the UK
August 16, 2018 - New digital pharmacy aims to help people living with chronic care conditions
August 16, 2018 - Preventing ACL injuries in high school athletes
August 16, 2018 - Experts provide insight into novel concepts and approaches for stroke rehabilitation
August 16, 2018 - Scientists reverse congenital blindness in mouse model
August 16, 2018 - Study shows link between use of benzodiazepines and increased risk of Alzheimer’s disease
August 16, 2018 - Trial shows PARP inhibitor as novel treatment option for patients with advanced breast cancers
August 16, 2018 - Prenatal exposure to violence increases toddlers’ aggressive behavior to their mothers
August 16, 2018 - Can manipulating gut microbes improve cardiac function in patients with heart failure?
August 16, 2018 - Hearts of newborn piglets can completely heal after heart attacks
August 16, 2018 - Ablating the mutant p53 gene in mice with colorectal cancer inhibits tumor growth
August 16, 2018 - Higher BMI in people with prediabetes related to evening preference and lack of sufficient sleep
August 16, 2018 - Using peripheral nerve blocks to treat facial pain may produce long-term pain relief
August 16, 2018 - Neural stem cells are the key to tail regeneration
August 16, 2018 - Study compares genetic and neural contributions to ADHD in children with or without TBI
August 16, 2018 - Adding energy drinks to alcohol may exacerbate negative effects of binge drinking
August 16, 2018 - Eye Examination Can Help Detect Abuse in Children
August 16, 2018 - Know the Difference: Rheumatoid Arthritis or Osteoarthritis?
August 16, 2018 - From ‘sea of mutations,’ two possible cancer links rise to the surface
August 16, 2018 - Does medical school take too long?
August 16, 2018 - Brown University researchers reveal key physical properties of ‘giant’ cancer cells
August 16, 2018 - Regular resistance training improves exercise motivation
August 16, 2018 - Feds urge states to encourage cheaper plans off the exchanges
August 16, 2018 - Seven activities that prevent you from getting quality sleep during summer
August 16, 2018 - Five ways to tell if your baby is getting enough milk from breastfeeding
August 16, 2018 - From Pigs to Peacocks, What’s Up With Those ‘Emotional-Support Animals’?
August 16, 2018 - Breast cancers enlist the help of normal cells to help them spread and survive
August 16, 2018 - Engaging with “high-need” patients outside the clinic
August 16, 2018 - Research illuminates how online forum may offer suicide prevention support for males
August 16, 2018 - Researchers identify way to grow immune cells at large scale for preventing cancer reoccurrence
August 15, 2018 - Keck Medicine of USC’s hospitals ranked among nation’s best for the 10th consecutive year
August 15, 2018 - Researchers compare existing approaches for automating diagnostic procedures of skin lesions
August 15, 2018 - Autism risk determined by health of mom’s gut, research reveals
August 15, 2018 - WELL for Life challenges you to explore the great outdoors
August 15, 2018 - ‘Zombie’ gene protects elephants from cancer, study finds
August 15, 2018 - Ebola outbreak in Congo spreads to active combat zone
August 15, 2018 - Study highlights pollution exposure of babies in prams
August 15, 2018 - Study provides insight into link between sleep apnea and lipid metabolism
August 15, 2018 - New study focuses on promise of gene therapy for Amish nemaline myopathy
August 15, 2018 - Researchers discover new approach to alleviate chronic itch
August 15, 2018 - Uncovering the Mysteries of MS: Medical Imaging Helps NIH Researchers Understand the Tricky Disease
August 15, 2018 - Autistic people at greater risk of becoming homeless – new research
August 15, 2018 - New imaging technique can spot tuberculosis infection in an hour
August 15, 2018 - Scientists study effects of eating breakfast versus fasting overnight before exercise
August 15, 2018 - Talking with children about suicide could save lives
August 15, 2018 - Grip strength of children predicts future cardiometabolic health
August 15, 2018 - New polyclonal immunotherapy successfully neutralizes Ebola virus
August 15, 2018 - Innovative oncofertility program launched by RMA of New York and Mount Sinai Health System
August 15, 2018 - Study shows efficacy, safety of AAV5-based gene therapy to treat sheep model of achromatopsia
August 15, 2018 - Simple score helps predict which hospitalized heart attack patients are at high risk of readmissions
August 15, 2018 - New discoveries show how protein droplets do more than keep cells’ interiors tidy
August 15, 2018 - Study shows impact of optimizing airport flight patterns on human health
August 15, 2018 - Life experiences of feeling unwanted or unplanned associated with attachment insecurity
August 15, 2018 - ACS Briefing Discusses Use of Lessons From Combat Care
August 15, 2018 - Study identifies distinct origin of ADHD in children with history of brain injury
August 15, 2018 - IgG3 antibody stops B cells from fighting pathogens in HIV patients
August 15, 2018 - Scientists discover key vulnerability of mixed lineage leukemia
August 15, 2018 - College students may experience pressures from secondary exposure to opioid abuse
August 15, 2018 - Powerful new microscope reveals inner workings of human cells with unprecedented clarity
August 15, 2018 - Married people who fight nastily more likely to suffer from leaky guts, study suggests
August 15, 2018 - Working Out After Baby – Drugs.com MedNews
August 15, 2018 - Rheumatoid Factor (RF) Test: MedlinePlus Lab Test Information
August 15, 2018 - ADHD linked to an increased risk of injury in children, study finds
August 15, 2018 - UIC researchers receive NIH funding to develop a better way to regenerate bone or tissues
August 15, 2018 - Study reveals how immune cells in the brain influence sexual behavior
August 15, 2018 - Researchers move closer to finding potential soft spot in drug-resistant tuberculosis
August 15, 2018 - Real-time dynamic monitoring of cell’s nucleus for effective cancer screening
August 15, 2018 - Lower rates of Medicare preventive care visits found in racial, ethnic minority older adults
August 15, 2018 - Scientists identify stress hormone as key factor in failure of immune system to inhibit leukemia
August 15, 2018 - Cytoplan introduces three new nutritional supplements
Using CRISPR-Cas9 genome editing to correct mutation responsible for sickle cell disease

Using CRISPR-Cas9 genome editing to correct mutation responsible for sickle cell disease

image_pdfDownload PDFimage_print

Research published in Nature Medicine describes collaborative effort to reduce off-target CRISPR-Cas9 genome editing – removing barriers for human therapeutic applications

Genome editing using the CRISPR-Cas9 system has tremendous promise for therapeutic correction of genetic errors in human cells. Prior to adoption as a medical therapeutic, safety concerns relating to off-target effects must be minimized to mitigate risks that may arise from the unintended action of this system at sites similar, but not identical, to the desired gene target site. In a study published in Nature Medicine today, researchers at Integrated DNA Technologies (IDT) and the laboratory of Prof. Matthew Porteus at Stanford University describe a novel Cas9 mutant that shows improved specificity and maintains high activity when used in the medically relevant ribonucleoprotein (RNP) format. Potential for medical use of the new mutant enzyme was demonstrated in human hematopoietic stem and progenitor cells (HSPCs), where it was able to correct the mutation in the beta-hemoglobin gene responsible for sickle cell disease (SCD).

Several groups previously described Cas9 mutants with improved specificity; however, all show significantly reduced activity when used in the clinically relevant RNP format. These previous mutants were developed using intelligent design based on known protein crystal structures. Instead, IDT scientists used an unbiased method to screen approximately 250,000 random Cas9 mutants to identify those rare mutants that improved specificity without compromising activity. After several rounds of selection, a single mutant emerged, now known as Alt-R HiFi Cas9 nuclease, that provides the desired high on-target, low off-target characteristics. In the published study, a collaborative team from IDT and Stanford demonstrates the robust on-target editing and minimal off-target cleavage achieved by HiFi Cas9 in several therapeutically relevant loci in hard-to-edit HSPCs. They also show HiFi Cas9-mediated correction of the sickle cell disease-causing p.E6V mutation in patient-derived HSPCs.

Mark Behlke, MD, PhD, chief scientific officer at IDT and a co-author of the study, said:

Previous attempts at improving Cas9 specificity characterized the mutants using plasmid-based methods that result in sustained overexpression of the Cas9 protein, which increases off-target activity and is not ideal for medical applications. This sustained overexpression, however, rescued function of the mutants that otherwise showed low activity when used in the more transient RNP format. We specifically performed a broad screen to identify a mutant that performs well when used at the lower protein levels achieved with RNP delivery, maximizing safety and further reducing unwanted side effects. Prof. Porteus demonstrated utility using the new system to correct the SCD mutation in normal human blood-forming stem cells while minimizing known off-target activity. We anticipate significant interest in use of the new Cas9 mutant in translational medical applications.”

The novel HiFi Cas9 nuclease is now commercially available as Alt-R HiFi Cas9 Nuclease V3. The Nature Medicine paper can be accessed at: https://doi.org/10.1038/s41591-018-0137-0

Posted in: Genomics

Tags: Blood, Cas9, Cell, CRISPR, DNA, Enzyme, Gene, Genetic, Genome, Genome Editing, Hemoglobin, Laboratory, Mutation, Nuclease, Plasmid, Protein, Research, Sickle Cell Disease

Tagged with:

About author

Related Articles