Bioengineer Gang Bao uses gene editing to repair up to 40 percent of bone marrow cells from patients
Scientists have successfully used gene editing to repair 20 to 40 percent of stem and progenitor cells taken from the peripheral blood of patients with sickle cell disease, according to Rice University bioengineer Gang Bao.
Bao, in collaboration with Baylor College of Medicine, Texas Children’s Hospital and Stanford University, is working to find a cure for the hereditary disease. A single DNA mutation causes the body to make sticky, crescent-shaped red blood cells that contain abnormal hemoglobin and can block blood flow in limbs and organs.
In his talk at the annual American Association for the Advancement of Science meeting in Austin Feb. 16, Bao revealed results from a series of tests to see whether CRISPR/Cas9-based editing can fix the mutation. His presentation was part of a scientific session titled “Gene Editing and Human Identity: Promising Advances and Ethical Challenges.”
“Sickle cell disease is caused by a single mutation in the beta-globin gene (in the stem cell’s DNA),” he said. “The idea is to correct that particular mutation, and then stem cells that have the correction would differentiate into normal blood cells, including red blood cells. Those will then be healthy blood cells.”
Bao’s lab collaborated with Vivien Sheehan, an assistant professor of pediatrics and hematology at Baylor and a member of the sickle cell program at Texas Children’s, to collect stem and progenitor cells (CD34-positive cells) from patients with the disease. These were then edited in the Bao lab with CRISPR/Cas9 together with a custom template, a piece of DNA designed to correct the mutation.
The gene-edited cells were injected into the bone marrow of immunodeficient mice and tested after 19 weeks to see how many retained the edit. “The rate of repair remained stable, which is great,” Bao said. This engraftment study was carried out in the lab of Matt Porteus, an associate professor of pediatrics at Stanford.
Another major finding of the study is that the CRISPR/Cas9 system could introduce large alterations to the genes in patients’ cells, in addition to small mutations or deletions. These off-target effects could cause a disease.
The findings, part of an upcoming paper, are a step toward treating sickle cell disease. Obstacles in the way of a cure include optimizing the CRISPR/Cas9 system to eliminate off-target effects, as well as finding a way to further increase the amount of gene-corrected stem cells.
Bao pointed out that researchers still don’t know whether repairing as much as 40 percent of the cells is enough to cure a patient. “We’d like to say, ‘Yes,’” he said, “but we don’t really know yet. That’s something we hope to learn from an eventual clinical trial.”
The Latest on: Sickle cell disease
- Do I need to screen my partner for sickle cell? on December 9, 2018 at 11:53 pm
Sickle cell anaemia is an inherited disease affecting the red blood cell’s red pigment leading to the normally disc-shaped cells becoming sickle-shaped hence getting entangled in the smaller blood ves... […]
- Clinical Challenges: Test Your Knowledge of Sickle Cell Disease on December 7, 2018 at 9:24 am
The material on this site is for informational purposes only, and is not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider. © 2018 MedPage Today, LLC ... […]
- How Global Blood Therapeutics Is Capitalizing on Its Sickle Cell Disease Approval on December 7, 2018 at 6:40 am
Global Blood Therapeutics Inc. (NASDAQ: GBT) shares dipped on Friday after the company announced that it would be conducting a secondary offering. This offering comes on the heels of a key U.S ... […]
- A treatment for sickle-cell disease proves effective in Africa on December 6, 2018 at 4:16 pm
A drug that protects children in wealthy countries against painful and sometimes lethal bouts of sickle-cell disease has been proven safe for use in Africa, where the condition is far more common, sci... […]
- Clinical Challenges: Sickle Cell Management in the ED on December 6, 2018 at 8:03 am
The most common complication of sickle cell disease (SCD) is a vaso-occlusive crisis. The sudden nature of these crises, marked by intermittent, unexpected episodes of severe pain, leads most SCD pati... […]
- Inexpensive sickle cell diagnostic tool shows perfect accuracy in Uganda on December 4, 2018 at 4:27 pm
SAN DIEGO — An inexpensive, easy-to-use diagnostic tool for sickle cell disease showed 100% accuracy among a large cohort of children from Uganda, according to findings presented during the late-break... […]
- Sickle Cell Disease-Pipeline Insight 2018 on December 4, 2018 at 1:13 am
Sickle Cell Disease-Pipeline Insight, 2018" report by Publisher outlays comprehensive Insight of present scenario and growth prospects across Sickle Cell Disease. Pipeline analysis of therapeutic drug... […]
- Gene therapies could transform sickle cell disease into a curable illness on December 3, 2018 at 10:31 am
Manny Johnson keeps catching himself rubbing a spot on the upper right side of his chest. Starting when he was a teenager, the 21-year-old from Boston depended on a port implanted there to ease his mo... […]
- One to watch at ASH18: She’s 17 and she studies chronic pain in sickle cell disease on December 3, 2018 at 7:58 am
SAN DIEGO — Aithanh Nguyen is skipping school to attend the American Society of Hematology’s annual meeting, but she has a legit excuse: On Monday, Nguyen was slated to take the podium here to present ... […]
- Global Blood's Sickle Cell Disease Drug Snags Accelerated FDA Approval Pathway on December 3, 2018 at 7:55 am
Global Blood Therapeutics Inc (NASDAQ: GBT) shares are trading at a nearly three-month high, with a FDA event being the catalyst. Global Blood announced Monday that the FDA has agreed to allow filing ... […]
via Google News and Bing News