A patient with genetic blindness became the first person to receive a direct human trial of CRISPR-Cas9 gene therapy. According to a recent report on the British “Nature” website, scientists conducted the first clinical trial to directly apply CRISPR-Cas9 gene therapy to humans to treat hereditary eye disease-Leber’s congenital amaurosis (LCA10). They said that this trial aims to test the ability of the gene editing technology to remove the gene mutations that cause LCA10, which is a milestone.
LCA10 is the main cause of blindness in children, and there is currently no treatment. CRISPR-Cas9 is known as the “genetic cut”. In the latest experiment, the components of this gene editing system will be encoded in the viral genome and then directly injected into the near photoreceptor cells of the patient’s eye. Previously, when scientists treated eye diseases, they would first remove the cell genome from the patient, then use CRISPR-Cas9 to edit the genome, and then inject the edited cells back into the patient.
The latest experiment is called “Brightness” (BRILLIANCE). It was carried out by Mark Penrus, an expert on inherited retinal diseases at Oregon Health and Science University in the United States, and Editas Medicine in the United States. The researchers hope that the technology can delete the CEP290 gene that causes LCA10. A sudden change.
Artur Sidsey, an expert on retinal diseases at the University of Pennsylvania, said that traditional gene therapy uses viruses to insert healthy copies of mutated genes into affected cells, but CEP290 is too large to fit the entire gene into the viral genome. Moreover, although the mutation in CEP290 disables the light-sensitive cells of the photoreceptors in the retina, these cells still exist and survive in the eyes of LCA10 patients.
Penless said: “We hope that CRISPR-Cas9 can reactivate these cells and improve patients’ vision.”
Of course, this is not the first time that gene editing technology has been used in human trials. Previously, zinc finger nuclease has been directly used in human clinical trials-an American company used a zinc finger-based therapy to treat Hunter syndrome. In the trial, the researchers inserted a healthy copy of the affected gene into a specific location in the liver cell genome. Although the therapy appears to be safe, initial results indicate that it may not help alleviate the symptoms of Hunter syndrome.
Fyodor Unov, a genome editing researcher at the University of California, Berkeley, said that compared with treating cells in a petri dish, the direct use of CRISPR-Cas9 in the body is a major leap, but the technical challenges and safety risks are also greater.