CRISPR Gene Editing and It’s Direct Use in the Human Body
This is just a 10 minute OLLI Lecture on the Science Breakthroughs of 2021.
CRISPR is biological genome editing allowing the destruction of a bad gene, or eventually snipping out a bad gene out and replacing it with a good gene. Usually, blood cells are extracted from the body, genes are edited “in-vitro”, and then reinjected into the body, or stem cells are put into bone marrow for the generation of new cells. The scientific advances being noted in CRISPR are very limited trials of doing this directly in the body, or “in-vivo”.
Gene editing is being given clinical trials to help blood disorders, cancers, inherited eye disease, diabetes, infectious diseases, and protein-folding disorders.
This presentation is taken from a comprehensive article by Hope Henderson for the Innovative Genomics Institute (IGI), at innovativegenomics.com. It is also related to the collaboration of IGI, UCSF, UCLA, UC Berkeley, and Graphite Bio. It was dated March 29, 2022.
One of CRISPR successes is the in-vivo treatment of the inheritable Sickle Cell Disease, where some of the blood cells are elongated like sickles, and can block arteries. This especially affects Black Americans. CRISPR can correct the mutation causing this by extracting blood stem cells and removing it, and then injecting them into the patients bone marrow.
Trials are being carried out to directly apply CRISPR in the body, or using base editing, which does not break DNA chains. One problem, is that the patient with “in vitro” then needs chemotherapy in hospitalization to oblate the old bone marrow. This presents problems in costs and scalability to many patients. These problems may be solved if the changes can be made “in vivo”.
A breakthrough was made in a small trial of using CRISPR on TTR protein amploidosis, which is caused by a misfolded protein. Here the cells build up and damage nerves and the heart. In the trial, the blood levels of the bad proteins dropped 52% to 87%.
In Leber Congenital Amaurosis LCA10, CRISPR corrected in vivo a nucleotide mutation in a photoreceptor gene. But since the patient was already blind, the ability of the brain to take sight signals may already be lost. They will try this with higher doses and younger subjects.
In the future biologists will try replacing a DNA sequence with the correct one. They will also try activation and inhibition using CRISPRa and CRISPRi.
UC Irvine has its own Sue and Bill Gross Stem Cell Research Center, which gives a series of talks.
