Harvard Stem Cell Institute (HSCI) researchers at Massachusetts General (MGH) and Boston Children’s hospitals (BCH) for the first time have used a relatively new gene-editing technique to create what could prove to be an effective technique for blocking HIV from invading and destroying patients’ immune systems.
This is the first published report of a group using CRISPR Cas technology to efficiently and precisely edit clinically relevant genes out of cells collected directly from people, in this case human blood forming stem cells and T-cells.
In their Cell Stem Cell paper, Rossi and Cowan showed they could edit β2M out of T-cells and CCR5 out of hematopoietic stem/progenitor cells (HSPCs) efficiently, predictably, and precisely. They further showed that edited HSPCs could go on to produce the normal portfolio of blood and immune cells.
The pair also addressed concerns about just how exact CRISPR is.
“There have been a couple of papers suggesting that CRISPR has high off-target activity,” Rossi explained. “We decided to test its accuracy in primary blood-forming stem cells under six different experimental conditions.”
The team deeply sequenced (an average of 3,400 sequencing passes, compared with the 50 usually used for whole-genome sequencing) sites in the genome that could possibly confuse CRISPR when trying to edit CCR5 out of HSPCs.
Source by : Science Daily News