CRISPR gene editing in T-cells. T-cells are a big part of the immune system and help protect the body from disease. This technique is used to add or delete base pairs at a specific loci. In order to understand the technique, you must first understand what CRISPR is. CRISPR is a naturally occurring part of the immune system in many bacteria. Cas enzymes are used in conjunction with this to cut out specific parts of DNA sequences. The CRISPR DNA sequences tell the Cas enzymes (usually Cas9) where to cut. In this case, a scientist would "feed" the Cas 9 a sequence and the CRISPR would be transported into the cells through a virus.
Alexander Marson and his team have found a way to use this technique to strengthen T-cells against cancer cells. The team used an electrical field to create holes in the cell membranes of the T-cells rather than using a virus. This allowed them to forcibly insert CRISPR into the cells. They were able to alter the DNA down to individual letters rather than large chunks.
When cancer attacks T-cells, they alter a particular gene called PD-1. This tells the T-cells to stop fighting to prevent harm to normal cells, but it's really doing so to stop fighting cancer cells. The research team believes they can use the editing technique to alter the PD-1 gene to get the T-cells to fight back against the cancer cells. The issue with this technique is that there is no telling how long the T-cells will remain in the body and if they begin to attack normal cells it would be a huge issue. This must be addressed before actually being able to use this technique on people.
This technique has been controversial since it was discovered. If improved, it could provide ways of editing genes in any organism. It could provide ways of altering genes in embryos eventually, which could lead to many ethical problems. On the other side, it could help find new therapies for curing the incurable. There is no way of knowing where this technique could take us, but it definitely needs to be researched more to find out.