T cell editing

A gene-editing technique called Crispr has been developed by American scientists which could fight against diseases such as type 1 diabetes.

Type 1 diabetes is characterised by killer T cells – a form of white blood cell circulating in the bloodstream – incorrectly targeting insulin-producing cells in the pancreas. This leads to high blood glucose levels and the signs of diabetes.

T cells are involved in a number of other disease processes, such as HIV and cancer, but until this breakthrough, healthy DNA strands have not been able to replace mutations.

If the behaviour of T cells can be altered, then scientists might to be able to prevent the killer T cells from attacking pancreatic cells.

How does Crispr work?

Crispr (Clustered, Regularly Interspaced, Short Palindromic Repeat) enables precise positions on a DNA molecule to be identified. Then, using an enzyme called Cas9, these strands can be removed and replaced.

The technique was devised by researchers at the University of California (UC), San Francisco. Using Crispr, they disabled the CXCR4 protein on the surface of T cells – this can be exploited by HIV when T cells are infected, causing AIDS to develop.

In another finding which could have implications for cancer immunotherapy, the scientists converted a T cell protein called PD-1. This is involved in controlling the immune system’s attack on cancer cells, and their aim is for T cells to be created that could keep cancer at bay.

Dr. Alexander Marson, UC, said: “Genome editing in human T-cells has been a notable challenge for the field. So we spent the past year and a half trying to optimise editing in functional T-cells. There are a lot of potential therapeutic applications, and we want to make sure we are driving this as hard as we can.”

If “gene editing” can be further conducted on T cells, a number of Crispr/Cas-9 based therapies could be developed for disease such as type 1 diabetes, HIV and cancer.