Scientific breakthrough in T cell editing could fight off diseases

American scientists have devised a gene-editing technique, known as Crispr, which can modify human T cells to protect against diseases such as type 1 diabetes.
T cells are a type of white blood cell which circulate in the bloodstream. They are involved in many disease processes, including type 1 diabetes, HIV and cancer, but up until now, scientists have not been able to replace mutations with healthy strands of DNA.
In type 1 diabetes, killer T cells incorrectly target the insulin-producing beta cells within the pancreas. This severely affects the ability of the pancreas to produce insulin, leading to high blood sugar levels and the signs of diabetes.
If scientists can change the behaviour of T cells, they may be able to stop the killer T cells from attacking pancreatic cells.
What is Crispr?
Crispr (Clustered, Regularly Interspaced, Short Palindromic Repeat) was developed by investigators at the University of California (UC), San Francisco. This approach enabled UC researchers to identify precise positions on a DNA molecule, and using an enzyme called Cas9, remove the strands and replace them.
In one study, scientists used Crispr to disable the CXCR4 protein on the surface of T cells – this can be exploited by HIV when T cells are infected, which causes AIDS.
They also converted another T cell protein, called PD-1, which is involved in controlling the immune system’s attack on cancer cells. This finding could have implications for cancer immunotherapy, with the researchers aiming for T cells to be generated that could keep the disease at bay.
By conducting “gene editing” on T cells, a number of Crispr/Cas9-based therapies could emerge for diseases such as type 1 diabetes, cancer and HIV.
Dr. Alexander Marso, 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.”