Modifying human immune cells to fight CANCER and HIV
Immune cells which are known as T cells are formidable fighters against cancer and HIV. Researchers at the University of California, San Francisco have figured out how to help T cells fight back using the latest gene editing technique called CRISPR - gene editing technique. It’s no surprise that since scientists first discovered CRISPR in bacteria three years ago, it has taken the world by storm. Microbes evolved CRISPR to edit viruses out of their DNA. Now it’s been used to precisely edit everything from the DNA of crops to editing the HIV virus out of human DNA. Particularly, blood borne T cells can against viruses and cancer. Controlling these cells by rewriting their DNA is the key to cure incurable diseases. It’s all very doable: simply filter T cells from a person’s blood, edit their DNA and return them to the individual to do their job.
The challenge is delivering the CRISPR machinery into T cells. Usually it’s done by packaging CRISPR into a harmless virus that ferries it into cells. So, the scientists try brute force. They zapped T cells from healthy donors with an electric field. This made temporary holes in the cells’ membrane, big enough for the intact CRISPR machinery to pop through. They also managed to edit the DNA in 20 percent of T cells.
The challenge is delivering the CRISPR machinery into T cells. Usually it’s done by packaging CRISPR into a harmless virus that ferries it into cells. So, the scientists try brute force. They zapped T cells from healthy donors with an electric field. This made temporary holes in the cells’ membrane, big enough for the intact CRISPR machinery to pop through. They also managed to edit the DNA in 20 percent of T cells.
Yet in contrast to their brute force entry, they were able to achieve very fine editing, changing individual letters of the cell’s DNA for the first time, as opposed to inserting or deleting large chunks. For instance they altered a doorway used by HIV known as CXCR4, so the deadly virus would not be able to enter and infect these T cells.
However the editing approach raises some concerns since T cells are long-term residents – sometimes remaining in the body for years. And if they are unleashed against cancer, one has to be sure they will not then go on to attack normal cells. That is the danger because you create something that you cannot control. From now, scientists have to work ahead to figure out how to ensure safety of the T cells. After all, it is an exciting time for cell-based therapies.
However the editing approach raises some concerns since T cells are long-term residents – sometimes remaining in the body for years. And if they are unleashed against cancer, one has to be sure they will not then go on to attack normal cells. That is the danger because you create something that you cannot control. From now, scientists have to work ahead to figure out how to ensure safety of the T cells. After all, it is an exciting time for cell-based therapies.