A new class of cancer treatments recruits the cells in our blood to fight tumors, using gene-editing tools to transform a type of white blood cell called T cell from an immune cell that usually targets bacterial or fungal infections into a living cancer drug.
The genetic alterations could boost immune systems to fight cancers on their own successfully. Researchers remove T cells from patients and slip new genes into the cells. After clinicians return the modified T cells to patients, the cells, like microscopic bloodhounds, lead the immune system on the hunt for tumors.
“We are living in an amazing moment in cancer immunotherapies,” said Alexander Marson, a microbiology and immunology professor at the University of California at San Francisco.
In 2017, the Food and Drug Administration began approving genetically altered immune cells for small groups of patients, such as those with aggressive non-Hodgkin lymphoma or a rare form of childhood leukemia. Other experimental trials, involving cancers such as multiple myeloma and melanoma, show encouraging results.
But further developments have been slowed, with a bottleneck arising not from red tape but demand. Delivery systems able to insert new genes into immune cells are in short supply.
Disabled viruses, which inject genes into cells like a shot from a syringe, are the current standard. Just a few biotechnology companies, equipped with expensive manufacturing systems, can produce the viral vectors.
Wait times for new viruses can be as long as several years, as James M. Wilson, who directs the gene therapy program at the University of Pennsylvania’s Perelman School of Medicine, told the New York Times in November.
Marson and his colleagues have developed a new, faster method to reprogram T cells, as they described Wednesday in the journal Nature. Rather than relying on viruses to deliver the genetic package, researchers jolted T cells with electricity. The shock relaxed the membranes that surround the cells, making them receptive to the new genetic material.
If chains of edited genes floated nearby, as they did in the study, the DNA commuted through the membrane. With the help of CRISPR-Cas9, a molecular system often likened to cut-and-paste, the new DNA fused into the cell's nucleus.
“It is a turning point,” said Vincenzo Cerundolo, director of the Human Immunology Unit at Oxford University, who was not involved with this study. “It is a game-changer in the field, and I'm sure that this technology has legs.”
He predicts cheaper therapies and much faster development times as swiftly as a week, rather than the months required to manufacture a virus. Researchers previously used the delivery technique, called electroporation, to coax genetic material into cells.
Last year, for example, Harvard University scientists translated a movie of galloping horse into DNA. Through electroporation, they inserted the clip (an animated GIF) into bacteria.