Vaccine-like mRNA injection can be used to make CAR T cells in the body

An experimental immunotherapy can temporarily reprogram patients’ immune cells to attack a specific target via only a single injection of messenger RNA (mRNA), similar to the mRNA-based COVID-19 vaccines, according to a new study from researchers in the Perelman School of Medicine.

The researchers, whose work is published in Science, demonstrated the new approach with an mRNA preparation that reprograms T cells—a powerful type of immune cell—to attack heart fibroblast cells. Heart failure is often driven in part by these fibroblast cells, which respond to heart injury and inflammation by chronically overproducing fibrous material that stiffens the heart muscle, impairing heart function—a condition called fibrosis. In experiments in mice that model heart failure, the reduction in cardiac fibroblasts caused by the reprogrammed T cells led to a dramatic reversal of fibrosis.

“Fibrosis underlies many serious disorders, including heart failure, liver disease, and kidney failure, and this technology could turn out to be a scalable and affordable way to address an enormous medical burden,” says senior author Jonathan A. Epstein, chief scientific officer for Penn Medicine and executive vice dean and the William Wikoff Smith Professor of Cardiovascular Research in the Perelman School of Medicine. “But the most notable advancement is the ability to engineer T cells for a specific clinical application without having to take them out of the patient’s body.”

The new technique is based on chimeric antigen receptor (CAR) T cell technology, which, until now, has required the harvesting of a patient’s T cells and their genetic reprogramming in the lab to recognize markers on specific cell types in the body. These specially targeted T cells can then be multiplied using cell culture techniques and reinfused into the patient to attack a specific cell type.

Read more at Penn Medicine News.