Nature 573, 430–433 (2019)

T cells can be programmed to help damaged hearts. Normally, an injury to the heart, such as a heart attack, activates a subclass of cells known as cardiac fibroblasts, which deposit additional extracellular matrix proteins, resulting in fibrosis, which worsens heart function and signals to cardiomyocytes, negatively impacting their function.

Credit: Mutlu Kurtbas / E+ / Getty

A group of scientists in the United States and Germany engineered T cells that identify the pathological fibroblast using a protein unique to the latter cells. They show in mice that, following heart injury, the engineered T cells are able to eliminate the fibroblasts that have gone awry in the heart and improve cardiac function.