MIT researchers have developed a way to reprogramme natural killer cells, which are part of the immune system, inside the body. They use tiny fat-based particles to carry messenger RNA, or mRNA, into these cells. The mRNA provides instructions for making proteins that help the cells recognise and destroy their targets. This could avoid the time and expense of changing cells in a laboratory before returning them to a patient.
In tests in mice, the researchers successfully changed about 80 per cent of the natural killer cells they targeted. In a test involving an aggressive skin cancer called melanoma, three of five treated mice had their cancer disappear completely. In mice with T cell lymphoma, a cancer affecting another type of immune cell, tumours disappeared after five injections.
The team also tested mice with autoimmune hepatitis, an illness in which T cells attack liver cells. After one injection, the harmful T cells were destroyed and liver damage healed. The researchers hope the approach could eventually help treat other illnesses caused by T cells attacking the body.
