Cancerous white blood cells from people with a form of leukaemia have been reprogrammed into immune cells that do not cause the disease in animals.

Immature immune cells called B cells cannot develop fully in people with precursor B-cell acute lymphoblastic leukaemia (B-ALL). Ravindra Majeti and his colleagues at Stanford University in California isolated diseased cells with specific mutations from 12 patients with B-ALL.

The researchers reprogrammed the cells by culturing them with molecules that promote the development of myeloid cells, which include several types of white blood cell. They ended up with cells that were similar to macrophages, which engulf pathogens, and did not develop into cancer when transplanted into mice. Turning on a myeloid regulatory gene in the cells achieved the same result.

This could be a therapeutic strategy for some people with B-ALL, the authors say.

Proc. Natl Acad. Sci. USA http://doi.org/24t (2015)