Researchers in Germany, using gene editing, have corrected an exaggerated immune response that is a key feature of a rare childhood disease.

The study, led by EARA member the Max Delbrück Center (MDC), and also involving EARA member Charité Berlin and the University Medical Center Hamburg-Eppendorf, may lead to a new way to treat familial hemophagocytic lymphohistiocytosis (FHL), a disease of the immune system commonly affecting young children.

FHL is caused by gene mutations and can often be fatal because the mutations prevent immune cells in the body from destroying virus-infected cells – for example by Eppstein-Barr virus (EBV) – leading to excessive, life-threatening inflammation.

But using CRISPR gene editing, the team were able to repair these defective immune cells in EBV-infected mice as well as in blood samples taken from two babies with FHL, dampening the immune response and returning it to normal.

Prof Klaus Rajewsky, at MDC, said: “We very much hope that our mechanism of action is a leap forward in treating FHL, either to gain more time for a successful bone marrow transplant or even as a treatment itself.”