Novel gene therapy reverses haemophilia
Scientists using mice have developed a new way to deliver gene therapies. By using hollow particles to deliver a gene into cells, they successfully reversed haemophilia symptoms.
Gene therapy can be used to treat diseases caused by a mutated or missing gene. The technique involves delivering a correct copy of the gene. However, current methods haven't worked too well in patients;often the gene binds at the wrong place in the DNA or doesn't integrate itself into the cell. The new technique using very small nanoparticles to deliver the genes aimed to overcome these problems. The team also used a genetic element known as Sleeping Beauty to help integrate the genes into the cells' DNA.
Haemophilia is a blood disorder caused by a lack of a protein called Factor VIII (FVIII). FVIII helps blood clot after injury; so lack of the protein means blood cannot clot effectively. The team loaded the nanoparticles with the gene that produces the FVIII protein (along with the Sleeping Beauty element), and covered the particle with chemicals to seek out and selectively bind to specialised liver cells. They then injected the particles into mice and monitored the effect on blood clotting time and levels of the FVIII protein.
At five and 50 weeks the clotting times of the treated mice were about the same as in normal mice, and much longer than in the untreated group. At 50 weeks the levels of Factor VIII in the blood of mice given the nanoparticles were also the same as in normal mice.
Using nanoparticles with the Sleeping Beauty genetic element seems to work well, and could represent a viable way to deliver gene therapies for various diseases.