A team of researchers report a novel approach in which three different gene delivery vectors were injected intravenously and directly into the kidneys of mice, rekindling hope to treat kidney diseases with gene therapy.

Before gene therapy can be used to treat renal diseases, delivery of therapeutic genes to the kidney must become much more efficient. Jeffrey Rubin, Tien Nguyen, Kari Allen, Katayoun Ayasoufi, and Michael Barry from the Mayo Clinic co-authored an article published in the journal Human Gene Therapy. As the kidney filters out large compounds from the bloodstream, the researchers chose to study the ability to deliver three different sized vectors via an intravenous route: small adeno-associated virus (AAV) vectors (25 nm), larger adenovirus vectors (100 nm) and lentiviral vectors (120 nm).

To bypass this filtering mechanism, they also tested two different direct injection routes into the kidney and found these to be superior to intravenous injections. However, some of the vectors were able to leak out of the kidney, creating the possibility for off-target tissue effects. The potential for direct injections opens new possibilities for treating kidney diseases with gene therapy, but additional improvements are needed, the authors wrote.

"The Mayo Clinic team has performed an important head-to-head comparison of currently available gene therapy technology, to identify which may best be used to address this important group of diseases," said Terence R. Flotte, Dean, Provost and Executive Deputy Chancellor, University of Massachusetts Medical School.