Researchers at the Institut de Recerca de l'Hospital Universitari Vall d'Hebron, Barcelona (IR-HUVH) have published a work which reveals a potential risk in the gene therapy based on hematopoietic stem cells: the risk of immunization against the therapeutic gene and its subsequent rejection. The danger had been suspected, but so far it had not been possible to verify it experimentally. The study is published in the journal 'Molecular Therapy'.
Staff | 2 February 2010
In gene therapy, the genetic information of cells is modified by introducing one foreign gene (called 'transgene') that modulates the activity of certain proteins, with the objective of correcting the symptoms of a genetic disease. In the study, conducted in mice, transgenes were transferred to cells in the bone marrow, called hematopoietic cells, responsible for the production of all blood cells.
The researchers found that when these transgenes are expressed at high levels, they trigger an immune response against the protein they produce or against the transplanted cells themselves. This does not happen when the expression is weaker. This response causes rejection of transplanted cells, so they miss their target therapy and may prevent or reduce the effectiveness of possible future treatments.
The present study is a further sign of alarm, as it provides relevant information regarding other potential risks or complications of such therapies: the possible induction of immune responses. Furthermore, research has been carried out in bone marrow tissue, usually not very susceptible in triggering responses of this type.
