High transduction efficiency of human amniotic fluid stem cells mediated by adenovirus vectors.

In the last few years some studies have shown the possibility of deriving progenitors with various potential from the amniotic fluid. Amniocentesis is a widely accepted method for prenatal diagnosis; it is associated with low risk both for the mother and the fetus and overcomes the ethical problems commonly associated to other sources. Recently we have described that amniotic fluid stem (AFS) cells, for their ability to differentiate to various lineages, could represent a good candidate for therapeutic applications. For gene therapy purposes human AFS (hAFS) cells should be genetically modified with a therapeutic gene and delivered systematically or injected directly into the tissue of interest. The aim of this study was to investigate the feasibility of transducing hAFS cells with adenoviral vectors and to determine whether transduced stem cells retain the ability to differentiate into different lineages. Herein, we showed that hAFS cells could be efficiently infected by first generation adenovirus vectors. In addition, we demonstrated that infection and expression of two different marker genes, LacZ and EGFP, have no effect on cells phenotype and differentiation potential. In particular, on undifferentiated status, hAFS cells continued to express both the transgenes and stemness cell markers OCT4 and SSEA4. When cultured under mesenchymal conditions, infected cells could still differentiate into osteocytes and adipocytes expressing lineage specific genes. These preliminary findings suggest that adenovirus may be useful to engineer populations of pluripotent stem cells, which may be used in a wide range of gene therapy treatments.