Adenovirus-mediated suicide gene therapy in an in vitro model of reactive gliosis

Adenovirus-mediated herpes simplex thymidine kinase/ganciclovir (HSV-tk/GCV ) system has been demonstrated to be efficient for the treatment of experim ental brain tumors. However, no study has been directed to the elimination of proliferating cellular populations in other pathological conditions. In this study we used this suicide gene approach in a primary culture of astro cytes, as a model of reactive gliosis, in order to evaluate its efficiency as a therapeutic strategy for post-traumatic astrogliosis in vivo. First, w e evaluated the peak of astrocytic proliferation to characterize our model. Second, the efficiency of adenovirus-mediated lacZ gene transfer is shown to be dependent on vector multiplicity of infection (MOI). As expected, the cells transfected with the HSV-tk gene showed an increase in sensibility t o GCV compared with cells transfected with lacZ gene. Finally, an unexpecte d interaction between the adenoviral vector and bromodeoxyuridine (BrdU) or [H-3]-Thymidine ([H-3]-Thy) was evidenced in transfected cultures, whose i nterpretation is discussed. The present study demonstrates that a recombina nt adenoviral vector carrying the th gene confers to in vitro cultured astr ocytes a cytotoxic sensibility to GCV, and that this system constitutes a p otentially efficient tool to eliminate the hyperplasia of astrocytes follow ing injury to the central nervous system in vivo. (C) 1999 Wiley-Liss, Inc.