New approaches towards ex vivo and in vivo gene therapy.
A number of hurdles have to be overcome for efficient and specific gene therapy approaches. Here, we report on two different strategies that should lead to an improvement of current protocols. A strategy is presented to tag unique chromosomal integration sites by means of retroviral infection, which can be reused for exchange with the gene of interest by action of site-specific recombinases. Targeting exchange is achieved in one step with 100% efficiency by a stringent positive selection, which makes further screening superfluous. With this strategy a predictable gene expression is obtained for foreign genes integrated into a predefined chromatin structure. A second approach aims at the stabilization of mouse retroviruses towards human serum which is a prerequisite for in vivo gene therapy protocols. To stabilize murine leukemia virus-based retroviruses against human serum, complement regulatory proteins were fused to the retroviral ENV proteins. This resulted in infectious and human complement-protected particles.
Hauser
H
H
Department of Gene Regulation and Differentiation, GBF - National Research Institute for Biotechnology, Braunschweig, Germany. hha@gbf.de
Spitzer
D
D
Verhoeyen
E
E
Unsinger
J
J
Wirth
D
D
D016475:3T3 Cells; D000818:Animals; D018958:CD55 Antigens / Q000235:genetics; D002875:Chromosomes / Q000235:genetics; D003165:Complement System Proteins / Q000235:genetics; D015870:Gene Expression; D018390:Gene Targeting; D015316:Genetic Therapy / Q000639:trends*; D006801:Humans; D009052:Leukemia Virus, Murine / Q000235:genetics; D051379:Mice; D011951:Receptors, Complement / Q000235:genetics; D012190:Retroviridae / Q000235:genetics; D014170:Transformation, Genetic; D014760:Viral Fusion Proteins / Q000235:genetics
D018958:CD55 Antigens; D011951:Receptors, Complement; D014760:Viral Fusion Proteins; D003165:Complement System Proteins