2 NOVEL ADENOVIRUS VECTOR SYSTEMS PERMITTING REGULATED PROTEIN EXPRESSION IN GENE-TRANSFER EXPERIMENTS

Two new adenovirus vector systems based on the tetracycline-regulated Tet-ON- (Gossen, M., ct al., Science 268:1766-1769, 1995) and the RU 4 86-regulated progesterone antagonist (Wang, Y., et al., Proc. Natl. Ac ad. Sci. USA 91:8180-8184, 1991)-induced gene expression systems are d escribed. We show that both systems permit a tight control of chloramp henicol acetyltransferase reporter gene expression in a variety of cel l types, with induction levels of approximately 1,800-fold (Tet-ON sys tem) and 600-fold (RU 486-regulated system), respectively. A significa nt advantage of our vector systems is that reporter protein expression can be adjusted over a wide range by varying the amount of inducer. T he Tet-ON system is also shown to permit an efficient control of repor ter gene expression in mice.