Controlled gene product delivery from a regulatable retroviral vector

A tetracycline regulated retroviral vector for expressing a coding sequence, the vector comprising the following DNA sequences operatively linked from 5' to 3':

• (a) DNA comprising a first promoter;
• (b) DNA encoding a selectable marker under the transcriptional control of said first promoter in (a);
• (c) DNA comprising a second promoter different from the first promoter in (a) and different from the third promoter in (g);
• (d) DNA encoding a tetracycline regulator unit (tTA) under the transcriptional control of said second promoter;
• (e) an endonuclease site;
• (f) DNA comprising a tetracycline response unit (tetO) in an antisense orientation relative to said DNA encoding said regulator unit of (d);
• and
• (g) DNA comprising a third promoter different from the first promoter in (a) and different from the second promoter in (c) wherein said DNA comprising said response unit of (f) is comprised within said third promoter,
• wherein a coding sequence can be incorporated into the vector and operably linked to the third promoter of (g).