Abstract: Host cells may be treated for an infection or a hyperproliferative disorder which is characterized by the presence, in the affected cells, of a trans-acting factor capable of regulating gene expression by inserting into the cells a polynucleotide construct having a cis-acting regulatory sequence which is regulated by the trans-acting factor and an effector gene which renders said cell susceptible to protection or destruction. For example, the cis-acting region may be homologous to the HIV tar region, and the effector gene may encode ricin A or HSV-1 thymidine kinase. Upon infection with HIV, the HIV tat protein activates the tar region, and induces transcription and expression of ricin A, resulting in cell death, or of HSV-1 tk, resulting in cell death upon treatment with dideoxynucleoside agents such as acyclovir and gancyclovir.

Abstract: The present invention is directed to a DNA construct which is useful for immunization or gene therapy. The construct of the invention comprises muscle specific regulatory elements, such as a promoter or a promoter and one or more enhancer elements, and a DNA sequence under control of the muscle specific regulatory elements. Several DNA sequences may be incorporated into the DNA construct. In one embodiment, the DNA sequence codes for an antigen, antigenic determinant or an epitope of an antigen. In a second embodiment, the DNA sequence is a normal muscle gene which is effected in a muscle disease. In a third embodiment, the DNA sequence is an antisense for blocking an abnormal muscle gene. In a fourth embodiment, the DNA sequence codes for a protein which circulates in the mammalian blood or lymphatic systems.