Retroviral vectors

摘要

Retroviral vector particles having an RNA genome carrying sequences which provide in the DNA provirus at least one selected gene located within an intron in a transcription unit of the provirus, which transcription unit further comprises a polynucleotide response element responsive to a nucleus to cytoplasm transport factor such as HIV Rev. Expression of the selected genes is thus rendered Rev-dependent and so is dependent upon the presence of HIV.