| abstract |
The present invention relates to the field of molecular biology, especially recombinant DNA technology, especially concerning retroviral vectors. Retroviral vectors are very suitable vehicles for transferring genetic material of interest into certain cells in so-called gene therapy strategies. However, the retroviral vectors described so far are not ideal. They may give rise to recombination events resulting in helper (pathogenic) virus, they may express viral proteinaceous materials leading to immune responses, etc. These and other drawbacks are overcome by the vectors, cells, kits and methods of the present invention by providing a vector derived from a retrovirus, comprising a sequence responsible for transcriptional control, including an enhancer, which vector further comprises a site for insertion of at least one gene of interest, a packaging signal, said vector having no superfluous retroviral sequences and no open reading frame encoding at least parts of viral proteins, characterized in that the enhancer is an enhancer that is active in undifferentiated cells. |