| 摘要 |
<p>The present invention pertains to recombinant retrovirus vectors having a U3-free 5' LTR, a partially deleted 3' LTR, all essential cis-acting sequences for replication, an internal promoter recognizable by a selected host cell, and a non-retroviral gene under the control of the recognized promoter wherein (a) the U3-free 5' LTR is positioned 5' of the non-retroviral gene and has a transcriptional promoter and enhancer different from that of the original retroviral promoter and enhancer replacing the original U3 region of the 5'LTR; (b) the partially deleted 3' LTR is positioned 3' of the non-retroviral gene and has no U3 sequences except for those required at the attachment site for viral integration; (c) an exogenous polyadenylation addition signal sequence recognized by the selected host cell and positioned on the vector 3' to the 3'LTR viral integration site; and (d) the internal recognized promoter is positioned adjacent to the non-retroviral gene on the vector to permit expression of the non-retroviral gene in the host cell; whereby the vector can produce progeny virus in a helper cell with the progeny virus being capable of infecting the selected host cell and forming a provirus in the host cell, with the non-retroviral gene being expressible in the host cell, but the provirus in the host cell will be replication incompetent even in the presence of a helper virus.</p> |
