Vector for integration site independent gene expression in mammalian host cells which permit immunoglobulin gene expression

摘要

A vector for the integration of a gene into the genetic material of a mammalian host cell such that the gene may be expressed by the host cell. The vector comprises a promoter and the gene and in an immunoglobulin dominant control region derived from the mouse &lgr; immunoglobulin gene locus capable of eliciting host cell-type restricted, integration site independent, copy number dependent expression of said gene. The DNasel super hypersensitive site exemplified are i) about 2.35 kb upstream of the CAP site of the rearranged &lgr;.sub.1 gene, ii) about 2.5 kb upstream of the genomic V&lgr;.sub.2 segment or iii) about 30 kb downstream of the rearranged &lgr;.sub.1 gene. Mammalian host cells transformed with the vector are disclosed as are transgenic mammals transformed with the vector and a method of producing a polypeptide comprising culturing a transformed mammalian cell. A method of gene therapy comprising the steps of i) removing stem cells from the body of a mammal, ii) optionally killing stem cells remaining in the body, iii) transforming the removed stem cells with the vector containing a gene deficient or absent in the body, and iv) replacing the transformed stem cells in the body is also disclosed. Also disclosed is functional mouse immunoglobulin &lgr;.sub.1 enhancer consisting of a DNA sequence comprising all or a functional part of the DNA sequence between the EcoRI site 3.8 kb downstream of the Xho I site in the rearranged mouse &lgr;. sub.1 gene and the SnaBI site 10 kb downstream of this Xho I site. The functional mouse immunoglobulin &lgr;.sub.1 enhancer may comprise all or a functional part of i) the 1.3 kb first HindIII to HindIII DNA fragment downstream of the EcoRI site 3.8 kb downstream of the Xho I site in the rearranged mouse &lgr;.sub.1 gene, ii) the 3.3 kb HindIII to HindIII DNA fragment downstream of the EcoRI site 3.8 kb downstream of the Xho I site in the rearranged mouse &lgr; .sub.1 gene and spanning the SnaBI site 10 kb downstream of this Xho I site.