title: The establishment of IL-2 producing cells by genetic engineering.
abstract: Expression plasmids containing human interleukin-2(IL-2) cDNA under the control of viral promoters (SV40 early region, MuLV LTR, HTLV-I LTR, and ASV (Y73) LTR) were introduced into TK- mouse L cells and human FL cells to establish IL-2 producing cells. The highest levels of IL-2 producing clones were obtained in TK+ mouse L cells transformed with a recombinant plasmid having MuLV LTR as a promoter, whereas transformed cells of human FL cells (G418r) were revealed to produce IL-2 at the highest level when the cells were transfected with a plasmid containing HTLV LTR as a promoter. These results suggest that these promoter/enhancer regions possess different cell specificities in gene expression. To obtain higher levels of IL-2 production using gene amplification, the hybrid plasmids containing the hamster DHFR and human IL-2 genes were constructed and transfected into DHFR- CHO cells. DHFR+ colonies produced IL-2 at about the same level as that produced by TK+ L cells transformed with the recombinants containing MuLV LTR. Selection of methotrexate-resistant cells resulted in a 5- to 30-fold increase of IL-2 production. These cells produced IL-2 stably for at least 3 months, even in the absence of methotrexate.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D005784:Gene Amplification; D005818:Genetic Engineering / Q000379:methods; D005822:Genetic Vectors; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics*; D007739:L Cells / Q000378:metabolism; D051379:Mice; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013539:Simian virus 40 / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics
chemical_list: D007376:Interleukin-2; D004247:DNA; D013937:Thymidine Kinase