Abstract
We have constructed expression vectors for Chinese hamster ovary (CHO) cells that produce both selectable marker and recombinant cDNA from a single primary transcript via differential splicing. These vectors produce stable CHO cell clones that, when pooled, produce abundant amounts of secreted recombinant proteins compared with the amounts produced by conventional expression approaches that have selectable marker and the cDNA of interest under control of separate transcription units. Our vectors divert most of the transcript to product expression while linking it, at a fixed ratio, to dihydrofolate reductase (DHFR) expression to allow selection of stable transfectants. Pools of clones with increased expression of the product gene can be efficiently generated by selection in methotrexate. The high level of expression from pools allows convenient and rapid production of milligram amounts of recombinant proteins.
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- Abrams J. M., Thorpe S. M., Schimke R. T. Intronic positioning maximizes co-expression and co-amplification of nonselectable heterologous genes. J Biol Chem. 1989 Aug 25;264(24):14016–14021. [PubMed] [Google Scholar]
- Busslinger M., Hurst J., Flavell R. A. DNA methylation and the regulation of globin gene expression. Cell. 1983 Aug;34(1):197–206. doi: 10.1016/0092-8674(83)90150-2. [DOI] [PubMed] [Google Scholar]
- Cepko C. L., Roberts B. E., Mulligan R. C. Construction and applications of a highly transmissible murine retrovirus shuttle vector. Cell. 1984 Jul;37(3):1053–1062. doi: 10.1016/0092-8674(84)90440-9. [DOI] [PubMed] [Google Scholar]
- Chu G., Hayakawa H., Berg P. Electroporation for the efficient transfection of mammalian cells with DNA. Nucleic Acids Res. 1987 Feb 11;15(3):1311–1326. doi: 10.1093/nar/15.3.1311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davies M. V., Kaufman R. J. The sequence context of the initiation codon in the encephalomyocarditis virus leader modulates efficiency of internal translation initiation. J Virol. 1992 Apr;66(4):1924–1932. doi: 10.1128/jvi.66.4.1924-1932.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eaton D. L., Wood W. I., Eaton D., Hass P. E., Hollingshead P., Wion K., Mather J., Lawn R. M., Vehar G. A., Gorman C. Construction and characterization of an active factor VIII variant lacking the central one-third of the molecule. Biochemistry. 1986 Dec 30;25(26):8343–8347. doi: 10.1021/bi00374a001. [DOI] [PubMed] [Google Scholar]
- Gasser C. S., Simonsen C. C., Schilling J. W., Schimke R. T. Expression of abbreviated mouse dihydrofolate reductase genes in cultured hamster cells. Proc Natl Acad Sci U S A. 1982 Nov;79(21):6522–6526. doi: 10.1073/pnas.79.21.6522. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jang S. K., Davies M. V., Kaufman R. J., Wimmer E. Initiation of protein synthesis by internal entry of ribosomes into the 5' nontranslated region of encephalomyocarditis virus RNA in vivo. J Virol. 1989 Apr;63(4):1651–1660. doi: 10.1128/jvi.63.4.1651-1660.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaufman R. J., Murtha P., Davies M. V. Translational efficiency of polycistronic mRNAs and their utilization to express heterologous genes in mammalian cells. EMBO J. 1987 Jan;6(1):187–193. doi: 10.1002/j.1460-2075.1987.tb04737.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaufman R. J., Sharp P. A. Amplification and expression of sequences cotransfected with a modular dihydrofolate reductase complementary dna gene. J Mol Biol. 1982 Aug 25;159(4):601–621. doi: 10.1016/0022-2836(82)90103-6. [DOI] [PubMed] [Google Scholar]
- Levinson A. D. Expression of heterologous genes in mammalian cells. Methods Enzymol. 1990;185:485–487. doi: 10.1016/0076-6879(90)85040-u. [DOI] [PubMed] [Google Scholar]
- Liu C. C., Simonsen C. C., Levinson A. D. Initiation of translation at internal AUG codons in mammalian cells. Nature. 1984 May 3;309(5963):82–85. doi: 10.1038/309082a0. [DOI] [PubMed] [Google Scholar]
- Neumann E., Schaefer-Ridder M., Wang Y., Hofschneider P. H. Gene transfer into mouse lyoma cells by electroporation in high electric fields. EMBO J. 1982;1(7):841–845. doi: 10.1002/j.1460-2075.1982.tb01257.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelletier J., Sonenberg N. Internal initiation of translation of eukaryotic mRNA directed by a sequence derived from poliovirus RNA. Nature. 1988 Jul 28;334(6180):320–325. doi: 10.1038/334320a0. [DOI] [PubMed] [Google Scholar]
- Pennica D., Holmes W. E., Kohr W. J., Harkins R. N., Vehar G. A., Ward C. A., Bennett W. F., Yelverton E., Seeburg P. H., Heyneker H. L. Cloning and expression of human tissue-type plasminogen activator cDNA in E. coli. Nature. 1983 Jan 20;301(5897):214–221. doi: 10.1038/301214a0. [DOI] [PubMed] [Google Scholar]
- Potter H., Weir L., Leder P. Enhancer-dependent expression of human kappa immunoglobulin genes introduced into mouse pre-B lymphocytes by electroporation. Proc Natl Acad Sci U S A. 1984 Nov;81(22):7161–7165. doi: 10.1073/pnas.81.22.7161. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Presta L. G., Lahr S. J., Shields R. L., Porter J. P., Gorman C. M., Fendly B. M., Jardieu P. M. Humanization of an antibody directed against IgE. J Immunol. 1993 Sep 1;151(5):2623–2632. [PubMed] [Google Scholar]
- Simonsen C. C., Levinson A. D. Isolation and expression of an altered mouse dihydrofolate reductase cDNA. Proc Natl Acad Sci U S A. 1983 May;80(9):2495–2499. doi: 10.1073/pnas.80.9.2495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Suva L. J., Winslow G. A., Wettenhall R. E., Hammonds R. G., Moseley J. M., Diefenbach-Jagger H., Rodda C. P., Kemp B. E., Rodriguez H., Chen E. Y. A parathyroid hormone-related protein implicated in malignant hypercalcemia: cloning and expression. Science. 1987 Aug 21;237(4817):893–896. doi: 10.1126/science.3616618. [DOI] [PubMed] [Google Scholar]
- Urlaub G., Chasin L. A. Isolation of Chinese hamster cell mutants deficient in dihydrofolate reductase activity. Proc Natl Acad Sci U S A. 1980 Jul;77(7):4216–4220. doi: 10.1073/pnas.77.7.4216. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Watt F., Molloy P. L. Cytosine methylation prevents binding to DNA of a HeLa cell transcription factor required for optimal expression of the adenovirus major late promoter. Genes Dev. 1988 Sep;2(9):1136–1143. doi: 10.1101/gad.2.9.1136. [DOI] [PubMed] [Google Scholar]
- Yates J. L., Warren N., Sugden B. Stable replication of plasmids derived from Epstein-Barr virus in various mammalian cells. 1985 Feb 28-Mar 6Nature. 313(6005):812–815. doi: 10.1038/313812a0. [DOI] [PubMed] [Google Scholar]
- de Sauvage F. J., Hass P. E., Spencer S. D., Malloy B. E., Gurney A. L., Spencer S. A., Darbonne W. C., Henzel W. J., Wong S. C., Kuang W. J. Stimulation of megakaryocytopoiesis and thrombopoiesis by the c-Mpl ligand. Nature. 1994 Jun 16;369(6481):533–538. doi: 10.1038/369533a0. [DOI] [PubMed] [Google Scholar]