Inducible expression of amplified human beta interferon genes in CHO cells

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.4.1.166· OSTI ID:6030259

McCormick, F; Trahey, M; Innis, M; Dieckmann, B; Ringold, G

Plasmid DNA containing the human beta-interferon (IFN-..beta..) gene and mouse dihydrofolate reductase cDNA was transfected into dihydrofolate reductase-negative Chinese hamster ovary cells. Dihydrofolate reductase-positive transformants were obtained, and cells containing amplified copies of mouse dihydrofolate reductase were selected by exposure to increasing methotrexate concentrations. These cells were found to express high levels of human IFN-..beta.. after polyriboinosinic acid-polyribocytidylic acid superinduction or NDV infection; this was a result of coamplification of the IFN-..beta.. gene. Levels of expression of 1 U/cell per day were achieved on superinduction, giving corresponding titers of up to 10/sup 10/ U/liter medium in culture supernatants. Constitutive production of IFN-..beta.. at rates of about 0.5% of superinduced rates was observed; cells producing these levels of IFN-..beta.. had acquired resistance to cytotoxic antiviral effects of IFN-..beta... Two forms of human IFN-..beta.. were produced; a major glycosylated 23,000-dalton form and an unglycosylated 18,500-dalton form. The latter had greatly reduced antiviral activity. IFN-..beta.. production was very sensitive to cellular growth rate; the highest levels were produced by density-arrested cultures. Regulation of IFN-..beta.. production by polyriboinosinic acid-polyribocytidylic acid or by cell density effects required the presence of DNA sequences 5' to the IFN-..beta..-coding sequences; replacement of these sequences with the simian virus 40 early promoter resulted in uninducible, density-independent production of IFN-..beta...

• Research Organization: Cetus Corp., Emeryville, CA 94608
• OSTI ID: 6030259
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 4:1; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BIOLOGICAL FUNCTIONS
CELL CONSTITUENTS
CHO CELLS
CLASSIFICATION
CLONING
DNA
DNA SEQUENCING
DNA-CLONING
ENZYME INDUCTION
ENZYMES
FUNCTIONS
GENE AMPLIFICATION
GENE REGULATION
GENES
GROWTH FACTORS
INFECTIVITY
INTERFERON
LYMPHOKINES
MAMMALS
MAN
MICROORGANISMS
MITOGENS
MUTANTS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PARASITES
PHENOTYPE
PLASMIDS
PRIMATES
PRODUCTION
PROTEINS
RECOMBINANT DNA
SIMIAN VIRUS
STRUCTURAL CHEMICAL ANALYSIS
VERTEBRATES
VIRUSES