Production of human tissue-type plasminogen activator in different mammalian cell lines using an Epstein-Barr virus vector.
Human tissue-type plasminogen activator (t-PA) cDNA inserted into an Epstein-Barr virus (EBV) derived expression vector was transfected into human HeLa, 293, K-562 and hamster CHO-K1 cells and the expression of t-PA was studied. The best t-PA producing cell clones were found among CHO-K1 cells (up to 11 micrograms d-1 per 10(6) cells). However, HeLa and 293 cells were most efficiently transfected, e.g. about 70% of the selected cell clones were t-PA positive. The vector DNA copy numbers correlated with the mRNA levels and the protein levels for all cell lines analysed, with the exception for the K-562 cell line, where the production of t-PA was very low. The results obtained indicated that the highest expression levels were achieved in low density cultures.
Orion Corporation, Genetic Engineering Laboratory, Helsinki, Finland.
A
A
Jalanko
J
J
Pirhonen
G
G
Pohl
L
L
Hansson
D000818:Animals; D002452:Cell Count; D002460:Cell Line; D006224:Cricetinae; D004247:DNA / Q000235:genetics*; D005822:Genetic Vectors; D006367:HeLa Cells; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D012333:RNA, Messenger / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D004247:DNA; D010959:Tissue Plasminogen Activator