Status and transcriptional activity of a bovine-papillomavirus-I-based expression vector in a recombinant production cell line.
We have analysed the status and transcriptional activity of the bovine papillomavirus-I (complete BPV-I genome)-based expression vector pCES in CI27i-cell-line-derived 3TI cells used for the industrial production of recombinant human erythropoietin (rhuEpo). Complete tandem head-to-tail integration of about 600 vector copies at a single site of the cellular genome was observed. Deletions, insertions or rearrangements of pCES-specific sequences or extrachromosomal copies of vector sequences were not detected. Transcriptional analyses demonstrated that rhuEpo was abundantly expressed. BPV-I early transcription was detected, as expected from a BPV-I-transformed cell line; however, compared with the mouse metallothionein-I-promoter-driven rhuEpo-specific transcription, it was very weak. Late BPV-I transcription was also not detected in 3TI cells under conditions of large-scale rhuEpo production. Therefore this expression system proved to be safe and suitable for the production of rhuEpo.
Fibi
M R
MR
Behringwerke AG, Marburg, Federal Republic of Germany.
Kunz
J
J
Weimer
T
T
Schulz
R
R
Teifke
P
P
Grzeschik
K H
KH
Johannsen
R
R
Zettlmeissl
G
G
D000818:Animals; D001483:Base Sequence; D052688:Bovine papillomavirus 1 / Q000235:genetics*; D002999:Clone Cells; D004921:Erythropoietin / Q000096:biosynthesis / Q000235:genetics*; D005285:Fermentation; D015870:Gene Expression; D005822:Genetic Vectors; D016679:Genome, Viral; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D011994:Recombinant Proteins; D004921:Erythropoietin