Mr. Fibi et al., STATUS AND TRANSCRIPTIONAL ACTIVITY OF A BOVINE-PAPILLOMAVIRUS-I-BASED EXPRESSION VECTOR IN A RECOMBINANT PRODUCTION CELL-LINE, Biotechnology and applied biochemistry, 23, 1996, pp. 83-93
We have analysed the status and transcriptional activity of the bovine
papillomavirus-1 (complete BPV-1 genome)-based expression vector pCES
in C127i-cell-line-derived 3T1 cells used for the industrial producti
on 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 seque
nces were not detected. Transcriptional analyses demonstrated that rhu
Epo was abundantly expressed, BPV-1 early transcription was detected,
as expected from a BPV-1-transformed cell line; however, compared with
the mouse metallothionein-1-promoter-driven rhuEpo-specific transcrip
tion, it was very weak. Late BPV-1 transcription was also not detected
in 3T1 cells under conditions of large-scale rhuEpo production. There
fore this expression system proved to be safe and suitable for the pro
duction of rhuEpo.