title: Analysis of expression kinetics and activity of a new B-domain truncated and full-length FVIII protein in three different cell lines.
abstract: Transient expression of full-length wild-type (wt) and a new B-domain truncated (deltaB) FVIII has been investigated in three eukaryotic cell lines (HEK-293, COS, CHO). When expressed in CHO cells, both FVIII proteins reached the same peak antigen levels, whereas in HEK-293 and COS cells those of FVIII/deltaB were up to sixfold those of FVIII/wt. Investigation of specific activity of the recombinant FVIII proteins using a chromogenic and a one-stage assay in addition to the FVIII-antigen ELISA revealed large variations: In HEK-293 cells specific activity of FVIII/deltaB measured with both assays was higher than that of FVIII/wt. In COS cells specific activity of both FVIII proteins was higher measured in the one-stage assay than in the chromogenic assay. In CHO cells both FVIII proteins had similar specific activity in each assay. In summary, expression kinetics and specific activity of conditioned medium vary depending on cell type used.
authors.affiliation: Institute for Experimental Hematology and Transfusion Medicine, University of Bonn, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Haack
authors.forename: C
authors.initials: C
authors.lastname: Schmitt
authors.forename: W
authors.initials: W
authors.lastname: Poller
authors.forename: J
authors.initials: J
authors.lastname: Oldenburg
authors.forename: P
authors.initials: P
authors.lastname: Hanfland
authors.forename: H H
authors.initials: HH
authors.lastname: Brackmann
authors.forename: R
authors.initials: R
authors.lastname: Schwaab
mesh_terms: D000818:Animals; D016466:CHO Cells; D019556:COS Cells; D002460:Cell Line; D006224:Cricetinae; D004622:Embryo, Mammalian; D005169:Factor VIII / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007668:Kidney; D007700:Kinetics; D015202:Protein Engineering; D011994:Recombinant Proteins; D017384:Sequence Deletion; D014162:Transfection; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D014841:von Willebrand Factor; D005169:Factor VIII