Abstract: Provided are methods, expression systems, kits, and vectors for constitutive and/or cumate-inducible expression of a gene of interest in CHO cells. The expression systems and methods described herein employ CHO cells that are stably transfected with a nucleic acid molecule encoding a reverse cumate transactivator (rcTA), the expression of which is regulated by a cymene repressor (CymR). for constitutive and/or cumate-inducible expression of a gene of interest.

Abstract: Processes, vectors and engineered cell lines for large-scale transfection and protein production in mammalian cells, especially Chinese Hamster Ovary (CHO) cells are described in which transfection efficiencies are realized through the use of a single vector system, the use of functional oriP sequences in all plasmids, the use of codon-optimized Epstein-Barr virus nuclear antigen-1 (EBNA1) constructs, the use of a fusion protein between a truncated Epstein-Barr virus nuclear antigen-1c (EBNA1c) protein and a herpes simplex virus protein VP16, the use of a 40 kDa fully deacetylated poly(ethylenimine) as a transfection reagent, the use of co-expression of a fibroblast growth factor (FGF) and/or the use of protein kinase B to potentiate heterologous gene expression enhancement by valproic acid (VPA).

Abstract: Processes, vectors and engineered cell lines for large-scale transfection and protein production in mammalian cells, especially Chinese Hamster Ovary (CHO) cells are described in which transfection efficiencies are realized through the use of a single vector system, the use of functional oriP sequences in all plasmids, the use of codon-optimized Epstein-Barr virus nuclear antigen-1 (EBNA1) constructs, the use of a fusion protein between a truncated Epstein-Barr virus nuclear antigen-1c (EBNA1c) protein and a herpes simplex virus protein VP16, the use of a 40 kDa fully deacetylated poly(ethylenimine) as a transfection reagent, the use of co-expression of a fibroblast growth factor (FGF) and/or the use of protein kinase B to potentiate heterologous gene expression enhancement by valproic acid (VPA).

Abstract: Processes vectors and engineered cell lines for large-scale transfection and protein production in mammalian cells, especially Chinese Hamster Ovary (CHO) cells are described in which transfection efficiencies are realized through the use of a single vector system, the use of functional oriP sequences in all plasmids, the use of codon-optimized Epstein-Barr virus nuclear antigen-1 (EBNA1) constructs the use of a fusion protein between a truncated Epstein-Barr virus nuclear antigenen-1c (EBNA1c) protein and a herpes simplex virus protein VP16, the use of a 40 kDa fully deacetylated poly(ethylenimine) as a transfection reagent, the use of co-expression of a fibroblast growth factor (FGF) and/or the use of protein kinase B to potentiate heterologous gene expression enhancement by valproic acid (VPA).

Abstract: Processes vectors and engineered cell lines for large-scale transfection and protein production in mammalian cells, especially Chinese Hamster Ovary (CHO) cells are described in which transfection efficiencies are realized through the use of a single vector system, the use of functional oriP sequences in all plasmids, the use of codon-optimized Epstein-Barr virus nuclear antigen-1 (EBNA1) constructs the use of a fusion protein between a truncated Epstein-Barr virus nuclear antigenen-1c (EBNA1c) protein and a herpes simplex virus protein VP16, the use of a 40 kDa fully deacetylated poly(ethylenimine) as a transfection reagent, the use of co-expression of a fibroblast growth factor (FGF) and/or the use of protein kinase B to potentiate heterologous gene expression enhancement by valproic acid (VPA).

Abstract: A method of purifying a recombinant interferon protein involves providing an aqueous mixture of the recombinant protein and contaminating proteins; precipitating the contaminating proteins from the aqueous mixture at a pH in a range of from 0.5 to 6; separating the aqueous mixture from the precipitated contaminating proteins; and, eluting the separated aqueous mixture through a cation exchange column using a mobile phase with a salt or pH gradient, the gradient being from lower salt concentration or pH to higher salt concentration or pH, to produce a recombinant interferon protein fraction separated from other components of the aqueous mixture. The method provides for the recovery of recombinant interferon proteins in better yield and purity.