Quantitative correlation between transcriptional levels of ER chaperone, peroximal protein and FVIII productivity in human Hek-293 cell line

Hek-293 cell line presents good production platform for recombinant therapeutic proteins, however little is known about the components that contribute to the cellular control of recombinant protein production. In this study, we generated a Hek-293 producing recombinant factor VIII (FVIII) and we evaluated the immunoglobulin-binding protein (BiP) and phytanoil-CoA α-hydroxylase (PAHX) expression levels which are known for diminishing FVIII production. Our analyses showed that the recombinant cell population expresses 3.1 ± 1.4 fold of BIP mRNA (P = 0.0054) and 97.8 ± 0.5 fold of PAHX mRNA (P = 0.0016) compared to nontransduced cells. The amount of these proteins was inversely correlated to the secreted FVIII. In conclusion, BIP and PAHX expression are augmented in human cells producing FVIII and they antagonize the amount of therapeutic factor VIII in the cell culture.

This study was supported by the Center for Cell-based Therapy (CTC) and Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP. The authors acknowledge Dr. Garry P. Nolan for contributing with the pBMN-I-GFP vector and David Marco Antonio for statistical support. We thank Fernanda Udinal and Alessandra Almeida for English language support. We also thank Sandra Navarro Bresciani for preparing the figures.

This study was supported by the Center for Cellbased Therapy (CTC) and Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP. The authors acknowledge Dr. Garry P. Nolan for contributing with the pBMNIGFP vector and David Marco Antonio for statistical support. We thank Fernanda Udinal and Alessandra Almeida for English language support. We also thank Sandra Navarro Bresciani for preparing the figures.