Characterization of CNTF Secreting Mammalian Cell Lines for Encapsulated Cell Therapy

Abstract

Abstract: : Purpose: The objective of the current study was to characterize the CNTF secreting cell lines that will be used for encapsulated cell therapy for treating retinal degenerative diseases. Methods: Two stable CNTF secreting human mammalian cell lines were established by transfecting human RPE cells with a CNTF gene containing plasmids. The CNTF secreting cell lines are designated as NTC-201-10 and NTC-201-6A. The growth characteristics, morphology and CNTF production were monitored for over a year in culture. Their genetic stability, CNTF gene insertion site and copy number were evaluated. CNTF production and other factors secreted by the cells were evaluated by ELISA and 2D gel electrophoresis for paretnal cells and CNTF gene transfected cells. Results: Both NTC-201-10 and NTC-201-6A cell lines maintained normal RPE morphology with stable CNTF output in vitro for over a year. Un-encapsulated NTC-201-10 cell line produced ~200 ng/10⁶ cells/day, and NTC-201-6A cell line produced ~800 ng/10⁶ cells/day. Genetic stability studies indicated that both cell lines are stable over the passages of master cell bank, working cell bank, and end-of-production. Conclusions: Two stable CNTF secreting cell lines were successfully established. They maintained normal growth characteristics and morphology for over a year in vitro, and produced biologically active CNTF. Their encapsulated performance and safety profile made them ideal for Encapsulated Cell Therapy.

Keywords: retinal pigment epithelium • degenerations/dystrophies • retinitis