Growth of recombinant Drosophila melanogaster Schneider 2 cells producing rabies virus glycoprotein in bioreactor employing serum-free medium

Abstract

Drosophila melanogaster Schneider 2 (S2) cells have been increasingly used as a suitable expression system for the production of different recombinant proteins, and the employment of bioreactors for large-scale culture is an important tool for this purpose. In this work, Drosophila S2 cells producing the rabies virus glycoprotein RVGP were cultivated in bioreactor, employing a serum-free medium, aiming an improvement in cell growth and in glycoprotein production. To overcome cell growth limitation commonly observed in stirred flasks, different experiments in bioreactor were performed, in which some system modifications were carried out to attain the desired goal. The study showed that this cell line is considerably sensitive to hydrodynamic forces, and a high cell density (about 16.0 x 10(6) cells mL(-1)) was only obtained when Pluronic F68((R)) percentage was increased to 0.6% (w/v). Despite ammonium concentration affected RVGP production, and also cell growth, an elevated amount of the target protein was obtained, attaining 563 ng 10(-7) cells.

Fig. 1

Cell growth (a) and viability (b) for runs 1 (●), 2 (■), 3 (△), 4 (◊) and 5 (□)

Fig. 2

Glucose (a), glutamine (b), lactate (c) and NH₄⁺ (d) profiles for runs 1 (●), 2 (■), 3 (△), 4 (◊) and 5 (□)

Fig. 3

RVGP (□) and RVGP cell content () (bar graphs), and viable cell concentration (▲), NH₄⁺ concentration (◊), lactate concentration (✶) and pH (○) for runs 1 (a), 2 (b) and 3 (c)

Fig. 4

RVGP (□) and RVGP cell content () (bar graphs), and viable cell concentration (▲), NH₄⁺ concentration (◊), lactate concentration (✶) and pH (○) for runs 4 (a) and 5 (b)