title: PH, pCO2, and temperature effect on R-adenovirus production.
abstract: The effects of pH, carbon dioxide vapor pressure, pCO(2), and temperature on E1 and E3 deleted recombinant adenovirus vector (rAV) production with HEK293S cells have been studied in the ranges of pH = 6.7-7.7, pCO(2) = 0.05-0.20 atm, and T = 32-39 degrees C, respectively. The experiments were performed in four 500-mL bioreactors in parallel, which make possible the reduction of inter-run variability. Cell concentration and viability, relative oxygen uptake rate (OUR), fluorescence, and viral titer were measured. It was found that, although pH and pCO(2) did not affect significantly cell viability in the range studied, they had an important effect on virus titer. pCO(2) allowed the maximum production of rAV at 0.05 atm, and pH showed a very sharp optimum at 7.2. Temperature had an effect on both cell metabolism and virus titer. Low temperature prolonged cell viability and high OUR. Most of all, a 3-fold increase in virus yield was found at 35 degrees C compared to that at 37 degrees C, while 32 degrees C was not as beneficial (1.5-fold increase). This finding could have an important impact on large-scale production. This phenomenon was modeled using a simple 3-parameter synthesis-decay model. This model shows how the optimum gain in virus production at 35 degrees C is due to a balance between the production and decay processes at that temperature.
authors.affiliation: Laboratoire d'Optimisation des Bioprocédés (LOB), Chemical Engineering Department, Centre de Recherche sur la Fonction, la Structure et l'Ingénierie des Protéines, Université Laval, Québec, Canada G1K 7P4.
authors.forename: Mario
authors.initials: M
authors.lastname: Jardon
authors.forename: Alain
authors.initials: A
authors.lastname: Garnier
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology*; D002245:Carbon Dioxide / Q000378:metabolism*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003198:Computer Simulation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000737:chemistry / Q000254:growth & development / Q000502:physiology* / Q000821:virology*; D008954:Models, Biological; D010101:Oxygen Consumption / Q000502:physiology; D010865:Pilot Projects; D011786:Quality Control; D013696:Temperature; D014776:Virus Cultivation / Q000379:methods
chemical_list: D002245:Carbon Dioxide