High-yield retroviral production using a temperature-modulated two-stage operation.
For clinical trials, large amounts of high-titer retroviral supernatants are required. However, retroviral concentration is relatively low compared with other viral vectors. Moreover, less than half of retroviral vectors suspended in a collected supernatant are infectious because of their short half-lives. In this study, a culture medium of ecotropic retrovirus-producing GP + E86/LNCX cells in tissue culture dishes was circulated through a reservoir, which was arranged with an incubator or ice-bath stage. Titers determined from the retroviral supernatant circulated through an ice-cold reservoir increased for a week from the beginning of retroviral production, while the titers from static production with circulation through the 37 degrees C reservoir reached a plateau after 3 days of retroviral production. After 5 days, 10 times more infectious retroviruses were obtained by circulating and keeping the majority of supernatant longer in the cold reservoir than in the production vessel at 37 degrees C in comparison with the number collected from the static tissue culture dish without circulating the culture medium. Furthermore, the concentration of transduction inhibitors in the supernatant was decreased along with the retardation of retroviral decay at low temperature. The two-stage operation developed in this study should be easily applied to large-scale bioreactors for mass production of high-titer retroviral supernatants.
Kwon
Young Jik
YJ
Department of Chemical Engineering, University of Southern California, Los Angeles, California 90089,USA.
Peng
Ching-An
CA
D000818:Animals; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D002460:Cell Line / Q000821:virology*; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D010865:Pilot Projects; D012190:Retroviridae / Q000254:growth & development*; D013696:Temperature; D014779:Virus Replication / Q000502:physiology*