Integrated optimization of retrovirus production for gene therapy

摘要

Currently, a large number of gene therapy applications make use of retroviruses as vehicles for gene delivery [1], since retroviruses provide permanent integration of foreign genes in cellular DNA [2] and, in contrast to other viral delivery systems, stable helper cell lines for their production are available [3]. However, several factors are limiting the commercial production procedures and wider clinical applications of retrovirus mediated gene delivery. The most relevant are the low titers obtained in culture, which seldom rise above 10~6 infective particles per milliliter and the low retrovirus stability not only during culture but also during downstream processing and storage [4]. This stresses the need for integrated optimization since degradation will occur in all steps of the production process. Nonetheless, few protocols and systematic optimization methods have been published. For this purpose in the present work the production of retroviruses was mathematically modeled in order to optimize the controllable intermediary steps between helper cell growth and final retrovirus titer.