Effects of Antioxidants on the Production of hCTLA4Ig and Cell Viability in Transgenic Rice Cell Cultures

초록

Rice cells were transformed to express human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig). With RAmy3D promoter system, expression of the target protein could be strongly induced by sugar starvation. Oxidative stress leads to increased production of reactive oxygen species (ROS) in plant cells. ROS are toxic to the cells and generally lead to non-controlled oxidation of cellular macromolecules. In addition, ROS-induced genotoxic damage can induce structural changes in DNA. ROS levels need to be controlled during cell cultures and the supplementation of antioxidants can reduce apoptosis caused by ROS. In this study, the effects of N-acetyl cysteine (NAC) and reduced glutathione on cell viability and protein production in the transgenic rice cell cultures under oxidative stress were investigated. Effects of antioxidants at various concentrations were confirmed by comparing protein production levels. Spinner flask cultures were performed with 10 mM NAC at two different sparging rates (0.1 and 0.2 vvm). It was found that long-term survival of transgenic rice cells and enhanced production of hCTLA4Ig were possible by reducing ROS levels with the additions of antioxidants in transgenic rice cell cultures.