Polyols as a Protectant against Proteases for the Production of hCTLA4Ig in Transgenic Rice Cell Cultures

초록

Application of plant cell cultures for the production of recombinant biopharmaceuticals has emerged as an alternative to conventional platforms. Transgenic rice cell cultures provide an effective bridge between these platforms. Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was expressed using RAmy3D promoter, which was regulated by sugar levels. At the same time with the production of hCTLA4Ig by sugar starvation, proteases were released and accumulated in the extracellular environment. Secreted hCTLA4Ig was unstable in the medium, and rapidly degraded by proteases after day 6. In order to reduce the degradation of hCTLA4Ig, protection effects of polyols such as polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone were evaluated. It was found that these polyols lowered the degradation of target protein by plant proteases and improved the production level in transgenic rice cell culture. In conclusion, utilization of polyols might be an efficient integrated process in cell culture platforms and it could provide positive effects on stabilization as well as the enhancement of hCTLA4Ig productivity.