What factors influence selection of a host cell for transient transfection?

Answer

The ideal host cells for protein production aimed at supporting biotherapeutic development should exhibit robust cell growth to allow scalability, and they should produce proteins that meet customers’ standards for quality and posttranslational modification. CHO cell lines, which are most commonly used for commercial protein manufacturing, typically meet these criteria. Thus, starting the biotherapeutic development process in CHO cells, rather than in HEK cells, will harmonize early stage discovery efforts with later stage development activities, which greatly reduces risks that might arise from misleading data due to host cell variability. It should be noted that even some commercially available CHO cell lines may present issues with protein quality (e.g., degradation or increased levels of host cell proteins) that are not observed in the CHO cells that will be used for manufacturing. Therefore, it is very important to perform testing of host cell lines to ensure there are no issues with protein quality before moving into later stage of the drug development process. In other words, analyzing and developing your biotherapeutics by using the same host cell line from the beginning to the end of the development spectrum can really help you to avoid/reduce risk and accelerate timelines.