Antibody Production in Plant Cell Cultures

Monoclonal antibodies (MoAbs) are a highly diversified class of proteins with major research and commercial applications such as diagnostics and therapeutics. Currently, the dominant method for producing MoAbs is through the hybridoma technique. However, this technique is slow, tedious, labor intensive, and expensive. The production of MoAbs in cultured transgenic plant cells can offer some advantages over that in the over that in the mammalian systems. The media to cultivate plant cells are well defined and inexpensive. Contamination by bacteria or fungi is easily monitored in plant tissue cultures. Furthermore, these contaminants are usually not potent pathogens to human beings. In our interdisciplinary research efforts, heavy chain monoclonal antibody (HC MAb) was inserted into Ti plasmid vector and transferred into A. tumefaciens for the transformation in tobacco cells. It was found that 76% of the transformants produced HC MAb. The presence of HC MAb in the cell membrane fraction indicated that the signal peptide was functional and efficient. The change of the HC MAb concentration during a batch culture followed a similar trend as dry cell concentration, indicating that the production of HC MAb was growth related. The long-term repeated subcultures of 11 cell lines showed that there was no obvious trend of neither the decrease nor the increase of the productivity with the repeated subcultures.