PROTEIN PRODUCTION IN TRANSGENIC ALFALFA PLANTS

摘要

This invention is directed to characterizing a host system suitable for the production of functional transgenic proteins, such as anti-human IgG, for use in applications requiring Government regulatory approval. It is well known that regulatory agencies required stable, consistent master cell banks and master cell lines for the production of transgenic proteins in order to ensure sufficient material for appropriate characterization, clinical trials, and potential sales. Current plant production systems require the establishment of seed banks for this purpose. However, there are many drawbacks related to such a system for the production of a continuous reliable transgenic protein source. An aspect of this invention is directed to characterizing a plant production system suitable for transgenic proteins that meet the stringent regulatory requirements. Another aspect of this invention exemplifies the production and characterization of an anti-human IgG for use as blood grouping reagents, through the expression of corresponding genes in transgenic alfalfa plants. The cDNAs of the heavy and light chains of a human IgG-specific IgG2a(kappa) murine mAb (C5-1) were transferred into alfalfa through Agrobacterium infection. Transgenic plants expressing the light- and heavy-chain encoding mRNAs were obtained and plants from the Fl progeny (obtained by sexual crossing) were found to express fully assembled C5-1. Furthermore, the transgenic protein was stable in vivo, as well as during extraction and purification procedures. Purification yielded a unique H2L2 form with a reactivity indistinguishable from hybridoma-derived C5-1 in standardized serological tests. Results indicate that plant-derived transgenic proteins, such as mAbs can be used as diagnostic reagents as effectively as hybridoma-derived mAbs, and demonstrates the usefulness of the transformed alfalfa system to produce large amounts of proteins, including multimeric proteins such as mAbs.