High-level and stable accumulation of single-chain Fv antibodies in plant storage organs.

摘要

In order to explore transgenic plants for large-scale production of pharmaceutical proteins as recombinant antibodies, the accumulation and stability of functionally active single-chain Fv antibodies were studied in transgenic tobacco (Nicotiana tabacum) plants. Two different single-chain Fv antibodies were used, which were expressed in different plant organs and plant cell compartments. For ubiquitous expression in tobacco plants transcription of the single-chain Fv genes was controlled by the strong CaMV 35S promoter. For storage-organ-specific expression two seed-specific Vicia faba promoters from the legumin B4 and the unknown seed protein gene were used. Plant expression systems where the recombinant antibody fragments are retained in the endoplasmic reticulum provided not only high accumulation levels of active antibodies in leaves and seeds but also allowed short- and long-term storage of highly active immunoglobulins in harvested plant material at room temperature.