Patent ID: 6080560
Filing Date: 2000-06-27
Classification: C07K,C12N

Abstract:
A method for obtaining a conformationally active mammalian antibody from plant cells in culture, comprising the steps of:providing an expressible DNA construct comprising an expressible selectable marker gene and, in 5' to 3' order, a promoter that promotes transcription in tobacco cells in cell culture, a plant signal sequence that encodes a peptide that directs secretion of a protein from the tobacco cells, a DNA sequence that encodes a secretable mammalian single chain antibody, and a transcription terminator functional in the tobacco cells;transforming tobacco suspension cells with the DNA construct;selecting for transgenic tobacco cells that have acquired the selectable marker of the DNA construct;culturing the transgenic tobacco cells in a liquid suspension culture under conditions such that the cells secrete the mammalian single chain antibody encoded by the DNA construct into the liquid culture to a concentration over 25 mg/l, the accumulated mammalian single chain antibody comprising more than 10% of the total secreted protein in the medium; andisolating the accumulated single chain mammalian antibody away from the tobacco cells.