Genetically engineered antibodies.

The technology needed to genetically engineer antibodies is evolving rapidly and the potential utility of these novel reagents is being explored with vigor. The process includes cloning of the antibody genes, their in vitro manipulation and mutagenesis, expression in a suitable host/vector system, and, for commercial production, scale-up, purification, and product evaluation. At each step, significant advances have been achieved recently. For example: at first, antibody genes were cloned from genomic libraries by using adjacent DNA probes; techniques for rapid sequencing by primer extension of total mRNA allowed more specific screening with synthesized oligomers; finally, antibody genes can now be created de novo by chemical synthesis. Moreover, such synthesis allows total control over the antibody sequence so that molecules of any configuration can be produced. New reagents created in this way include murine antibodies whose constant regions and variable-region frameworks have been replaced with human sequence to enhance immunocompatibility with patients, to switch immunoglobulin class, or both.