High-level production of recombinant immunoglobulins in mammalian cells.

Successful high-level expression of recombinant immunoglobulins has now been reported in several different types of mammalian cells. This has been achieved using random integration of immunoglobulin genes co-linked with a drug-resistance gene into cellular DNA. After gene integration, increases in immunoglobulin-gene expression are obtained by selection for increases in expression of the drug-resistance marker. Expression levels attained by this method are several fold higher than those produced by a good hybridoma. Soon, site-specific homologous recombination may replace random integration as the favored methodology for initial expression of all proteins in mammalian cells, including immunoglobulins.