Optimization of growth and secretion of human monoclonal antibodies by hybridomas cultured in serum-free media.

To facilitate the production and purification of human monoclonal antibodies, we evaluated the ability of human hybridomas to adapt to chemically defined-serum free media. From a panel of human hybridomas secreting antibody against serotype specific lipopolysaccharide determinants of gram-negative bacteria, the growth and secretion properties of the two hybridomas producing antibodies against two strains of Pseudomonas aeruginosa, 4-8KH15 and 4-10KH139, were analysed. Both clones did not grow in protein-free medium. However, it was possible to adapt them to serum-free media consisting of a basal medium supplemented with insulin, transferrin, ethanolamine, and selenite. Antibody secretion rates were equal (4-8KH15: 26-31 micrograms IgM/10(6) cells/day) or higher (4-10KH139: 58-90 micrograms IgM/10(6) cells/day) in serum-free media as compared to conventional serum-supplemented medium. Our studies suggest that adaptation of the described hybridomas to selected serum-free media results in an antibody production which is very high as compared with reports in comparable systems. The establishment of these conditions will significantly facilitate the production of large amounts of human monoclonal antibodies which is a prerequisite for a therapeutical application.