Expression of Antibody Fusion Proteins in Mammalian Cells

Recombinant DNA technology provides a means to mimic nature and build multidomain proteins that display several functions. This ability is being applied by the pharmaceutical industry to develop novel products. Fusion proteins of antibodies and enzymes formed one of the earliest examples of protein engineering (1 ). By genetic engineering “magic bullets,” comprising a targeting agent linked to an active agent can be produced in one step, without recourse to laborious conjugation chemistry A wide range of recombinant molecules have now been constructed where the binding specificity of an antibody or T-cell receptor variable domain, cytokine, growth factor, or other protein ligand (e.g., CD4) is fused to another protein domain, for example, a toxin, enzyme, cytokine, or antibody constant region. Progress in this area is summarized in recent reviews (2 ,3 ).