Construction of a chimeric antibody with therapeutic potential for cancers which overexpress c-erbB-2

We describe the chimerization of a monoclonal antibody directed against the c-erbB-2 protein using a novel PCR method for cloning immunoglobulin variable region genes. We also describe the characterization of the chimera and show its potential use for treating cancers which overexpress the c-erbB-2 protein. The genomic DNA fragments of heavy and light chain variable genes were cloned by PCR using uniquely designed primers which allowed for isolation of genes containing functional promoters, signal and coding sequences. The chimeric genes were then constructed by linking variable regions of murine genes to human constant gamma 1 and kappa genes. Expression of the chimeric immunoglobulin genes resulted in production of properly assembled chimeric antibody with improved biological properties.