Production of a functional monoclonal antibody recognizing human colorectal carcinoma cells from a baculovirus expression system.

The light and heavy chain cDNA of a murine monoclonal antibody (MoAb) with specificity for human colorectal carcinoma cells have been expressed separately, together, and as a dual construct in insect cells infected with recombinant baculoviruses. High levels of the MoAb were expressed under the control of the polyhedrin promoter. The antibody maintained its specific binding to human colorectal carcinoma cells and mediated lysis of these cells by human lymphocytes, monocytes, and murine macrophages, as determined in antibody-directed cellular cytotoxicity (ADCC) assays. The recombinant immunoglobulin (Ig), like its ascitic counterpart, did not mediate lysis by either human or rabbit complement. The expression of a recombinant antibody exhibiting both functional binding site and Fc region capacities shows that the baculovirus system could be employed in the production of therapeutic Ig.