Preparation of mouse-human chimeric antibody against pancreatic cancer-associated mucin.

A murine monoclonal antibody, designated Nd2, was generated using a purified mucin from the human pancreatic cancer cell line SW1990 as the immunogen. Administration of Nd2 into the patients with pancreatic cancer has shown that Nd2 is of clinical use for in vivo diagnostics of pancreatic cancer. In this study, starting with a previously established hybridoma producing Nd2, we have established a transfected cell line expressing a recombinant chimeric Nd2 composed of mouse-derived antigen-binding variable regions and human-derived constant regions. The chimeric Nd2 was shown to bind purified mucin from SW1990 cells with the same dose-response curve as the original Nd2. Immunohistochemical experiments have shown that the reactivity of the chimeric Nd2 in normal and malignant pancreatic tissue is also the same as that of the original Nd2. Replacement of a substantial portion of the mouse protein makes this chimeric Nd2 more promising for clinical application than the original mouse-derived Nd2 because its antigenicity is expected to be reduced.