Human tumor antigens identified with monoclonal antibodies

MoAbLc1 (IgM) and MoAbLc2 (IgG/sub 2a/) were produced against human lung carcinoma cell line (ChaGo). Lc1 recognizes a ≅ 330-kd/≅ 310-kd glycoprotein complexes, and Lc2 recognizes a ≅ 60-kd/≅ 47-kd protein complex. With a panel of cell lines of different tissue origin, Lc1 showed a more restricted reactivity to ChaGo; it cross-reacted with another lung carcinoma cell line (SK-Lc-2) and two breast carcinoma cell lines, but failed to react with cell lines of fetal lung, of colon, esophageal, prostate, stomach, and ovarian carcinomas, of B and T lymphoblastoid cells, neuroblastomas, glioblastoma, astrocytoma, and human peripheral blood lymphocytes. New and improved methods were developed for the production of indium-111-labeled MoAbs for tumor imaging. To facilitate the application of bicyclic anhydride diethylenetriaminepentaacetic acid (BADTPA) to In-111 labeling of antibodies, we have modified the original method by using C-14-labeled BADTPA, which allows precise quantitation of DTPA molecules incorporated. A new heterobifunctional reagent, 2,6-dioxo-N-(carboxyl)morpholine (DCM) was synthesized for chelating In-111 to MoAbs, and demonstrated higher retention of immunoreactivity of the labeled antibody