Monoclonal antibodies to Lewis lung carcinoma.

Hybridoma cultures producing monoclonal antibodies were derived from fusions of the parent myeloma P3-X63-Ag8-U1 with spleen cells of BALB/c mice which had been immunized with the Lewis lung carcinoma (3LL) of C57BL/6 mice. Four monoclonal antibodies (A8-2.7, C6-1.2, D12-2.7), and G8-1.6) showed high reactivity to 3LL cells but showed no or low reactivity to other tumor cells, cultured cell lines, and normal tissues from C57BL/6 mouse. The C6-1.2 antibody was confirmed to have a binding capacity specific to 3LL cells by absorption assay and inhibition assay. Antigenic analysis indicated that the C6-1.2 antibody bound to 3LL surface glycoprotein (approximately 45,000 daltons), and other antibodies reacted with proteins (less than 10,000 daltons) on the cell surface of 3LL. Administration of C6-1.2 antibody i.v. reduced the metastasis into the lungs of 3LL in C57BL/6 mice.