Processing of Antibodies Bound to B-Cell Lymphomas and Other Hematological Malignancies1

In an attempt to recognize general patterns in the processing of Abs (antibodies) bound to the surface of tumor cells, eight monoclonal anti bodies were tested on 10 hematological malignancies of various histolÃ3g ica! types. The results were compared with previous findings obtained with carcinomas, melanomas, and gliomas, using some of the same anti bodies. The data demonstrated that some B-cell lymphomas appear to be unusual in that Abs were unable to bind to them irreversibly; except for those Abs that were rapidly internalized, none of the Abs tested was able to bind irreversibly to the B-cell lymphomas Raji or RL. In contrast, most Abs bound irreversibly to the tumors of other histolÃ3gica! types, including other hematological tumors. Irreversible Ab binding to B-cell lymphomas was achieved by cross-linking the Abs on the cell surface. Such differences between cell lines may be due to differences in the supramolecular struc ture of the surface membrane, which affect the frequency or stability of bivalent Ab binding. The Ab binding interaction could not be described in terms of "functional affinity." These results may lead to improvements in the use of Abs for tumor immunotherapy and for other purposes.