Abstract
We have investigated the ability of murine monoclonal antibodies (MoAb) to lyse human leukemic cells in vitro using human serum as a source of complement (C'). The human C'-fixing ability of five of seven MoAb is documented. Studies with two of these MoAb (BA-1 and BA-2) indicated that their human C'-fixing ability and subsequent lysis of leukemic cells was through activation of the classical pathway of C', was independent of donor serum source, and occurred with a number of different target cells. BA-1 and BA-2 could effectively lyse fresh leukemic cells in the presence of 100% human serum, and BA-1 plus human serum could effectively lyse leukemic cells in the presence of a 20- fold excess of normal human bone marrow cells. Our results have potential implications for immunotherapy trials utilizing murine MoAb.
