Degradation of xenogeneic, cytotoxic anti tumor antibodies by tumor derived lysosomal enzymes and the generation of products blocking humoral cytotoxicity

This is a study on the effect of tumor derived lysosomal enzymes on some of the biological activities of tumor antibodies. The capacity of lysosome treated xenogeneic tumor antibodies to mediate complement dependent cytotoxicity and to block such an activity was investigated. In a previous study it was found that lysosomal extracts from mouse tumors could degrade IgG in vitro. Such degradation was not unique for tumor derived lysosomal enzymes having been demonstrated in extracts from normal tissues as well.