Tumour cell-antibody interactions. I. In vivo experiments.

Goats were immunized with membrane fractions of the L5178Y tumour syngenic to DBA/2 mice. IgG fractions of this antiserum were made tumour specific by repeated in vitro and in vivo absorptions with normal cells and concentrated by adsorption to and elution from tumour cells. In vivo studies indicated that the accumulation of 125I-labelled antibody in tumour tissue could not be improved by extensive purification and concentration. The observed clearance rates of radioactivity from tumours and whole animals showed that the metabolism of antibodies was significantly accelerated in the presence of target cells. It is suggested that a rapid neutralization and degradation of antibody by the target tissue prevents its accumulation in tumour nodules.