A trial of using antibodies as carriers of alkylating agents. II. Evaluation of ability to form 32P-cyclophosphamide + immune antibody complexes with homologous antigen.

32P-cyclophosphamide was found to combine with gamma-globulin fractions of immune sera. Immune sera incubated with 32P-cyclophosphamide retained ability to react specifically with homologous antigen in vitro in the system: MN antigens of human erythrocytes + rabbit anti-MN antibody, and probably reacted selectively with target antigens in vivo in the system: antigens of guinea pig kidney tissue + rabbit antibodies against these antigens. Hemagglutination, passive hemagglutination and precipitation in agar gel tests were used in the experiments. Ability to combine of the immune antibody + 32P-cyclophosphamide complex with homologous antigens was evaluated by measurements of radioactivity of studied materials (erythrocyte agglutinates and organ homogenates). The results indicate feasibility of using immune antibodies as carriers of cytostatic agents.