Localization and biodistribution of conjugate ATG-Dex-DNR in nude mice as models for human leukemia.

131I-labelled anti-thymoglobuline (ATG), 131I-labelled immunoconjugate ATG-Dex-DNR and 131I-labelled Ts-MoAb as control antibody, respectively, were injected by intraperitoneal (i.p.) administration into nude mice used as models for human T-cell leukemia. SPECT imaging was performed from day 1 to day 8 following i.p. injection. The results showed that radioimmunoimaging of human tumor xenografts was clearest day 3 after injection in both of ATG and ATG-Dex-DNR groups, whereas it's not the case in Ts-MoAb group. Nude mice were killed 8th day after injection with antibody or conjugate. The tumor, as well as different dissected normal organs including heart, liver, lungs, kidney, femur and intestine, were harvested, weighed precisely, and radioiodine-counted. T/NT ratios in experimental group was greater than 1.0 (ranged from 1.246-7.865), and in control group they were less than 1.0 (ranged from 0.263-0.757, except for tumor/femur ratio). Our results indicated that ATG and ATG-Dex-DNR had specific affinity to cell line of T-cell leukemia CEM.