Thy 1.2+ leukemia cells eradicated from in vitro leukemia-bone marrow cell mixtures by antibody-toxin conjugates.
A conjugate constituted by a monoclonal anti-Thy 1.2 antibody chemically coupled to the toxic subunit of ricin was synthesized. The conjugate was specifically cytotoxic for Thy 1.2+ (EL 4) but not for Thy 1.2- (BW5147) thymoma cells. In vitro treatment of bone marrow-leukemia cell mixtures (10:1 and 1:1 bone marrow to EL 4 cell ratios) with anti-Thy 1.2-ricin A chain totally eradicated EL 4 tumor cells, while the number of myeloid colony-forming units and pluripotent colony-forming units developed in vitro and in vivo was unaffected, which suggested that the treatment had no toxic side effects at least on the precursor cells examined.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects; D066298:In Vitro Techniques; D007942:Leukemia, Experimental / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D012276:Ricin / Q000276:immunology / Q000627:therapeutic use*
D000911:Antibodies, Monoclonal; D012276:Ricin