Studies on the localization of radiolabeled antibodies to a mouse myeloma protein

Abstract

In vivo localization of radiolabeled antibody to a γG‐type myeloma protein secreted by a transplantable plasma cell tumor of BALB/c mice has been studied, using Pressman's paired‐labeled antibody method. Specific localization of radiolabeled antibody to the myeloma protein was seen only in mice injected with the antibody 4 days after subcutaneous transplantation of 3 million tumor cells, when these mice were autopsied 8 days after antibody injection. Reasons for absence of antibody localization under many other experimental conditions include a strong cross‐reaction between rabbit antibody to the myeloma protein and normal mouse serum γG globulin, and presence of the myeloma protein in serum in relatively high amounts. However, significant prolongation in survival of mice bearing the transplanted plasma cell tumor was obtained when relatively large quantities of rabbit antibody to the myeloma protein or to the myeloma cell were injected. The significance of these findings with regard to future studies on the localization of radiolabeled antibodies in cancer patients is discussed.

Localization of an 125I-Labeled Rat Transplantation Antibody in Tumors Carrying the Corresponding Antigen

“…Such highly preferential localization has been surprisingly difficult to demonstrate (1)(2)(3). Such highly preferential localization has been surprisingly difficult to demonstrate (1)(2)(3).…”