Preparation of Highly Radioactive Bovine Anti-mouse Lymphocyte Antibody

Abstract

FOR use in humans the active components of anti-lymphocytic serum (ALS) must be sufficiently free of irrelevant substances, concentrated and non-toxic for it to be injected intravenously. With this in mind earlier investigations designed in the context of an experimental model¹ were aimed at (1) preparing pure anti-lymphocytic antibody (ALSAb) from anti-lymphocytic globulin preparations (ALG) and (2) increasing the biological activity of such preparations by labelling the protein in them with a low energy gamma-emitting isotope (¹²⁵I). It was hoped that the specifically localized irradiation would play a role in incapacitating the target lymphocytes¹. ALS raised in rabbits is widely used, but many workers have reported considerable variation in the quality of ALS from individual rabbits. It would therefore be advantageous to raise ALS in larger animals such as cattle or pigs so that larger pools of material could be obtained. The earlier experiments with ALSAb prepared from rabbit ALS have been extended in the experiments described here, in which the effectiveness of purified bovine anti-mouse lymphocyte antibody (BALSAb) and ¹²⁵I-BALSAb has been measured. A preliminary investigation has also been made of the possibility of using a column of thymocytes bound to ‘Sepharose’, for the preparation of BALSAb.