Production and characterization of two immunotoxins specific for M5b ANLL leukaemia

✍ Scribed by R. Tecce; R. Fraioli; P. De Fabritiis; A. Sandrelli; A. Savarese; L. Santoro; M. Cuomo; P. G. Natali

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: French
• Weight: 773 KB
• Volume: 49
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910490228

✦ Synopsis

We describe the production and functional characterization of 2 monocytic-cell-lineage-specific immunotoxins constructed with saporin emitoxin (SAP) from Saponaria offici- nalis. Interest in the production of these immunotoxins, of possible clinical relevance, has been raised by the availability of 2 MAbs of high specificity for circulating monocytes and M5b ANLL, thus envisaging their potential use in bonemarrow purging. SAP emitoxin was selected on the basis of the low cytotoxicity in unconjugated form, as opposed to highly specific cytotoxicity and favourable pharmacokinetical properties in the conjugated form. SPDP conjugation produced immunotoxins which retained serological specificity and protein-synthesis-inhibitory activity. The 2 immunotoxins did not interfere with bone-marrow progenitor-cell growth in a CFU-GM colony assay. On the contrary, they were capable of killing monocytic cells selectively, as demonstrated in phenotypical and functional assays. Thus these 2 novel immunotoxins appear to be promising reagents in purging autologous bone marrow prior to transplantation in patients suffering from monocytic leukaemia.