Cytosolic immunization allows the expression of preATF‐saporin chimeric toxin in eukaryotic cells

• Published in: The FASEB journal 2000-02, Vol.14 (2), p.391-398
• Main Authors: Serena Fabbrini, M., Carpani, Daniela, Soria, Marco R., Ceriotti, Aldo
• Format: Article
• Language: English
• Subjects: Animals; Antibodies - pharmacology; anti‐cancer therapy; Cytosol; Eukaryotic Cells; Humans; Immunotoxins - immunology; Immunotoxins - metabolism; intracellular immunization; N-Glycosyl Hydrolases; Oocytes; Plant Proteins - biosynthesis; Plant Proteins - immunology; Protein Precursors - biosynthesis; Receptors, Cell Surface - metabolism; Receptors, Urokinase Plasminogen Activator; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - immunology; Recombinant Proteins - biosynthesis; ribosome-inactivating protein; ribosome‐inactivatingproteins; saporin; U937 Cells; urokinase amino‐terminal fragment; urokinase receptor; Urokinase-Type Plasminogen Activator - biosynthesis; Urokinase-Type Plasminogen Activator - immunology; Xenopus
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.14.2.391

ABSTRACT In this work, we have devised an intracellular immunization strategy for the expression in high amounts of ATF‐saporin, a targeted chimeric toxin constituted by the ATF receptor binding domain of human urokinase and the plant ribosome‐inactivating protein saporin, which has been shown to be highly cytotoxic to target cells. This strategy may allow the production of highly toxic secretory proteins in eukaryotic cells, avoiding cell suicide caused by autointoxication. The procedure consists of equipping host cells with cytosolic neutralizing antibodies directed toward the toxic domain of the heterologous polypeptide. We show that this intracellular immunization is essential for the synthesis of correctly folded, biologically active ATF‐SAP in the high amounts needed to investigate its in vivo anti‐metastatic potential. Such a strategy should be generally useful for the production of toxic molecules of therapeutic value whose folding and maturation require transit through the eukaryotic secretory pathway. Fabbrini, M. S., Carpani, D., Soria, M. R., Ceriotti, A. Cytosolic immunization allows the expression of preATF‐saporin chimeric toxin in eukaryotic cells. FASEB J. 14, 391–398 (2000)