title: Interleukin 2 toxin: a step toward selective immunomodulation.
abstract: We have used protein engineering and recombinant DNA methodologies to genetically replace the eukaryotic cell receptor binding domain of diphtheria toxin with interleukin 2 (IL-2). The toxin-related T cell growth factor fusion gene has been cloned in Escherichia coli K12. Recombinant strains of E coli produce a 68,086 K hybrid toxin, IL-2 toxin that retains immunologic properties intrinsic to both its diphtheria toxin and IL-2 components. IL-2 toxin has been found to selectively inhibit protein synthesis in both human and murine T cell lines that bear high affinity IL-2 receptors, whereas the hybrid toxin is not active against cells that do not bear this receptor. The cytotoxic action of IL-2 toxin is specifically blocked by free IL-2 and monoclonal antibodies that bind to the p55 (Tac antigen) subunit of the high affinity IL-2 receptor. In addition, IL-2 toxin, like diphtheria toxin itself, must pass through an acidic compartment in order to deliver its adenosine diphosphate ribosyl transferase activity to the cytosol of target T cells. In a murine delayed type hypersensitivity (DTH) model system, we have shown that IL-2 toxin treatment induces a marked immunosuppression.
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity; D004167:Diphtheria Toxin / Q000276:immunology / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D005818:Genetic Engineering / Q000379:methods; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000627:therapeutic use*; D051379:Mice; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins / Q000276:immunology / Q000627:therapeutic use
chemical_list: D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; C054780:DAB(486)-interleukin 2; D004167:Diphtheria Toxin; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins