Interleukin 2 toxin: a step toward selective immunomodulation.
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.
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CHEMICAL CHEMICAL GENE-Y GENE-Y GENE-Y GENE-N GENE-Y GENE-Y GENE-N GENE-N GENE-Y GENE-Y GENE-Y GENE-N GENE-N GENE-Y GENE-N GENE-N GENE-Y
adenosine diphosphate ribosyl IL-2 interleukin 2 IL-2 T cell growth factor IL-2 IL-2 IL-2 IL-2 receptors IL-2 IL-2 p55 Tac IL-2 receptor IL-2 eukaryotic cell receptor binding domain adenosine diphosphate ribosyl transferase Interleukin 2