1. A long-lived IL-2 mutein that selectively activates and expands regulatory T cells as a therapy for autoimmune disease.
- Author
-
Peterson, Laurence B., Bell, Charles J.M., Howlett, Sarah K., Pekalski, Marcin L., Brady, Kevin, Hinton, Heather, Sauter, Denise, Todd, John A., Umana, Pablo, Ast, Oliver, Waldhauer, Inja, Freimoser-Grundschober, Anne, Moessner, Ekkehard, Klein, Christian, Hosse, Ralf J., and Wicker, Linda S.
- Subjects
- *
T cells , *AUTOIMMUNE diseases , *CHIMERIC proteins , *STOICHIOMETRY , *EPIGENETICS - Abstract
Abstract Susceptibility to multiple autoimmune diseases is associated with common gene polymorphisms influencing IL-2 signaling and T reg function, making T reg -specific expansion by IL-2 a compelling therapeutic approach to treatment. As an in vivo IL-2 half-life enhancer we used a non-targeted, effector-function-silent human IgG1 as a fusion protein. An IL-2 mutein (N88D) with reduced binding to the intermediate affinity IL-2Rβγ receptor was engineered with a stoichiometry of two IL-2N88D molecules per IgG, i.e. IgG-(IL-2N88D) 2. The reduced affinity of IgG-(IL-2N88D) 2 for the IL-2Rβγ receptor resulted in a T reg -selective molecule in human whole blood pSTAT5 assays. Treatment of cynomolgus monkeys with single low doses of IgG-(IL-2N88D) 2 induced sustained preferential activation of T regs accompanied by a corresponding 10–14-fold increase in CD4+ and CD8+ CD25+FOXP3+ T regs ; conditions that had no effect on CD4+ or CD8+ memory effector T cells. The expanded cynomolgus T regs had demethylated FOXP3 and CTLA4 epigenetic signatures characteristic of functionally suppressive cells. Humanized mice had similar selective in vivo responses; IgG-(IL-2N88D) 2 increased T regs while wild-type IgG-IL-2 increased NK cells in addition to T regs. The expanded human T regs had demethylated FOXP3 and CTLA4 signatures and were immunosuppressive. These results describe a next-generation immunotherapy using a long-lived and T reg -selective IL-2 that activates and expands functional T regs in vivo. Patients should benefit from restored immune homeostasis in a personalized fashion to the extent that their autoimmune disease condition dictates opening up the possibility for remissions and cures. Highlights • A human IL-2 molecule mutated to decrease binding to the intermediate affinity IL-2 receptor preferentially activates Tregs. • Two IL-2 muteins fused to human IgG1 allow for sustained, preferential expansion of Tregs in cynomolgus and humanized mice. • As compared to the wild type IL-2 fusion protein, humanized mice expand fewer NK cells in response to the mutein. • The dynamic range of Treg increase based on dose suggests the ability to individualize dosing for particular diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF