title: Sustained in vivo signaling by long-lived IL-2 induces prolonged increases of regulatory T cells.
abstract: Regulatory T cells (Tregs) expressing FOXP3 are essential for the maintenance of self-tolerance and are deficient in many common autoimmune diseases. Immune tolerance is maintained in part by IL-2 and deficiencies in the IL-2 pathway cause reduced Treg function and an increased risk of autoimmunity. Recent studies expanding Tregs in vivo with low-dose IL-2 achieved major clinical successes highlighting the potential to optimize this pleiotropic cytokine for inflammatory and autoimmune disease indications. Here we compare the clinically approved IL-2 molecule, Proleukin, with two engineered IL-2 molecules with long half-lives owing to their fusion in monovalent and bivalent stoichiometry to a non-FcRγ binding human IgG1. Using nonhuman primates, we demonstrate that single ultra-low doses of IL-2 fusion proteins induce a prolonged state of in vivo activation that increases Tregs for an extended period of time similar to multiple-dose Proleukin. One of the common pleiotropic effects of high dose IL-2 treatment, eosinophilia, is eliminated at doses of the IL-2 fusion proteins that greatly expand Tregs. The long half-lives of the IL-2 fusion proteins facilitated a detailed characterization of an IL-2 dose response driving Treg expansion that correlates with increasingly sustained, suprathreshold pSTAT5a induction and subsequent sustained increases in the expression of CD25, FOXP3 and Ki-67 with retention of Treg-specific epigenetic signatures at FOXP3 and CTLA4.
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: charlie.bell@cimr.cam.ac.uk.
authors.forename: Charles J M
authors.initials: CJ
authors.lastname: Bell
authors.affiliation: Former Roche Site of Pharmaceutical Research and Early Development, Discovery Inflammation, Nutley, NJ 07110, USA. Electronic address: yongliang.sun@pfizer.com.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Former Roche Site of Pharmaceutical Research and Early Development, Discovery Inflammation, Nutley, NJ 07110, USA. Electronic address: umn2001@med.cornell.edu.
authors.forename: Urszula M
authors.initials: UM
authors.lastname: Nowak
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: janclark@btinternet.com.
authors.forename: Jan
authors.initials: J
authors.lastname: Clark
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: sarah.howlett@cimr.cam.ac.uk.
authors.forename: Sarah
authors.initials: S
authors.lastname: Howlett
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: marcin.pekalski@cimr.cam.ac.uk.
authors.forename: Marcin L
authors.initials: ML
authors.lastname: Pekalski
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: xin.yang@cimr.cam.ac.uk.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: oliver.ast@roche.com.
authors.forename: Oliver
authors.initials: O
authors.lastname: Ast
authors.affiliation: Roche Pharmaceutical Research and Early Development, Oncology Discovery & Translational Area, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: inja.waldhauer@roche.com.
authors.forename: Inja
authors.initials: I
authors.lastname: Waldhauer
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: anne.freimoser-grundschober@roche.com.
authors.forename: Anne
authors.initials: A
authors.lastname: Freimoser-Grundschober
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: ekkehard.moessner@roche.com.
authors.forename: Ekkehard
authors.initials: E
authors.lastname: Moessner
authors.affiliation: Roche Pharmaceutical Research and Early Development, Oncology Discovery & Translational Area, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: pablo.umana@roche.com.
authors.forename: Pablo
authors.initials: P
authors.lastname: Umana
authors.affiliation: Roche Pharmaceutical Research and Early Development, Oncology Discovery & Translational Area, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: christian.klein.ck1@roche.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Klein
authors.affiliation: Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Zurich, Wagistrasse 18, CH-8952 Schlieren, Switzerland. Electronic address: ralf.hosse@roche.com.
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Hosse
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom. Electronic address: linda.wicker@cimr.cam.ac.uk.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Wicker
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 OXY, United Kingdom; Former Roche Site of Pharmaceutical Research and Early Development, Discovery Inflammation, Nutley, NJ 07110, USA. Electronic address: larry.peterson@cimr.cam.ac.uk.
authors.forename: Laurence B
authors.initials: LB
authors.lastname: Peterson
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D060908:CTLA-4 Antigen / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004802:Eosinophilia / Q000139:chemically induced; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007376:Interleukin-2 / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D053645:Interleukin-2 Receptor alpha Subunit / Q000172:deficiency / Q000378:metabolism; D018655:Lymphocyte Count; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D060908:CTLA-4 Antigen; D051858:Forkhead Transcription Factors; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D050799:STAT5 Transcription Factor; C082598:aldesleukin
keywords: Autoimmunity; Cytokine therapy; Graft versus host disease; IL-2 fusion proteins; Regulatory T cells