title: Generation and large-scale expansion of human inducible regulatory T cells that suppress graft-versus-host disease.
abstract: Adoptive transfer of thymus-derived natural regulatory T cells (nTregs) effectively suppresses disease in murine models of autoimmunity and graft-versus-host disease (GVHD). TGFß induces Foxp3 expression and suppressive function in stimulated murine CD4+25- T cells, and these induced Treg (iTregs), like nTreg, suppress auto- and allo-reactivity in vivo. However, while TGFß induces Foxp3 expression in stimulated human T cells, the expanded cells lack suppressor cell function. Here we show that Rapamycin (Rapa) enhances TGFß-dependent Foxp3 expression and induces a potent suppressor function in naive (CD4+ 25-45RA+) T cells. Rapa/TGFß iTregs are anergic, express CD25 at levels higher than expanded nTregs and few cells secrete IL-2, IFNγ or IL-17 even after PMA and Ionomycin stimulation in vitro. Unlike other published methods of inducing Treg function, Rapa/TGFß induces suppressive function even in the presence of memory CD4+ T cells. A single apheresis unit of blood yields an average ~240 × 10⁹ (range ~ 70-560 × 10⁹) iTregs from CD4+25- T cells in ≤ 2 weeks of culture. Most importantly, Rapa/TGFß iTregs suppress disease in a xenogeneic model of GVHD. This study opens the door for iTreg cellular therapy for human diseases.
authors.affiliation: Department of Pediatrics, Division of Hematology/Oncology and Blood and Marrow Transplantation, University of Minnesota Cancer Center, Minneapolis, MN, USA. hippe002@umn.edu
authors.forename: K L
authors.initials: KL
authors.lastname: Hippen
authors.forename: S C
authors.initials: SC
authors.lastname: Merkel
authors.forename: D K
authors.initials: DK
authors.lastname: Schirm
authors.forename: C
authors.initials: C
authors.lastname: Nelson
authors.forename: N C
authors.initials: NC
authors.lastname: Tennis
authors.forename: J L
authors.initials: JL
authors.lastname: Riley
authors.forename: C H
authors.initials: CH
authors.lastname: June
authors.forename: J S
authors.initials: JS
authors.lastname: Miller
authors.forename: J E
authors.initials: JE
authors.lastname: Wagner
authors.forename: B R
authors.initials: BR
authors.lastname: Blazar
mesh_terms: D000818:Animals; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006086:Graft vs Host Disease / Q000517:prevention & control*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D020123:Sirolimus / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D016212:Transforming Growth Factor beta; D020123:Sirolimus