title: Differential effects of rapamycin and retinoic acid on expansion, stability and suppressive qualities of human CD4(+)CD25(+)FOXP3(+) T regulatory cell subpopulations.
abstract: Adoptive transfer of ex vivo expanded CD4(+)CD25(+)FOXP3(+) regulatory T cells is a successful therapy for autoimmune diseases and transplant rejection in experimental models. In man, equivalent manipulations in bone marrow transplant recipients appear safe, but questions regarding the stability of the transferred regulatory T cells during inflammation remain unresolved. In this study, protocols for the expansion of clinically useful numbers of functionally suppressive and stable human regulatory T cells were investigated. Regulatory T cells were expanded in vitro with rapamycin and/or all-trans retinoic acid and then characterized under inflammatory conditions in vitro and in vivo in a humanized mouse model of graft-versus-host disease. Addition of rapamycin to regulatory T-cell cultures confirms the generation of high numbers of suppressive regulatory T cells. Their stability was demonstrated in vitro and substantiated in vivo. In contrast, all-trans retinoic acid treatment generates regulatory T cells that retain the capacity to secrete IL-17. However, combined use of rapamycin and all-trans retinoic acid abolishes IL-17 production and confers a specific chemokine receptor homing profile upon regulatory T cells. The use of purified regulatory T-cell subpopulations provided direct evidence that rapamycin can confer an early selective advantage to CD45RA(+) regulatory T cells, while all-trans retinoic acid favors CD45RA(-) regulatory T-cell subset. Expansion of regulatory T cells using rapamycin and all-trans retinoic acid drug combinations provides a new and refined approach for large-scale generation of functionally potent and phenotypically stable human regulatory T cells, rendering them safe for clinical use in settings associated with inflammation.
authors.affiliation: Department of Nephrology and Transplantation, King's College London, Medical Research Council (MRC) Centre for Transplantation, Guy’s Hospital, London, UK.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Scottà
authors.forename: Marianna
authors.initials: M
authors.lastname: Esposito
authors.forename: Henrieta
authors.initials: H
authors.lastname: Fazekasova
authors.forename: Giorgia
authors.initials: G
authors.lastname: Fanelli
authors.forename: Francis C
authors.initials: FC
authors.lastname: Edozie
authors.forename: Niwa
authors.initials: N
authors.lastname: Ali
authors.forename: Fang
authors.initials: F
authors.lastname: Xiao
authors.forename: Mark
authors.initials: M
authors.lastname: Peakman
authors.forename: Behdad
authors.initials: B
authors.lastname: Afzali
authors.forename: Pervinder
authors.initials: P
authors.lastname: Sagoo
authors.forename: Robert I
authors.initials: RI
authors.lastname: Lechler
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D019264:Adoptive Transfer / Q000379:methods; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D051858:Forkhead Transcription Factors / Q000276:immunology; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D051379:Mice; D020123:Sirolimus / Q000494:pharmacology*; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D014212:Tretinoin; D020123:Sirolimus