title: Rapamycin-conditioned donor dendritic cells differentiate CD4CD25Foxp3 T cells in vitro with TGF-beta1 for islet transplantation.
abstract: Dendritic cells (DCs) conditioned with the mammalian target of rapamycin (mTOR) inhibitor rapamycin have been previously shown to expand naturally existing regulatory T cells (nTregs). This work addresses whether rapamycin-conditioned donor DCs could effectively induce CD4(+)CD25(+)Foxp3(+) Tregs (iTregs) in cell cultures with alloantigen specificities, and whether such in vitro-differentiated CD4(+)CD25(+)Foxp3(+) iTregs could effectively control acute rejection in allogeneic islet transplantation. We found that donor BALB/c bone marrow-derived DCs (BMDCs) pharmacologically modified by the mTOR inhibitor rapamycin had significantly enhanced ability to induce CD4(+)CD25(+)Foxp3(+) iTregs of recipient origin (C57BL/6 (B6)) in vitro under Treg driving conditions compared to unmodified BMDCs. These in vitro-induced CD4(+)CD25(+)Foxp3(+) iTregs exerted donor-specific suppression in vitro, and prolonged allogeneic islet graft survival in vivo in RAG(-/-) hosts upon coadoptive transfer with T-effector cells. The CD4(+)CD25(+)Foxp3(+) iTregs expanded and preferentially maintained Foxp3 expression in the graft draining lymph nodes. Finally, the CD4(+)CD25(+)Foxp3(+) iTregs were further able to induce endogenous naïve T cells to convert to CD4(+)CD25(+)Foxp3(+) T cells. We conclude that rapamycin-conditioned donor BMDCs can be exploited for efficient in vitro differentiation of donor antigen-specific CD4(+)CD25(+)Foxp3(+) iTregs. Such in vitro-generated donor-specific CD4(+)CD25(+)Foxp3(+) iTregs are able to effectively control allogeneic islet graft rejection.
authors.affiliation: Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Pothoven
authors.forename: T
authors.initials: T
authors.lastname: Kheradmand
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: J L
authors.initials: JL
authors.lastname: Houlihan
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Degutes
authors.forename: S D
authors.initials: SD
authors.lastname: Miller
authors.forename: X
authors.initials: X
authors.lastname: Luo
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000276:immunology*; D006084:Graft Rejection / Q000276:immunology; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D016381:Islets of Langerhans Transplantation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D020123:Sirolimus / Q000494:pharmacology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C508018:Il2ra protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D053773:Transforming Growth Factor beta1; D020123:Sirolimus