title: Generation of antigen-specific, Foxp3-expressing CD4+ regulatory T cells by inhibition of APC proteosome function.
abstract: We tested the hypothesis that immature APC, whose NF-kappaB-signaling pathway and thus maturation was blocked by the proteosome inhibitor benzyloxycarbonyl-isoleucyl-glutamyl(O-tert-butyl)-alanyl-leucinal (PSI), could be a source of Ag-specific regulatory T (Treg) cells. DO11.10 CD4(+) T cells that were incubated with Ag- and PSI-pulsed APC proliferated poorly, produced less IL-2, IFN-gamma, and IL-10 in secondary cultures, and inhibited the response of both naive and memory CD4(+) T cells stimulated by Ag-pulsed APC. The generation of PSI-APC Treg cells required IL-10 production by APC. PSI-APC Treg cell inhibition required cell-cell contact but not IL-10 or TGF-beta. Addition of IL-2 did not reverse, but Ab to CTLA-4 did reverse partially the inhibitory effect. Depletion of CD25(+) T cells before initial culture with PSI-APC did not affect Treg generation. PSI-APC Treg cells expressed high levels of Foxp3, inhibited proliferation of naive DO11.10 T cells in vivo, and abrogated colitis driven by a memory Th1 response to bacterial-associated Ag. We conclude that NF-kappaB-blocked, immature APC are able to induce the differentiation of Treg cells that can function in vitro and in vivo in an Ag-specific manner.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, University of Alabama, Birmingham, AL 35294, USA.
authors.forename: Yingzi
authors.initials: Y
authors.lastname: Cong
authors.forename: Astrid
authors.initials: A
authors.lastname: Konrad
authors.forename: Nuzhat
authors.initials: N
authors.lastname: Iqbal
authors.forename: Robin D
authors.initials: RD
authors.lastname: Hatton
authors.forename: Casey T
authors.initials: CT
authors.lastname: Weaver
authors.forename: Charles O
authors.initials: CO
authors.lastname: Elson
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D001854:Bone Marrow Cells / Q000187:drug effects / Q000201:enzymology / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003092:Colitis / Q000276:immunology / Q000473:pathology / Q000517:prevention & control; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D051858:Forkhead Transcription Factors; D007156:Immunologic Memory; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D009842:Oligopeptides / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000502:physiology*; D061988:Proteasome Inhibitors; D016192:Resting Phase, Cell Cycle / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D018984:Epitopes, T-Lymphocyte; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007166:Immunosuppressive Agents; D009842:Oligopeptides; D061988:Proteasome Inhibitors; C090535:benzyloxycarbonyl-isoleucyl-glutamyl(O-tert-butyl)-alanyl-leucinal; D046988:Proteasome Endopeptidase Complex