title: Tolerogenic dendritic cells induce CD4+CD25hiFoxp3+ regulatory T cell differentiation from CD4+CD25-/loFoxp3- effector T cells.
abstract: IL-10-differentiated dendritic cells (DC10) induce allergen tolerance in asthmatic mice, during which their lung Th2 effector T cells (Teffs) are displaced by activated CD4(+)CD25(hi)Foxp3(+) T cells. Intestinal DCs promote oral tolerance by inducing Ag-naive T cells to differentiate into CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs), but whether DCs can induce Teffs to differentiate into Tregs remains uncertain. In this study, we addressed this question in OVA-asthmatic mice that were treated with DC10. OVA-presenting DC10 treatment maximally activated lung Tregs in these animals at 3 wk posttreatment, as determined by upregulation of activation markers (ICOS, programmed cell death-1, glucocorticoid-induced TNFR-related protein, LAG3, and CTLA-4) and in functional assays. This in vitro regulatory activity was ≥90% reduced by treatment with anti-IL-10 but not anti-TGF-β Abs. In parallel cultures, OVA- but not house dust mite (HDM)-presenting DC10 induced ≈43% of CFSE-labeled CD25(-/lo)Foxp3(-) Teffs from asthmatic OVA-TCR transgenic mice to differentiate into tolerogenic CD25(hi)Foxp3(+) Tregs. We recapitulated this in vivo using OVA-asthmatic mice that were coinjected with OVA- or HDM-presenting DC10 (i.p.) and CFSE-labeled CD4(+)CD25(-/lo)Foxp3(-) Teffs (i.v.) from the lungs of asthmatic DO11.10 mice. From ≈7 to 21% of the activated (i.e., dividing) DO11.10 Teffs that were recovered from the lungs, lung-draining lymph nodes, or spleens of the OVA-DC10 recipients had differentiated into CD4(+)CD25(hi)Foxp3(+) Tregs, whereas no CFSE-positive Tregs were recovered from the HDM-DC10-treated animals. These data indicate that DC10 treatments induce tolerance at least in part by inducing Teffs to differentiate into CD4(+)CD25(hi)Foxp3(+) Tregs.
authors.affiliation: Department of Veterinary Microbiology, of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.forename: Wojciech
authors.initials: W
authors.lastname: Dawicki
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Zhang
authors.forename: Jennifer
authors.initials: J
authors.lastname: Town
authors.forename: John R
authors.initials: JR
authors.lastname: Gordon
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D002469:Cell Separation; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000276:immunology; D007108:Immune Tolerance / Q000276:immunology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D010047:Ovalbumin