title: Human CD4+CD25+ regulatory T cells inhibit the differentiation of osteoclasts from peripheral blood mononuclear cells.
abstract: Regulatory T cell (Treg) is a subset of CD4+ T lymphocytes expressing CD25 with immunosuppressive activity. However the function of Tregs onto osteoclastogenesis remains unknown. We investigated the effect and regulatory mechanism of Treg focusing on osteoclastogenesis from PBMCs. Tregs were isolated from PBMCs by magnetic cell sorting-column and analyzed by flow cytometry. RT-PCR was performed to identify Foxp3 mRNA. Using PBMCs and Tregs coculture system, we could find that Tregs inhibited osteoclasts differentiation from PBMCs and reduced the resorbed areas on pit assay (p <0.01). This suppression of osteoclast differentiation was cytokine-dependent, not cell-to-cell direct contact proved by Transwell system. Tregs-induced osteoclast differentiation was blocked by anti-TGF-beta or anti-IL-4 antibody treatment. These results suggest that Tregs inhibit osteoclast differentiation from PBMCs in a cytokine-dependent manner, not by cell-to-cell contact manner and that TGF-beta and IL-4 may be the key cytokines for this suppressive function of Tregs.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736, Republic of Korea.
authors.forename: Yong Gil
authors.initials: YG
authors.lastname: Kim
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Lee
authors.forename: Seong-Su
authors.initials: SS
authors.lastname: Nah
authors.forename: Se Hwan
authors.initials: SH
authors.lastname: Mun
authors.forename: Bin
authors.initials: B
authors.lastname: Yoo
authors.forename: Hee-Bom
authors.initials: HB
authors.lastname: Moon
mesh_terms: D015704:CD4 Antigens / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000276:immunology; D010010:Osteoclasts / Q000166:cytology* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D053645:Interleukin-2 Receptor alpha Subunit