title: CD4+CD25+ regulatory T cells down-regulate co-stimulatory molecules on antigen-presenting cells.
abstract: CD4+CD25+ T cells have been shown to inhibit experimentally induced organ-specific autoimmune disease and depletion of these regulatory T cells from normal mice results in development of such conditions. Furthermore, CD4+CD25+ T cells suppress the IL-2 production and thereby the proliferation of polyclonally activated CD4+CD25- T cells in vitro. The suppression in vitro is independent of secreted factors but requires interactions between CD4+CD25- and CD4+CD25+ T cells and antigen-presenting cells (APC). We have now further investigated the function of CD4+CD25+ T cells in vitro and have focused on their interactions with APC. We found that CD4+CD25+ T cells down-regulated the expression of the co-stimulatory molecules CD80 and CD86 on dendritic cells. The steady-state level of CD80 mRNA was also decreased, while the steady-state level of CD86 mRNA was not, suggesting that distinct mechanisms regulate the expression of these molecules. The down-regulation occurred even in the presence of stimuli that would normally increase the expression of CD80 and CD86 molecules. Thus, down-regulation of co-stimulatory molecules may be an additional effector function of these regulatory T cells.
authors.affiliation: Department of Cell and Molecular Biology, University of Lund, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Cederbom
authors.forename: H
authors.initials: H
authors.lastname: Hall
authors.forename: F
authors.initials: F
authors.lastname: Ivars
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D018122:B7-1 Antigen / Q000096:biosynthesis* / Q000235:genetics; D051940:B7-2 Antigen; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002455:Cell Division; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D015536:Down-Regulation; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D015375:Receptors, Interleukin-2
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; C497966:Cd86 protein, rat; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2