title: Requirements for growth and IL-10 expression of highly purified human T regulatory cells.
abstract: Human regulatory T cells (T(R)) cells have potential for the treatment of a variety of immune mediated diseases but the anergic phenotype of these cells makes them difficult to expand in vitro. We have examined the requirements for growth and cytokine expression from highly purified human T(R) cells, and correlated these findings with the signal transduction events of these cells. We demonstrate that these cells do not proliferate or secrete IL-10 even in the presence of high doses of IL-2. Stimulation with a superagonistic anti-CD28 antibody (clone 9.3) and IL-2 partially reversed the proliferative defect, and this correlated with reversal of the defective calcium mobilization in these cells. Dendritic cells were effective at promoting T(R) cell proliferation, and under these conditions the proliferative capacity of T(R) cells was comparable to conventional CD4 lymphocytes. Blocking TGF-β activity abrogated IL-10 expression from these cells, while addition of TGF-β resulted in IL-10 production. These data demonstrate that highly purified populations of T(R) cells are anergic even in the presence of high doses of IL-2. Furthermore, antigen presenting cells provide proper co-stimulation to overcome the anergic phenotype of T(R) cells, and under these conditions they are highly sensitive to IL-2. In addition, these data demonstrate for the first time that TGF-β is critical to enable human T(R) cells to express IL-10.
authors.affiliation: Department of Pediatrics, Medical College of Wisconsin and the Children's Research Institute, Milwaukee, WI 53226, USA.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bonacci
authors.forename: Brandon
authors.initials: B
authors.lastname: Edwards
authors.forename: Shuang
authors.initials: S
authors.lastname: Jia
authors.forename: Calvin B
authors.initials: CB
authors.lastname: Williams
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Hessner
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Gauld
authors.forename: James W
authors.initials: JW
authors.lastname: Verbsky
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D003713:Dendritic Cells / Q000166:cytology; D020869:Gene Expression Profiling; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology*; D007376:Interleukin-2 / Q000494:pharmacology; D009000:Monocytes / Q000166:cytology; D020411:Oligonucleotide Array Sequence Analysis; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology
chemical_list: D000906:Antibodies; D018106:CD28 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D016212:Transforming Growth Factor beta; D016753:Interleukin-10