title: In vitro expansion improves in vivo regulation by CD4+CD25+ regulatory T cells.
abstract: CD4+CD25+ T regulatory cells (Tregs) can actively suppress immune responses and thus have substantial therapeutical potential. Clinical application is, however, frustrated by their scarcity, anergic status, and lack of defined specificity. We found that a single injection of a small number of expanded but not fresh HY-specific Tregs protected syngeneic male skin grafts from rejection by immune-competent recipients. The expanded Tregs were predominantly located in the grafts and graft-draining lymph nodes. In vitro expanded Tregs displayed a phenotype of CD25highCD4lowFoxp3+CTLA4+, and also up-regulated IL10 and TGFbeta while down-regulating IFN-gamma, GM-CSF, IL5, and TNF-alpha production. Furthermore, expanded Tregs appeared to express a reduced level of Foxp3, which could be prevented by adding TGFbeta to the culture, and they also tended to lose Foxp3 following the repeated stimulation. Finally, a proportion of expanded HY-specific Tregs secreted IL2 in response to their cognate peptide, and this finding could be confirmed using Tregs from Foxp3GFP reporter mice. We not only demonstrated that expanded Tregs are superior to fresh Tregs in suppressing T cell responses against alloantigens, but also revealed some novel immunobiological properties of expended Tregs which are very instructive for modifying current Treg expansion procedures.
authors.affiliation: Cancer Immunotherapy Group, Department of Immunology, Imperial College London, UK. jianguo.chai@csc.mrc.ac.uk
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Chai
authors.forename: David
authors.initials: D
authors.lastname: Coe
authors.forename: Daxin
authors.initials: D
authors.lastname: Chen
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Simpson
authors.forename: Julian
authors.initials: J
authors.lastname: Dyson
authors.forename: Diane
authors.initials: D
authors.lastname: Scott
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D060908:CTLA-4 Antigen; D016207:Cytokines / Q000378:metabolism; D005260:Female; D051858:Forkhead Transcription Factors / Q000032:analysis / Q000378:metabolism; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control*; D006182:H-Y Antigen / Q000032:analysis / Q000276:immunology; D007108:Immune Tolerance; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016038:Skin Transplantation; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000637:transplantation*; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015704:CD4 Antigens; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D016207:Cytokines; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D006182:H-Y Antigen; D053645:Interleukin-2 Receptor alpha Subunit