title: Isolation strategies of regulatory T cells for clinical trials: phenotype, function, stability, and expansion capacity.
abstract: Recent clinical results demonstrate the highly effective potency of regulatory T cells (Tregs) to control graft-versus-host disease (GvHD). In this presented study, we directly compared different Treg subpopulations in order to define the most promising Treg target cell population for cellular intervention studies with respect to their phenotype, functional properties, stability, and expansion capacity. Different Treg cell populations have been isolated from healthy donors and characterized by fluorescence activated cell sorting (FACS) analysis for their phenotypic marker and purity, functional properties by suppression assay, stability by Treg-specific demethylated region (TSDR) of the Foxp3 promoter and their in vitro expansion capacity. The direct comparison of the respective Treg target cell populations identified CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs as the most promising Treg population for fresh cell infusions in clinical trials with respect to cell yield, phenotype, function, and stability. The CD4(+)CD25(hi) Tregs qualified as the best candidate for in vitro expansion combining a highly stable phenotype with strong suppressive potential and attractive cell yield after repetitive stimulation. The suppressive capacity of freshly isolated CD4(+)CD25(hi)CD45RA(+) and CD49d(-)CD127(-) Tregs is comparable to freshly isolated CD4(+)CD25(hi), but inferior to CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs. In vitro expansion of CD4(+)CD25(hi)CD45RA(+) and CD49d(-)CD127(-) Tregs resulted in cell populations with less suppressive potency compared with CD4(+)CD25(hi) expanded Tregs correlating well with a higher TSDR demethylation level. In conclusion, future clinical trials should favor CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs for direct Treg cell transfer, whereas CD4(+)CD25(hi) Tregs qualify as best candidate for in vitro expansion.
authors.affiliation: Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Germany.
authors.forename: Sya N
authors.initials: SN
authors.lastname: Ukena
authors.forename: Matthias
authors.initials: M
authors.lastname: Höpting
authors.forename: Sarvari
authors.initials: S
authors.lastname: Velaga
authors.forename: Philipp
authors.initials: P
authors.lastname: Ivanyi
authors.forename: Jens
authors.initials: J
authors.lastname: Grosse
authors.forename: Udo
authors.initials: U
authors.lastname: Baron
authors.forename: Arnold
authors.initials: A
authors.lastname: Ganser
authors.forename: Anke
authors.initials: A
authors.lastname: Franzke
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D002455:Cell Division; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured / Q000166:cytology / Q000276:immunology / Q000637:transplantation; D002986:Clinical Trials as Topic; D019175:DNA Methylation; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000235:genetics; D006801:Humans; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology / Q000637:transplantation*; D055815:Young Adult
chemical_list: D015703:Antigens, CD; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors