title: A reproducible immunopotency assay to measure mesenchymal stromal cell-mediated T-cell suppression.
abstract: OBJECTIVE
  The T-cell suppressive property of bone marrow-derived mesenchymal stromal cells (MSCs) has been considered a major mode of action and basis for their utilization in a number of human clinical trials. However, there is no well-established reproducible assay to measure MSC-mediated T-cell suppression.
  
  
  METHODS
  At the University of Wisconsin-Madison Production Assistance for Cellular Therapy (PACT) Center, we developed an in vitro quality control T-cell suppression immunopotency assay (IPA) that uses anti-CD3 and anti-CD28 antibodies to stimulate T-cell proliferation. We measured MSC-induced suppression of CD4+ T-cell proliferation at various effector-to-target cell ratios with the use of defined peripheral blood mononuclear cells and in parallel compared with a reference standard MSC product. We calculated an IPA value for suppression of CD4+ T cells for each MSC product.
  
  
  RESULTS
  Eleven MSC products generated at three independent PACT centers were evaluated for cell surface phenotypic markers and T-cell suppressive properties. Flow cytometry results demonstrated typical MSC cell surface marker profiles. There was significant variability in the level of suppression of T-cell proliferation, with immunopotency assay values ranging from 27% to 88%. However, MSC suppression did not correlate with human leukocyte antigen-DR expression.
  
  
  CONCLUSIONS
  We have developed a reproducible immunopotency assay to measure allogeneic MSC-mediated suppression of CD4+ T cells. Additional studies may be warranted to determine how these in vitro assay results may correlate with other immunomodulatory properties of MSCs, in addition to evaluating the ability of this assay to predict in vivo efficacy.
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Debra D
authors.initials: DD
authors.lastname: Bloom
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Centanni
authors.affiliation: Waisman Biomanufacturing, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Neehar
authors.initials: N
authors.lastname: Bhatia
authors.affiliation: Waisman Biomanufacturing, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Emler
authors.affiliation: Waisman Biomanufacturing, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Drier
authors.affiliation: Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Glen E
authors.initials: GE
authors.lastname: Leverson
authors.affiliation: Molecular & Cellular Therapeutics, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: McKenna
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children's Hospital, Houston, Texas, USA.
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Gee
authors.affiliation: EMMES Corporation Inc, Rockville, Maryland, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Lindblad
authors.affiliation: Waisman Biomanufacturing, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Hei
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA; University of Wisconsin Carbone Cancer Center, Madison, Wisconsin, USA. Electronic address: pxh@medicine.wisc.edu.
authors.forename: Peiman
authors.initials: P
authors.lastname: Hematti
mesh_terms: D000906:Antibodies / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001854:Bone Marrow Cells / Q000166:cytology; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D007118:Immunoassay; D056747:Immunomodulation / Q000276:immunology*; D007165:Immunosuppression Therapy / Q000379:methods*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D059630:Mesenchymal Stem Cells / Q000276:immunology*; D015203:Reproducibility of Results
chemical_list: D000906:Antibodies; D000954:Antigens, Surface; D018106:CD28 Antigens; D017252:CD3 Complex
keywords: PACT; T-cell suppression; mesenchymal stromal cells; potency assay