title: Cryopreservation does not alter main characteristics of Good Manufacturing Process-grade human multipotent mesenchymal stromal cells including immunomodulating potential and lack of malignant transformation.
abstract: OBJECTIVE
  The immunomodulating capacity of multipotent mesenchymal stromal cells (MSCs) qualifies them as a therapeutic tool in several diseases. However, repeated transplantation with products of reproducible characteristics may be required. This could be achieved with cryopreserved aliquots of Good Manufacturing Practice (GMP)-grade MSCs. However, the impact of cryopreservation on the characteristics of GMP-MSCs is ill defined.
  
  
  METHODS
  We produced fresh and cryopreserved MSCs from human donors with a xenogen-free GMP protocol. Immunogenicity and immunomodulating capacity were tested in co-culture with putative recipient-specific peripheral blood mononuclear cells (PBMCs). Risk of malignant transformation was assessed in vitro and in vivo.
  
  
  RESULTS
  Cryopreservation had no impact on viability and consensus criteria of MSCs. In co-culture with PBMCs, MSCs showed low immunogenicity and suppressed mitogen-stimulated proliferation of PBMC irrespective of cryopreservation. Cytogenetic aberrations were not observed consistently in fresh and cryopreserved products, and no signs of malignant transformation occurred in functional assays. MSC products from an elderly pretreated donor showed reduced functional quality, but imminent failure of functional criteria could be detected by an increased population doubling time in early passages.
  
  
  CONCLUSIONS
  This study is the first systematic analysis on cryopreservation of xenogen-free human bone marrow-derived GMP-MSCs. The data support that cryopreservation does not alter the characteristics of the cells and thus may allow the generation of products for serial transplantation. In addition, the protocol allowed early detection of MSC products with low functional capacity.
authors.affiliation: Universitätsklinik und Poliklinik für Innere Medizin IV, Halle (Saale), Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Luetzkendorf
authors.affiliation: Universitätsklinik und Poliklinik für Innere Medizin IV, Halle (Saale), Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Nerger
authors.affiliation: Einrichtung für Transfusionsmedizin, Halle (Saale), Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Hering
authors.affiliation: Einrichtung für Transfusionsmedizin, Halle (Saale), Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Moegel
authors.affiliation: Institut für Humangenetik, Universitätsklinikum Halle, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Hoffmann
authors.affiliation: Institut für Humangenetik, Universitätsklinikum Halle, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Hoefers
authors.affiliation: Universitätsklinik und Poliklinik für Innere Medizin IV, Halle (Saale), Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Mueller-Tidow
authors.affiliation: Universitätsklinik und Poliklinik für Innere Medizin IV, Halle (Saale), Germany. Electronic address: lutz.mueller@uk-halle.de.
authors.forename: Lutz P
authors.initials: LP
authors.lastname: Mueller
mesh_terms: D000328:Adult; D000368:Aged; D002454:Cell Differentiation / Q000276:immunology; D049109:Cell Proliferation; D002470:Cell Survival; D002471:Cell Transformation, Neoplastic / Q000276:immunology*; D064987:Cell- and Tissue-Based Therapy; D002478:Cells, Cultured; D018920:Coculture Techniques; D015925:Cryopreservation; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D056747:Immunomodulation / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D059630:Mesenchymal Stem Cells / Q000276:immunology*; D008875:Middle Aged; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000276:immunology*; D011786:Quality Control; D055815:Young Adult
keywords: GMP; MSC; cryopreservation; immunogenicity; immunomodulation; malignant transformation