title: Clinical-grade, large-scale, feeder-free expansion of highly active human natural killer cells for adoptive immunotherapy using an automated bioreactor.
abstract: OBJECTIVE
  Natural killer (NK) cell-based adoptive immunotherapy is a promising approach for the treatment of cancer. Ex vivo expansion and activation of NK cells under good manufacturing practice (GMP) conditions are crucial for facilitating large clinical trials. The goal of this study was to optimize a large-scale, feeder-free, closed system for efficient NK cell expansion.
  
  
  METHODS
  Peripheral blood mononuclear cells (PBMCs) from healthy donors and myeloma patients were cultured for 21 days using flasks, cell culture bags and bioreactors. Final products from different expansions were evaluated comparatively for phenotype and functionality.
  
  
  RESULTS
  Significant NK cell expansions were obtained in all systems. The bioreactor yielded a final product rich in NK cells (mean 38%) ensuring that a clinically relevant cell dose was reached (mean 9.8 x 10⁹ NK cells). Moreover, we observed that NK cells expanded in the bioreactor displayed significantly higher cytotoxic capacity. It was possible to attribute this partially to a higher expression level of NKp44 compared with NK cells expanded in flasks.
  
  
  CONCLUSIONS
  These results demonstrate that large amounts of highly active NK cells for adoptive immunotherapy can be produced in a closed, automated, large-scale bioreactor under feeder-free current GMP conditions, facilitating clinical trials for the use of these cells.
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Tolga
authors.initials: T
authors.lastname: Sutlu
authors.forename: Birgitta
authors.initials: B
authors.lastname: Stellan
authors.forename: Mari
authors.initials: M
authors.lastname: Gilljam
authors.forename: Hernan Concha
authors.initials: HC
authors.lastname: Quezada
authors.forename: Hareth
authors.initials: H
authors.lastname: Nahi
authors.forename: Gösta
authors.initials: G
authors.lastname: Gahrton
authors.forename: Evren
authors.initials: E
authors.lastname: Alici
mesh_terms: D057205:Automation, Laboratory; D019149:Bioreactors; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods; D049109:Cell Proliferation; D002469:Cell Separation; D003602:Cytotoxicity, Immunologic; D005240:Feasibility Studies; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D009101:Multiple Myeloma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D055629:Natural Cytotoxicity Triggering Receptor 2 / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: C112837:NCR2 protein, human; D055629:Natural Cytotoxicity Triggering Receptor 2