title: Antigen-independent and antigen-dependent methods to numerically expand CD19-specific CD8+ T cells.
abstract: OBJECTIVE
  Preclinical and clinical trials are investigating the potential of T cells genetically modified to express a first-generation CD19-specific chimeric antigen receptor (CAR), designated CD19R, for adoptive immunotherapy of B-lineage leukemias and lymphomas. Currently, our genetically modified CD19-specific CD8+ (CD19R+CD8+) T cells are expanded ex vivo using a rapid expansion protocol (REP) to clinically meaningful numbers after antigen-independent activation with anti-CD3epsilon and recombinant human interleukin-2 on a double-cell feeder-layer of gamma-irradiated allogeneic peripheral blood mononuclear cells and a lymphoblastoid cell line. We now compare the ability of the REP with CD19-dependent numerical expansion using CD19+ artificial antigen-presenting cells to propagate CD19R+CD8+ T cells.
  
  
  METHODS
  We evaluated long-term (28 days) propagation, CD19R CAR expression, and cytolytic activity of CD19R+CD8+ T cells expanded by either a REP or an antigen expansion protocol (AEP) using K562-derived artificial antigen-presenting cells coexpressing CD19 antigen and two T-cell costimulatory molecules (4-1BB ligand and major histocompatibility class I-related chains A) in the presence of exogenous recombinant human interleukin-2 and recombinant human interleukin-15.
  
  
  RESULTS
  Populations of CD19R+CD8+ T cells could be numerically expanded on AEP to meet anticipated clinical need. The AEP was superior to REP, as this method selected for an outgrowth of T cells with increased CD19R CAR expression and improved redirected cytolytic activity.
  
  
  CONCLUSIONS
  Robust propagation of CD19R+CD8+ T cells achieved by AEP supports qualifying this cell line for use in current good manufacturing practices for CAR+ T cells as an alternative to REP for adoptive immunotherapy clinical trials.
authors.affiliation: Division of Molecular Medicine, Beckman Research Institute and City of Hope National Medical Center, Duarte, Calif., USA.
authors.forename: Tontanai
authors.initials: T
authors.lastname: Numbenjapon
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Serrano
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Chang
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Forman
authors.forename: Michael C
authors.initials: MC
authors.lastname: Jensen
authors.forename: Laurence J N
authors.initials: LJ
authors.lastname: Cooper
mesh_terms: D000938:Antigen-Presenting Cells / Q000502:physiology; D018941:Antigens, CD19 / Q000032:analysis / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D045744:Cell Line, Tumor; D006801:Humans; D016219:Immunotherapy, Adoptive; D011948:Receptors, Antigen, T-Cell / Q000032:analysis
chemical_list: D018941:Antigens, CD19; D011948:Receptors, Antigen, T-Cell