title: Ex vivo expansion of highly cytotoxic human NK cells by cocultivation with irradiated tumor cells for adoptive immunotherapy.
abstract: Adoptive natural killer (NK) cell therapy may offer an effective treatment regimen for cancer patients whose disease is refractory to conventional therapy. NK cells can kill a wide range of tumor cells by patterned recognition of target ligands. We hypothesized that tumor targets sensitive to NK lysis would drive vigorous expansion of NK cells from human peripheral blood mononuclear cells (PBMC). Here, we provide the basis for developing a novel ex vivo expansion process. By screening class I-negative or -mismatched tumor cell lines we identified a Jurkat T-lymphoblast subline termed KL-1, which was highly effective in specifically expanding NK cells. KL-1 addition to PBMC cultures achieved approximately 100-fold expansion of NK cells with nearly 90% purity, accompanied by reciprocal inhibition of T-cell growth. Marked elevations in expression of activation receptors, natural cytotoxicity receptors (NKp30, NKp44), and adhesion molecules (CD11a, ICAM-1) were associated with high tumor-lytic capacity, in both in vitro and in vivo models. KL-1-mediated expansion of NK cells was contact dependent and required interactions with CD16, the Fcγ receptor on NK cells, with ligands that are expressed on B cells. Indeed, B-cell depletion during culture abrogated selective NK cell expansion, while addition of EBV-transformed B cells further augmented NK expansion to approximately 740-fold. Together, our studies define a novel method for efficient activation of human NK cells that employs KL-1-lysed tumor cells and cocultured B cells, which drive a robust expansion of potent antitumor effector cells that will be useful for clinical evaluation.
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seon Ah
authors.initials: SA
authors.lastname: Lim
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Kim
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Chung Hee
authors.initials: CH
authors.lastname: Sonn
authors.forename: Kwanghee
authors.initials: K
authors.lastname: Kim
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
authors.forename: Jong Gwon
authors.initials: JG
authors.lastname: Choi
authors.forename: Il-Kyu
authors.initials: IK
authors.lastname: Choi
authors.forename: Chae-Ok
authors.initials: CO
authors.lastname: Yun
authors.forename: Jae-Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Cassian
authors.initials: C
authors.lastname: Yee
authors.forename: Vinay
authors.initials: V
authors.lastname: Kumar
authors.forename: Kyung-Mi
authors.initials: KM
authors.lastname: Lee
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002450:Cell Communication / Q000276:immunology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D061252:Feeder Cells / Q000378:metabolism / Q000528:radiation effects; D020869:Gene Expression Profiling; D006801:Humans; D016219:Immunotherapy, Adoptive; D007694:Killer Cells, Natural / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D019038:Platelet Glycoprotein GPIb-IX Complex; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D008024:Ligands; D008562:Membrane Glycoproteins; D019038:Platelet Glycoprotein GPIb-IX Complex; C094990:adhesion receptor