title: PD1 blockade enhances cytotoxicity of in vitro expanded natural killer cells towards myeloma cells.
abstract: Aiming for an adoptive natural killer (NK) cell therapy, we have developed a novel protocol to expand NK cells from peripheral blood. With this protocol using anti-human CD16 antibody and interleukin (IL)-2, NK (CD3-CD56+) cells could be expanded about 4000-fold with over 70% purity during a 21-day culture. The expanded NK (exNK) cells were shown to be highly cytotoxic to multiple myeloma (MM) cells (RPMI8226) at low NK-target cell ratios. Furthermore, NK cells expanded in the presence of a blocking antibody (exNK+PD1-blockage) against programmed cell death protein-1 (PD1), a key counteracting molecule for NK and T cell activity, demonstrated more potent cytolytic activity against the RPMI8226 than the exNK cells without PD1 blocking. In parallel, the exNK cells showed significantly higher expression of NK activation receptors NKG2D, NKp44 and NKp30. In a murine model of MM, transfusion of exNK cells, exNK+PD1-blockage, and exNK plus intratumor injection of anti-PD-L2 antibody (exNK+PD-L2 blockage) all significantly suppressed tumor growth and prolonged survival of the myeloma mice. Importantly, exNK+PD1-blockage presented more efficient therapeutic effects. Our results suggest that the NK cell expansion protocol with PD1 blockade presented in this study has considerable potential for the clinical application of allo- and auto-NK cell-based therapies against malignancies.
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Clinical Laboratory Department of The Second Hospital, Shandong University, Jinan, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Feng
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Shi
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.
authors.forename: Xiangling
authors.initials: X
authors.lastname: Xing
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Liu
authors.affiliation: Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.|Department of Medicine-Solna, Clinical Pharmacology Group, Karolinska Institutet, Karolinska University Hospital-Solna, Stockholm, Sweden.
authors.forename: Nailin
authors.initials: N
authors.lastname: Li
authors.affiliation: Karolinska Institutet, Institute of Environmental Medicine, Division of Molecular Toxicology, Stockholm, Sweden.|Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Fadeel
authors.affiliation: Hematology Department, The Second Hospital of Shandong University, Jinan, China.|Institute of Biotherapy for Hematological Malignancies, Shandong University, Jinan, China.|Shandong University-Karolinska Institutet Collaborative Laboratory for Stem Cell Research, The Second Hospital of Shandong University, Jinan, China.|Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Chengyun
authors.initials: C
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007376:Interleukin-2 / Q000494:pharmacology; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D016513:Mice, SCID; D009101:Multiple Myeloma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D061026:Programmed Cell Death 1 Receptor / Q000037:antagonists & inhibitors* / Q000276:immunology; D011897:Random Allocation; D023041:Xenograft Model Antitumor Assays
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: PD1; anti-tumor activity; in vitro expansion; myeloma; natural killer cells