title: Expression of chimeric antigen receptors in natural killer cells with a regulatory-compliant non-viral method.
abstract: Natural killer (NK) cells hold promise for cancer therapy. NK cytotoxicity can be enhanced by expression of chimeric antigen receptors that re-direct specificity toward target cells by engaging cell surface molecules expressed on target cells. We developed a regulatory-compliant, scalable non-viral approach to engineer NK cells to be target-specific based on transfection of mRNA encoding chimeric receptors. Transfection of eGFP mRNA into ex vivo expanded NK cells (N=5) or purified unstimulated NK cells from peripheral blood (N=4) resulted in good cell viability with eGFP expression in 85+/-6% and 86+/-4%, 24 h after transfection, respectively. An mRNA encoding a receptor directed against CD19 (anti-CD19-BB-z) was also transfected into NK cells efficiently. Ex vivo expanded and purified unstimulated NK cells expressing anti-CD19-BB-z exhibited enhanced cytotoxicity against CD19(+) target cells resulting in > or =80% lysis of acute lymphoblastic leukemia and B-lineage chronic lymphocytic leukemia cells at effector target ratios lower than 10:1. The target-specific cytotoxicity for anti-CD19-BB-z mRNA-transfected NK cells was observed as early as 3 h after transfection and persisted for up to 3 days. The method described here should facilitate the clinical development of NK-based antigen-targeted immunotherapy for cancer.
authors.affiliation: MaxCyte Inc, Gaithersburg, MD 20878, USA. linhongl@maxcyte.com
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: L N
authors.initials: LN
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Feller
authors.forename: C
authors.initials: C
authors.lastname: Allen
authors.forename: R
authors.initials: R
authors.lastname: Shivakumar
authors.forename: J
authors.initials: J
authors.lastname: Fratantoni
authors.forename: L A
authors.initials: LA
authors.lastname: Wolfraim
authors.forename: H
authors.initials: H
authors.lastname: Fujisaki
authors.forename: D
authors.initials: D
authors.lastname: Campana
authors.forename: N
authors.initials: N
authors.lastname: Chopas
authors.forename: S
authors.initials: S
authors.lastname: Dzekunov
authors.forename: M
authors.initials: M
authors.lastname: Peshwa
mesh_terms: D018941:Antigens, CD19 / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D018274:Electroporation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism*; D011946:Receptors, Antigen / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D018941:Antigens, CD19; D011946:Receptors, Antigen; D049452:Green Fluorescent Proteins