Expression of chimeric antigen receptors in natural killer cells with a regulatory-compliant non-viral method.
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.
Li
L
L
MaxCyte Inc, Gaithersburg, MD 20878, USA. linhongl@maxcyte.com
Liu
L N
LN
Feller
S
S
Allen
C
C
Shivakumar
R
R
Fratantoni
J
J
Wolfraim
L A
LA
Fujisaki
H
H
Campana
D
D
Chopas
N
N
Dzekunov
S
S
Peshwa
M
M
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
D018941:Antigens, CD19; D011946:Receptors, Antigen; D049452:Green Fluorescent Proteins