Good manufacturing practices production of natural killer cells for immunotherapy: a six-year single-institution experience.
BACKGROUND
Natural killer (NK) cells, a subset of lymphocytes and part of the innate immune system, play a crucial role in defense against cancer and viral infection. Herein is a report on the experience of clinical-scale, good manufacturing practices (GMPs) production of NK cells to treat advanced cancer.


METHODS
Two types of NK cell enrichments were performed on nonmobilized peripheral blood mononuclear cell apheresis collections with a cell selection system (CliniMACS, Miltenyi): CD3 cell depletion to enrich for NK cells and CD3 cell depletion followed by CD56 cell selection to obtain a more pure NK cell product. After overnight incubation with interleukin-2 (IL-2), cells were washed, resuspended in 5 percent human serum albumin, and then released for infusion.


RESULTS
A total of 70 NK cell therapy products have been manufactured for patient infusion since 2000. For the CD3 cell-depleted NK cell products, the mean purity, recovery, and viability were 38, 79, and 86 percent, respectively. For the CD3 cell-depleted/CD56 cell-enriched NK cell products, the mean purity, recovery, and viability were 90, 19, and 85 percent, respectively. Gram stain, sterility, and endotoxin testing were all within acceptable limits for established lot release. Compared to the resting processed cells, IL-2 activation significantly increased the function of cells in cytotoxicity assays.


CONCLUSIONS
Clinical-scale production of NK cells is efficient and can be performed under GMPs. The purified NK cell product results in high NK cell purity with minimal contamination by T cells, monocytes, and B cells, but it requires more time for processing and results in a lower NK cell recovery when compared to NK cell enrichment with CD3 cell depletion alone. Additional laboratory studies and results from clinical trials will identify the best source and type of NK cell product.
McKenna
David H
DH
Department of Laboratory Medicine and Pathology, Division of Transfusion Medicine, University of Minnesota Medical School, Minnesota 55108, USA. mcken020@umn.edu
Sumstad
Darin
D
Bostrom
Nancy
N
Kadidlo
Diane M
DM
Fautsch
Susan
S
McNearney
Sarah
S
Dewaard
Rose
R
McGlave
Philip B
PB
Weisdorf
Daniel J
DJ
Wagner
John E
JE
McCullough
Jeffrey
J
Miller
Jeffrey S
JS
D001800:Blood Specimen Collection / Q000379:methods*; D017252:CD3 Complex / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D016238:Cytapheresis / Q000379:methods*; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007167:Immunotherapy; D007694:Killer Cells, Natural; D016131:Lymphocyte Subsets / Q000378:metabolism; D012189:Retrospective Studies
D017252:CD3 Complex; D019002:CD56 Antigen