Background: With increasing clinical use of NK-92 cells and their CAR-modified
derivatives in cancer immunotherapy, there is a growing demand for efficient
production processes of these “off-the-shelf” therapeutics. In order to ensure safety
and prevent the occurrence of secondary tumors, (CAR-)NK-92 cell proliferation has to be
inactivated before transfusion. This is commonly achieved by gamma irradiation. Recently,
we showed proof of concept that low energy electron irradiation (LEEI) is a new method for
NK-92 inactivation. LEEI has several advantages over gamma irradiation, including a faster
reaction time, a more reproducible dose rate and much less requirements on radiation
shielding. Here, LEEI was further evaluated as a promising alternative to gamma irradiation
yielding cells with highly maintained cytotoxic effector function.
Methods: Effectiveness and efficiency of LEEI and gamma irradiation were analyzed using
NK-92 and CD123-directed CAR-NK-92 cells. LEE-irradiated cells were extensively
characterized and compared to gamma-irradiated cells via flow cytometry, cytotoxicity
assays, and comet assays, amongst others.
Results: Our results show that both irradiation methods caused a progressive decrease
in cell viability and are, therefore, suitable for inhibition of cell proliferation. Notably, the NKmediated
specific lysis of tumor cells was maintained at stable levels for three days postirradiation,
with a trend towards higher activities after LEEI treatment as compared to
gamma irradiation. Both gamma irradiation as well as LEEI led to substantial DNA damage
and an accumulation of irradiated cells in the G2/M cell cycle phases. In addition,
transcriptomic analysis of irradiated cells revealed approximately 12-fold more
differentially expressed genes two hours after gamma irradiation, compared to LEEI.
Analysis of surface molecules revealed an irradiation-induced decrease in surface
expression of CD56, but no changes in the levels of the activating receptors NKp46,
NKG2D, or NKp30.
Conclusions: The presented data show that LEEI inactivates (CAR-)NK-92 cells as
efficiently as gamma irradiation, but with less impact on the overall gene expression. Due
to logistic advantages, LEEI might provide a superior alternative for the manufacture of
(CAR-)NK-92 cells for clinical application.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:84299 |
| Date | 24 March 2023 |
| Creators | Walcher, Lia, Kistenmacher, Ann-Kathrin, Sommer, Charline, Böhlen, Sebastian, Ziemann, Christina, Dehmel, Susann, Braun, Armin, Tretbar, Uta Sandy, Klöß, Stephan, Schambach, Axel, Morgan, Michael, Löffler, Dennis, Kämpf, Christoph, Blumert, Conny, Reiche, Kristin, Beckmann, Jana, König, Ulla, Standfest, Bastian, Thoma, Martin, Makert, Gustavo R., Ulbert, Sebastian, Kossatz-Böhlert, Uta, Köhl, Ulrike, Dünkel, Anna, Fricke, Stephan |
| Publisher | Frontiers Research Foundation |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1664-3224, 684052 |
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