Co-Expression of an IL-15 Superagonist Facilitates Self-Enrichment of GD2-Targeted CAR-NK Cells and Mediates Potent Cell Killing in the Absence of IL-2

Malena Bodden; Aline Häcker; Jasmin Röder; Anne Kiefer; Congcong Zhang; Anita Bhatti; Jordi Pfeifer Serrahima; Evelyn Ullrich; Ines Kühnel; Winfried S Wels

doi:10.3390/cancers15174310

Co-Expression of an IL-15 Superagonist Facilitates Self-Enrichment of GD₂-Targeted CAR-NK Cells and Mediates Potent Cell Killing in the Absence of IL-2

Cancers (Basel). 2023 Aug 29;15(17):4310. doi: 10.3390/cancers15174310.

Authors

Malena Bodden^{1

2}, Aline Häcker¹, Jasmin Röder^{1

2}, Anne Kiefer¹, Congcong Zhang¹, Anita Bhatti¹, Jordi Pfeifer Serrahima¹, Evelyn Ullrich^{2

3

4}, Ines Kühnel¹, Winfried S Wels^{1

2

3}

Affiliations

¹ Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt, Germany.
² Frankfurt Cancer Institute, Goethe University, 60590 Frankfurt, Germany.
³ German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a Partnership between DKFZ and University Hospital Frankfurt, 60590 Frankfurt, Germany.
⁴ Department of Pediatrics, Experimental Immunology and Cell Therapy, Goethe University, 60590 Frankfurt, Germany.

Abstract

In contrast to T lymphocytes, natural killer (NK) cells do not require prior sensitization but are rapidly activated upon encountering virally infected or neoplastic cells. In addition, NK cells can be safely applied in an allogeneic setting, making them important effector cells for the development of off-the-shelf therapeutics for adoptive cancer immunotherapy. To further enhance their therapeutic potential, here, we engineered continuously expanding NK-92 cells as a clinically relevant model to express a humanized second-generation chimeric antigen receptor (CAR) with a composite CD28-CD3ζ signaling domain (hu14.18.28.z) that targets the disialoganglioside GD₂, which is expressed at high levels by neuroblastoma cells and other tumors of neuroectodermal origin. In a separate approach, we fused an IL-15 superagonist (RD-IL15) to the GD₂-CAR via a P2A processing site. Lentivirally transduced NK-92/hu14.18.28.z and NK-92/hu14.18.28.z_RD-IL15 cells both displayed high and stable CAR surface expression and specific cytotoxicity toward GD₂-positive tumor cells. GD₂-CAR NK cells carrying the RD-IL15 construct in addition expressed the IL-15 superagonist, resulting in self-enrichment and targeted cell killing in the absence of exogenous IL-2. Furthermore, co-culture with RD-IL15-secreting GD₂-CAR NK cells markedly enhanced proliferation and cytotoxicity of bystander immune cells in a paracrine manner. Our results demonstrate that GD₂-CAR NK cells co-expressing the IL-15 superagonist mediate potent direct and indirect antitumor effects, suggesting this strategy as a promising approach for the further development of functionally enhanced cellular therapeutics.

Keywords: GD2; NK-92; chimeric antigen receptor; interleukin-15; natural killer cells.

Abstract

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