Silje Zandstra Krokeide

• Sætersmoen, Michelle Lu; Kotchetkov, Ivan S.; Torralba-Raga, Lamberto; Mansilla-Soto, Jorge; Sohlberg, Ebba & Krokeide, Silje Zandstra [Show all 9 contributors for this article] (2024). Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor. Med. ISSN 2666-6359. p. 1–17. doi: 10.1016/j.medj.2024.09.010. Full text in Research Archive Show summary

  Background Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A+ CD8+ T cells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells. Methods We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain. The cytotoxic function of A/C switch-transduced NK and T cells was evaluated against tumor cells with varying levels of HLA-E expression. In vivo efficacy was assessed using a xenograft model of glioblastoma. Findings A/C switch-transduced NK and T cells exhibited superior and specific cytotoxicity against tumor cells with medium to high HLA-E expression. A/C switch-expressing human T cells demonstrated enhanced anti-tumor function in a glioblastoma xenograft model. The activity of the modified T cells was governed by an equilibrium between A/C switch levels and HLA-E expression, creating a therapeutic window to minimize on-target, off-tumor toxicities. Normal cells remained insensitive to A/C switch T cells, even after interferon (IFN)-γ pretreatment to induce HLA-E expression. Conclusions The A/C switch receptor effectively targets tumor cells expressing high levels of HLA-E, either alone or in combination with other engineered specificities, to overcome the suppressive NKG2A/HLA-E checkpoint. This approach offers a promising therapeutic strategy with a favorable safety profile for targeting HLA-E-overexpressing tumors. Funding This work was funded by The Research Council of Norway, the Norwegian Cancer Society, and the National Cancer Institute.

• Orellana, Daniel Alfredo Palacios; Majhi, Rakesh Kumar; Szabo, Edina Krisztina; Clement, Dennis; Lachota, Mieszko Krzysztof & Netskar, Herman Krogstad [Show all 11 contributors for this article] (2024). The G Protein-Coupled Receptor GPR56 Is an Inhibitory Checkpoint for NK Cell Migration. Journal of Immunology. ISSN 0022-1767. 213(9), p. 1349–1357. doi: 10.4049/jimmunol.2400228. Full text in Research Archive
• Hammer, Quirin; Perica, Karlo; Mbofung, Rina M.; Ooijen, Hanna van; Martin, Karen Elizabeth & Momayyezi, Pouria [Show all 19 contributors for this article] (2024). Genetic ablation of adhesion ligands mitigates rejection of allogeneic cellular immunotherapies. Cell Stem Cell. ISSN 1934-5909. 31, p. 1376–1386. doi: 10.1016/j.stem.2024.06.011. Full text in Research Archive Show summary

  Allogeneic cellular immunotherapies hold promise for broad clinical implementation but face limitations due to potential rejection of donor cells by the host immune system. Silencing of beta-2 microglobulin (B2M) expression is commonly employed to evade T cell-mediated rejection by the host, although the absence of B2M is expected to trigger missing-self responses by host natural killer (NK) cells. Here, we demonstrate that genetic deletion of the adhesion ligands CD54 and CD58 in B2M-deficient chimeric antigen receptor (CAR) T cells and multi-edited induced pluripotent stem cell (iPSC)-derived CAR NK cells reduces their susceptibility to rejection by host NK cells in vitro and in vivo. The absence of adhesion ligands limits rejection in a unidirectional manner in B2M-deficient and B2M-sufficient settings without affecting the antitumor functionality of the engineered donor cells. Thus, these data suggest that genetic ablation of adhesion ligands effectively alleviates rejection by host immune cells, facilitating the implementation of universal immunotherapy.

• Clement, Dennis; Szabo, Edina Krisztina; Krokeide, Silje Zandstra; Wiiger, Merete Thune; Vincenti, Marianna & Orellana, Daniel Alfredo Palacios [Show all 13 contributors for this article] (2023). The Lysosomal Calcium Channel TRPML1 Maintains Mitochondrial Fitness in NK Cells through Interorganelle Cross-Talk. Journal of Immunology. ISSN 0022-1767. 211(9), p. 1348–1358. doi: 10.4049/jimmunol.2300406. Full text in Research Archive Show summary

  Abstract Cytotoxic lymphocytes eliminate cancer cells through the release of lytic granules, a specialized form of secretory lysosomes. This compartment is part of the pleomorphic endolysosomal system and is distinguished by its highly dynamic Ca2+ signaling machinery. Several transient receptor potential (TRP) calcium channels play essential roles in endolysosomal Ca2+ signaling and ensure the proper function of these organelles. In this study, we examined the role of TRPML1 (TRP cation channel, mucolipin subfamily, member 1) in regulating the homeostasis of secretory lysosomes and their cross-talk with mitochondria in human NK cells. We found that genetic deletion of TRPML1, which localizes to lysosomes in NK cells, led to mitochondrial fragmentation with evidence of collapsed mitochondrial cristae. Consequently, TRPML1−/− NK92 (NK92ML1−/−) displayed loss of mitochondrial membrane potential, increased reactive oxygen species stress, reduced ATP production, and compromised respiratory capacity. Using sensitive organelle-specific probes, we observed that mitochondria in NK92ML1−/− cells exhibited evidence of Ca2+ overload. Moreover, pharmacological activation of the TRPML1 channel in primary NK cells resulted in upregulation of LC3-II, whereas genetic deletion impeded autophagic flux and increased accumulation of dysfunctional mitochondria. Thus, TRPML1 impacts autophagy and clearance of damaged mitochondria. Taken together, these results suggest that an intimate interorganelle communication in NK cells is orchestrated by the lysosomal Ca2+ channel TRPML1.

• Giang, Kim Anh; Boxaspen, Thorstein; Diao, Yumei; Nilvebrant, Johan; Kosugi-Kanaya, Mizuha & Kanaya, Minoru [Show all 11 contributors for this article] (2023). Affibody-based hBCMA x CD16 dual engagers for NK cell-mediated killing of multiple myeloma cells. New Biotechnology. ISSN 1871-6784. 77, p. 139–148. doi: 10.1016/j.nbt.2023.09.002. Full text in Research Archive Show summary

  We describe the development and characterization of the (to date) smallest Natural Killer (NK) cell re-directing human B Cell Maturation Antigen (hBCMA) x CD16 dual engagers for potential treatment of multiple myeloma, based on combinations of small 58 amino acid, non-immunoglobulin, affibody affinity proteins. Affibody molecules to human CD16a were selected from a combinatorial library by phage display resulting in the identification of three unique binders with affinities (KD) for CD16a in the range of 100 nM–3 µM. The affibody exhibiting the highest affinity demonstrated insensitivity towards the CD16a allotype (158F/V) and did not interfere with IgG (Fc) binding to CD16a. For the construction of hBCMA x CD16 dual engagers, different CD16a binding arms, including bi-paratopic affibody combinations, were genetically fused to a high-affinity hBCMA-specific affibody. Such 15–23 kDa dual engager constructs showed simultaneous hBCMA and CD16a binding ability and could efficiently activate resting primary NK cells and trigger specific lysis of a panel of hBCMA-positive multiple myeloma cell lines. Hence, we report a novel class of uniquely small NK cell engagers with specific binding properties and potent functional profiles.

• Haroun-Izquierdo, Alvaro; Vincenti, Marianna; Netskar, Herman Krogstad; Ooijen, Hanna van; Zhang, Bin & Bendzick, Laura [Show all 30 contributors for this article] (2022). Adaptive single-KIR+NKG2C+ NK cells expanded from select superdonors show potent missing-self reactivity and efficiently control HLA-mismatched acute myeloid leukemia. Journal for ImmunoTherapy of Cancer (JITC). 10:e005577(11), p. 1–13. doi: 10.1136/jitc-2022-005577. Full text in Research Archive Show summary

  Background Natural killer (NK) cells hold great promise as a source for allogeneic cell therapy against hematological malignancies, including acute myeloid leukemia (AML). Current treatments are hampered by variability in NK cell subset responses, a limitation which could be circumvented by specific expansion of highly potent single killer immunoglobulin-like receptor (KIR)+NKG2C+ adaptive NK cells to maximize missing-self reactivity. Methods We developed a GMP-compliant protocol to expand adaptive NK cells from cryopreserved cells derived from select third-party superdonors, that is, donors harboring large adaptive NK cell subsets with desired KIR specificities at baseline. We studied the adaptive state of the cell product (ADAPT-NK) by flow cytometry and mass cytometry as well as cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq). We investigated the functional responses of ADAPT-NK cells against a wide range of tumor target cell lines and primary AML samples using flow cytometry and IncuCyte as well as in a mouse model of AML. Results ADAPT-NK cells were >90% pure with a homogeneous expression of a single self-HLA specific KIR and expanded a median of 470-fold. The ADAPT-NK cells largely retained their adaptive transcriptional signature with activation of effector programs without signs of exhaustion. ADAPT-NK cells showed high degranulation capacity and efficient killing of HLA-C/KIR mismatched tumor cell lines as well as primary leukemic blasts from AML patients. Finally, the expanded adaptive NK cells had preserved robust antibody-dependent cellular cytotoxicity potential and combination of ADAPT-NK cells with an anti-CD16/IL-15/anti-CD33 tri-specific engager led to near-complete killing of resistant CD45dim blast subtypes. Conclusions These preclinical data demonstrate the feasibility of off-the-shelf therapy with a non-engineered, yet highly specific, NK cell population with full missing-self recognition capability.

• Rolseth, Veslemøy; Krokeide, Silje Z; Kunke, David; Neurauter, Christine Gran; Suganthan, Rajikala & Sejersted, Yngve [Show all 9 contributors for this article] (2013). Loss of Neil3, the major DNA glycosylase activity for removal of hydantoins in single stranded DNA, reduces cellular proliferation and sensitizes cells to genotoxic stress. BBA - Molecular Cell Research. ISSN 0167-4889. 1833(5), p. 1157–1164. doi: 10.1016/j.bbamcr.2012.12.024. Full text in Research Archive
• Krokeide, Silje Zandstra; Lærdahl, Jon Kristen; Salah, Medya; Luna, Luisa; Cederkvist, Fritjof Henning & Fleming, Aaron M. [Show all 9 contributors for this article] (2013). Human NEIL3 is mainly a monofunctional DNA glycosylase removing spiroimindiohydantoin and guanidinohydantoin. DNA Repair. ISSN 1568-7864. 12(12), p. 1159–1164. doi: 10.1016/j.dnarep.2013.04.026. Full text in Research Archive
• Regnell, Christine E; Hildrestrand, Gunn Annette; Sejersted, Yngve; Medin, Tirill; Moldestad, Olve & Rolseth, Veslemøy [Show all 11 contributors for this article] (2012). Hippocampal Adult Neurogenesis Is Maintained by Neil3-Dependent Repair of Oxidative DNA Lesions in Neural Progenitor Cells. Cell reports. 2(3), p. 503–510. doi: 10.1016/j.celrep.2012.08.008. Full text in Research Archive Show summary

  Accumulation of oxidative DNA damage has been proposed as a potential cause of age-related cognitive decline. The major pathway for removal of oxidative DNA base lesions is base excision repair, which is initiated by DNA glycosylases. In mice, Neil3 is the main DNA glycosylase for repair of hydantoin lesions in single-stranded DNA of neural stem/progenitor cells, promoting neurogenesis. Adult neurogenesis is crucial for maintenance of hippocampus-dependent functions involved in behavior. Herein, behavioral studies reveal learning and memory deficits and reduced anxiety-like behavior in Neil3−/− mice. Neural stem/progenitor cells from aged Neil3−/− mice show impaired proliferative capacity and reduced DNA repair activity. Furthermore, hippocampal neurons in Neil3−/− mice display synaptic irregularities. It appears that Neil3-dependent repair of oxidative DNA damage in neural stem/progenitor cells is required for maintenance of adult neurogenesis to counteract the age-associated deterioration of cognitive performance.

• Sejersted, Yngve; Hildrestrand, Gunn Annette; Kunke, David; Rolseth, Veslemøy; Krokeide, Silje Z. & Neurauter, Christine Gran [Show all 13 contributors for this article] (2011). Endonuclease VIII-like 3 (Neil3) DNA glycosylase promotes neurogenesis induced by hypoxia-ischemia. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 108(46), p. 18802–18807. doi: 10.1073/pnas.1106880108. Full text in Research Archive

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