bims-nakice Biomed News
on Natural killer cells
Issue of 2026–07–26
thirteen papers selected by
Santosh Phuyal, Oslo Universitetssykehus
  1. Unconventional functions of natural killer cells in homeostasis and disease.
  2. TLR-Mediated Calcium Signaling Regulates Killing Capacity of Expanded NK Cells: Challenges for Potential AML Immunotherapy.
  3. Quantifying NK-cell Cytotoxicity Potentiated by Chimeric Antigen Receptors and Therapeutic Antibodies Using Live-cell Imaging and Flow Cytometry.
  4. KRASG12D inhibition reprograms the tumor-induced immunosuppressive environment and enhances NK cell-mediated antitumor immunity.
  5. Therapeutic targeting of CD47 using a tri-specific NK cell engager to inhibit multiple myeloma.
  6. Human NKG2C+ adaptive NK cells for Cancer immunotherapy.
  7. Collective dynamics of natural killer cells interacting with cancer and fibroblast cells.
  8. Enhancing CAR-NK persistence to unlock its full therapeutic potentials.
  9. Cytokine-induced expandable memory NK cells with significant metabolic, epigenetic remodeling, and persistence properties.
  10. CD244 overexpression indicates NK cell dysfunction and tumor progression in diffuse large B-cell lymphoma.
  11. Cell biology: Cytoplasmic rivers carry molecular cargo.
  12. Simultaneous measurement of target and effector cell death, apoptosis, and proliferation in cell therapy development using flow cytometry.
  13. The actin crosslinker Fimbrin is required for force sensing at tricellular junctions.
  1. J Immunol. 2026 Jul 10. pii: vkag148. [Epub ahead of print]215(7):
    Unconventional functions of natural killer cells in homeostasis and disease.
    Anusha Anukanth, Stephen N Waggoner.
      NK cells are classically defined by their rapid cytotoxicity against tumor cells and infected cells and by early inflammatory cytokine production. However, unconventional roles for NK cells as regulators of immunity and tissue homeostasis have recently been uncovered. Beyond their classical roles, NK cells can orchestrate leukocyte trafficking, curtail responses of other immune cells, remove protein aggregates, support pregnancy, and contribute to healthy tissue regeneration. We discuss the importance of these myriad functional activities of NK cells in infection, cancer, autoimmunity, atopic and allergic disease, pregnancy, tissue injury, and neurodegenerative diseases. The functional pleiotropy of NK cells provides new avenues of translational utility for these innate lymphocytes and represents an unexplored complexity in conventional clinical applications of NK cells against infection and cancer.
    Keywords:  homeostasis; immunotherapy; innate lymphoid cell; plasticity; tissue
    DOI:  https://doi.org/10.1093/jimmun/vkag148
  2. J Leukoc Biol. 2026 Jul 23. pii: qiag092. [Epub ahead of print]
    TLR-Mediated Calcium Signaling Regulates Killing Capacity of Expanded NK Cells: Challenges for Potential AML Immunotherapy.
    Vojtěch Graman, Adéla Jílková, Marek Jedlička, Veronika Švubová, Zuzana Tomášiková, Matúš Otruba, Kateřina Kuglerová, Eva Mašínová, Jana Szabová, Michal Santocki, Tereza Fiedlerová, Marcela Hortová Kohoutková, Jan Frič.
      Natural killer (NK) cells are central to cancer immunosurveillance and immunotherapy. Their ability to engage in killing is critical for efficient target elimination and depends on tightly regulated Ca2+ signaling controlling granzyme degranulation. TLR engagement has been linked to Ca2+ signaling in other immune cell types, while specific role in NK cells remains unresolved. Given that NK cells express a broad range of TLRs, and that presence of TLR ligands-including damage- and pathogen-associated molecular patterns-can influence clinical scenarios including adoptive NK cell therapy, investigating TLR-driven Ca2+ signaling in NK cells is particularly relevant. Here, we examined how stimulation with selected TLR ligands influences Ca2+ signaling and NK cell activity. Immediate stimulation induced a rapid elevation of cytosolic Ca2+ in expanded NK cells. Functionally, TLR stimulation increased degranulation and enhanced cytotoxicity at high effector-to-target ratios. Under conditions of target excess, however, TLR-treated NK cells displayed impaired killing, likely due to unbalanced Ca2+ levels. These findings demonstrate that TLR signaling directly modulates Ca2+ flux in NK cells and can either potentiate or impair cytotoxic activity depending on context. While clinical implications remain hypothetical, such TLR-driven dysregulation affect NK cell killing activity in the inflammatory or pathogen-rich environments frequently encountered after chemotherapy. Our findings suggest that TLR-Ca2+ impact on cytotoxicity should be considered in adoptive transfer therapies where previous treatment affects systemic levels of TLR ligands, such as in patients with AML, where NK cell immunotherapy is frequently tested in trials.
    Keywords:  AML; NK cell; Toll-like receptor; calcium; cytotoxicity
    DOI:  https://doi.org/10.1093/jleuko/qiag092
  3. J Vis Exp. 2026 Jul 03.
    Quantifying NK-cell Cytotoxicity Potentiated by Chimeric Antigen Receptors and Therapeutic Antibodies Using Live-cell Imaging and Flow Cytometry.
    Yuxin G Chen, James O Townsend, Wilfredo F Garcia-Beltran.
      Natural killer (NK) cells are innate lymphocytes that play a critical role in protective immunity against diverse intracellular pathogens and cancers. Their primary function is to kill target cells that are infected, malignantly transformed, or coated by antibodies via antibody-dependent cellular cytotoxicity (ADCC). NK cells can also be genetically engineered to express chimeric antigen receptors (CARs) that enable targeted recognition of specific antigens. Quantitative measurement of NK-cell cytotoxicity is essential for assessing baseline functionality and for preclinical evaluation of monoclonal antibodies and CAR-engineering strategies. However, in vitro functional assays remain highly variable across laboratories due to differences in cell preparation, target cells, effector-to-target ratios, co-incubation times, and readout methods, limiting reproducibility and cross-study comparisons. This article presents a standardized protocol for quantitative assessment of NK-cell cytotoxicity using flow cytometry and real-time, live-cell imaging. Primary human NK cells and CAR-expressing NK-92 cells were evaluated for their ability to kill cancer cells and antibody-coated target cells in a 96-well plate format to measure natural cytotoxicity, CAR-mediated killing, and ADCC. Target-cell survival was measured either continuously using live-cell imaging or at a defined time point by flow cytometry, which also enabled phenotypic characterization of NK cells and target cells. These protocols provide a robust framework using routine tissue culture, imaging, and flow cytometry methods to enable reproducible quantification of NK-cell effector functions for studies of innate immunity and NK cell-based immunotherapies.
    DOI:  https://doi.org/10.3791/71377
  4. Sci Adv. 2026 Jul 24. 12(30): eaec9236
    KRASG12D inhibition reprograms the tumor-induced immunosuppressive environment and enhances NK cell-mediated antitumor immunity.
    Tuo Hu, Taiwei Mo, Lin Wang, Qiuqing Ke, Liangjie Chi, Hongyuan Chen, Chao Xu, Chenshen Huang, Aiping Lin, Shaoxin Cai, Haiyu Chen, Wenyu Wang, Longyang Jin, Junzhang Zhao, Haoyun Liu, Chuanyuan Liu, Yimamu Baihetiyaer, Abudumaimaitijiang Tuersun, Abuduhalike Abulimiti, Yan Zheng, Zuwei Wang, Shi Chen, Jie Cao, Shiyun Lu, Xueping Huang, Fangqin Xue, Chunbo He.
      KRASG12D mutation drives oncogenic progression and creates an immunosuppressive microenvironment in cancers like pancreatic ductal adenocarcinoma and colorectal cancer. We investigate the immunomodulatory mechanisms of the KRASG12D inhibition and its synergy with natural killer (NK) cell therapies. We demonstrate that KRASG12D inhibition with MRTX1133 remodels the immune landscape by reducing myeloid-derived suppressor cell (MDSC) accumulation and facilitating infiltration and activation of NK and CD8+ T cells. Crucially, MRTX1133 reverses systemic immunosuppression, restoring the fitness of adoptively transferred NK cells. Mechanistically, KRASG12D inhibition impairs IFNGR1 palmitoylation and subsequent lysosomal degradation. MRTX1133 stabilizes IFNGR1 by reducing palmitoyltransferase expression and the palmitate pool. This stabilization increases IFN-γ/IFNGR signaling and up-regulates NK cell-activating ligands ICAM1 and ULBP1, thereby sensitizing cancer cells to NK cells. Consequently, combining MRTX1133 with IL-15 or adoptive NK cell therapy yields synergistic antitumor responses and prolonged survival. Our findings provide mechanistic rationale for combining KRASG12D inhibitors with NK cell-based immunotherapies to improve outcomes for patients with KRASG12D-mutant cancers.
    DOI:  https://doi.org/10.1126/sciadv.aec9236
  5. Cancer Immunol Immunother. 2026 Jul 20.
    Therapeutic targeting of CD47 using a tri-specific NK cell engager to inhibit multiple myeloma.
    Ratchaneewan Sumankan, Prin Sungwan, Natthanich Boonsatit, Seiji Okada, Aussara Panya.
      Multiple myeloma (MM), a hematological malignancy, remains an incurable disease due to the development of resistance to the treatment; thus, there is an urgent need for new and effective therapeutic strategies, particularly for patients who do not respond to standard therapies. High levels of Cluster of Differentiation 47 (CD47) expression have been reported in MM and are associated with disease progression. CD47 acts as a cancer immune escape mechanism by binding to SIRPα protein, resulting in inhibiting phagocytosis of macrophages and NK cell activity. Therefore, blocking the CD47 signaling pathway has emerged as a promising strategy for cancer immunotherapy. In this study, we confirmed that MM cells have high CD47 expression. We generated and characterized a tri-specific killer engager targeting CD47, namely TriKE-CD47, that targets both CD47 on MM cells and CD16 on NK cells. Additionally, it incorporates an IL-15 moiety to enhance NK cell proliferation. TriKE-CD47 treatment promoted a remarkable proliferation of NK cells overexpressing CD16 (N6 cells). Co-culturing MM cells with N6 cells, primary NK cells, and monocyte-derived macrophages in the presence of 200 ng of TriKE-CD47 significantly improved NK cytotoxicity and macrophage phagocyte activities against MM cells. Notably, the efficacy of TriKE-CD47 was directly correlated with CD47 expression levels on the target cells reflecting the specificity of TriKE-CD47 to target antigen. Furthermore, TriKE-CD47 effectively suppressed tumor growth in MM xenograft mice models. Taken together, these findings strongly supported that TriKE-CD47 could be a potential therapeutic for MM patients.
    Keywords:  Biologics; Cluster of Differentiation 47 (CD47); Immunotherapy; Multiple myeloma; Natural killer cell; Tri-specific killer engager (TriKE)
    DOI:  https://doi.org/10.1007/s00262-026-04431-x
  6. Int Immunopharmacol. 2026 Jul 18. pii: S1567-5769(26)01006-4. [Epub ahead of print]186 117160
    Human NKG2C+ adaptive NK cells for Cancer immunotherapy.
    Qiao Tang, Zhigang Tian, Jiacheng Bi.
      Natural killer (NK) cells are key components of the innate immune system and play a pivotal role in tumor immunosurveillance. In recent years, a subset of NKG2C+ adaptive NK cells induced by human cytomegalovirus (HCMV) infection has attracted considerable attention because of its distinctive memory-like properties. This subset has shown substantial therapeutic potential in preclinical models of both haematological malignancies and solid tumors, and early-phase clinical trials in acute myeloid leukaemia (AML) and ovarian cancer have indicated a favorable safety profile with preliminary signs of efficacy. By applying a "super-donor" selection strategy and combining NKG2C-specific activation with cytokine stimulation, efficient ex vivo expansion of NKG2C+ adaptive NK cells can be achieved. When further integrated with synthetic immunology approaches-such as NK cell engagers (NKCEs) or engineered receptors-together with epigenetic modulation and metabolic reprogramming, the antitumor functions of this subset can be comprehensively augmented. These advances may unlock its therapeutic potential and offer new directions and paradigms for next-generation cancer immunotherapy.
    Keywords:  HCMV; Human NKG2C(+) adaptive NK cells; Immunotherapy; NKG2C/CD94
    DOI:  https://doi.org/10.1016/j.intimp.2026.117160
  7. Phys Rev E. 2026 Jun;113(6): L062401
    Collective dynamics of natural killer cells interacting with cancer and fibroblast cells.
    Yun-Xuan Zhang, Shu-Chen Liu, Lin I.
      Natural killer cells (NKCs) can distinguish the difference between normal and abnormal cells, and kill the latter. Nevertheless, regardless of the past intensive studies on the intracellular crosstalk via extracellular vesicles, the generic dynamical behaviors of the NKCs around its co-cultured cells in their attacking process remains an elusive intriguing issue. Here, using the binary mixtures of NKCs and normal fibroblast/cancer cells, we experimentally reveal the above unexplored issue. It is found that, NKCs initially assess and identify the type of co-cultured cells. For cancer cells, NKCs attach to them, recruit neighboring NKCs to form clusters, and exhibit anchored fluctuating motion around the cancer cells in the killing process, until the death of cancer cells. In response, CCs also aggregate into larger clusters than those of the NKC free case, until their death, to avoid NKC attacking. In contrast, when interacting with normal fibroblasts, NKCs continuously scout around the cells, without forming large clusters. They cause little effect on fibroblast motion.
    DOI:  https://doi.org/10.1103/mf3s-pcwt
  8. Front Immunol. 2026 ;17 1870668
    Enhancing CAR-NK persistence to unlock its full therapeutic potentials.
    Ovini Amarasinghe, Heqing Ma, Cédric S Tremblay, Sam K P Kung.
      Chimeric Antigen Receptor-Natural Killer Cell (CAR-NK) is a promising next-generation immunotherapy. Persistence of CAR-NK cell therapy is considered a key hurdle limiting its full therapeutic potential. This review highlighted the causes of poor CAR-NK persistence and summarized strategies developed to improve CAR-NK persistence in both hematologic malignancies and solid tumors. These strategies included cytokine and cytokine signaling mediated strategies; optimization of NK cell source and CAR design; intrinsic and extrinsic checkpoint disruption and metabolic reprogramming; and lymphodepletion, alloevasion and fratricide evasion strategies. Multiple strategies that aim at improving in vivo persistence should prove useful in enhancing therapeutic efficacy of CAR-NK.
    Keywords:  CAR; NK; genetic engineering; persistence; tumor immunotherapy
    DOI:  https://doi.org/10.3389/fimmu.2026.1870668
  9. Cell Death Discov. 2026 Jul 21.
    Cytokine-induced expandable memory NK cells with significant metabolic, epigenetic remodeling, and persistence properties.
    Hongye Wang, Jingwei Tu, Yi Luo, Xinxin Yuan, Xin Fang, Zhengyi Lu, Li Han, Yongjia Xue, Wencheng Zhang, Qianggang Dong, Zhiying He.
      Recent investigations have indicated that NK cells induced overnight with IL-12/15/18 cytokines possess memory-like characteristics (refers as CIML NK, cytokine induced memory-like NK cells), demonstrating enhanced effector function and prolonged persistence. Preclinical studies and very early clinical trials revealed the promising clinical activity of CIML NK cells in the treatment of hematological malignancies, especially acute myelocytic leukemia (AML). However, the current manufacturing method for CIML NK cells do not endow these cells the ability to expand robustly ex vivo. The low production efficiency limits their clinical application. In this study, we established a novel expansion platform for generating memory-like NK cells by first inducing memory properties through stimulation with CD16a, IL-15, and IL-18, followed by a robust expansion phase. This method can effectively and stably expand healthy donor-derived Peripheral NK (PBNK) cells by more than 200-fold within two weeks, with a purity exceeding 95%. Importantly, these ex vivo expanded NK (ExNK) cells exhibited hypomethylated state in the CNS-1 region (Conserved Noncoding Sequence 1) of IFNG gene, stronger metabolic ability, and enhanced effector function when compared to CIML NK cells. Based on these features, we named these expanded NK cells but still possess memory-like characteristics as mExNK (memory-like expanded NK cells). Bulk mRNA-seq further uncovered a high similarity between mExNK and CIML NK cells, with both highly expressing genes being related to proliferation, metabolism, and memory. Mouse tumor models proved that the infused mExNK exhibited longer persistence in vivo and stronger effector functions. Taken together, the method described herein showed an enhanced expansion efficiency for human CIML NK cells and would facilitate their clinic applications in cancer therapy.
    DOI:  https://doi.org/10.1038/s41420-026-03260-2
  10. Front Immunol. 2026 ;17 1855521
    CD244 overexpression indicates NK cell dysfunction and tumor progression in diffuse large B-cell lymphoma.
    Yiming Yang, Biyang Zeng, Huimin Yang, Xin Liu, Peilin Li, Chao Mai, Shunhai Jian, Qiqi Zhu.
       Background: CD244, expressed in the tumor microenvironment (TME), is associated with impaired function of natural killer (NK) and T cells; however, its role in diffuse large B-cell lymphoma (DLBCL) remains poorly understood. This study aimed to elucidate the immunological significance and regulatory mechanisms of CD244 in DLBCL.
    Methods: Using single-cell and bulk RNA sequencing, we analyzed CD244 expression patterns, its major intracellular adaptor molecules, and correlations with immune checkpoints, metabolic alterations, and immune activity. The clinical and biological implications of CD244 expression, including associations with clinicopathological characteristics, TME composition, prognosis, and response to immune checkpoint blockade (ICB) therapy, were investigated by integrating single-cell and bulk RNA sequencing, immunohistochemistry, and reverse transcription-quantitative polymerase chain reaction. Intercellular communication networks, key transcription factors, and somatic mutations were further evaluated to uncover regulatory mechanisms.
    Results: NK cells were the primary CD244-expressing population in DLBCL, co-overexpressing PDCD1, CTLA4, LAG3, TIGIT, PTGER4, and CD160. EAT2 was identified as CD244's predominant intracellular adaptor, suggesting that CD244-associated inhibitory signaling may contribute to metabolic dysregulation and immune dysfunction in NK cells. Elevated CD244 expression correlated with an immunosuppressive TME, worse clinicopathological features, poorer outcomes, and increased potential responsiveness to ICB. Furthermore, CD244 expression may be regulated by STAT3 activation in NK cells and ASXL3 mutations in tumor cells via the BTLA-TNFRSF14 pathway.
    Conclusions: This study highlights the critical role of CD244 in NK cell dysfunction and DLBCL progression, providing a promising target for optimizing immunotherapy.
    Keywords:  CD244; clinicopathological analysis; diffuse large B-cell lymphoma; immunotherapy; natural killer cells; prognosis; single-cell RNA sequencing; tumor microenvironment
    DOI:  https://doi.org/10.3389/fimmu.2026.1855521
  11. Curr Biol. 2026 Jul 20. pii: S0960-9822(26)00645-7. [Epub ahead of print]36(14): R792-R793
    Cell biology: Cytoplasmic rivers carry molecular cargo.
    R Dyche Mullins.
      Molecules in the cytoplasm of an animal cell move by diffusion, motor activity, and/or fluid flow. A recent study demonstrates how directed, but often subtle, cytoplasmic drift currents carry cytoskeletal components to the leading edge of crawling cells, where they assemble into functional networks.
    DOI:  https://doi.org/10.1016/j.cub.2026.05.040
  12. STAR Protoc. 2026 Jul 23. pii: S2666-1667(26)00356-4. [Epub ahead of print]7(3): 104703
    Simultaneous measurement of target and effector cell death, apoptosis, and proliferation in cell therapy development using flow cytometry.
    Kristian Thomson, Kendra Klatt, Niklas Engels, Camille Dourlens, Daniel Schäfer, Melissa Quadflieg, Hannah Johanssen, Raphael Koch, Jürgen Wienands, Gerald Wulf.
      The development of cellular immunotherapies against cancer requires an efficient assessment of malignant target cell killing. However, the fate of effector cells is equally important, particularly in the context of immunomodulatory tumors. Here, we present a high-throughput protocol for simultaneously measuring viability, apoptosis, and proliferation of cytotoxic effector cells and their targets. We describe steps for co-culturing target and effector cells, staining procedures for viability and apoptosis, adding fluorescent counting beads for cell quantification, and procedures for flow-cytometric analysis.
    Keywords:  Cancer; Cell Biology; Health Sciences; High Throughput Screening; Immunology
    DOI:  https://doi.org/10.1016/j.xpro.2026.104703
  13. Dev Cell. 2026 Jul 24. pii: S1534-5807(26)00270-4. [Epub ahead of print]
    The actin crosslinker Fimbrin is required for force sensing at tricellular junctions.
    Nilay Taneja, Claire A Looney, Michael F Moubarak, Meriel J McGovern, Kenji Yeoh, Jennifer A Zallen.
      Epithelial cells sense and respond to mechanical forces by reinforcing connections between adherens junctions and the actin cytoskeleton. Tricellular junctions are key sites of mechanotransduction in epithelial cells, but how force responses are coordinated at these structures during epithelial remodeling is poorly understood. We show that the actin crosslinking protein Fimbrin is recruited by forces to tricellular junctions in Drosophila and promotes actin reorganization and cell adhesion during epithelial remodeling. In the absence of Fimbrin, cells fail to reorganize actin or recruit junction-stabilizing proteins to tricellular junctions under tension, disrupting cell adhesion. Conversely, increasing Fimbrin activity constitutively activates multiple force-response pathways, aberrantly stabilizing adhesion. We show that Fimbrin directs force responses by amplifying actomyosin contractility, and that force-regulated actin remodeling and Plastin3 and Afadin localization occur at tricellular junctions in the mouse embryo. These results suggest that conserved mechanisms underlie force responses at tricellular junctions in fly and mouse epithelia.
    Keywords:  Drosophila; Fimbrin; Mechanotransduction; actin crosslinker; actin cytoskeleton; cell adhesion; epithelial morphogenesis; myosin
    DOI:  https://doi.org/10.1016/j.devcel.2026.07.001
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