NK cells switch from granzyme B to death receptor–mediated cytotoxicity during serial killing

Isabel Prager; Clarissa Liesche; Hanna van Ooijen; Doris Urlaub; Quentin Verron; Niklas Sandström; Frank Fasbender; Maren Claus; Roland Eils; Joël Beaudouin; Björn Önfelt; Carsten Watzl

doi:10.1084/jem.20181454

894 The bispecific innate cell engagers AFM13 (CD30/CD16A) and AFM24 (EGFR/CD16A) increase the fraction of tumor target-responsive NK cells and boost serial killing

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.894 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A938-A938

Author(s):

Chiara Zambarda ◽

Karolin Guldevall ◽

Chiara Zambarda ◽

Karolin Guldevall ◽

Christian Breunig ◽

...

Keyword(s):

Nk Cells ◽

Single Cell ◽

Tumor Cells ◽

Cell Biology ◽

Nk Cell ◽

Biological Evaluation ◽

Target Cells ◽

List Type ◽

Tumor Target ◽

Serial Killing

BackgroundThe use of bispecific natural killer (NK) cell engagers has emerged as a successful strategy for immune cell activation and killing of tumor cells through antibody-dependent cellular cytotoxicity (ADCC). Among these, tetravalent, bispecific innate cell engagers (ICE®) with specificity for the activating receptor CD16A selectively triggering innate responses from NK cells or macrophages represent the most clinically advanced concept. The CD30/CD16A specific ICE® AFM13, has shown efficacy in patients with CD30+ lymphomas as monotherapy1 and combination therapy with check-point inhibitors2 and most recently in combination with adoptive NK cell therapy.3 The EGFR/CD16A specific ICE® AFM24, targeting a variety of solid tumors like colorectal, or lung cancer with a unique mode of action independent of EGFR signaling inhibition, is currently evaluated in an ongoing Ph1/2a clinical study.MethodsWe used a microchip-based screening with single cell resolution4 to elucidate the dynamic responses of individual NK cells towards tumor target cells upon treatment with AFM13 or AFM24.ResultsWe found that AFM13 and AFM24 mediated potent activation of NK cells, leading to increased responsive cytotoxic NK cells and significantly increased the number of NK cells that exerted engagement with multiple target cells rendering these NK cells serial killers. Strikingly, bispecific ICE® molecules triggered stronger cytotoxic responses compared to monoclonal antibodies. One suggested strategy to boost killing by NK cells is to use molecular inhibitors or protein constructs that prevent shedding of CD16.5 However, previous results have shown that this can lead to impaired detachment from target cells, reducing the capacity for an individual NK cell to form serial contacts to target cells.6 We observed that the elevated NK cell killing induced by ICE® molecules was largely conserved when cells were treated with the shedding inhibitor Batimastat. Analysis of the functional dynamics of NK cells revealed that inhibition of CD16 shedding prevented NK cell detachment from target cells, resulting in cell cluster formation. This might strongly impact targeting of distant tumor cells by an individual NK cell thus limiting its anti-tumoral activity.ConclusionsIn conclusion, we show that both AFM13 and AFM24 increase the fraction of tumor-target responsive NK cells and boost serial killing of target cells by individual NK cells. Based on these data, ICE® molecules can be characterized as potent anti-tumoral agents leveraging the enormous potential of NK cells while maintaining crucial features of NK cell biology.AcknowledgementsWe thank members of the Önfelt lab for their valuable help and feedback.ReferencesSawas A, Elgedawe H, Vlad G, Lipschitz M, Chen P-H, Rodig SJ, et al. Clinical and biological evaluation of the novel CD30/CD16A tetravalent bispecific antibody (AFM13) in relapsed or refractory CD30-positive lymphoma with cutaneous presentation: a biomarker phase Ib/IIa study (NCT03192202). Blood 2018;132(Supplement 1):2908–2908.Bartlett NL, Herrera AF, Domingo-Domenech E, Mehta A, Forero-Torres A, Garcia-Sanz R, et al. A phase 1b study of AFM13 in combination with pembrolizumab in patients with relapsed or refractory Hodgkin lymphoma. Blood 2020. Blood 2020;136(21):2401–2409.Kerbauy LN, Marin ND, Kaplan M, Banerjee PP, Berrien-Elliott MM, Becker-Hapak M, et al. Combining AFM13, a bispecific CD30/CD16 antibody, with cytokine-activated blood and cord blood–derived NK cells facilitates CAR-like responses against CD30 + malignancies. Clin Cancer Res Epub 2021.Guldevall K, Brandt L, Forslund E, Olofsson K, Frisk TW, Olofsson PE, et al. Microchip screening platform for single cell assessment of NK cell cytotoxicity. Front Immunol 2016;7:119.Romee R, Foley B, Lenvik T, Wang Y, Zhang B, Ankarlo D, et al. NK cell CD16 surface expression and function is regulated by a disintegrin and metalloprotease-17 (ADAM17). Blood 2013;121(18):3599–608.Srpan K, Ambrose A, Karampatzakis A, Saeed M, Cartwright ANR, Guldevall K, et al. Shedding of CD16 disassembles the NK cell immune synapse and boosts serial engagement of target cells. J Cell Biol 2018;217(9):3267–83.Ethics ApprovalThis work was performed with NK cells from healthy anonymous blood donors, which requires no ethical permit according to local regulations.

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IPH2101, a Novel Anti-Inhibitory KIR Monoclonal Antibody, and Lenalidomide Combine to Enhance the Natural Killer (NK) Cell Versus Multiple Myeloma (MM) Effect.

Blood ◽

10.1182/blood.v114.22.3870.3870 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3870-3870 ◽

Cited By ~ 1

Author(s):

Don Benson ◽

Courtney E Bakan ◽

Shuhong Zhang ◽

Lana Alghothani ◽

Jing Liang ◽

...

Keyword(s):

Clinical Trial ◽

Nk Cells ◽

Tumor Cells ◽

Nk Cell ◽

Phase 1 ◽

Granzyme B ◽

Cell Activity ◽

Target Cells ◽

Nk Cell Activity ◽

Immune Complex Formation

Abstract Abstract 3870 Poster Board III-806 Background NK cell activity against tumor cells is regulated by a balance of inhibitory and activating signals mediated by receptors on NK cells that recognize inhibitory and activating ligands expressed by cancer cells. IPH2101 (1-7F9) is a novel monoclonal anti-inhibitor KIR blocking antibody that has been shown to augment NK cell function against MM targets. Moreover, lenalidomide has been shown to expand and activate NK cells in vivo and in vitro. We have previously reported that the combination of IPH2101 and lenalidomide enhances NK cell mediated cytotoxicity against MM cells compared to each agent alone (Zhang et al., AACR 2009). We expand our studies to investigate potential mechanisms for the enhancement of NK cell activity by the combination of IPH2101 and lenalidomide. Methods The effects of IPH2101 and lenalidomide alone and in combination were studied using primary human NK cells from healthy donors as well as from MM patients. The MM cell lines U266 and RPMI 8226 as well as primary tumor cells from marrow aspirates of MM patients served as target cells. The effect of lenalidomide on MM activating and inhibitory ligand expression was studied by flow cytometry. NK cell trafficking was investigated with standard transwell plate migration assay. Immune complex formation between NK cell effectors and MM tumor targets was characterized by flow cytometry in control conditions and with NK cells pre-treated with IPH2101 and lenalidomide. The effects of IPH2101 and lenalidomide were studied regarding interferon-gamma and granzyme B production by ELISPOT and target-specific cytotoxicity studies were conducted to complement effector-based assays. Results IPH2101 (30 ug/ml) significantly enhanced cytotoxicity against U266 cells and primary MM tumor cells by both purified NK cells at effector:target (E:T) ratios of 10:1 or less, and also of freshly isolated peripheral blood mononuclear cells (PBMC) at E:T ratios of 60:1 or less, from more than 10 random donors. In addition, treatment of PBMC with 5-10 μmol/L lenalidomide for 72h without interleukin (IL)-2 increased NK cell lysis of U266. Treatment of PBMC from normal donors did not enhance the expression of the NK receptors KIR, NKG2D, NCR, TRAIL, and DNAM-1. Incubation of U266 cells with lenalidomide (5 uM) for 3-5 days resulted in significant enhancement of cytotoxicity by normal donor NK cells. This was associated with upregulation of the activating ligands, MICA, ULBP-2, DR4, and CD112. Using blocking antibodies to NKG2D, TRAIL, and DNAM-1, lenalidomide enhancement of MM cell killing was abrogated indicating the importance of the modulation of the ligands to the latter receptors by lenalidomide. Although IPH2101 and lenalidomide did not significantly increase NK cell migration into normal media, migration was enhanced 2.98-fold (+/− 0.36, p < 0.05) towards U266 cell targets (n= 3, p < 0.05) and MM patient serum 3.2-fold (+/− 0.4, n=3, p < 0.05). IPH2101 and lenalidomide also led to a 2.3-fold (+/− 0.43, p < 0.05) increase in immune complex formation between NK cells and MM tumor cells. IPH2101 and lenalidomide also augmented NK cell interferon gamma production against MM (control mean 303 spots/well +/− 13 versus 525 +/− 83, n=3, p < 0.05) and granzyme B production (control mean 115 +/− 98 versus 449 +/−72, n=3, p < 0.05). Importantly, in all experiments described herein, the effects of IPH2101 and lenalidomide together were greater than either agent alone. Conclusions Taken together, our data suggest that IPH2101 and lenalidomide may exert complementary mechanisms on both effector and target cells to enhance NK cell mediated killing of MM cells. Moreover, these agents have no predicted clinical cross-toxicities. A single-agent phase 1 clinical trial of IPH2101 has shown the mAb to be safe and well tolerated in MM patients. These findings support a phase 1/2 clinical trial of IPH2101 with lenalidomide as a first dual-innate immunotherapy for patients with MM. Disclosures: Andre: Innate Pharma: Employment. Squiban:Innate pharma: Employment. Romagne:Innate Pharma: Employment.

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Optimizing NK-92 Serial Killers: Gamma Irradiation, CD95/FasLigation, And NK Or LAK Attack Limit Cytotoxic Efficacy

10.21203/rs.3.rs-1193866/v1 ◽

2021 ◽

Author(s):

Lydia T Navarrete-Galvan ◽

Michael Guglielmo ◽

Judith Cruz Amaya ◽

Julie Smith-Gagen ◽

Vincent C. Lombardi ◽

...

Keyword(s):

Gamma Irradiation ◽

Cytotoxic Activity ◽

Nk Cells ◽

Nk Cell ◽

Death Receptor ◽

Serial Killers ◽

Raji Cells ◽

Serial Killing ◽

Genetic Deletion ◽

High Cytotoxic Activity

Abstract Background: The NK cell line NK-92 and its genetically modified variants are receiving attention as immunotherapies to treat a range of malignancies. However, since NK-92 cells are themselves tumors, they require irradiation prior to transfer and are potentially susceptible to attack by patients’ immune systems. Here, we investigated NK-92 cell-mediated serial killing for the effects of gamma-irradiation and ligation of the death receptor Fas (CD95), and NK-92 cell susceptibility to attack by activated primary blood NK cells. Methods: To evaluate serial killing, we used 51 Cr-release assays with low NK-92 effector cell to target Raji, Daudi or K562 tumor cell (E:T) ratios to determine killing frequencies at 2-, 4-, 6-, and 8-hours. Results: NK-92 cells were able to kill up to 14 Raji cells per NK-92 cell in eight hours. NK-92 cells retained high cytotoxic activity immediately after irradiation with 10 Gy but the cells surviving irradiation lost >50% activity one day after irradiation. Despite high expression of CD95, NK-92 cells maintained their viability following overnight Fas/CD95-ligation but lost some cytotoxic activity. However, one day after irradiation, NK-92 cells were more susceptible to Fas ligation, resulting in decreased cytotoxic activity of the cells surviving irradiation. Irradiated NK-92 cells were also susceptible to killing by both unstimulated and IL-2 activated primary NK cells (LAK). In contrast, non-irradiated NK-92 cells were more resistant to attack by NK and LAK cells. Conclusions: Irradiation is deleterious to both the survival and cytotoxicity mediated by NK-92 cells and renders the NK-92 cells susceptible to Fas-initiated death and death initiated by primary blood NK cells. Therefore, replacement of irradiation as an antiproliferative pretreatment and genetic deletion of Fas and/or NK activation ligands from adoptively transferred cell lines are indicated as new approaches to increase therapeutic efficacy.

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Murine NK Cells Require Activation-Dependent Expression of Granzyme B and Perforin To Become Potent Cytotoxic Effectors.

Blood ◽

10.1182/blood.v108.11.920.920 ◽

2006 ◽

Vol 108 (11) ◽

pp. 920-920

Author(s):

Todd A. Fehniger ◽

Sheng F. Cai ◽

Xuefang Cao ◽

Andrew J. Bredemeyer ◽

Rachel M. Presti ◽

...

Keyword(s):

Cell Death ◽

Nk Cells ◽

Target Cell ◽

Post Infection ◽

Nk Cell ◽

Granzyme B ◽

Poly I:C ◽

Wild Type

Abstract NK cells predominantly utilize the granule exocytosis pathway to kill virus-infected and malignant target cells. Current paradigms suggest that resting NK cells have pre-formed granules containing granzymes A, B, and perforin and are ready to kill targets immediately upon proper recognition by NK receptors. Here, we report that resting murine NK cells in the spleen exhibit poor cytotoxicity (5.4±1.6% target cell death, 20:1 E:T ratio and 4 hour incubation), compared with cytokine-activated (IL-15, 48 hours) splenic NK cells (59.7±10.6% target cell death), against the RMAS tumor cell line in vitro as measured by a flow-based killing assay. In addition, using intracellular flow cytometric analysis with monoclonal antibodies specific for granzymes A, B, and perforin, we find that resting murine NK cells express abundant granzyme A (86.2±1.9% positive), but little or no granzyme B (4.4±5.4% positive) or perforin (2.6±1.8% positive). Activation of murine NK cells with IL-15 induces robust expression of both perforin (59.1±2.0% positive) and granzyme B (91.5±7.9% positive), which correlates with increased cytotoxicity. Further, granzyme B cluster −/− (26±6.7% target cell death) and perforin −/− (5.7±1.3% target cell death) NK cells have poor cytotoxicity in vitro despite IL-15 activation. Poly I:C simulates RNA virus infection and activates NK cell cytotoxicity in vivo through TLR3 and cytokine cascades. NK cell granzyme B and perforin expression is induced in vivo 24 hours after poly I:C injection, correlating with increased in vitro NK killing of tumor targets. In wild type mice infected with murine cytomegalovirus (MCMV), NK cell expression of both perforin (83.5±4.9% positive) and granzyme B (89.3±2.1% positive) is upregulated in the spleen, peaking 2–4 days post-infection and returning to baseline by 8 days post-infection. In addition, MCMV titers are significantly elevated at day 3 post-infection in both granzyme B cluster −/− (P<0.01) and perforin −/− (P<0.01) mice, compared to wild type mice. Moreover, survival following MCMV infection was significantly lower in granzyme B cluster −/− and perforin −/− mice, compared with wild type mice (P<0.001, see survival curve). Thus, our findings show that murine NK cells require the activation of granzyme B and perforin to become potent cytotoxic effectors. We also demonstrate for the first time that granzyme B is critical for early host defense against MCMV. These findings explain the long-standing observation that murine NK cells require prior activation for potent natural killing of tumor targets in vitro. Further, this requirement for activation-dependent granzyme B and perforin expression in NK cells may influence outcomes in murine models of innate immune anti-tumor and anti-viral responses. Figure Figure

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The pharmalogical reactivation of p53 function improves breast tumor cell lysis by granzyme B and NK cells through induction of autophagy

Cell Death and Disease ◽

10.1038/s41419-019-1950-1 ◽

2019 ◽

Vol 10 (10) ◽

Cited By ~ 7

Author(s):

Marie Chollat-Namy ◽

Thouraya Ben Safta-Saadoun ◽

Djazia Haferssas ◽

Guillaume Meurice ◽

Salem Chouaib ◽

...

Keyword(s):

Breast Cancer ◽

Nk Cells ◽

Tumor Cells ◽

Nk Cell ◽

P53 Protein ◽

Granzyme B ◽

Mitochondrial Outer Membrane ◽

Cytotoxic Lymphocyte ◽

Apoptotic Pathway ◽

Mitochondrial Outer Membrane Permeabilization

Abstract Cytotoxic T lymphocytes (CTL) and natural killer cells (NK)-mediated elimination of tumor cells is mostly dependent on Granzyme B apoptotic pathway, which is regulated by the wild type (wt) p53 protein. Because TP53 inactivating mutations, frequently found in human tumors, could interfere with Granzyme B-mediated cell death, the use of small molecules developed to reactivate wtp53 function in p53-mutated tumor cells could optimize their lysis by CTL or NK cells. Here, we show that the pharmalogical reactivation of a wt-like p53 function in p53-mutated breast cancer cells using the small molecule CP-31398 increases their sensitivity to NK-mediated lysis. This potentiation is dependent on p53-mediated induction of autophagy via the sestrin-AMPK-mTOR pathway and the ULK axis. This CP31398-induced autophagy sequestrates in autophagosomes several anti-apoptotic proteins, including Bcl-XL and XIAP, facilitating Granzyme B-mediated mitochondrial outer membrane permeabilization, caspase-3 activation and Granzyme B- or NK cell-induced apoptosis. Together, our results define a new way to increase cytotoxic lymphocyte-mediated lysis of p53-mutated breast cancer cell, through a p53-dependent autophagy induction, with potential applications in combined immunotherapeutic approaches.

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Pediatric Tumors-Mediated Inhibitory Effect on NK Cells: The Case of Neuroblastoma and Wilms’ Tumors

Cancers ◽

10.3390/cancers13102374 ◽

2021 ◽

Vol 13 (10) ◽

pp. 2374

Author(s):

Andrea Pelosi ◽

Piera Filomena Fiore ◽

Sabina Di Matteo ◽

Irene Veneziani ◽

Ignazio Caruana ◽

...

Keyword(s):

Nk Cells ◽

Solid Tumors ◽

Tumor Cells ◽

Stromal Cells ◽

Cell Function ◽

Nk Cell ◽

Wilms Tumor ◽

Suppressor Cells ◽

Inhibitory Effect ◽

Cell Contact

Natural killer (NK) cells play a key role in the control of cancer development, progression and metastatic dissemination. However, tumor cells develop an array of strategies capable of impairing the activation and function of the immune system, including NK cells. In this context, a major event is represented by the establishment of an immunosuppressive tumor microenvironment (TME) composed of stromal cells, myeloid-derived suppressor cells, tumor-associated macrophages, regulatory T cells and cancer cells themselves. The different immunoregulatory cells infiltrating the TME, through the release of several immunosuppressive molecules or by cell-to-cell interactions, cause an impairment of the recruitment of NK cells and other lymphocytes with effector functions. The different mechanisms by which stromal and tumor cells impair NK cell function have been particularly explored in adult solid tumors and, in less depth, investigated and discussed in a pediatric setting. In this review, we will compare pediatric and adult solid malignancies concerning the respective mechanisms of NK cell inhibition, highlighting novel key data in neuroblastoma and Wilms’ tumor, two of the most frequent pediatric extracranial solid tumors. Indeed, both tumors are characterized by the presence of stromal cells acting through the release of immunosuppressive molecules. In addition, specific tumor cell subsets inhibit NK cell cytotoxic function by cell-to-cell contact mechanisms likely controlled by the transcriptional coactivator TAZ. These findings could lead to a more performant diagnostic approach and to the development of novel immunotherapeutic strategies targeting the identified cellular and molecular targets.

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Control of Lytic Function by Mitogen-activated Protein Kinase/Extracellular Regulatory Kinase 2 (ERK2) in a Human Natural Killer Cell Line: Identification of Perforin and Granzyme B Mobilization by Functional ERK2

Journal of Experimental Medicine ◽

10.1084/jem.187.11.1753 ◽

1998 ◽

Vol 187 (11) ◽

pp. 1753-1765 ◽

Cited By ~ 116

Author(s):

Sheng Wei ◽

Ana M. Gamero ◽

Jin Hong Liu ◽

Angela A. Daulton ◽

Nichola I. Valkov ◽

...

Keyword(s):

Nk Cells ◽

Tumor Cells ◽

Nk Cell ◽

Mapk Pathway ◽

Granzyme B ◽

Mitogen Activated Protein Kinase ◽

Target Cells ◽

Mapk Activation ◽

Mitogen Activated Protein

The signal pathways that control effector function in human natural killer (NK) cells are little known. In this study, we have identified the critical role of the mitogen-activated protein kinase (MAPK) pathway in NK lysis of tumor cells, and this pathway may involve the mobilization of granule components in NK cells upon interaction with sensitive tumor target cells. Evidence was provided by biological, biochemical, and gene transfection methods. NK cell binding to tumor cells for 5 min was sufficient to maximally activate MAPK/extracellular signal–regulatory kinase 2 (ERK2), demonstrated by its tyrosine phosphorylation and by its ability to function as an efficient kinase for myelin basic protein. MAPK activation was achieved in NK cells only after contact with NK-sensitive but not NK-resistant target cells. In immunocytochemical studies, cytoplasmic perforin and granzyme B were both maximally redirected towards the tumor contact zone within 5 min of NK cell contact with tumor cells. A specific MAPK pathway inhibitor, PD098059, could block not only MAPK activation but also redistribution of perforin/granzyme B in NK cells, which occur upon target ligation. PD098059 also interfered with NK lysis of tumor cells in a 5-h 51Cr-release assay, but had no ability to block NK cell proliferation. Transient transfection studies with wild-type and dominant-negative MAPK/ERK2 genes confirmed the importance of MAPK in NK cell lysis. These results document a pivotal role of MAPK in NK effector function, possibly by its control of movement of lytic granules, and clearly define MAPK involvement in a functional pathway unlinked to cell growth or differentiation.

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Single-fluorescent protein reporters allow parallel quantification of NK cell-mediated granzyme and caspase activities in single target cells

10.1101/328260 ◽

2018 ◽

Author(s):

Clarissa Liesche ◽

Patricia Sauer ◽

Maren Claus ◽

Roland Eils ◽

Joël Beaudouin ◽

...

Keyword(s):

Cell Death ◽

Nk Cells ◽

Caspase 3 ◽

Fluorescent Protein ◽

Nk Cell ◽

Granzyme B ◽

Target Cells ◽

Caspase 8 ◽

Cytotoxic Lymphocytes ◽

Cell Death Mechanisms

1.AbstractNatural killer (NK) cells eliminate infected and tumorigenic cells through delivery of granzymes via perforin pores or by activation of caspases via death receptors. In order to understand how NK cells combine different cell death mechanisms it is important to quantify target cell responses on a single cell level. However, currently existing reporters do not allow the measurement of several protease activities inside the same cell. Here we present a strategy for the comparison of two different proteases at a time inside individual target cells upon engagement by NK cells. We developed single-fluorescent protein reporters containing the RIEAD or the VGPD cleavage site for the measurement of granzyme B activity. We show that these two granzyme B reporters can be applied in combination with caspase-8 or caspase-3 reporters. While we did not find that caspase-8 was activated by granzyme B, our method revealed that caspase-3 activity follows granzyme B activity with a delay of about 6 minutes. Finally, we illustrate the comparison of several different reporters for granzyme A, M, K and H. The here presented approach is a valuable means for the investigation of the temporal evolution of cell death mediated by cytotoxic lymphocytes.

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Identification of Molecular Markers of Tumor Cell Sensitivity and Resistance to Natural Killer Cells through Genome-Wide CRISPR Activation and CRISPR Editing Screens in Multiple Myeloma Cell Lines: Implications for Anti-Myeloma Immunotherapy

Blood ◽

10.1182/blood-2018-99-118736 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1115-1115

Author(s):

Sara Gandolfi ◽

Michal Sheffer ◽

Emily Lowry ◽

Olga Dashevsky ◽

Ryosuke Shirasaki ◽

...

Keyword(s):

Multiple Myeloma ◽

Molecular Markers ◽

High Risk ◽

Tumor Cell ◽

Nk Cells ◽

Tumor Cells ◽

Research Funding ◽

Nk Cell ◽

Death Receptor ◽

Genome Wide

Abstract Natural killer (NK) cells represent a promising immunotherapeutic approach as they can potently kill tumor cells without triggering graft-versus-host reactions. Indeed, infusion of high numbers of NK cells, either autologous or allogeneic, after their ex vivo expansion and activation, has been feasible and safe in clinical studies. However, prior studies and early clinical trials indicate that tumor cells can exhibit decreased response to NK due to the protective effect of nonmalignant mesenchymal stromal cells; and depending on the genetic background of the tumor cells. To our knowledge, since earlier subgenome-scale RNAi-based studies, there have been no genome-wide CRISPR-based screens to identify candidate markers conferring tumor cell resistance or sensitivity to NK cells in multiple myeloma (MM). To address this void, and building on a recent loss-of-function (LOF) study by our group on solid tumors, we sought to identify genes regulating the response of MM cells to the cytotoxic activity of NK cells by conducting a genome-wide CRISPR/Cas9-based gene editing (Brunello library of sgRNA) and gene activation (Calabrese library of sgRNA) screens in MM.1S cells co-cultured with primary NK (pNK) cells (effector-to-target [E:T] ratio of 3.75:1) derived from healthy donor peripheral blood mononuclear cells (PBMCs) cultured in vitro in GMP SCGM medium with IL-2. Briefly, MM.1S cells engineered to stably express the nuclease SpCas9 (Brunello) or a catalytically inactive programmable RNA-dependent DNA-binding protein (dCas9)-VP64 (Calabrese) were also transduced with lentiviral particles for a pool of ~70,000 (Brunello library) or ~120,000 (Calabrese) sgRNAs, targeting exons of ~20,000 genes (plus non-targeting control sgRNAs), under conditions of transduction which allow for an average of no more than 1 sgRNA to be incorporated in a given cell. This allowed us to convert the initial population of MM.1S cells into heterogeneous pools in which each gene is subject to individual LOF or gain-of-function (GOF), due to Cas9-mediated editing, by only 1 sgRNA. Flow cytometry was performed to verify pNK viability, purity (CD56 and CD3), and expression of p46 receptor, surrogate marker of NK cell activity. These screens identified genes whose knock-out (Brunello sgRNA library) or activation (Calabrese sgRNA library) led to NK cells resistance or potential sensitivity. The hits observed in the current MM-oriented study exhibited, compared to our similar studies in solid tumor model, substantial gene level differences, but notable overlap at the pathway level (including death receptor pathways, NK activating pathways), which suggests that mechanisms determining tumor cell response vs. resistance to NK cells operate through modules consistent across tumors, but manifested through potentially different members of the respective pathways in different neoplasms. For instance, in this MM-oriented study, we identified that NK cell sensitivity of tumor cells is modulating by activation of several metabolic and homeostatic genes, receptor kinases, and interestingly membrane-bound proteins of the mucin family, e.g. MUC1, and MUC4, which have been reported to play a role in NK-mediated tumor killing in other types of cancer. MUC1 in particular has a clinical relevance as a small molecule inhibitor with prior preclinical studies in MM is available. Interestingly, our GOF screen identified as potential NK cell sensitizers TNFRSF10B, a death receptor related to TNFRSF10A (a hit identified in our studies in solid tumors), the putative death receptor adaptor TRADD, and the NK ligands PVR and ULBP1. Interestingly, genes such as PTEN and TP53, commonly associated with high-risk MM, didn't affect the response to NK cell, suggesting that NK cell-based therapies may potentially have a role in treatment of MM patients with high-risk clinical or biological features. In conclusion, this is the first study applying both LOF and GOF genome-wide screens to NK cell response in MM. The combination of such screens performed in parallel provide complementary and orthogonal information that allows us to identify genes that might not have been appreciated if only either LOF or GOF alone screens had been performed. We envision that the methodology and results presented herein will provide a framework towards validation of molecular markers which can help to optimize and individualize the use of NK cell-based therapy in MM. Disclosures Mitsiades: Abbvie: Research Funding; TEVA: Research Funding; EMD Serono: Research Funding; Janssen/ Johnson & Johnson: Research Funding; Takeda: Other: employment of a relative.

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Natural Killer Cell Death Mediated By NKG2D-Trogocytosis

Blood ◽

10.1182/blood.v122.21.18.18 ◽

2013 ◽

Vol 122 (21) ◽

pp. 18-18

Author(s):

Kyohei Nakamura ◽

Masafumi Nakayama ◽

Mitsuko Kawano ◽

Tomonori Ishii ◽

Hideo Harigae ◽

...

Keyword(s):

Cell Death ◽

Confocal Microscopy ◽

Cell Surface ◽

Nk Cells ◽

Tumor Cells ◽

Nk Cell ◽

Surface Expression ◽

Cell Surface Expression ◽

Target Cells ◽

Dependent Manner

Abstract Introduction The activating receptor, NKG2D, plays crucial role in natural killer (NK) cell-mediated effector function. NKG2D is involved not only in host defense against tumor and viral infection, but also in autoimmune diseases by recognizing stress-induced self-ligands (NKG2DLs). However, the negative feedback regulation of NKG2D has not been fully understood. It has been reported that NK cells undergo rapid apoptosis upon interaction with NK-sensitive tumor cells, suggesting that activation-induced NK cell death can be triggered in certain situations. In this study, we aimed to elucidate underlying mechanism of NK cell death, especially focused on NKG2D-NKG2DLs interaction. Methods NK cells were purified from splenocytes of C57BL/6, perforin-/-, and DAP10-/-/12-/- mice, and cultured with rhIL-2 (1000 U/ml) for 5 days. We used these IL-2-activated NK cells as effector cells and three target cell lines: mouse T cell lymphoma RMA cells (RMA), RMA lacking MHCI expression (RMA-S), and RMA stably expressing an NKG2DL, Rae-1δ (RMA/Rae-1δ). CFSE-labeled NK cells were co-cultured with target cells for 2 hours, and stained with anti-NK1.1 mAb propidium iodide (PI). The percentage of PI-positive cells within CFSE+ NK1.1+ population was measured by flowcytometry. The cell surface expression of Rae-1 on NK cells after co-culture with target cells was evaluated by flowcytometry and confocal microscopy. Results NK cells from WT mice rapidly underwent cell death when co-cultured with Rae-1δ, but not with RMA or RMA-S, suggesting that NKG2D-Rae-1 interaction is involved in NK cell death. NK cells from perforin-/-, and DAP10-/-/12-/- mice did not undergo cell death, highlighting the importance of the NKG2D pathway for NK cell death. However, cross-linking of NKG2D receptor failed to induce NK cell death. To understand underlying the mechanism of NK cell death, we evaluated the cell surface expression of NKG2DLs on NK cells after co-culture with tumor cells. We found that cell surface expression of Rae-1 on NK cells was remarkably induced after co-culture with RMA/Rae-1δ, but no with RMA or RMA-S, implying that these Rae-1-positive NK cells may be lysed by NK cells through NKG2D-induced perforin pathway. The cell surface induction of Rae-1 on NK cells was very rapid (within 5min), and it occurred cell-cell contact dependent manner. Interestingly, NK cells from C57/BL6 mice rapidly became BALB/c allele Rae-1γ-positive after co-culture with RMA/Rae-1γ, indicating that NK cells acquire tumor-derived Rae-1. Consistently, acquisition of Rae-1 by NK cells was confirmed by confocal microscopy. Therefore, NK cells rapidly dress tumor-derived Rae-1 after interaction with tumor cells through intercellular membrane transfer, namely trogocytosis. Trogocytosis of Rae-1 was significantly inhibited in NK cells from DAP10-/-/12-/- mice and by chemical inhibitors of PI3K and Syk, indicating that it requires NKG2D-signaling. To confirm whether Rae-1-dressed NK cells can be recognized and lysed by other NK cells, we used sort-purified Rae-1-dressed NK cells as target cells. Rae-1-dressed NK cells were lysed by WT NK cell in an E/T-ratio dependent manner through NKG2D-induced perforin pathway. Furthermore, adoptively transferred Rae-1-dressed NK cells were significantly eliminated in Rag-1-deficient mice, indicating that Rae-1-dressed NK cells are also recognized and lysed in vivo. Conclusion Upon interaction with NKG2DLs-expressing tumor cells NK cells rapidly dress tumor-derived NKG2DLs, and subsequently undergo fratricide. Our results provide novel insights into activation-induced NK cell death via dynamic intercellular communications. Disclosures: No relevant conflicts of interest to declare.

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