scholarly journals Off-the-Shelf Natural Killer Cells with Multi-Functional Engineering Using a Novel Anti-CD19 Chimeric Antigen Receptor Combined with Stabilized CD16 and IL15 Expression to Enhance Directed Anti-Tumor Activity

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4541-4541
Author(s):  
Dan S Kaufman ◽  
Ryan Bjordahl ◽  
Huang Zhu ◽  
Robert Blum ◽  
Andres Bahena ◽  
...  
Keyword(s):  
B Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Chimeric Antigen Receptor ◽  
Research Funding ◽  
Nk Cell ◽  
B Cell Malignancies ◽  
Renewable Source ◽  
Cell Immunotherapy ◽  
Anti Tumor Activity

Abstract T lymphocytes that express an anti-CD19 chimeric antigen receptor (CAR) to redirect target specificity exhibit remarkable remissions in B cell malignancies. However, these cells are typically produced in a patient-specific manner that is relatively inefficient and expensive. Additionally, CAR-T cell treatment can lead to severe adverse events (SAEs) such as cytokine release syndrome (CRS) and neurotoxicity, as well as graft versus host disease (GvHD) when given in allogeneic setting. To circumvent these safety issues while maintaining multi-faceted anti-tumor activity, we developed an off-the-shelf natural killer (NK) cell consisting of a novel CAR combined with other effector mechanisms to enhance targeted cytotoxicity. NK cells are potent anti-tumor effector cells that play an important role in innate and adaptive immunity. Multiple clinical studies have demonstrated that adoptive transfer of allogeneic NK cells can induce durable remissions in patients with cancers that have relapsed or are refractory to standard therapies without detection of SAEs such as CRS. However, NK cells are challenging to genetically engineer, and are dependent on cytokine support for persistence and exhibit donor-to-donor variability factors that make it difficult to create a consistent clinical product from NK cells. Here we report the use of human induced pluripotent stem cells (iPSCs) to produce a renewable source of precisely engineered NK cells. This iPSC platform was utilized to evaluate a combination of CARs comprised of distinct NK-cell specific signaling and transmembrane domains with an autonomous protein to create a persistent and targeted NK cell immunotherapy. The selected NK cell optimized CAR (NK-CAR) backbone contains an NKG2D transmembrane domain, a 2B4 co-stimulatory domain, and a CD3ζ signaling domain to mediate a potent NK cell activating signal. To provide directed anti-tumor activity, anti-CD19 scFv was added to the NK-CAR backbone, engineered at the iPSC stage and subsequently differentiated on-demand to produce a uniform population of CAR-expressing NK cells. In addition, an IL-15RF fusion transgene was introduced to provide self-stimulating signals to support NK cell function and persistence. The IL-15RF construct was created by fusing IL-15Rα to IL-15 at the C-terminus through a flexible linker. As a third modality, a metalloprotease ADAM17-resistant version of the high-affinity CD16a (hnCD16) 158V variant was introduced at the iPSC stage to augment antibody-dependent cellular-cytotoxicity (ADCC) when used in combination with monoclonal antibodies. The selected iPSC clone exhibits stable expression of all three modalities and represents a renewable source of starting material for the reproducible generation of NK cells consisting of NK-CAR, IL-15RF and hnCD16 with product purity that is greater than 95% CD45+CD56+ with a product expansion greater than one million-fold over the course of the manufacturing process. In preclinical studies, these multi-functional engineered NK cells demonstrated enhanced directed cytotoxicity against CD19+ tumor targets when compared to non-engineered NK cells or iPSC-derived NK cells engineered with other CAR constructs. Additionally, the multi-functional engineered iPSC-CAR-NK cells significantly reduced tumor burden in a xenograft model of B acute lymphoblastic leukemia (p<0.05 at day 28). NK cells with IL-15RF inclusion demonstrated improved proliferation in the absence of cytokine support, as well as improved potency when immediately thawed and tested for efficacy. NK-CAR + IL-15RF eliminated 94% and 86% of target cells in the presence and absence of IL-2, respectively, while NK-CAR efficacy was reduced from 98% target elimination in the presence of IL-2 to 56% in the absence of IL-2. In conclusion, these studies demonstrate iPSCs serve as an optimal platform to provide a renewable multi-engineered NK cell product suitable for an "off-the-shelf" approach and serve as preclinical proof of concept for program FT519, a standardized CAR-targeted NK cell immunotherapy against B cell malignancies. Disclosures Kaufman: Fate Therapeutics: Consultancy, Research Funding. Bjordahl:Fate Therapeutics Inc.: Employment. Mahmood:Fate Therapeutics Inc.: Employment. Bonello:Fate Therapeutics Inc.: Employment. Lee:Fate Therapeutics Inc.: Employment. Cichocki:Fate Therapeutics Inc.: Consultancy, Research Funding. Valamehr:Fate Therapeutics Inc.: Employment.

scholarly journals CIS checkpoint deletion enhances the fitness of cord blood derived natural killer cells transduced with a chimeric antigen receptor

2020 ◽  
Author(s):  
May Daher ◽  
Rafet Basar ◽  
Elif Gokdemir ◽  
Natalia Baran ◽  
Nadima Uprety ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Chimeric Antigen Receptor ◽  
Nk Cell ◽  
Aerobic Glycolysis ◽  
Protein A ◽  
Antigen Receptor ◽  
Negative Regulator ◽  
Combined Strategy ◽  
Anti Tumor Activity

AbstractImmune checkpoint therapy has produced remarkable improvements in the outcome for certain cancers. To broaden the clinical impact of checkpoint targeting, we devised a strategy that couples targeting of the cytokine-inducible SH2-containing (CIS) protein, a key negative regulator of interleukin (IL)-15 signaling, with chimeric antigen receptor (CAR) engineering of natural killer (NK) cells. This combined strategy boosted NK cell effector function through enhancing the Akt/mTORC1 axis and c-MYC signaling, resulting in increased aerobic glycolysis. When tested in a lymphoma mouse model, this combined approach improved NK cell anti-tumor activity more than either alteration alone, eradicating lymphoma xenografts without signs of any measurable toxicity. We conclude that combining CIS checkpoint deletion with CAR engineering promotes the metabolic fitness of NK cells in an otherwise suppressive tumor microenvironment. This approach, together with the prolonged survival afforded by CAR modification, represents a promising milestone in the development of the next generation of NK cells for cancer immunotherapy.

scholarly journals Suppressing Synthesis of the Long Isoform of the Prolactin Receptor Is a Targeted Strategy to Prevent and Treat B Cell Malignancies

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1135-1135
Author(s):  
Adeleh Taghi Khani ◽  
Anil Kumar ◽  
Kelly Radecki ◽  
Sung June Lee ◽  
Mary Lorenson ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Nk Cells ◽  
Malignant Transformation ◽  
Nk Cell ◽  
B Cell Lymphoma ◽  
B Cell Malignancies ◽  
Autoreactive B Cells ◽  
Cell Numbers ◽  
Bcl2 Expression

Abstract Rationale B cell malignancies, including leukemia and lymphoma, are high-risk lymphoid neoplasms. B cell malignancies predispose to autoimmune diseases including systemic lupus erythematosus (SLE) which increase the risk of developing these malignancies by &gt;5-fold. Increased prolactin (PRL) expression is known to exacerbate SLE and promote the survival of autoreactive B cells. Furthermore, PRL induces expression of the protooncogenes, MYC and BCL2, in lymphoid tissues. However, whether PRL drives the initiation and maintenance of B cell malignancies was not known. Results We first tested our hypothesis that PRL, specifically signaling through the pro-proliferative and anti-apoptotic long isoform (LF) of the PRL receptor (PRLR), drives the progression of SLE to B cell malignancies. To this end, we knocked down the LF PRLR in MRL-lpr mice predisposed to developing SLE using a splice-modulating oligomer (SMO) that blocks splicing to produce the LF PRLR without affecting the short isoforms. LF PRLR knockdown reduced splenic and circulating B cell numbers in MRL-lpr SLE mice (Fig.1a). Consistent with reduced B cell numbers, BCL2 expression in B cells of SLE mice was suppressed after LF PRLR knockdown, although MYC was unaltered (Fig.1b). By sequencing the immunoglobulin heavy chains (IGH), we compared the composition of the splenic B cell repertoire between control- and LF PRLR SMO-treated SLE mice. Control oligomer treated SLE mice accumulated splenic B cells with long complementary determining region 3 (CDR3) and B cells with non-functional IGH, characteristics of autoreactive B cells. Treatment with the LF PRLR SMO reduced both. We then measured the expression of enzymes known to induce malignant transformation of B cells, namely recombination activating genes 1/2 (RAG1/2) and activation-induced cytidine deaminase (AID), in B cells of SLE mice in controls versus LF PRLR knockdown. Importantly, LF PRLR knockdown significantly reduced RAG1 (Fig.1c) and AID expression in splenic B cells of SLE mice (Fig.1d,e). Our findings thus underscore a causal role for LF PRLR signaling in promoting of malignant transformation of B cells in SLE. Because PRL induces the expression of BCL2 and MYC in lymphocytes, we next determined whether LF PRLR promotes the survival of overt B cell malignancies that overexpress MYC and BCL2, including diffuse large B cell lymphoma (DLBCL) and B-cell acute lymphoblastic leukemia (B-ALL). We observed that B-lymphoblasts expressed significantly higher levels of PRL and the LF PRLR as compared to normal B cells (Fig.1f). We also found that higher expression of PRL at diagnosis predicts poor clinical outcome in DLBCL patients (P=0.0244), and that patients with MYC/BCL2-overexpressing ALLs with a poor prognosis had significantly higher expression of the LF PRLR compared to their MYC lowBCL2 low counterparts (P&lt;0.0001). These observations suggested that LF PRLR may modulate MYC and BCL2 expression. Knockdown of the LF PRLR using the LF PRLR SMO in MYC/BCL2-driven human B cell malignancies killed lymphoblasts and reduced MYC and BCL2 protein levels (Fig.1g). Because we previously showed that MYC-driven lymphoid malignancies are sensitive to natural killer (NK) cell-mediated immune clearance, we also examined whether LF PRLR knockdown synergized with NK cells in killing DLBCL. We found that LF PRLR knockdown enhanced NK cell-mediated killing of B-lymphoblasts (Fig.1h). Of note, no reductions were observed in NK cell viability or MYC levels within NK cells upon LF PRLR knockdown, suggesting that LF PRLR selectively kills B-lymphoblasts without negatively impacting NK homeostasis. Conclusion Our studies identify the specific knockdown of LF PRLR as a potentially safe and targeted strategy to prevent the onset of B cell malignancies in SLE patients and to treat flagrant DLBCL and B-ALL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Cord Blood Derived Natural Killer Cells Engineered with a Chimeric Antigen Receptor Targeting CD19 and Expressing IL-15 Have Long Term Persistence and Exert Potent Anti-Leukemia Activity

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3091-3091 ◽  
Author(s):  
Enli Liu ◽  
Yijiu Tong ◽  
Gianpietro Dotti ◽  
Barbara Savoldo ◽  
Muharrem Muftuoglu ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Phase 1 ◽  
Leukemia Cell ◽  
Antigen Presenting Cells ◽  
Caspase 9 ◽  
Antigen Presenting

Abstract Natural killer (NK) cells are a major component of the innate immune system, possessing the ability to lyse their targets without the need for prior sensitization or specificity for antigen. Besides their classical role in providing potent antitumor and antiviral immunity, NK cells can reduce the risk of graft-versus-host disease (GVHD) by targeting host antigen-presenting cells, as well as activated alloreactive donor T cells, indicating that NK-mediated graft-versus-leukemia (GVL) responses may occur in the absence of GVHD. Although most groups have relied on autologous or adult peripheral blood donor-derived NK cells, we have studied umbilical CB as a potential source of NK cells because of their availability as an "off-the-shelf" frozen product and their potent preclinical activity against leukemia cells. To overcome the obstacle of limited numbers of NK cells in a single CB unit, we have established GMP-compliant conditions for the ex vivo expansion of clinically relevant doses of such cells. By using GMP grade K562-based artificial antigen-presenting cells (aAPCs), which express membrane-bound IL-21 (clone 9.mbIL21), to numerically expand highly functional and mature CB-derived NK cells. To further enhance the GVL effect independent of KIR-ligand mismatch, we have genetically modified human CB-derived NK cells with a retroviral vector, CAR19-CD28-zeta-2A-IL15 (CAR19/IL15), which incorporates the genes for CAR-CD19, IL-15 to enhance proliferation and survival, and the inducible caspase-9 molecule. CB-NK cells could be stably transduced with CAR19/IL15, proliferated efficiently in vitro and maintained superior effector function against CD19-expressing leukemia cell lines and primary CLL cells. Moreover, the effector functions of both NK-CAR and nontransduced NK cells against K562 were comparable, indicating that the genetic modification of CB-NK cells does not alter their intrinsic cytotoxicity against NK-sensitive targets. Because of concerns over autonomous, uncontrolled NK cell growth due to autocrine production of IL15, we also incorporated into our construct a suicide gene based on the inducible caspase-9 (IC9) gene. The addition of as little as 10 nM of the small molecule dimerizer CID AP20187 to cultures of iC9/CAR19/IL15+ NK cells induced apoptosis/necrosis of >60% of transgenic cells within 4 hours as assessed by annexin-V-7AAD staining. The infusion of CAR.CD19.IL15-transduced CB-NK cells into a NOD-SCID-gamma null model of lymphoblastic lymphoma (Raji model) resulted in impressive anti-tumor responses (Fig. 1). Moreover, adoptively infused CAR-transduced CB NK persisted for up to 70 days post-infusion (Fig. 2), supporting our hypothesis that IL-15 enhances the proliferation and survival of the engineered CB-NK cells. Based on these promising data, we now propose to manufacture a GMP-grade CAR19-CD28-zeta-2A-IL15 vector for a phase 1 dose escalation trial in patients with high risk B-cell leukemia. Disclosures Wierda: Celgene Corp.: Consultancy; Glaxo-Smith-Kline Inc.: Research Funding. Rezvani:Pharmacyclics: Research Funding.

Exome Sequencing of Aggressive Natural Killer Cell Leukemia and Drug Profiling Highlight Candidate Driver Pathways in Malignant Natural Killer Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 700-700
Author(s):  
Olli Dufva ◽  
Tiina Kelkka ◽  
Shady Awad ◽  
Nodoka Sekiguchi ◽  
Heikki Kuusanmäki ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Exome Sequencing ◽  
Cell Lines ◽  
Hierarchical Clustering ◽  
Research Funding ◽  
Drug Sensitivity ◽  
Somatic Mutations ◽  
Nk Cell ◽  
Negative Regulator

Abstract Background Natural killer (NK) cell malignancies are rare lymphoid neoplasms characterized by aggressive clinical behavior and poor treatment outcomes. Clinically they are classified as extranodal NK/T-cell lymphoma, nasal type (NKTCL) and aggressive NK cell leukemia (ANKL). Both subtypes are almost invariably associated with Epstein-Barr virus (EBV). Recently, genomic studies in NKTCL have identified recurrent somatic mutations in JAK-STAT pathway molecules STAT3 and STAT5b as well as in the RNA helicase gene DDX3X in addition to previously detected chromosomal aberrations. Here, we identified somatic mutations in 4 cases of ANKL in order to understand whether these entities share common alterations at the molecular level. To further establish common patterns of deregulated oncogenic signaling pathways operating in malignant NK cells, we performed drug sensitivity profiling using NK cell lines representing ANKL, NKTCL and other malignant NK cell proliferations. We aimed to identify sensitivities to agents that selectively target components of pathways required for survival of malignant NK cells in an unbiased manner. Methods Exome sequencing was performed on peripheral blood or bone marrow of ANKL patients using the NK cell negative fraction or other healthy tissue as control. Profiling of drug responses was performed with a high-throughput drug sensitivity and resistance testing (DSRT) platform comprising 461 approved and investigational oncology drugs. The NK cell lines KAI3, KHYG-1, NKL, NK-YS, NK-92, SNK-6 and YT and IL-2-stimulated and resting NK cells from healthy donors were used as sample material. All drugs were tested on a 384-well format in 5 different concentrations over a 10,000-fold concentration range for 72 h and cell viability was measured. A Drug Sensitivity Score (DSS) was calculated for each drug using normalized dose response curve values. Results The ANKL patients displayed mutations in genes reported as recurrently mutated in NKTCL, such as FAS, TP53, NRAS, STAT3 and DDX3X. Additionally, novel alterations in genes previously implicated in the pathogenesis of NKTCL were detected. These included an inactivating mutation in INPP5D (SHIP), a negative regulator of the PI3K/mTOR pathway and a missense mutation in PTPRK, a negative regulator of STAT3 activation. Interestingly, the total number of nonsilent somatic mutations in 3 out of 4 ANKL patients (97, 82 and 45) was remarkably high compared to other hematological malignancies analyzed in our variant calling pipeline. Analysis of drug sensitivities in NK cell lines showed a close correlation between all cell lines and a markedly higher correlation with those of IL-2 stimulated than resting healthy NK cells, suggesting that malignant NK cells may share a common drug response pattern. Furthermore, in an unsupervised hierarchical clustering the NK cell lines formed a distinct group from other leukemia cell lines tested (Fig. A). Among pathway-selective compounds (namely, kinase inhibitors and rapalogs), the drugs most selective for malignant NK cells fell into two major categories: PI3K/mTOR inhibitors (e.g. temsirolimus, buparlisib) and inhibitors of aurora and polo-like kinases such as rigosertib and GSK-461364 (Fig. B). JAK inhibitors (e.g. ruxolitinib, gandotinib) and CDK inhibitors (e.g. dinaciclib) showed strong efficacy in both malignant NK cells and IL-2 activated healthy NK cells. Conclusions Our exome sequencing results suggest that candidate driver alterations affecting similar signaling pathways underlie the pathogenesis of ANKL as has been reported in NKTCL. Drug sensitivity profiling highlights the PI3K/mTOR pathway as a potential major driver of malignant NK cell proliferation, whereas JAK-STAT signaling appears to be essential in both healthy and malignant NK cells. Components of these pathways harbored mutations in our small cohort of ANKL patients and have been shown to be deregulated by mutations or other mechanisms in previous studies, underlining their importance as putative drivers. The systematic large-scale characterization of drug responses also identified these pathways as potential targets for novel therapy strategies in NK cell malignancies. Figure 1. (A) Unsupervised hierarchical clustering based on drug sensitivity scores (DSS) of NK, AML, CML and T-ALL cell lines. (B) Scatter plot comparing DSS of malignant NK cell lines (average) and healthy IL-2 stimulated NK cells. Figure 1. (A) Unsupervised hierarchical clustering based on drug sensitivity scores (DSS) of NK, AML, CML and T-ALL cell lines. (B) Scatter plot comparing DSS of malignant NK cell lines (average) and healthy IL-2 stimulated NK cells. Disclosures Mustjoki: Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding.

Myeloma-Derived Exosomes and Soluble Factors Suppress Natural Killer Cell Function

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2066-2066
Author(s):  
Tarun K. Garg ◽  
Jessica I Gann ◽  
Priyangi A Malaviarachchi ◽  
Kate Stone ◽  
Veronica Macleod ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Nk Cells ◽  
Natural Killer ◽  
Adhesion Molecules ◽  
Research Funding ◽  
Cell Function ◽  
Immune Escape ◽  
Nk Cell ◽  
Soluble Factors

Abstract Introduction The complex makeup of the tumor microenvironment (ME) exerts selective pressure on cancer cells leading to immune escape, and novel immunotherapeutic interventions have emerged from evolving knowledge of the immune system and tumor cells. Natural killer (NK) cells are innate immune cells that exert potent anti-tumor effects. Previously we have reported that ex vivo expansion of NK cells by co-culture PBMCs with K562mbIL15-41BBL can generate large numbers of highly active expanded NK cells (ENKs). These ENKs expand further upon adoptive transfer in vivo both in a murine model and in patients (Garg et al. 2012, Szmania et al. 2015), and have been shown to persist and retain their cytolytic ability. We are currently applying ENK therapy in a Phase II clinical trial at our institute in gene expression profiling-defined high-risk multiple myeloma (MM), a patient population which fares poorly despite the use of novel drugs and autologous stem cell transplantation. A potential obstacle to successful NK cell-based therapies is the suppression of NK cells in the MM bone marrow ME (BM-ME) by immunosuppressive cells, various soluble factors (SF), microRNAs, and exosomes. Exosomes are endosomal-derived, 30-130nm microvesicles present in almost all body fluids. Their number is significantly higher in cancer patients. Tumor-derived exosomes contain a wide range of bioactive molecules, such as microRNA, RNA, DNA and protein, and play a major role in immune escape, promoting tumor progression. Their size, structure, and presence in serum allow them to transport their cargo to distant targets. This study was designed to characterize the potential adverse effects of myeloma-derived exosomes (MEXs) and myeloma-derived SF (MSF) on NK cell function and determine if such inhibition can be overcome by cytokine support. Methods MEXs were isolated from OPM2 myeloma cell line-derived conditioned media (MCM) using the Total Isolation Reagent (Life Technologies, Carlsbad CA). Transmission electron microscopy (TEM), flow cytometry, and western blot (WB) analysis were used for characterization of exosomes. Fresh NK cells (non-activated) and ENKs were incubated with MCM or MEXs and evaluated for their viability and cytolytic ability in standard 4-hour chromium release assays. Flow cytometry was used to evaluate the immunophenotype of these cells, including activation, costimulatory, inhibitory receptors, and adhesion molecules. Results TEM confirmed the presence of exosomes in MCM (size and morphology). Interestingly, OPM2-derived MEXs did not express the exosome-specific marker CD9, but did express CD63, and CD81. Flow cytometry showed that MEXs contain MICA/B, TGFβ, TRAIL-R1, TRAIL-R2, MHC class I, HLA-E, and ICAM3. NK cells exposed to MEXs demonstrated a dose-dependent, significant decrease in specific lysis of the MM cell lines JJN3, OPM2, and U266 in cytotoxicity assays compared to control NK cells (13%-51%, p<0.0005). In addition, a time-dependent decrease in NK cell-mediated lysis was observed in these MM cell lines at 24hours (14%-34%) versus 48hours (30%-48%; p<0.0005). A similar downward trend in the activity of ENKs incubated with MEXs was also noted but to a lesser extent. We hypothesize that highly-activated ENKs are able to partially overcome MEX-mediated inhibition compare to resting NK cells. We also noted a considerable decrease in the cytolytic ability of ENKs incubated with MCM which contains suppressive soluble factors in addition to MEXs (28%-58%, p<0.0005). Further, this suppression in ENK activity was partly rescued by fresh IL2 incubation (18-36%, p<0.01). Many of the activating receptors (NKp46, NKp30, NKp44, NKG2D), costimulatory receptors (2B4, NTB-A, NKp80, DNAM-1), activation markers (CD26, CD69), and adhesion molecules (LFA-1, CD54) were down regulated on the ENK cells incubated with MCM. However, differences were not as significant in these receptors on ENK cells incubated with MEX. Conclusion MEXs and other SF released from myeloma cells are capable of modulating the function and phenotype of NK cells and ENKs. MCM is more immunosuppressive as it contains both MEX and MSF. Cytolytic ability of ENKs could be partially restored by incubation in fresh IL2 medium. Further characterization of MEXs and MCM by proteomics is in progress. (Data will be presented). Disclosures Davies: Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Morgan:Bristol Meyers: Consultancy, Honoraria; Janssen: Research Funding; Univ of AR for Medical Sciences: Employment; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding.

scholarly journals Activation-Induced Release of the TNF-Family Member BAFF By NK Cells Facilitates Resistance of Chronic Lymphoid Leukemia Cells to Direct and Rituximab-Induced NK Lysis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1963-1963
Author(s):  
Julia S Wild ◽  
Stefanie Raab ◽  
Benjamin J Schmiedel ◽  
Andreas Maurer ◽  
Pascal Schneider ◽  
...  
Keyword(s):  
B Cell ◽  
Nk Cells ◽  
Family Member ◽  
Nk Cell ◽  
Close Relative ◽  
Functional Explanation ◽  
B Cell Malignancies ◽  
Lymphoid Leukemia ◽  
Chronic Lymphoid Leukemia ◽  
Activated State

Abstract NK cells are cytotoxic lymphocytes that play an important role in the immunosurveillance of leukemia and, due to their ability to mediate antibody-dependent cellular cytotoxicity (ADCC), substantially contribute to the therapeutic benefit of antitumor antibodies like Rituximab. Available data indicate that the ability of NK cells to mediate ADCC is compromised in Chronic Lymphoid Leukemia (CLL), but the underlying mechanisms are still unclear. The TNF family member B cell activating factor (BAFF) was described to be aberrantly produced in mature B cell malignancies and contributes to disease pathophysiology e.g. by acting as a growth and survival signal for CLL cells. Here we report that NK cells express and release BAFF, and NK cell activation, notably including FcγRIIIa stimulation by Rituximab, results in increased secretion of BAFF (but not its close relative APRIL). Expression on the cell surface was neither detectable in resting nor in activated state. NK cell-derived BAFF enhanced the metabolic activity of primary CLL cells and protected CLL cells from chemotherapy-induced cell death. Moreover, exposure to BAFF profoundly diminished direct and Rituximab-induced lysis of primary CLL cells by allogeneic and autologous NK cells, while NK activation and degranulation per se remained unaffected. Notably, sensitivity of CLL cells to both chemotherapeutic treatment as well as direct lysis and Rituximab-induced ADCC of NK cells could be restored by the anti-BAFF antibody Belimumab (Benlysta®), which is approved for the treatment of systemic lupus erythematosus. Thus, our data provide evidence for the involvement of BAFF in the resistance of CLL cells to chemotherapy. Moreover, our results offer a functional explanation for the reportedly compromised ability of NK cells to combat lymphoid as compared to myeloid leukemias as well as their impaired ability to mediate ADCC upon Rituximab treatment in CLL patients. Our findings point to a possible benefit of combinatory approaches employing Rituximab and Belimumab for chemo-immunochemotherapy of B cell malignancies. Disclosures No relevant conflicts of interest to declare.

scholarly journals Cord Blood Derived Natural Killer Cells Loaded with a Tetravalent Bispecific Antibody Construct (AFM13) As Off-the-Shelf Cell Therapy for CD30+ Malignancies

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 341-341
Author(s):  
Lucila Kerbauy ◽  
Mecit Kaplan ◽  
Pinaki P Banerjee ◽  
Francesca Lorraine Wei Inng Lim ◽  
Ana Karen Nunes Cortes ◽  
...  
Keyword(s):  
T Cell ◽  
Cord Blood ◽  
Nk Cells ◽  
Natural Killer ◽  
Research Funding ◽  
Bispecific Antibody ◽  
Nk Cell ◽  
Ex Vivo

Abstract Chimeric antigen receptors to redirect T cell specificity against tumor antigens have shown remarkable clinical responses against CD19+ malignancies. However, the manufacture of an engineered autologous T cell product is expensive and cumbersome. Natural killer (NK) cells provide an alternative source of immune effectors for the treatment of cancer. NK cell cytolytic function can be directed towards specific targets by exploiting their ability to mediate antibody-dependent cellular cytotoxicity (ADCC) through the NK cell Fc receptor, CD16 (FcγRIIIa). AFM13 is a tetravalent bispecific antibody construct based on Affimed's ROCK™ platform. AFM13 is bispecific for CD30 and CD16A, designed for the treatment of CD30 expressing malignancies. It binds CD16A on the surface of NK cells, thus activating and recruiting them to CD30 expressing tumor cells and mediating subsequent tumor cell killing. Since autologous NK effector function is impaired in many patients with malignancies, we propose to overcome this by the use of allogeneic NK cells in combination with AFM13. Cord blood (CB) is a readily available ("off-the-shelf") source of allogeneic NK cells that can be expanded to large, highly functional therapeutic doses. The feasibility and safety of therapy with allogeneic ex vivo expanded CB-derived NK cells have been shown by our group and others. In this study, we hypothesized that we can redirect the specificity of NK cells against CD30+ malignancies by preloading ex vivo activated and expanded CB-derived NK cells with AFM13 prior to adoptive infusion. Briefly, mononuclear cells were isolated from fresh or frozen CB units by ficoll density gradient centrifugation. CD56+ NK cells were cultured with rhIL-12, rhIL-18 and rhIL-15 for 16 hrs, followed by ex vivo expansion with rhIL-2 and irradiated (100 Gy) K562-based feeder cells expressing membrane-bound IL-21 and CD137-ligand (2:1 feeder cell:NK ratio). After 14 days, NK cells were loaded with serial dilutions of AFM13 (0.1, 1, 10 and 100 mg/ml). After washing twice with PBS, we tested the effector function of AFM13-loaded NK-cells (AFM13-NK) compared to expanded CB-NK cells without AFM13 against Karpas-299 (CD30 positive) and Daudi (CD30 negative) lymphoma cell lines by 51Cr release and intracellular cytokine production assays. AFM13-NK cells killed Karpas-299 cells more effectively at all effector:target ratios tested than unloaded NK cells (Figure 1) and produced statistically more INFγ and CD107a (P=0.0034; P=0.0031 respectively, n=4). In contrast, AFM13-NK cells and unloaded NK cells exerted similar cytotoxicity against Daudi cells. Next, we established the optimal concentration of AFM13 for loading (determined to be 100 μg/ml) and the optimal incubation time to obtain maximal activity (1 h) in a series of in vitro experiments. We also confirmed that the activity of AFM13-NK cells against Karpas-299 cells remains stable for at least 72h post-wash (Figure 2). Additionally, we characterized the phenotype of AFM13-NK vs. unloaded NK cells by flow cytometry using monoclonal antibodies against 22 markers, including markers of activation, inhibitory receptors, exhaustion markers and transcription factors. Compared to unloaded NK cells, AFM13-NK cells expressed higher levels of CD25, CD69, TRAIL, NKp44, granzyme B and CD57, consistent with an activated phenotype. We next tested the in vivo anti-tumor efficacy of AFM13-NK cells in an immunodeficient mouse model of FFluc-Karpas-299. Briefly, six groups of NOD/SCID/IL2Rγc null mice (n=5 per group) were transplanted by tail-vein injection with 1 x 10e5 FFluc-transduced Karpas cells. Group 1 and 6 received tumor alone or tumor + AFM13 and served as a control. Groups 2-4 receive Karpas FFLuc with either expanded NK cells or AFM13-NK cells (NK cells loaded with AFM13) or expanded NK cells and AFM13 injected separately. Group 5 received AFM13-NK cells without tumor. Initial studies confirm the antitumor activity of AFM13-NK cells. In summary, we have developed a novel premixed product, comprised of expanded CB-NK cells loaded with AFM13 to 'redirect' their specificity against CD30+ malignancies. The encouraging in vitro and in vivo data observed in this study, provide a strong rationale for a clinical trial to test the strategy of an off-the-shelf adoptive immunotherapy with AFM13-loaded CB-NK cells in patients with relapsed/refractory CD30+ malignancies. Disclosures Champlin: Sanofi: Research Funding; Otsuka: Research Funding. Koch:Affimed GmbH: Employment. Treder:Affimed GmbH: Employment. Shpall:Affirmed GmbH: Research Funding. Rezvani:Affirmed GmbH: Research Funding.

scholarly journals Continuous IL-15 Signaling Leads to Functional Exhaustion of Human Natural Killer Cells through Metabolic Changes That Alters Their In Vivo Anti-Tumor Activity

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 551-551 ◽  
Author(s):  
Martin Felices ◽  
Alexander Lenvik ◽  
Sami Chu ◽  
Ron McElmurry ◽  
Sarah Cooley ◽  
...  
Keyword(s):  
Cell Death ◽  
Nk Cells ◽  
Natural Killer ◽  
Research Funding ◽  
Nk Cell ◽  
Cellular Stress ◽  
Functional Assay ◽  
Functional Exhaustion

Abstract Natural Killer (NK) cells represent an exciting immunotherapeutic approach to treat cancer. We have shown that in vivo expansion and activation of donor NK cells supported by administration of IL-2 induces remission in patients with refractory AML. Recent clinical studies by our group have shown that IL-15 is superior to IL-2 to support NK cell persistence 14 days after adoptive transfer. However, only 36% of patients treated with 12 consecutive days of IL-15 had NK cell expansion to the level of ≥100 donor derived NK cells/µL blood compared to 10% in subjects treated with IL-2 (p=0.02). This leads us to conclude that we might not know the optimal route and interval to administer in vivo IL-15. We hypothesized that daily uninterrupted IL-15 dosing could lead to exhaustion or NK cellular stress. Therefore we designed an in vitro model system in which enriched NK cells are treated with three 3-day cycles of continuous IL-15 (IL-15cont) or were rested with a "gap" (skipping the middle cycle [IL-15gap]) before returning to the last cycle of IL-15. IL-15cont treatment yielded more proliferation and higher cell numbers compared to IL-15gap (4.8±0.44 vs. 1.9±0.26 million cells/ml, p < 0.0001) when cells were analyzed at the end of the three cycles (on day 9, where all in vitro measurements were taken). However, NK cell death, measured by flow cytometry, in the IL-15cont group was higher (18.9±2.2 vs 14.9±1.7 % cell death, p = 0.035) and this group also had an enrichment in genes involved in cell cycle checkpoint/ arrest, perhaps indicating more cellular stress in the IL-15cont. In an in vitro flow cytometric functional assay, the IL-15cont group had decreased activation when compared to the IL-15 gap group against K562 targets (43.6±2.1 vs 55.6±2.7 % CD107a [degranulation], p < 0.0001; 1.9±0.41 vs 7.1±0.93 % IFNg [inflammatory cytokine production], p = 0.0055). The decrease in NK cell activation correlated with a strong decrease in tumor target killing in an in vitro chromium release assay (Figure 1A) measuring killing of acute promyelocytic leukemia (HL-60) cell targets, in which the IL-15cont NK cells were potently outperformed by the IL-15gap cells (6.4±2.6 vs 51.5±4.8 % killing at 2.5:1 effector:target ratio, p < 0.0001). We used an in vivo xenogeneic model of AML, where conditioned NSG (NOD scid gamma) mice are engrafted with HL-60luc tumor targets 3 days prior to infusion with nothing, IL-15cont or IL-15gap human NK cells prepared within our 9 day culture system. Only the IL-15gap NK group mediated statistically significant tumor control when compared to tumor alone at two weeks following NK cell infusion (Figure 1B). To probe deeper into the functional defect we evaluated signaling after these treatments and noted decreased phosphorylation of several proteins in the IL-15cont group. These data led us to explore proteins involved in metabolism and we noted that CPT1A, a critical enzyme involved in fatty acid oxidation (FAO), was strongly increased in the IL-15gap treated NK cells (protein MFI of 15,759±2,603 [IL-15gap] vs 5,273±744 [IL-15cont], p = 0.009). Metabolic analysis using a Seahorse XFe24 analyzer showed an increased mitochondrial spare respiratory capacity (SRC) in the IL-15gap group, denoting better capability of the IL-15gap NK cells to respond to energetic demands (Figure 1C). In a separate experiment the groups were treated with etomoxir to inhibit CPT1A, and the SRC phenotype was reversed, with the IL-15gap group containing lower SRC than the IL-15cont group. To test these findings in a functional assay we repeated the IL-15cont treatment in combination with rapamycin, which can induce CPT1A through inhibition of mTORC1, and saw restoration of function to levels similar to IL-15gap (40.8±2.0 vs 49.3±2.9 % CD107a in the IL-15cont vs IL-15cont + rapamycin, p = 0.005; 2.4±0.47 vs 4.8±1.0 % IFNg in the IL-15cont vs IL-15cont + rapamycin, p = 0.03). These data indicate that NK cell functional exhaustion via continuous IL-15 signaling is mediated by a decrease in FAO. Intermittent IL-15 dosing or altering metabolism through other mechanisms may overcome this competition. These findings could impact ongoing clinical trials through simple alterations in dosing strategies in order to minimize NK cell exhaustion in the immunotherapeutic setting. Disclosures Cooley: Fate Therapeutics: Research Funding. Miller:Oxis Biotech: Consultancy, Other: SAB; Fate Therapeutics: Consultancy, Research Funding.

scholarly journals Natural Killer Cells in Immunotherapy: Are We Nearly There?

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3139 ◽  
Author(s):  
Mireia Bachiller ◽  
Anthony M. Battram ◽  
Lorena Perez-Amill ◽  
Beatriz Martín-Antonio
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cancer Patients ◽  
Clinical Studies ◽  
Nk Cell ◽  
Innate Immune ◽  
Novel Studies ◽  
Cell Immunotherapy

Natural killer (NK) cells are potent anti-tumor and anti-microbial cells of our innate immune system. They are equipped with a vast array of receptors that recognize tumor cells and other pathogens. The innate immune activity of NK cells develops faster than the adaptive one performed by T cells, and studies suggest an important immunoregulatory role for each population against the other. The association, observed in acute myeloid leukemia patients receiving haploidentical killer-immunoglobulin-like-receptor-mismatched NK cells, with induction of complete remission was the determinant to begin an increasing number of clinical studies administering NK cells for the treatment of cancer patients. Unfortunately, even though transfused NK cells demonstrated safety, their observed efficacy was poor. In recent years, novel studies have emerged, combining NK cells with other immunotherapeutic agents, such as monoclonal antibodies, which might improve clinical efficacy. Moreover, genetically-modified NK cells aimed at arming NK cells with better efficacy and persistence have appeared as another option. Here, we review novel pre-clinical and clinical studies published in the last five years administering NK cells as a monotherapy and combined with other agents, and we also review chimeric antigen receptor-modified NK cells for the treatment of cancer patients. We then describe studies regarding the role of NK cells as anti-microbial effectors, as lessons that we could learn and apply in immunotherapy applications of NK cells; these studies highlight an important immunoregulatory role performed between T cells and NK cells that should be considered when designing immunotherapeutic strategies. Lastly, we highlight novel strategies that could be combined with NK cell immunotherapy to improve their targeting, activity, and persistence.

Sign in / Sign up

Export Citation Format

Share Document