scholarly journals Obinutuzumab-Retreatment in Combination with Bendamustine Is Effective for Obinutuzumab Resistant Models in Vitro and In Vivo

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 11-12
Author(s):  
Yoriko Yamashita-Kashima ◽  
Natsumi Kawasaki ◽  
Keigo Yorozu ◽  
Shigeki Yoshiura ◽  
Takaaki Fujimura ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Single Agent ◽  
Xenograft Model ◽  
Cd107a Expression ◽  
Cd20 Expression

Background: Follicular lymphoma (FL) commonly recurs and is difficult to cure. Obinutuzumab (OBI) is a humanized type II anti-CD20 antibody. It's mode of action is mainly characterized by the induction of direct cell death and it shows stronger antibody-dependent cellular cytotoxicity (ADCC) than rituximab. While OBI is indicated for previously untreated or relapsed/refractory (r/r) FL, there is no evidence on the efficacy of retreatment with OBI in r/r FL after prior OBI-containing therapy. To demonstrate the effectiveness of OBI-retreatment in a non-clinical study, we established in vitro and in vivo OBI resistant models, consisting of human non-Hodgkin lymphoma (NHL) cells resistant to OBI-induced ADCC and OBI-resistant tumors established from NHL cells under xenotransplantation conditions, and investigated the combination efficacy of OBI and bendamustine (Benda) in these OBI-resistant models. Methods: OBI-induced ADCC resistant clones were established from an RL cell line by inducing ADCC three times with CD16-transfected NK-92 cells. The in vivo resistant model was established from a SU-DHL-4 xenograft model through repeated treatment with OBI and re-inoculation of the regrown tumors. CD20 expression was assessed by flow cytometry or immunohistochemistry (IHC). ADCC activity was evaluated using calcein-AM with CD16-transfected NK-92 cells. To examine antitumor activity, OBI, human immunoglobulin G (HuIgG), Benda, or vehicle were intravenously administered on Day 1, 8 and 15 (OBI and HuIgG) or Day 1 and 2 (Benda and vehicle), and tumor volume was measured. Intratumorally infiltrated NK cells were assessed by IHC of CD335. Cell surface CD107a expression was assessed by flow cytometry. Results: OBI-induced ADCC resistant clones derived from RL (RL-OR-8 and RL-OR-22) showed a reduction in ADCC sensitivity compared with RL. These resistant clones exhibited CD20 expression similar to RL. Pretreatment of the effector NK cells with Benda enhanced ADCC induction of OBI in RL-OR-8 and RL-OR-22. Treatment with OBI (30 mg/kg) in combination with Benda (13.3 mg/kg) also significantly increased antitumor activity compared with each single agent alone on Day 18 (when tumor volume reached euthanasia criteria (*) in control and OBI monotherapy groups) in the RL-OR-22 xenograft model (Table 1). An in vivo OBI resistant model derived from SU-DHL-4 xenografts (SU-DHL-4-OR-18-8) was also established. While SU-DHL-4 xenografted tumors disappeared in 6/6 mice after the third OBI treatment (6 mg/kg), SU-DHL-4-OR-18-8 tumors did not regress in 6/6 mice. CD20 expression in SU-DHL-4-OR-18-8 tumors did not decrease compared with SU-DHL-4 tumors. The ratio of CD335-positive cells to tumor cells after 6 mg/kg of OBI treatment (Day 4) in SU-DHL-4-OR-18-8 was significantly decreased compared with the ratio in SU-DHL-4 (0.31 ± 0.12% vs 0.93 ± 0.23%). The combination efficacy of OBI and Benda was also assessed in an SU-DHL-4-OR-18-8 xenograft model. OBI (6 mg/kg) in combination with Benda (25 mg/kg) significantly increased the antitumor activity compared with each single agent alone on Day 22 (*in control group) and 29 (Table 1). Finally, the expression of CD107a, an NK cell-degranulation marker, was detected to examine the effect of Benda on NK activity in vitro. Pretreating effector NK cells with Benda upregulated CD107a expression on NK cell surfaces after OBI treatment in RL-OR-8 and RL-OR-22. Conclusions: The decreased CD335-positive cell ratio observed in the in vivo SU-DHL-4-OR-18-8 resistant model suggests that the mechanism of resistance to OBI also involves the attenuation of ADCC as in the in vitro OBI-induced ADCC resistant clones. The combination treatment of OBI and Benda was effective in both RL-OR-22 and SU-DHL-4-OR-18-8 xenograft models. It is possible that activation of NK cells by Benda might be involved in this combination mechanism. Although the mechanisms need to be examined in more detail, these results indicate the possible effectiveness of OBI-retreatment after prior OBI-containing therapy. Disclosures Yamashita-Kashima: Nippon Shinyaku Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Current Employment. Kawasaki:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Yorozu:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Yoshiura:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Fujimura:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Kurasawa:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Harada:Chugai Pharmaceutical Co., Ltd.: Current Employment; Nippon Shinyaku Co., Ltd.: Research Funding. Yoshimura:Nippon Shinyaku Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Current Employment.

scholarly journals 852 Trifunctional NKp46/CD16a-NK cell engager targeting CD123 overcomes acute myeloid leukemia resistance to ADCC

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A893-A893
Author(s):  
Laurent Gauthier ◽  
Angela Virone-Oddos ◽  
Angela Virone-Oddos ◽  
Jochen Beninga ◽  
Benjamin Rossi ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Antitumor Activity ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Nk Cell ◽  
Ex Vivo ◽  
Activating Receptors ◽  
Acute Myeloid

BackgroundThere is a clear need for targeted therapies to treat acute myeloid leukemia (AML), the most common acute leukemia in adults. CD123 (IL-3 receptor alpha chain) is an attractive target for AML treatment.1 However, cytotoxic antibody targeting CD123 proved insufficiently effective in a combination setting in phase II/III clinical trials.2 T-cell engagers targeting CD123 displayed some clinical efficacy but were often associated with cytokine release syndrome and neurotoxicity.3 Interest in the use of NK cells for therapeutic interventions has increased in recent years, as a potential safer alternative to T cells. Several NK-cell activating receptors, such as CD16a, NKG2D, and the natural cytotoxicity receptors NKp30 and NKp46, can be targeted to induce antitumor immunity. We previously reported the development of trifunctional NK-cell engagers (NKCEs) targeting a tumor antigen on cancer cells and co-engaging NKp46 and CD16a on NK cells.4MethodsWe report here the design, characterization and preclinical development of a novel trifunctional NK cell engager (NKCE) targeting CD123 on AML cells and engaging the activating receptors NKp46 and CD16a on NK cells. The CD123 NKCE therapeutic molecule was engineered with humanized antibodies targeting NKp464 and CD123.5 We compared CD123-NKCE and a cytotoxic ADCC-enhanced antibody (Ab) targeting CD123, in terms of antitumor activity in vitro, ex vivo and in vivo. Pharmacokinetic, pharmacodynamic and safety profile of CD123-NKCE were evaluated in non-human primate (NHP) studies.ResultsThe expression of the high affinity Fc gamma receptor CD64 on patient-derived AML cells inhibited the ADCC of the Ab targeting CD123 in vitro and ex vivo, but not the antitumor activity of CD123-NKCE. CD123-NKCE had potent antitumor activity against primary AML blasts and AML cell lines, promoted strong NK-cell activation and induced cytokine secretion only in the presence of AML target cells. Its antitumor activity in mouse model was greater than that of the comparator antibody. Moreover, CD123-NKCE had strong and prolonged pharmacodynamic effects in NHP when used at very low doses, was well-tolerated up to high 3 mg/kg dose and triggered only minor cytokine release.ConclusionsThe data for activity, safety, pharmacokinetics, and pharmacodynamics provided here demonstrate the superiority of CD123-NKCE over comparator cytotoxic antibody, in terms of antitumor activity in vitro, ex vivo, in vivo, and its favorable safety profile, as compared to T-cell therapies. These results constitute proof-of-principle for the efficacy of CD123-NKCE for controlling AML tumors in vivo, and provide consistent support for their clinical development.ReferencesEhninger A, Kramer M, Rollig C, et al. Distribution and levels of cell surface expression of CD33 and CD123 in acute myeloid leukemia. Blood Cancer J 2014;4:e218.Montesinos P, Gail J Roboz GJ, et al. Safety and efficacy of talacotuzumab plus decitabine or decitabine alone in patients with acute myeloid leukemia not eligible for chemotherapy: results from a multicenter, randomized, phase 2/3 study. Leukemia 2021;35(1):62–74.Uy GL, Aldoss I, Foster MC, et al. Flotetuzumab as salvage immunotherapy for refractory acute myeloid leukemia. Blood 2021;137(6):751–762.Gauthier L, Morel A, Anceriz N, et al. Multifunctional natural killer cell engagers targeting NKp46 trigger protective tumor immunity. Cell 2019;177(7):1701–13.Jin L, Lee EM, Ramshaw HS, et al. Monoclonal antibody-mediated targeting of CD123, IL-3 receptor alpha chain, eliminates human acute myeloid leukemic stem cells. Cell Stem Cell 2009;5:31–42.

Mechanisms of IL-21 Enhancement of Rituximab Efficacy in a Lymphoma Xenograft Model.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1404-1404
Author(s):  
Steve D. Hughes ◽  
Ken Bannink ◽  
Cecile Krejsa ◽  
Mark Heipel ◽  
Becky Johnson ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Antibody Therapy ◽  
Xenograft Model ◽  
Tumor Model ◽  
Cell Types ◽  
Current Evidence

Abstract Interleukin 21 (IL-21) is an IL-2 family cytokine produced by activated CD4+ T cells. Potent effects of IL-21 have been observed on the growth, survival, and functional activation of T cells, B cells, and natural killer (NK) cells. A Phase I clinical trial of IL-21 in metastatic melanoma and renal cell carcinoma is currently in progress. We recently reported that IL-21 significantly enhanced rituximab mediated clearance of CD20+ lymphoma cell lines both in vitro and in vivo, and that these effects were potentially mediated through IL-21 enhancement of NK cell capacity to effect antibody dependent cellular cytotoxicity (ADCC). Specifically, NK cells treated with IL-21 showed increased cytotoxicity, granzyme B and IFNg production. Current studies aim to further evaluate the mechanisms by which IL-21 enhances ADCC. A number of observations suggest a multi-factorial basis for IL-21 synergy with rituximab. In a xenograft tumor model, SCID mice were injected IV with HS Sultan cells on day 0. Treatment with recombinant murine IL-21 (mIL-21; starting day 1) combined with rituximab (starting day 3) resulted in significantly increased survival (70% vs. 20% on day 100), compared to rituximab alone. In separate studies, the spleens of mice treated with mIL-21 showed increased numbers of activated macrophages and granulocytes. As macrophages and granulocytes can participate in ADCC, IL-21 synergy with rituximab in vivo may be partly dependent on its activation of these cell types. We have also evaluated whether direct effects of IL-21 on lymphoma cells contribute to enhancement of rituximab efficacy. The xenogeneic B lymphoma models in which IL-21 plus rituximab exhibited enhanced survival are highly aggressive and these models were not shown to respond to treatment with mIL-21 alone. In vitro studies were performed to determine if IL-21 could potentiate the growth inhibitory and pro-apoptotic effects of rituximab. In the absence of effector cells synergistic interaction was not observed. In addition, we tested the ability of IL-21 to enhance cytotoxicity when combined with antibodies targeting non-hematopoietic tumor cells (e.g. trastuzumab). Human NK cells treated with IL-21 displayed significantly increased cytotoxicity in ADCC assays using trastuzumab to target breast cancer cells expressing varying levels of HER-2 antigen. In summary, the current evidence suggests that IL-21 can enhance antibody-mediated tumor cell lysis through activation of multiple effectors of ADCC. Thus IL-21 may prove to be broadly applicable to monoclonal antibody therapy of cancer.

Stroma-Free Ex Vivo Expanded, CD34+ Cord Blood-Derived NK Cells Retain Lytic Activity After Long-Term Engraftment in NSGS Mice

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 580-580
Author(s):  
Mark Wunderlich ◽  
Mahesh Shrestha ◽  
Lin Kang ◽  
Eric Law ◽  
Vladimir Jankovic ◽  
...  
Keyword(s):  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
Employment Equity ◽  
Cell Product ◽  
Equity Ownership ◽  
Cellular Therapeutics

Abstract Abstract 580 Generating a large number of pure, functional immune cells that can be used in human patients has been a major challenge for NK cell-based immunotherapy. We have successfully established a cultivation method to generate human NK cells from CD34+ cells isolated from donor-matched cord blood and human placental derived stem cells, which were obtained from full-term human placenta. This cultivation method is feeder-free, based on progenitor expansion followed by NK differentiation supported by cytokines including thrombopoietin, stem cell factor, Flt3 ligand, IL-7, IL-15 and IL-2. A graded progression from CD34+ hematopoietic progenitor cells (HSC) to committed NK progenitor cells ultimately results in ∼90% CD3-CD56+ phenotype and is associated with an average 10,000-fold expansion achieved over 35 days. The resulting cells are CD16- and express low level of KIRs, indicating an immature NK cell phenotype, but show active in vitro cytotoxicity against a broad range of tumor cell line targets. The in vivo persistence, maturation and functional activity of HSC-derived NK cells was assessed in NSG mice engineered to express the human cytokines SCF, GM-CSF and IL-3 (NSGS mice). Human IL-2 or IL-15 was injected intraperitoneally three times per week to test the effect of cytokine supplementation on the in vivo transferred NK cells. The presence and detailed immunophenotype of NK cells was assessed in peripheral blood (PB), bone marrow (BM), spleen and liver samples at 7-day intervals up to 28 days post-transfer. Without cytokine supplementation, very few NK cells were detectable at any time-point. Administration of IL-2 resulted in a detectable but modest enhancement of human NK cell persistence. The effect of IL-15 supplementation was significantly greater, leading to the robust persistence of transferred NK cells in circulation, and likely specific homing and expansion in the liver of recipient mice. The discrete response to IL-15 versus IL-2, as well as the preferential accumulation in the liver have not been previously described following adoptive transfer of mature NK cells, and may be unique for the HSC-derived immature NK cell product. Following the in vivo transfer, a significant fraction of human CD56+ cells expressed CD16 and KIRs indicating full physiologic NK differentiation, which appears to be a unique potential of HSC-derived cells. Consistent with this, human CD56+ cells isolated ex vivo efficiently killed K562 targets in in vitro cytotoxicity assays. In contrast to PB, spleen and liver, BM contained a substantial portion of human cells that were CD56/CD16 double negative (DN) but positive for CD244 and CD117, indicating a residual progenitor function in the CD56- fraction of the CD34+ derived cell product. The BM engrafting population was higher in NK cultures at earlier stages of expansion, but was preserved in the day 35- cultured product. The frequency of these cells in the BM increased over time, and showed continued cycling based on in vivo BrdU labeling 28 days post-transfer, suggesting a significant progenitor potential in vivo. Interestingly, DN cells isolated from BM could be efficiently differentiated ex vivo to mature CD56+CD16+ NK cells with in vitro cytotoxic activity against K562. We speculate that under the optimal in vivo conditions these BM engrafting cells may provide a progenitor population to produce a mature NK cell pool in humans, and therefore could contribute to the therapeutic potential of the HSC-derived NK cell product. The in vivo activity of HSC-derived NK cells was further explored using a genetically engineered human AML xenograft model of minimal residual disease (MRD) and initial data indicates significant suppression of AML relapse in animals receiving NK cells following chemotherapy. Collectively, our data demonstrate the utility of humanized mice and in vivo xenograft models in characterizing the biodistribution, persistence, differentiation and functional assessment of human HSC-derived cell therapy products, and characterize the potential of HSC-derived NK cells to be developed as an effective off-the-shelf product for use in adoptive cell therapy approaches in AML. Disclosures: Wunderlich: Celgene Cellular Therapeutics: Research Funding. Shrestha:C: Research Funding. Kang:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Law:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Jankovic:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Zhang:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Herzberg:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Abbot:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Hariri:Celgene Cellular Therapeutics: Employment, Equity Ownership, Patents & Royalties. Mulloy:Celgene Cellular Therapeutics: Research Funding.

scholarly journals Engineered Interleukin-15 Autocrine Signaling Invigorates Anti-CD123 CAR-NK Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2806-2806
Author(s):  
Ilias Christodoulou ◽  
Michael Koldobskiy ◽  
Won Jin Ho ◽  
Andrew Marple ◽  
Wesley J. Ravich ◽  
...  
Keyword(s):  
Nk Cells ◽  
Peripheral Blood ◽  
Research Funding ◽  
Nk Cell ◽  
Xenograft Model ◽  
Blood Analysis ◽  
Target Cells ◽  
Interleukin 15 ◽  
Peripheral Blood Analysis

Abstract Introduction : Acute Myeloid Leukemia (AML) is an aggressive neoplastic disorder with poor outcomes in children and adults. NK cell adoptive transfer is an anti-cancer immunotherapy that has promise for AML treatment. We aimed to improve NK cell anti-tumor efficacy with expression of a Chimeric Antigen Receptor (CAR) on the cell surface. Our CAR consists of an extracellular single-chain variable fragment targeting the AML-associated antigen CD123 (IL3Rα) and intracellular domains derived from 2B4 and TCRζ. We sought to improve the persistence and long-term functionality of our CAR-NKs by introducing transgenic interleukin-15 (IL15). Methods: CD3-depleted PBMCs were first activated with lethally irradiated feeder cells, then transduced with transiently produced replication incompetent γ-retrovirus (αCD123.2B4.ζ, αCD123.2B4.ζ-IRES-sIL15, sIL15-IRES-mOrange) on day 4 of culture. CAR expression was measured on day 8 using FACS. Secretion of IL15 was verified with ELISA. Cytotoxicity was measured using ffLuc expressing target cells and bioluminescence (BL) measurement. In serial stimulation assays, target cells were repleted daily to maintain a 1:1 effector:target ratio. Immunophenotype and cell counts were assessed by FACS. Transcriptomic analysis (RNAseq) was performed on RNA derived from NK cells purified on D10. Xenograft modeling was performed using NSG mice engrafted with MV-4-11.ffLuc or MOLM-13.ffLuc AML cell lines. Mice were treated with NK cells on D4 or D4-7-10. Untreated mice served as controls. Tumor growth was serially tracked in vivo using BL imaging. NK cell persistence and expansion were measured in peripheral blood. Results: The 2B4.ζ CAR was well expressed on the surface of transduced NK cells (median transduction efficiency 95%, range 85-97%, n=3). 2B4.ζ CAR-NK treatment prolonged survival of AML engrafted mice when compared to treatment with unmodified NKs (median survival: 63 vs 55 days; n=8 mice; p=0.014). Serial peripheral blood analysis revealed a steady decline in circulating NK cells, which were undetectable in all cohorts within 21 days. NK cells were then engineered for constitutive secretion of IL15, with and without CAR expression. 2B4.ζ/sIL15 CAR-NKs had the most potent 24h-cytotoxicity against CD123+ targets (Fig. 1). After a 10-day chronic stimulation with MV-4-11, 2B4.ζ/sIL15- and sIL15-NKs expanded (x1.2 and x5.9 respectively), while NK cells without sIL15 decreased in number. In this assay, only 2B4.ζ/sIL15 CAR-NKs exhibited sustained tumor killing. Transcriptomic analysis after 10 days of serial stimulation showed sample clustering dependent on IL15 secretion. Differential gene expression analysis (DESeq2) identified upregulation of genes associated with cell cycle progression, apoptosis regulation, chemokine signaling, and NK cell mediated cytotoxicity in NK cells secreting IL15 compared to those without. In multiparameter flow cytometric analysis, 2B4.ζ/sIL15 CAR-NKs had a higher percentage of NK cells populating clusters defined by higher surface expression of NK cell activating receptors (NKp30, NKG2D, LFA-1) compared to 2B4.ζ and unmodified NK cells. In our MV-4-11 xenograft model, NKs armed with secreted IL15 expanded in vivo and had improved persistence. A single dose (D4) of 2B4.ζ/sIL15 CAR-NKs demonstrated an initial antitumor response, equivalent to that seen following 3 doses (D4-7-10) of 2B4.ζ CAR-NKs. However, mice treated with IL15-secreting NKs had short survival (Fig. 2). Compared to control mice, peripheral blood analysis showed increasing systemic hIL15 and higher levels of hTNFα. In our more aggressive MOLM-13 xenograft model, both single dose 2B4.ζ/sIL15 CAR-NK and multiple dose 2B4.ζ CAR-NK treatment prolonged survival compared to treatment with unmodified NKs. (27 and 26 vs 20 days; n=5 mice; p<0.01; Fig. 2). Conclusion: 2B4.ζ CAR-NKs have limited antitumor efficacy and short persistence in vivo. NK cells armored with secreted IL15 have enhanced anti-AML cytotoxicity and in vitro persistence. Introduction of IL15 secretion confers a distinctly activated phenotype that is maintained during chronic antigen stimulation. Constitutive local IL15 secretion improves in vivo NK cell persistence but may cause lethal toxicity when employed against AML. These results warrant further study and should impact the development of CAR-NK clinical products for patients with AML. Figure 1 Figure 1. Disclosures Ho: Rodeo Therapeutics/Amgen: Patents & Royalties; Exelixis: Consultancy; Sanofi: Research Funding. Bonifant: Kiadis Pharma: Research Funding; BMS: Research Funding; Merck, Sharpe, Dohme: Research Funding.

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.

The JAK Inhibitor Ruxolitinib Substantially Affects NK Cells in MPN Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3169-3169
Author(s):  
Kathrin Schönberg ◽  
Janna Rudolph ◽  
Maria Vonnahme ◽  
Isabelle Cornez ◽  
Sowmya Parampalli Yajnanarayana ◽  
...  
Keyword(s):  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Receptor Expression ◽  
Target Cells ◽  
Jak Inhibitor ◽  
Advisory Committees ◽  
Nk Cell Differentiation

Abstract Introduction: Ruxolitinib (INCB018424) is the first JAK inhibitor approved for treatment of myelofibrosis (MF). Ruxolitinib-induced reduction of splenomegaly and symptoms control is linked to a substantial suppression of MF-associated circulating pro-inflammatory and pro-angiogenic cytokines. However, an increased rate of infections in ruxolitinib-exposed patients with MF was recently described. Natural killer (NK) cells are innate immune effector cells eliminating malignant or virus-infected cells. Thus, the aim of this project was to define in more detail the impact of JAK inhibition on NK cell biology both in vitro and in vivo. Methods: 28 patients with myeloproliferative neoplasms (MPN) with or without ruxolitinib therapy and 12 healthy donors were analyzed for NK cell frequency, NK receptor expression and function. Phenotypic and functional NK cell markers (e.g. CD11b, CD27, KIR, NKG2A, NKG2D, NKp46, CD16, granzyme B, and perforin) were analyzed by FACS. NK cell function was evaluated by classical killing assays upon stimulation with MHC class I-deficient target cells K562. Finally, a set of additional in vitro experiments (e.g. analysis of lytic synapse formation by FACS and confocal microscopy) were performed to define in more detail the characteristics and potential mechanisms of ruxolitinib-induced NK cell dysfunction. Results: In addition to our recent finding that ruxolitinib induces NK cell dysfunction in vitro (e.g. reduced killing, degranulation and IFN-γ production), we here demonstrate that NK cell proliferation and cytokine-induced receptor expression as well as cytokine signalling are drastically impaired by ruxolitinib. Interestingly, reduced killing is at least in part due to a reduced capacity to form a mature lytic synapse with target cells. The significance of the in vitrofindings is underscored by a dramatically reduced proportion and absolute number of NK cells in ruxolitinib-treated MPN patients when compared to treatment-naïve patients or to healthy controls (mean percentage of NK cell frequency: ruxolitinib-naïve MPN patients 12.63% ±1.81; healthy donors 13.51% ±1.44; ruxolitinib-treated patients 5.47% ±1.27). A systematic analysis of NK cell receptor expression revealed that the reduction of NK cells in ruxolitinib-exposed individuals is most likely due to an impaired NK cell differentiation and maturation process, as reflected by a significantly increased ratio of immature to mature NK cells. Finally, the endogenous functional NK cell defect in MPN is further aggravated by intake of the JAK inhibitor ruxolitinib. Conclusion: We here provide compelling in vitro and in vivo evidence that inhibition of the JAK/STAT-pathway by ruxolitinib exerts substantial effects on the NK cell compartment in MPN patients due to the inhibition of NK cell differentiation and NK cell key functions. Our data may help to better understand the increased rate of severe infections and complement recent reports on ruxolitinib-induced immune dysfunction. Disclosures Koschmieder: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Travel, Accomodation, Expenses Other. Brümmendorf:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Wolf:Novartis: Consultancy, Honoraria, Research Funding, Travel and Accommodation Other.

scholarly journals Eomes and T-Bet Expression Are Required By Mature Primary Human NK Cells for Anti-Leukemia Responses In Vivo

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 194-194
Author(s):  
Pamela Wong ◽  
Carly C. Neal ◽  
Lily Chang ◽  
Julia A Wagner ◽  
Melissa M. Berrien-Elliott ◽  
...  
Keyword(s):  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Ex Vivo ◽  
T Box ◽  
Nsg Mice ◽  
Healthy Donors ◽  
And Function

Abstract Natural Killer (NK) cells are innate lymphoid cells that respond to hematologic cancers via cytotoxicity (perforin/granzyme and death receptors) and cytokine/chemokine production, yet the molecular determinants underlying their proliferation, function, and persistence are poorly understood. There are promising reports of pre-clinical and clinical NK cell responses to leukemia and lymphoma, which represent a nascent cellular therapy for these blood cancers. The T-box transcription factors (TFs) Eomes and T-bet are expressed by NK cells throughout their lifespan, and are required for development as evidenced by NK cell loss in Eomes and T-bet deficient mice. However, the roles of these TFs in mature human NK cell molecular programs and functions remain unclear. We hypothesized Eomes and T-bet, which are the only T-box TFs expressed in NK cells, are critical regulators of NK cell homeostasis and functionality, and are necessary for proper mature NK cell responses. To address this, we utilized the CRISPR-Cas9 system to genetically delete both Eomes and T-bet in primary human NK cells isolated from healthy donors, and investigated their role beyond guiding NK cell development, specifically in the anti-leukemia response. Gene-editing of primary human NK cells has been technically challenging, thus most reports that modified NK cells were performed with cell lines, in vitro-differentiated, or highly expanded NK cells that likely do not reflect primary human NK cell biology. Here, we introduced Cas9 mRNA and sgRNA targeting T-bet and Eomes by electroporation into unexpanded primary human NK cells isolated from healthy donors using the MaxCyte GT system. We observed highly efficient reductions of Eomes and T-bet protein expression, quantified by flow cytometry (p &lt; 0.0001, Fig A-B) without viability differences between control (sgRNA targeting TRAC, an unexpressed locus in NK cells), and Eomes/T-bet double CRISPR-edited (DKO) cells after one week in vitro. To study Eomes and T-bet in NK cell anti-leukemia response, control or DKO primary human NK cells were engrafted into NSG mice, supported with human IL-15, and challenged with K562 leukemia cells. Utilizing bioluminescent imaging to visualize leukemia burden, we observed that NK cells lacking both TFs were unable to suppress leukemia growth in vivo. To understand the mechanism responsible for impaired leukemia control, we investigated in vivo persistence and proliferation, cytotoxic effector molecule expression, as well as ex vivo degranulation and cytokine production of DKO NK cells compared to control NK cells. DKO or control human NK cells were transferred into NSG mice and supported with human IL-15. After 2-3 weeks, significantly fewer (&lt;30%) DKO NK cells persisted compared to control NK cells: spleen (5-fold decrease, control 240e3±65e3 vs DKO 47e3±15e3 NK cells, p&lt;0.01, Figure C), blood (6-fold decrease, p&lt;0.01), and liver (4-fold decrease, p&lt;0.05). Using intracellular flow cytometry, double T-bet/Eomes CRISPR-edited NK cells that lacked both Eomes and T-bet protein after in vivo transfer were identified. A proliferative defect was evident in flow-gated DKO (62±6% undivided), compared to unedited (WT) NK cells (4±2% undivided) assessed by CellTrace Violet dilution (Figure D). In addition, there were marked reductions in granzyme B and perforin protein (p&lt;0.001) in flow-gated DKO NK cells compared to controls. To assess DKO NK cell functional capacity, we performed an ex vivo functional assay on NK cells from spleens of the NSG mice as effectors, and K562 targets or IL-12/15/18 stimulation for 6 hours. Degranulation to K562 targets was impaired (p&lt;0.05), and IFN-γ production was reduced (p&lt;0.0001) after cytokine stimulation in flow-gated DKO NK cells (Figure E). Thus, CRISPR-editing of unexpanded, primary human NK cells revealed that Eomes and T-bet are required by mature human NK cells for their function and homeostasis, distinct from their role in development. This is translationally relevant, as defects in proliferation and function of human DKO NK cells manifested markedly reduced response against human leukemia cells in vivo in xenografts. These findings expand our understanding of key molecular regulators of mature NK cell homeostasis and function, with the potential to provide new avenues to enhance NK cell therapy. Figure 1 Figure 1. Disclosures Berrien-Elliott: Wugen: Consultancy, Patents & Royalties: 017001-PRO1, Research Funding. Foltz-Stringfellow: Kiadis: Patents & Royalties: TGFbeta expanded NK cells; EMD Millipore: Other: canine antibody licensing fees. Fehniger: HCW Biologics: Research Funding; Compass Therapeutics: Research Funding; Affimed: Research Funding; ImmunityBio: Research Funding; Wugen: Consultancy, Current equity holder in publicly-traded company, Patents & Royalties: related to memory like NK cells, Research Funding; Kiadis: Other; OrcaBio: Other; Indapta: Other.

Augmentation of antitumor effects by NK cell inhibitory receptor blockade in vitro and in vivo

Blood ◽  
2001 ◽  
Vol 97 (10) ◽  
pp. 3132-3137 ◽  
Author(s):  
Crystal Y. Koh ◽  
Bruce R. Blazar ◽  
Thaddeus George ◽  
Lisbeth A. Welniak ◽  
Christian M. Capitini ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Nk Cells ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Nk Cell ◽  
Class I ◽  
Inhibitory Receptors ◽  
Antitumor Effects

Abstract Subsets of natural killer (NK) cells are characterized by the expression of inhibitory and/or stimulatory receptors specific for major histocompatibility complex (MHC) class I determinants. In mice, these include the Ly49 family of molecules. One mechanism by which tumor cells may evade NK cell killing is by expressing the appropriate MHC class I and binding inhibitory Ly49 receptors. Therefore, the question of whether blocking the interaction between the Ly49 inhibitory receptors on NK and MHC class I cells on tumor cells augments antitumor activity was investigated. Blockade of Ly49C and I inhibitory receptors using F(ab′)2 fragments of the 5E6 monoclonal antibody (mAb) resulted in increased cytotoxicity against syngeneic tumors and decreased tumor cell growth in vitro. The effect of 5E6 F(ab′)2 was specific for the MHC of the tumor, as the use of F(ab′)2 of the mAb against Ly49G2 failed to increase NK activity. Treatment of leukemia-bearing mice with 5E6 F(ab′)2 fragments or adoptive transfer of NK cells treated ex vivo with the F(ab′)2 resulted in significant increases in survival. These results demonstrate that blockade of NK inhibitory receptors enhances antitumor activity both in vitro and in vivo, suggesting that NK inhibitory receptors can be responsible for diminishing antitumor responses. Therefore, strategies to block inhibitory receptors may be of potential use in increasing the efficacy of immunotherapy.

scholarly journals Sustained effector function of IL-12/15/18–preactivated NK cells against established tumors

2012 ◽  
Vol 209 (13) ◽  
pp. 2351-2365 ◽  
Author(s):  
Jing Ni ◽  
Matthias Miller ◽  
Ana Stojanovic ◽  
Natalio Garbi ◽  
Adelheid Cerwenka
Keyword(s):  
T Cells ◽  
Antitumor Activity ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Rational Design ◽  
Nk Cell ◽  
Killer Cell ◽  
Effector Function

Natural killer cell (NK cell)–based immunotherapy of cancer is hampered by the transient effector function of NK cells. Recently, mouse IL-12/15/18–preactivated NK cells were shown to persist with sustained effector function in vivo. Our study investigated the antitumor activity of such NK cells. A single injection of syngeneic IL-12/15/18–preactivated NK cells, but neither naive nor IL-15– or IL-2–pretreated NK cells, combined with irradiation substantially reduced growth of established mouse tumors. Radiation therapy (RT) was essential for the antitumor activity of transferred NK cells. IL-12/15/18–preactivated NK cells expressed high levels of IL-2Rα (CD25), and their rapid in vivo proliferation depended on IL-2 produced by CD4+ T cells. IL-12/15/18–preactivated NK cells accumulated in the tumor tissue and persisted at high cell numbers with potent effector function that required the presence of CD4+ T cells. RT greatly increased numbers and function of transferred NK cells. Human IL-12/15/18–preactivated NK cells also displayed sustained effector function in vitro. Our study provides a better understanding for the rational design of immunotherapies of cancer that incorporate NK cells. Moreover, our results reveal an essential role of CD4+ T cell help for sustained antitumor activity by NK cells linking adaptive and innate immunity.

Sign in / Sign up

Export Citation Format

Share Document