Immunostimulatory Properties of the Human Ortholog of the GMCSF/IL2 Fusion Protein for Cell Based Therapy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4894-4894
Author(s):  
Claudia Penafuerte Graduate ◽  
Jacques Galipeau
Keyword(s):  
Fusion Protein ◽  
Nk Cells ◽  
Cell Expansion ◽  
Cell Activation ◽  
Nk Cell ◽  
Ex Vivo ◽  
Potential Candidate ◽  
Activation Markers ◽  
Cell Based Therapy

Abstract NK cells constitute a potential candidate for cancer cell therapy because they express a diverse array of inhibitory and activating receptors, which recognize and kill infected or tumor cells without prior immune sensitization. However, autologous NK cell mediated adoptive immunotherapy is restricted due to insufficient cytolytic activity of NK cells from patient with aggressive malignancies. In contrast, the infusion of alloreactive NK cells has shown more successful outcomes in the treatment of cancer, but this approach also presents difficulties such as the high doses of cytokines required to induce NK cell expansion ex vivo, which may also sensitize NK cells to apoptosis. Therefore, a critical issue for NK cell based therapy is the use of appropriate growth factors or cytokines that promote NK cell expansion and activation. We have previously shown that a murine GM-CSF/IL-2 fusion protein (aka GIFT2) displays novel antitumor properties in vivo compared to both cytokines in combination regarding tumor site recruitment of macrophages and significant functional NK cell infiltration [Stagg et al., Cancer Research (December 2004)]. In the present work, we found that human GIFT2 will lead to a substantial two fold proliferation of human blood-derived NK cells which is significantly (p<0.05) superior to either IL2 or GMCSF single cytokine treatment or both cytokines combined at equimolar concentration. In addition, we observed that GIFT2 leads to robust expression of NK-cell activation markers CD69 and CD107a. In conclusion, the human GIFT2 fusokine is a novel and potent tool for ex vivo expansion of activated NK cells which may be of use in cell-based immunotherapy of cancer.

Therapeutic applications: natural killer cells in the clinic

Hematology ◽  
2013 ◽  
Vol 2013 (1) ◽  
pp. 247-253 ◽  
Author(s):  
Jeffrey S. Miller
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Adoptive Transfer ◽  
Cell Activation ◽  
Tumor Antigens ◽  
Nk Cell ◽  
Ex Vivo ◽  
T Cell Stimulation ◽  
Refractory Acute Myeloid Leukemia

Abstract Natural killer (NK) cells recognize targets stressed by malignant transformation or infection (particularly CMV). We now know that NK cells can be long-lived and remember past exposures. They become educated by interaction with MHC class I molecules to gain potent function to kill targets and produce cytokines. In the clinical setting, haploidentical NK cells can be transferred adoptively to treat cancer. Persistence and in vivo expansion of NK cells depends on lymphodepleting chemotherapy to make space for the release of endogenous IL-15. In vivo expansion is also enhanced by cytokine administration. IL-2 has been used at low doses to stimulate NK cells in vivo, but has the down side of stimulating CD25hi regulatory T cells. IL-15 is now being tested and has the advantage of avoiding inhibitory regulatory T cell stimulation. In refractory acute myeloid leukemia, leukemia clearance is correlated with the persistence and in vivo expansion of NK cells after adoptive transfer. Limitations to NK cell therapy include poor in vivo survival and lack of specificity. Monoclonal antibodies and bispecific or trispecific killer engagers to target CD16 on NK cells to enhance recognition of various tumor antigens and ADAM17 inhibition to prevent CD16 shedding after NK cell activation should promote enhanced killing of cancer with specificity. Future strategies to exploit favorable donor immunogenetics or to expand NK cells ex vivo from blood, progenitors, or pluripotent progenitors may overcome immune barriers of adoptive transfer and comparative clinical trials will be needed to test these approaches.

scholarly journals Daratumumab induces mechanisms of immune activation through CD38+ NK cell targeting

2019 ◽  
Author(s):  
Domenico Viola ◽  
Ada Dona ◽  
Enrico Caserta ◽  
Estelle Troadec ◽  
Emine Gulsen Gunes ◽  
...  
Keyword(s):  
Nk Cells ◽  
Immune Modulation ◽  
Cell Activation ◽  
Plasma Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Cell Targeting ◽  
Effector Cells ◽  
Cd38 Expression

AbstractDaratumumab (Dara), a multiple myeloma (MM) therapy, is an antibody against the surface receptor CD38, which is expressed not only on plasma cells but also on NK cells and monocytes. Correlative data have highlighted the immune-modulatory role of Dara, despite the paradoxical observation that Dara regimens decrease the frequency of total NK cells. Here we show that, despite this reduction, NK cells play a pivotal role in Dara anti-MM activity. CD38 on NK cells is essential for Dara-induced immune modulation, and its expression is restricted to NK cells with effector function. We also show that Dara induces rapid CD38 protein degradation associated with NK cell activation, leaving an activated CD38-negative NK cell population. CD38+ NK cell targeting by Dara also promotes monocyte activation, inducing an increase in T cell costimulatory molecules (CD86/80) and enhancing anti-MM phagocytosis activity ex-vivo and in vivo. In support of Dara’s immunomodulating role, we show that MM patients that discontinued Dara therapy because of progression maintain targetable unmutated surface CD38 expression on their MM cells, but retain effector cells with impaired cellular immune function. In summary, we report that CD38+ NK cells may be an unexplored therapeutic target for priming the immune system of MM patients.

A Novel Triple Umbilical Cord Blood Transplant (UCBT) Strategy To Promote NK Cell Immunotherapy (Unit 1) with a Fully Ablative Preparative Regimen Followed by a Double UCBT in Patients with Refractory AML.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3111-3111 ◽  
Author(s):  
Jeffrey S. Miller ◽  
Claudio G. Brunstein ◽  
Sarah Cooley ◽  
Michael R. Verneris ◽  
Angela Panoskaltsis-Mortari ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Ex Vivo ◽  
Treatment Options ◽  
Hematopoietic Stem ◽  
Preparative Regimen ◽  
Neutrophil Engraftment ◽  
Refractory Aml

Abstract Treatment options for refractory AML are usually ineffective. Previously, we tested adoptive transfer of haploidentical peripheral blood (PB) derived NK cells without transplantation and demonstrated correlation between in vivo NK cell expansion and those who achieved a complete remission. This therapy is limited by: the inability to expand NK cells in most patients, prolonged neutropenia in some patients and inconsistent efficacy. UCB, in contrast to adult PB, is rich in NK precursors with CD34+/CD7−, CD34+/CD7+ and CD34−/CD7+ phenotypes. We hypothesized that UCB-derived NK cells may show better in vivo expansion than adult derived NK cells after cytoreduction. Therefore, we tested our triple UCBT strategy in patients with refractory relapsed AML who were <45 years old, without active infection and eligible for myeloablative conditioning. The UCB NK product (unit 1) was CD3 depleted (using a CliniMacs system) and activated with IL-2 (1000U/ml for 16–20 hours). The UCB-derived NK cells (matched at 3 HLA loci and KIR-ligand mismatched when possible) were infused on day -12 after conditioning with cyclophosphamide 120 mg/kg, fludarabine 125 mg/m2 and TBI 1320 cGy on days -19 to -13. Subcutaneous IL-2 (10 MU) was was given on days -12, -10, -8, -6, -4 and -2 to facilitate in vivo NK cell expansion. On day 0, two UCB units (≥4/6 match) were transplanted for hematopoietic rescue and followed by mycophenolate mofetil and cyclosporine for GVHD prophylaxis. Compared to pre-treatment levels, endogenous IL-15 was markedly increased after the preparative regimen at the time of the NK UCB unit. The NK UCB units contained both precursor and mature NK cells. Three product samples were cultured for 28 days in limiting dilution on a murine stromal feeder, demonstrating cloning frequencies of 1:5, 1:9 and 1:12 infused UCB cells giving rise to NK progeny. Two of the 3 patients had partial chimerism derived from the NK product on day -1. Unexpectedly, these same two patients demonstrated prompt neutrophil engraftment on days 3 and 7 after hematopoietic stem cell rescue. In both instances, chimerism was achieved from the NK product. Of the non-NK and non-T cells in the NK UCB units from these 2 patients there were 9.6% and 5.3% CD34+/CD7− cells. In the third patient, the NK UCB unit had only 2% CD34+/CD7− cells and they did not contribute to neutrophil engraftment which occurred on day 36 after UCBT. Of note, 3/3 tolerated the NK infusion without toxicity and were leukemia-free at the time of engraftment. Two remain alive (one died of TRM) with one relapse before day 100. These data suggest UCB NK cells may be administered safely and, despite CD3 depletion and IL-2 activation (ex vivo and in vivo), provide long term engraftment potential that may dominate over unmanipulated UCB infused subsequently. In summary, UCB is a rich source of NK precursors capable of in vivo expansion which are potentially better suited than adult NK cells for use in treatment of patients with refractory AML.

Assessment of antitumor function of NK cells expanded with exosomes from K562.mb21 cells.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 132-132 ◽  
Author(s):  
Jeremiah Oyer ◽  
Sarah B. Gitto ◽  
Sara Khederzadeh ◽  
Kari Shaver ◽  
Dean A. Lee ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Ex Vivo ◽  
K562 Cells ◽  
In Vitro Cytotoxicity ◽  
Feeder Cell ◽  
Nsg Mice

132 Background: NK cells can kill malignant cells to provide innate immunity against tumors. Due to their low abundance in blood, a focus is to expand NK cells ex vivo having enhanced anti-tumor cytotoxicity to be used as a treatment. Our group has pioneered a cell-free method using plasma membrane (PM) particles derived from K562 cells expressing 41BBL and membrane-bound IL-21 (K562.mb21) which were developed for NK cell expansion. Compared to feeder cell based methods for NK cell expansion, PM21-particles improve safety and allow for potential wide-spread dissemination, and also allows direct in vivo use. Exosomes, vesicles naturally secreted by cells, may yet be another novel feeder cell free way for NK cell expansion and may have further advantageous therapeutic dimensions. Methods: EX21-exosomes and PM21-particles were prepared from K562.mb21 cells and characterized by Nanosight and Western blot analysis. CD3-depleted PBMCs were cultured with EX21 for 14 days, NK cell amounts were monitored and media changed every 2-3 days. In vitro cytotoxicity against K562 cells were comparatively assessed for EX21-NK cells and PM21-NK cells. In vivo anti-tumor efficacy of EX21- and PM21-NK cells was assessed in NSG mice implanted ip with SKOV3_luc ovarian tumor cells (1 x 106 cells seeded for 4 days). SKOV3-bearing mice were treated with vehicle, or two doses of EX21-NK cells or PM21-NK cells (1 x 107, in 5 day intervals), and with or without in vivo administration of EX21 (10 µg, 3x/week) or PM21-particles (600 µg, 3x/week). All groups were injected ip with IL-2 (10 KU, 3x/week). Survival analysis was performed with a Log-rank (Mantel-Cox) test. Results: NK cells cultured with EX21 expanded 530 fold (344-710) over 14 days compared to 735 fold (667-802) in presence of PM21-particles. Treatment of SKOV3 engrafted NSG mice with NK cells, expanded with either EX21 or with PM21, allowed significant ( < 0.0001) increase in survival compared to untreated animals (41-44 vs 29 days post treatment). Ip delivery of EX21 to SKOV3 bearing mice had no effect on survival in either untreated control or EX21-NK cell treated groups. Conclusions: EX21 efficiently expands NK cells and EX21-NK cells have equal anti-tumor effect as PM21-NK cells, both in vitro and in vivo.

Preclinical assessment of PM21-particle expanded natural killer cells for ovarian cancer treatment.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 127-127
Author(s):  
Jeremiah Oyer ◽  
Sarah B. Gitto ◽  
Deborah Altomare ◽  
Dean A. Lee ◽  
Alicja Copik
Keyword(s):  
Ovarian Cancer ◽  
Cell Therapy ◽  
Nk Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Ex Vivo ◽  
Feeder Cell ◽  
Nsg Mice ◽  
Nk Cell Therapy

127 Background: Ovarian cancer has high recurrence rate and could benefit from immunotherapy with NK cells. A necessity for NK cell therapy is an efficient way to generate high doses of NK cells. The best method currently used in clinical trials is ex vivo NK cell expansion by co-culture with K562 CML cells, modified to express 41-BBL and membrane bound IL21 (K562.mb21). However feeder cell based methods are limited to ex vivo co-culture, difficult to disseminate, and not allowed in many jurisdictions. To overcome these limitations and to further improve NK cell therapy, we developed a feeder cell free particle based method for NK cell stimulation. These particles (PM21) are nano-scale, made from cell membranes of K562.mb21 cells, and efficiently stimulate NK cell expansion (mean 825 fold in 14 days, range 163–2216, n = 13). Methods: PM21 particles were prepared from K562.mb21 cells with a procedure developed by our group. NK cells were expanded by culturing CD3 depleted PBMCs with PM21 particles or by co-culture with K562.mb21 cells for 14 days as previously described. NSG mice ( ≥ 8 per group) were implanted ip with 1 x 106 SKOV3 ovarian tumor cells, seeded 8 days, and then treated with vehicle or NK cells expanded with PM21 or K562.mb21 cells (two doses of 10 x 106, injected 6 days apart), with or without in vivo administration of PM21 particles (600 µg, 3x weekly), and IL2 (25 KU, 3x weekly), all delivered ip. Survival analysis was performed with log rank (Mantel-Cox) test. Results: Treatment of SKOV3 engrafted NSG mice with NK cells, expanded with K562.mb21 cells or with PM21 particles, allowed significant ( < 0.0001) 10 day increase in survival compared to untreated animals that succumbed on average 21 days after start of treatment. Administration of ip PM21 particles enhanced survival by 5 days (p = 0.056) over no in vivo PM21 groups. Conclusions: NK cells prepared with PM21 particles or with K562.mb21 cells are equivalent in anti-SKOV3 efficacy and in vivo application of PM21 particles provides further benefit. Clinical translation is underway and clinical trials are being planned. PM21 particles can be the next step in development of NK cell therapy for enhancing both efficacy and dissemination of NK cell therapeutics for ovarian cancer.

scholarly journals TLR1/2 Agonist Enhances Reversal of HIV-1 Latency and Promotes NK Cell-Induced Suppression of HIV-1-Infected Autologous CD4 + T Cells

2021 ◽  
Author(s):  
Siqin Duan ◽  
Xinfeng Xu ◽  
Jinshen Wang ◽  
Liwen Huang ◽  
Jie Peng ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Nk Cell ◽  
Ex Vivo ◽  
Shock And Kill ◽  
Infected Cells ◽  
Hiv 1

The complete eradication of human immunodeficiency virus type 1 (HIV-1) is blocked by latent reservoirs in CD4 + T cells and myeloid lineage cells. Toll-like receptors (TLRs) can induce the reversal of HIV-1 latency and trigger the innate immune response. To the best of our knowledge, there is little evidence show the “killing” effect of TLR1/2 agonists but only with a small “shock” potential. To identify a new approach for eradicating the HIV latent reservoir, we evaluated the effectiveness of SMU-Z1, a novel TLR1/2 small molecule agonist, in the “shock and kill” strategy. The results showed that SMU-Z1 can not only enhance latent HIV-1 transcription in ex vivo peripheral blood mononuclear cells (PBMCs) from aviremic HIV-1-infected donors receiving combined antiretroviral therapy (cART) but also in cells of myeloid-monocytic origin in vitro targeting the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Interestingly, activation marker CD69 was significantly upregulated in NK cells, B cells, and monocytes 48 hours after SMU-Z1 treatment. Furthermore, SMU-Z1 was able to activate T cells without global T cell activation, as well as increase NK cell degranulation and interferon-gamma (IFN-γ) production which further block HIV-1-infected CD4 lymphocytes. In summary, the present study found that SMU-Z1 can both enhance HIV-1 transcription and promote NK cell-mediated inhibition of HIV-1-infected autologous CD4 + T cells. These findings indicate that novel TLR1/2 agonist SMU-Z1 is a promising latency-reversing agent (LRA) for eradication of HIV-1 reservoirs. IMPORTANCE Multiple in vivo studies have shown that many LRAs implemented in the “shock and kill” approach could activate viral transcription but could not induce “killing” effectively. Therefore, a dual function LRA is needed for elimination of HIV-1 reservoirs. We previously developed a small molecule TLR1/2 agonist, SMU-Z1, and demonstrated that it could upregulate NK cells and CD8 + T cells with immune adjuvant and anti-tumor properties in vivo . In the present study, SMU-Z1 can activate innate immune cells without global T cell activation, induce production of proinflammatory and antiviral cytokines, and enhance the cytotoxic function of NK cells. We showed that SMU-Z1 displayed dual potential ex vivo in the “shock” of exposure of HIV-1 latently infected cells and in the “kill” of clearance of infected cells, which is critical for effective use in combination with therapeutic vaccines or broadly neutralizing antibody treatments aimed at curing AIDS.

scholarly journals Small Molecule Screening Identifies Rho-Associate Protein Kinase (ROCK) As a Regulator of NK Cell Cytotoxicity Against Cancer

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3607-3607
Author(s):  
Grace Lee ◽  
Sheela Karunanithi ◽  
Zachary Jackson ◽  
David Wald
Keyword(s):  
Cell Therapy ◽  
Cytotoxic Activity ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Akt Activation ◽  
Nk Cell Cytotoxicity ◽  
Rock Inhibition ◽  
Nk Cell Therapy

NK cells are a subset of lymphocytes that directly recognize and lyse tumor cells without the limitation of antigen specific receptor recognition. In addition to behaving as cytotoxic effector cells, NK cells unlike T cells are not thought to elicit graft versus host disease. The combination of these characteristics makes NK cells a powerful tool for adoptive cell therapy. Despite the promise of NK cell therapy, key hurdles in achieving significant clinical efficacy include both generating sufficient numbers of highly tumoricidal NK cells and maintaining the cytotoxic activity of these cells in vivo despite the immunosuppressive tumor microenvironment. Our lab and others have developed several feeder cell line-based expansion modules that robustly stimulate the ex vivo proliferation of NK cells. However, strategies to enhance and sustain the activity of NK cells once administered in vivo are still limited. In order to identify strategies to enhance the cytotoxic activity of NK cells, we developed a high-throughput small molecule screen (Figure 1A) that involved a calcein-based cytotoxicity assay of ex vivo expanded and treated NK cells against ovarian cancer cells (OVCAR-3). 20,000 compounds were screened and the screen was found to be highly robust (Z'&gt;0.59). We identified 29 hits that led to at least a 25% increase in cytotoxicity as compared to DMSO control-treated NK cells. One of the most promising hits was the pan-ROCK inhibitor, Y-27632 that led to an 30% increase in NK killing of the OVCAR-3 cells. We validated that ROCK inhibition leads to enhanced NK cell cytotoxic activity using Y-27632 (Figure 1B) as well as other well-established ROCK inhibitors such as Fasudil using a flow cytometry based killing assay. Y-27632 increased NK cell cytotoxicity in a dose- and time- dependent manner. ROCK inhibition consistently led to ~10-25% increase in NK cell cytotoxic activity directed against a variety of ovarian (Figure 1C) and other solid tumor cell lines (Figure 1D). Interestingly, we found that the NK hyperactivation persists for up to 48hrs after washing off the drug that may enable ex vivo stimulation before NK cell infusion. Our preliminary results showed that ROCK inhibition activates PI3K-dependent Akt activation (Figure 1E). We hypothesize that ROCK inhibition restores Akt activation which may be critical for NK cell activating receptor pathways and our current investigations will test these hypotheses. ROCK inhibitors, such as Y-27632 and Fasudil have been utilized in both preclinical and clinical studies for a variety of diseases such as atherosclerosis, neurodegenerative disorders, and ocular diseases. However, the consequences of ROCK inhibition in NK cells has not been thoroughly investigated. Our work shows a promising novel strategy to significantly enhance NK cell therapy against cancer that has high translational potential. Disclosures No relevant conflicts of interest to declare.

scholarly journals Combining Immunocytokine and Ex Vivo Activated NK Cells as a Platform for Enhancing Graft-Versus-Tumor Effects Against GD2+ Murine Neuroblastoma

2021 ◽  
Vol 12 ◽  
Author(s):  
Paul D. Bates ◽  
Alexander L. Rakhmilevich ◽  
Monica M. Cho ◽  
Myriam N. Bouchlaka ◽  
Seema L. Rao ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Cell Transplant ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Tnf Α

Management for high-risk neuroblastoma (NBL) has included autologous hematopoietic stem cell transplant (HSCT) and anti-GD2 immunotherapy, but survival remains around 50%. The aim of this study was to determine if allogeneic HSCT could serve as a platform for inducing a graft-versus-tumor (GVT) effect against NBL with combination immunocytokine and NK cells in a murine model. Lethally irradiated C57BL/6 (B6) x A/J recipients were transplanted with B6 bone marrow on Day +0. On day +10, allogeneic HSCT recipients were challenged with NXS2, a GD2+ NBL. On days +14-16, mice were treated with the anti-GD2 immunocytokine hu14.18-IL2. In select groups, hu14.18-IL2 was combined with infusions of B6 NK cells activated with IL-15/IL-15Rα and CD137L ex vivo. Allogeneic HSCT alone was insufficient to control NXS2 tumor growth, but the addition of hu14.18-IL2 controlled tumor growth and improved survival. Adoptive transfer of ex vivo CD137L/IL-15/IL-15Rα activated NK cells with or without hu14.18-IL2 exacerbated lethality. CD137L/IL-15/IL-15Rα activated NK cells showed enhanced cytotoxicity and produced high levels of TNF-α in vitro, but induced cytokine release syndrome (CRS) in vivo. Infusing Perforin-/- CD137L/IL-15/IL-15Rα activated NK cells had no impact on GVT, whereas TNF-α-/- CD137L/IL-15/IL-15Rα activated NK cells improved GVT by decreasing peripheral effector cell subsets while preserving tumor-infiltrating lymphocytes. Depletion of Ly49H+ NK cells also improved GVT. Using allogeneic HSCT for NBL is a viable platform for immunocytokines and ex vivo activated NK cell infusions, but must be balanced with induction of CRS. Regulation of TNFα or activating NK subsets may be needed to improve GVT effects.

scholarly journals The Advantages and Challenges of Anticancer Dendritic Cell Vaccines and NK Cells in Adoptive Cell Immunotherapy

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1363
Author(s):  
Elena V. Abakushina ◽  
Liubov I. Popova ◽  
Andrey A. Zamyatnin ◽  
Jens Werner ◽  
Nikolay V. Mikhailovsky ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Nk Cells ◽  
Nk Cell ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Adoptive Cell Therapy ◽  
Immune Effector ◽  
Effector Cells ◽  
Cell Immunotherapy

In the last decade, an impressive advance was achieved in adoptive cell therapy (ACT), which has improved therapeutic potential and significant value in promising cancer treatment for patients. The ACT is based on the cell transfer of dendritic cells (DCs) and/or immune effector cells. DCs are often used as vaccine carriers or antigen-presenting cells (APCs) to prime naive T cells ex vivo or in vivo. Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells are used as major tool effector cells for ACT. Despite the fact that NK cell immunotherapy is highly effective and promising against many cancer types, there are still some limitations, including insignificant infiltration, adverse conditions of the microenvironment, the immunosuppressive cellular populations, and the low cytotoxic activity in solid tumors. To overcome these difficulties, novel methods of NK cell isolation, expansion, and stimulation of cytotoxic activity should be designed. In this review, we discuss the basic characteristics of DC vaccines and NK cells as potential adoptive cell preparations in cancer therapy.

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.

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