Cord Blood-derived Natural Killer Research Articles

Phase II trial of umbilical cord blood-derived natural killer cells for multiple myeloma.

TPS3100Background: Multiple myeloma (MM) is an incurable disease characterized by immune dysregulation and exhaustion, whereby proliferation of malignant plasma cells is not checked by the native i...

Infusion of Ex Vivo Expanded Allogeneic Cord Blood-Derived Natural Killer Cells in Combination with Autologous Stem Cell Transplantation for Multiple Myeloma: Results of a Phase I Study

Background: Multiple myeloma (MM) is an incurable disease thought to be characterized by immune dysregulation and exhaustion, whereby proliferation of malignant plasma cells is not checked by the native immune system. Long term remissions in some patients after allogeneic stem cell transplant (SCT) suggest a graft versus myeloma effect; however the treatment-related toxicity limits the widespread use of this modality. Allogeneic natural killer (NK) cells are active in various hematologic malignancies and may have a role against MM, without concomitant graft versus host disease (GVHD). Umbilical cord blood is a potential source for allogeneic NK cells and ex vivo expanded umbilical cord blood-derived NK (CB-NK) cells demonstrate activity comparable to that of peripheral blood-derived NK cells. We describe here the results of a phase I, first-in-human study of ex vivo expanded allogeneic CB-NK cells in conjunction with high dose chemotherapy and autologous SCT.Methods: Patients with symptomatic MM who were appropriate candidates for high dose chemotherapy and autologous SCT were eligible. CB units with at least 4/6 match at HLA-A, B and DR were chosen for each patient. When possible, CB units with potential NK alloreactivity were prioritized. On day (-19) CB units were thawed and mononuclear cells (MNCs) were isolated by ficoll density gradient centrifugation. MNCs were cultured in a gas permeable bioreactor with irradiated (100 Gy) K562-based aAPCs expressing membrane bound IL-21 "Clone 9.mbIL21" (2:1 feeder cell:MNC ratio) and IL-2 (100 IU/mL). On day 7, cells were CD3-depleted via immunomagnetic depletion and remaining cells were re-stimulated with aAPC feeder cells and cultured for an additional 7 days. NK cell purity was determined after 14 days of culture. Due to pre-clinical data demonstrating synergy between lenalidomide and NK cells, patients received lenalidomide (10 mg orally daily) from days (-8) to day (-2). Melphalan 200 mg/m2 was given intravenously on day (-7). Freshly expanded CB-NK cells were infused on day (-5). Autologous peripheral blood progenitor cells (PBPC) were infused on day (0).Results: 12 patients have been enrolled thus far with 3 patients each on the following CB-NK cell dose levels: 5 e6 NK cells/kg, 1 e7 NK cells/kg, 5 e7 NK cells/kg and 1 e8 NK cells/kg. 11/12 patients had at least 1 high-risk feature of progressed/relapsed disease (n=7), high-risk cytogenetics (n=2) or International Staging System III disease (n=3). Successful NK expansion to target dose was achieved in all patients with median NK purity (CD56+/CD16+/CD3-) of 98.9% (96.8-99.7). Expanded cells demonstrated cytotoxicity against classic K562 and MM cell line targets. There were no infusional toxicities and no occurrence of GVHD. One patient (1 e8 NK cells/kg) failed to engraft due to a poor PBPC graft quality; this patient was rescued with a back-up autologous PBPC graft. There have been no other significant adverse events and no second primary malignancies. 11/12 patients are evaluable beyond day 100. Best response has been 8/12 nCR or better, 2/12 VGPR and 1/12 PR. 4/12 patients have progressed at a median of 330 days. By DNA microsatellite chimerism analysis, donor CB-NK cells were detected in 2 patients at the 1 e7 NK cells/kg dose and all 3 patients in the 1 e8 NK cells/kg dose, for at least 5 days after infusion. By a more sensitive flow cytometric chimerism assay using HLA class I-specific antibodies for donor or recipient, donor CB-NK cells were detected in 3 evaluable patients at doses of 1 e7 NK cells/kg, 5 e7 NK cells/kg and 1 e8 NK cells/kg for at least 12 days after infusion. Further analysis of these cells indicated persistence of an activated phenotype (NKG2D+/NKp30+) in vivo.Conclusion: CB-NK cells can be activated and expanded to clinical scale. This is the first clinical study of CB-NK cells for MM. When infused in the setting of myeloablative chemotherapy, up to 1 e8 allogeneic CB-NK cells/kg are well tolerated with no infusional toxicities or GVHD. These cells can persist for at least 12 days in vivo and demonstrate an active phenotype. Though clinical data are early, responses are encouraging in this high-risk patient population. Further updated data will be presented at the annual meeting. DisclosuresOff Label Use: Lenalidomide with high dose chemotherapy and autologous stem cell transplantation. Kaur:UT MD Anderson Cancer Center: Employment. Orlowski:Millennium Pharmaceuticals: Consultancy, Research Funding; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Genentech: Consultancy; Onyx Pharmaceuticals: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Acetylon: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding; Forma Therapeutics: Consultancy. Cooper:Intrexon: Equity Ownership, Patents & Royalties, Research Funding; ZIOPHARM Oncology: Employment, Equity Ownership, Patents & Royalties, Research Funding. Lee:Cyto-Sen: Equity Ownership; Ziopharm: Equity Ownership; Intrexon: Equity Ownership.

Potent ex vivo expanded, human CD34+ cord blood-derived natural killer cells for cancer immunotherapy

Meeting abstracts Clinical studies suggest that adoptive transfer of allogeneic natural killer (NK) cells represent a promising treatment for patients with hematological malignancies and solid tumors. Celgene Cellular Therapeutics has established a cultivation process to generate human NK cells

NK Cells Kill Myeloma Cells By Increasing ER Stress and Decreasing Autophagy Levels. NKG2D and NKP30 Are Involved In These Processes

Multiple myeloma (MM) plasma cells are equipped with an extensive endoplasmic reticulum (ER) for antibody production. Misfolding of newly synthesized immunoglobulins leads to ER stress and cell death. Plasma cells evade this by enhancing protein degradation through the proteasome pathway and the autophagy machinery. Because of this, MM cells are sensitive to proteasome inhibitors (PIs). However, autophagy induced by PIs and by reactive oxygen species (ROS) can increase drug resistance and lead to eventual relapse.We have previously demonstrated in vitro and in vivo sensitivity of MM cells to cord blood-derived natural killer (NK) cells, and have observed that this effect may involve NKG2D and NKP30.In this study we used confocal microscopy, chromium cytotoxicity assays and flow cytometry and we aimed to determine if there is a unique mechanism of NK cell-mediated cytotoxicity on MM cells involving ER stress, ROS and its dependence on NK cell receptors NKG2D and NKp30.We first demonstrated a difference in NK-mediated killing of MM cells vs K562 cells. As expected inhibition of GranzymeB (GrB) and Caspase3 pathway yielded a 13% reduction in NK-cytotoxicity against K562 cells; however, a 12% increase in killing was seen against ARP1 cells (p<0.001), indicating a GrB-Caspase3 independent mechanism for NK cell cytotoxicity against ARP1 cells. We observed a decrease in ROS levels after NK treatment for both cell lines (p<0.001), but inhibition of GrB and Caspase 3 abrogated the decrease in ROS only for K562 (p<0.001). By confocal microscopy we observed that NKG2D and NKP30 were transferred to tumor cells and entered the endocytic vesicle pathway. These receptors also appeared to play a more relevant role in the killing of MM cells (33%, 49% and 73% in ARP1 vs 4%, 3% and 19% in K562 cells of killing reduction after blocking NKG2D, NKP30 and both together, p<0.001). Regarding ER stress in ARP1 cells, we saw that after NK treatment there was a significant decrease in endocytic vesicle markers (EEA1 and Rab11, p<0.001) indicating a decrease in the transport of properly folded proteins. There was also a decrease in Rab7 and in Lysosomes (indicated by Lyso-Tracker probes) (p<0.001) and a dramatic increase for DNA-damage-inducible transcript 3 (CHOP) expression (p<0.001) indicating a decreased level of misfolded protein degradation and higher ER stress after exposure to NK cells. Blocking NKG2D abrogated the NK effect on ER stress (indicated by CHOP levels) and ROS levels in ARP1 cells. Blocking of NKP30 abrogated the NK effect on protein degradation activity (Rab7 levels), and ROS levels. To confirm that these receptors mediate killing of ARP1 cells by increasing ER stress, we performed cytotoxicity assays blocking these receptors and adding the PI bortezomib. Bortezomib did not improve NK cell killing at baseline in MM cells. However, bortezomib was able to partially reverse the deleterious effect of blocking NKG2D or NKp30 (33% enhanced killing for NKG2D-blocked and 57% for NKP30-blocked). Finally, we observed that NKG2D and NKP30 were also transferred secondarily to neighboring ARP1 from ARP1 cells which had been primarily synapsed to NK cells (p<0.001). In addition, these secondary ARP1 cells demonstrated decreased ROS levels after this contact. In a cytotoxicity assay, those ARP1 cells which had previously synapsed with NK cells demonstrated 7% of killing against new ARP1 cells.In summary, we describe a new mechanism of killing of MM cells by NK cells mediated by increased ER stress, decreased autophagy and dependent on NKG2D and NKP30. Furthermore, this cytotoxicity can be transmitted between MM cells. These findings could lead to new cellular therapeutic strategies for MM treatment. Disclosures:Shah:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Patients' Peripheral Blood as a Possible Source of Donor-Derived NK Cells for Ex Vivo Expansion and Genetic Modification for Post-Transplant Cellular Immunotherapy In Cord Blood Recipients

AbstractAbstract 2094Haploidentical natural killer (NK) cells can induce and consolidate remission in patients with high-risk acute myeloid leukemia (AML) (Rubnitz et al. J Clin Onc 24: 371, 2010). Recently, significantly reduced relapse rates were observed in AML patients who received killer immunoglobulin-like receptor ligand-mismatched cord blood, suggesting effective alloreactivity of cord blood-derived NK cells (Willemze et al. Leukemia 23: 492, 2009). Cord blood transplantation (CBT) is an effective alternative source for allogeneic hematopoietic cell transplantation in both children and adults. However, its therapeutic efficacy for malignant diseases is limited by the lack of available donor effector cells, such as cytotoxic T lymphocytes, lymphokine-activated killer cells, NK-like T cells and NK cells, for treatment of hematological relapse and posttransplant lymphoproliferative disorder and/or for scheduled posttransplant cellular immunotherapy against refractory diseases. We previously reported a method that induces NK cells to proliferate and reliably allows their genetic modification in healthy individuals and leukemia patients in remission receiving maintenance chemotherapy (Imai et al. Blood 106: 376, 2005). To explore the possibility of using patients' peripheral blood as a source for posttransplant NK cell therapy, we used our method to expand donor-derived NK cells from peripheral blood of CBT recipients early after engraftment. We also examined whether NK cells can be rendered cytotoxic against original leukemia blasts by transferring an antigen-specific artificial immunoreceptor gene. This study was approved by an institutional ethical committee. Patients received CBT for consolidation of hematological malignancy (n=7), neuroblastoma (n=1) or resolution of refractory EBV-associated hemophagocytic syndrome (n=1) with myeloablative (n=7) or reduced intensity conditioning (RIC) regimens (n=2). The patients were enrolled in the study after engraftment and peripheral blood was obtained after appropriate written consent was obtained. A chimerism study using short tandem repeat assays showed complete donor chimerism in all patients except one who received RIC-CBT. The peripheral blood was obtained at a median of 92 days post-CBT (range: 46–303 days) and subjected to ex vivo activation and expansion using a previously described protocol with slight modifications. Briefly, peripheral blood was coincubated with modified K562 cells expressing membrane-bound IL-15 and 4-1BB ligand (K562-mb15-41BBL) in the presence of low-dose IL-2 (10 U/mL). Most patients were on maintenance immunosuppressive therapy with calcineurin inhibitors with (n=3) or without (n=6) systemic corticosteroids. After 7 days of culture, a median 11.0-fold expansion (range: 5.3–28.9-fold) was observed in all but one patient who had been administered chemotherapy with Mylotarg for relapsed AML a few days before the blood sampling. The expansion rate in the first week was less efficient in CBT recipients than in healthy individuals (>20-fold), probably because of the immunosuppressants administered. However, an additional 2-week culture in the presence of high-dose IL-2 (1000 U/mL) yielded a median 206-fold expansion (range: 101–1381-fold in 21 days). The expanded NK cells exhibited upregulation of activating receptors including NKG2D, NCRp30 and NCRp44, and vigorous cytotoxicity against K562 cells (86.8–97.7% at an E/T ratio of 1:1). The NK cells were susceptible to retroviral genetic modification with the MSCV-IRES-GFP vector (median GFP-positive cells, 52.7%, n=10). Finally, peripheral NK cells from patients with acute lymphoblastic leukemia were expanded and transduced with the chimeric immunoreceptor gene anti-CD19-BB-ζ. The donor-derived NK cells expressed large amounts of anti-CD19 chimeric receptors on their surface and killed original leukemia blasts that were highly resistant to NK cell lysis (e.g. anti-CD19 vs. non-signaling receptor: 69% vs. 0% at an E/T ratio of 1:1). These results suggest that, in CBT recipients, ex vivo expansion and genetic modification of donor-derived NK cells from the patients' peripheral blood is feasible. Because peripheral blood can be easily and repeatedly obtained, the method described here will allow multiple scheduled infusions. This preliminary study may lead to a novel strategy for posttransplant donor-NK cell therapy in CBT recipients. Disclosures:No relevant conflicts of interest to declare.

Antigen Presenting Cell-Mediated Ex Vivo Expansion of Human Umbilical Cord Blood Cells Yields Log-Scale Expansion of Natural Killer Cells with Anti-Myeloma Activity

AbstractAbstract 2100 Background:Multiple myeloma (MM) is the second most common hematologic malignancy in adults and, to date, is incurable. Allogeneic natural killer (NK) cells are active in various hematologic malignancies and may have a role against MM. Umbilical cord blood is a potential source for allogeneic NK cells and ex vivo expanded umbilical cord blood-derived NK (UCB-NK) cells demonstrate activity comparable to that of peripheral blood-derived NK cells. Here we demonstrate the anti-myeloma activity of UCB-NK cells expanded to clinical grade by a novel technique using artificial antigen presenting feeder cells (“K562 Clone 9” cells) modified to express IL-21 (“K562-cl9-mIL21”). Methods:Cord blood mononuclear cells (CBMCs) were cultured in 10% human serum albumin media with IL-2 (500 IU/ml) and K562-cl9-mIL21 feeder cells (2:1 feeder: CBMC ratio) for 21 days. Thereafter, cells were subjected to CD3-immunomagnetic depletion. CD3-negative cells were then used as effector cells in functional assays. Flow cytometry was used to confirm NK cell purity (C56+/CD3- cells) and a standard chromium-51 assay was performed to determine NK cell cytotoxicity. Targets included K562 cells, MM cell lines RPMI 8226, ARP-1 and U266, autologous non-neoplastic UCB cells (negative control) and bone marrow-derived CD138+ plasma cells from myeloma patients. Results:Expansion of CBMCs with K562-cl9-mIL21 yielded a >2000 fold expansion of NK cells, compared with 47 fold expansion of CD56-selected cells cultured with IL-2 alone (p <0.05). After CD3 depletion, UCB-NK cultures were comprised of 92% CD56+/CD3- cells. K562-cl9-mIL21-expanded UCB-NK cells demonstrated cytotoxicity against the classic NK cell target K562 as well as MM cell lines RPMI 8226, ARP-1 and U266 (Fig 1). In addition, these UCB-NK cells were also active against primary, bone marrow-derived CD138+ plasma cells from myeloma patients, an effect which was augmented by pre-incubation of UCB-NK cells with lenalidomide (Figure 2, NK=UCB-NK cells, NKR=UCB-NK cells+lenalidomide). Conclusions:UCB-NK cells can be expanded ex vivo to clinically relevant doses for allogeneic NK cell therapy via co-culture with K562-cl9-mIL21 feeder cells. Expanded UCB-NK cells are cytotoxic to myeloma cell lines and primary myeloma cells. Further development of UCB-NK cells as an adjunct therapy in stem cell transplantation for myeloma is warranted. [Display omitted] Disclosures:Wang:Celgene: Research Funding; Onyx: Research Funding; Millenium: Research Funding; Novartis: Research Funding.

Improving clinical outcomes using adoptively transferred immune cells from umbilical cord blood

Because of the necessary immunodepletion prior to cord blood transplantation as well as the immaturity of cord blood immune cells, recipients experience a high incidence of viral infection in addition to complications observed after hematopoietic stem cell transplantation, such as relapse and graft-versus-host disease. We describe current immunotherapeutic approaches to treating these complications, including the generation of antigen-specific T cells from cord blood, redirecting cord blood T cells using chimeric antigen receptors, and generating cord blood-derived natural killer cells and regulatory T cells.

Defective Immune Synapse Formation Of Umbilical Cord Blood-Derived Natural Killer Cell S Is Abrogated By Ex Vivo Expansion

Defective Immune Synapse Formation Of Umbilical Cord Blood-Derived Natural Killer Cell S Is Abrogated By Ex Vivo Expansion

Cord Blood NK Cytotoxic Activity Can Be Selelctively Modulated by Accessory.

Introduction The expansion of cord blood (CB) derived natural killer (NK) cells is a promising cell therapy approach. CB NK cell expansion and activation has proven to be feasible and effective. However, the selectivity of NK killing in an allograft setting raises concern. Accessory cells, in particular dendritic cells and mesenchymal stem cells (MSCs), have been shown to interact with and modulate NK cell proliferation and function. We explored the ability of accessory cells to modulate NK activity in the setting of clinically-relevant CB NK expansion protocols.Methods Human MSCs were isolated from normal bone marrow donors. 5 × 106 CD56-selected NK cells or 5 × 107 unselected or CD3-depleted CB mononuclear cells (MNC) (averaging 10% CD56+ NK cells) were layered on top of the MSCs in the presence of 200u/mL IL-2. CB NK cells were tested for cytolytic activity by 51Cr release assay using MSCs and K562 AML cells. IFN-g secretion was detected by Elispot assay.Results Cord blood-derived NK cells activated by exposure to IL-2 efficiently kill allogeneic MSCs in vitro. A 4 hour chromium release assay revealed that CD56-selected CB NK cells lysed 60% of allogeneic MSCs at E:T ratio 10:1. MSC co-culture with CB NK induced IFN-g secretion as determined by IFN-γ Elispot assay. In contrast, unselected or CD3-depleted CB MNCs with equal numbers of CD56+ NK cells were unable to lyse MSCs despite IL-2 activation. This suggests that CB accessory cells can modulate the activation or cytolytic activity of CB-derived NK cells. To address these two possibilities, we tested the ability of these CB cultures to kill a classic NK target, K562 human myeloid leukemia cells. Surprisingly, in all three CB cultures NK efficiently lysed K562 cells, 95% of lysis at 10:1 E:T ratio by chromium release assay suggesting that these accessory cells did not prevent IL-2 activation of NK cells, but selectively-modulated the cytolytic activity. Thus, preserving anti-leukemia killing while protecting non-malignant MSCs.Conclusions Our data provide evidence for selective modulation of cord blood-derived NK cell cytolytic activity by CB accessory cells. Indeed, activation of cord-derived NK cells in the presence on CD3-depleted accessory cells yields NK cells capable of killing K562 target cells but not allogeneic MSCs. Although the underlying mechanism is unknown, this selective modulation of NK cells may be exploited in the clinical expansion of cord blood NK cells.

Expression of an early myelopoietic antigen (CD33) on a subset of human umbilical cord blood-derived natural killer cells

A new subset of natural killer (NK) cells was identified in human umbilical cord blood. This subset of CD56 +/CD3 − NK cells co-expressed the CD33 antigen, which is present on early hematopoietic progenitors confined to the myeloid lineage. The percentage of the CD56 +/CD33 + cells among the CD56 +/CD3 − NK cells was 7.9 ± 6.6% ( n = 27) with a range of 1.4–25.5% and a considerable individual variability. Additionally, the majority of freshly isolated CD56 +/CD33 + cells co-expressed the CD2 and CD7 antigen, a minor proportion co-expressed the CD8 antigen but essentially all of the cells stained negative for CD16 and CD57. Morphological analysis of the CD56 +/CD33 + cells showed the features of large agranular lymphocytes. From some of the samples, the CD56 +/CD33 + NK cells were cultivated and expanded in vitro by incubation of the cells with interleukin 2 (IL-2) for up to 50 days. Morphological analysis of the cultured CD56 +/CD33 + cells showed the features of large granular lymphocytes (LGL). The IL-2-expanded CD56 +/CD33 + NK cells showed only a low cytolytic activity against K562 target cells, whereas most of the NK activity of the expanded cells was contributed by the CD56 +/CD33 − NK cells.