Assessment of PD-1 expression in human resting and activated natural killer cells and murine tumor models.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 36-36
Author(s):  
Sean J. Judge ◽  
Cordelia Dunai ◽  
Ian R. Sturgill ◽  
Kevin M. Stoffel ◽  
William J. Murphy ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Ex Vivo ◽  
Fold Increase ◽  
Wild Type ◽  
Immunodeficient Mice

36 Background: Blockade of the PD-1/PD-L1/2 axis has revolutionized cancer therapy. Although reinvigorated PD-1+ T cells are the main effectors in the response to checkpoint blockade, the contribution of Natural Killer (NK) cells to PD-1/PD-L1 inhibition is under debate. While PD-1 has been identified on NK cells, this appears to be restricted to small populations under limited conditions. We sought to evaluate the extent of PD-1 expression in mouse and human resting and activated NK cells. Methods: Human NK cells were isolated from healthy donor PBMCs and cancer patients. Ex vivo activation and proliferation techniques included recombinant human cytokine and feeder line co-culture. Murine NK cells were isolated from splenocytes, and PBMCs from wild type and immunodeficient mice. We assessed NK cell surface markers and intracellular cytokine by flow cytometry, and gene expression by quantitative RT-PCR. Results: Over 21-days of ex vivo expansion, expression of PD-1 or PD-L1 on human NK cells was < 1% at all time points, while TIGIT+ expression increased to > 85%. Conversely, ConA stimulation of T cells increased PD-1 expression with no change in TIGIT expression. QRT-PCR demonstrated absent PD-1 expression in purified NK cells compared to a 5-fold increase in PD-1 gene expression in ConA stimulated PBMCs. PD-1/PD-L1 was also < 1% in the NK92 cell line and < 2.5% in peripheral CD56+CD3- NK cells from patients with soft tissue sarcoma (STS). NK cells from digested freshly resected STS show variable PD-1 ( < 10%) and minimal PD-L1 ( < 1%) expression with a small, but measurable population of intra-tumoral NK cells (1% of immune cells). In vivo mouse studies showed < 5% PD-1+ NK cells in spleen and tumor of CT26 tumor-bearing mice, while PD-L1+ NK cells increased in frequency from spleen (5-35%) to tumor (40-95%) in both wild type BALB/C and SCID mice. Conclusions: In contrast to prior studies, we did not observe a substantial PD-1+ population on human or murine NK cells after multiple activation strategies compared to T cells. Contrary to its application in T cells, our data suggest that PD-1 is not a useful marker for NK cell exhaustion/dysfunction. PD-L1 on NK cells may represent an important link between NK and T cell immunotherapy.

533 Cross-species immunogenomic analysis identifies pathways of canine natural killer cell response to cytokine therapy, and reveals convergence of activated dog and human natural killer transcriptomes

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A569-A569
Author(s):  
Alicia Gingrich ◽  
Taylor Reiter ◽  
Sean Judge ◽  
Daniel York ◽  
Mio Yanagisawa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clinical Trial ◽  
Phase I ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Ex Vivo ◽  
Phase I Clinical Trial ◽  
Gene Profiles

BackgroundNatural killer (NK) cells are key effectors of the innate immune system, but major differences between human and murine NK cells impede translation. Outbred dogs offer an important link for NK-based cancer immunotherapy studies. We compared gene expression profiles of dog NK signatures in vitro and from a phase I clinical trial of inhaled IL-15, and analyzed dog, mouse and human NK cells using a novel orthologous transcriptome.MethodsWe performed differential gene expression (DGE) using resting healthy donor CD5dim NK populations and following ex vivo activation using recombinant human (rh)IL-15 or co-culture with irradiated feeder cells. Eight dogs with naturally-occurring pulmonary metastases were enrolled on a Phase I clinical trial of inhaled rhIL-15 using a 3+3 cohort design with escalating doses of inhaled rhIL-15. Blood was collected from study dogs before, during, and after therapy. We compared DGE among healthy and cancer-bearing dogs and then across mouse, dog and human NK cells in resting and activated states using ~7000 1:1 orthologous genes.ResultsDGE revealed distinct transcriptional profiles between the ex vivo resting, IL-15 and co-cultured canine NK cells. Among treated patients, hierarchical clustering revealed that in vivo NK cell transcriptional signatures grouped by individual dog, and not amount of time exposed to treatment. PCA showed in vivo profiles of the clinical responders were distinctly separate from the non-responding patients (PC1 38%, PC2 12%). Patient in vivo NK cell transcription profiles most closely resembled those of ex vivo resting NK cells and not IL-15 treated or co-culture activated (PC1 43%, PC2 19%), likely reflecting key differences in activation. In cross-species analysis, PCA showed within-species spatial clustering of resting NK cells. After activation, variance between dog and human NK cells decreased, while variance between human and mouse NK cells increased (PC1 40%, PC2 28%).ConclusionsIn this first transcriptomic sequencing of dog NK cells, we demonstrate distinct gene profiles of ex vivo activated NK cells from healthy donors compared to circulating NK cells from dogs receiving inhaled rhIL-15 on a clinical trial. Baseline in vivo NK cell profiles appear to predict response to therapy more than changes over time. We also show distinct gene profiles of NK cells across the most commonly used mouse, dog, and human NK populations, with convergence of dog and human NK cells after activation. By defining the canine NK cell DGE signatures, these data fill a gap in translational NK studies.Ethics ApprovalThe canine clinical trial study was approved by IACUC and Clinical Trials Review Board (Inhaled IL-15 Immunotherapy for Treatment of Lung Metastases, Protocol #20179).

scholarly journals Potential of the NKG2D/NKG2DL Axis in NK Cell-Mediated Clearance of the HIV-1 Reservoir

2019 ◽  
Vol 20 (18) ◽  
pp. 4490 ◽  
Author(s):  
Maria G. Desimio ◽  
Daniela A. Covino ◽  
Margherita Doria
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Virus Reactivation ◽  
Major Drawback ◽  
Virus Eradication ◽  
Latent Hiv ◽  
Hiv 1

Viral persistency in latently infected CD4+ T cells despite antiretroviral therapy (ART) represents a major drawback in the fight against HIV-1. Efforts to purge latent HIV-1 have been attempted using latency reversing agents (LRAs) that activate expression of the quiescent virus. However, initial trials have shown that immune responses of ART-treated patients are ineffective at clearing LRA-reactivated HIV-1 reservoirs, suggesting that an adjuvant immunotherapy is needed. Here we overview multiple lines of evidence indicating that natural killer (NK) cells have the potential to induce anti-HIV-1 responses relevant for virus eradication. In particular, we focus on the role of the NKG2D activating receptor that crucially enables NK cell-mediated killing of HIV-1-infected cells. We describe recent data indicating that LRAs can synergize with HIV-1 at upregulating ligands for NKG2D (NKG2DLs), hence sensitizing T cells that exit from viral latency for recognition and lysis by NK cells; in addition, we report in vivo and ex vivo data showing the potential benefits and drawbacks that LRAs may have on NKG2D expression and, more in general, on the cytotoxicity of NK cells. Finally, we discuss how the NKG2D/NKG2DLs axis can be exploited for the development of effective HIV-1 eradication strategies combining LRA-induced virus reactivation with recently optimized NK cell-based immunotherapies.

scholarly journals Natural Killer Cell Responses in Hepatocellular Carcinoma: Implications for Novel Immunotherapeutic Approaches

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 926 ◽  
Author(s):  
Stefania Mantovani ◽  
Barbara Oliviero ◽  
Stefania Varchetta ◽  
Dalila Mele ◽  
Mario U. Mondelli
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Immune Escape ◽  
Nk Cell ◽  
Ex Vivo ◽  
Killer Cell ◽  
Current Status ◽  
Tumor Immune Escape

Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disease, particularly when cirrhosis ensues. Current treatment options include surgery, loco-regional procedures and chemotherapy, according to specific clinical practice guidelines. Immunotherapy with check-point inhibitors, aimed at rescuing T-cells from exhaustion, has been applied as second-line therapy with limited and variable success. Natural killer (NK) cells are an essential component of innate immunity against cancer and changes in phenotype and function have been described in patients with HCC, who also show perturbations of NK activating receptor/ligand axes. Here we discuss the current status of NK cell treatment of HCC on the basis of existing evidence and ongoing clinical trials on adoptive transfer of autologous or allogeneic NK cells ex vivo or after activation with cytokines such as IL-15 and use of antibodies to target cell-expressed molecules to promote antibody-dependent cellular cytotoxicity (ADCC). To this end, bi-, tri- and tetra-specific killer cell engagers are being devised to improve NK cell recognition of tumor cells, circumventing tumor immune escape and efficiently targeting NK cells to tumors. Moreover, the exciting technique of chimeric antigen receptor (CAR)-engineered NK cells offers unique opportunities to create CAR-NK with multiple specificities along the experience gained with CAR-T cells with potentially less adverse effects.

IL-2 Therapy Promotes the Expansion of Human CD4+CD25+ Regulatory T Cells and Selectively Upregulates the Expression of FOXP3 in T Cells In Vivo.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1257-1257
Author(s):  
Emmanuel Zorn ◽  
Erik A. Nelson ◽  
Mehrdad Mohseni ◽  
Despina Litsa ◽  
Haesook Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Regulatory T Cells ◽  
Nk Cells ◽  
Quantitative Pcr ◽  
Peripheral Blood ◽  
Fold Increase ◽  
Foxp3 Expression ◽  
Prolonged Administration

Abstract Recombinant IL-2 has been used extensively in clinical trials to enhance a wide range of immune responses. Overall this strategy has had limited efficacy. Recent evidence suggests that IL-2 plays a key role in the generation and maintenance of CD4+CD25+ regulatory T cells (Treg) in vivo. In our study, we investigated the effect of prolonged administration of recombinant IL-2 on Treg in vivo. In a retrospective analysis, we first examined CD4+CD25+ Treg in blood samples collected from 21 cancer patients before and after they started continuous treatment with IL-2 at a dose of 2 X 105 U/m2/day for 3 months. Nine patients received IL-2 beginning 3 months after CD6 T cell depleted allogeneic bone marrow transplantation (BMT) for CML. The remaining 12 patients received IL-2 as treatment for advanced solid tumors. Overall toxicity was minimal and none of the transplant patients developed GVHD following IL-2 administration. Previous reports demonstrated that this prolonged treatment with low-dose IL-2 resulted in the expansion of CD56+CD3− NK cells in peripheral blood. Further analysis showed that 15 patients exhibited an expansion of Treg in peripheral blood 26 to 77 days after beginning IL-2 as demonstrated by an increase in the CD4+CD25+/CD3+ ratio (median fold increase 2.68; range 1.3 to 59). Three patients had no significant change and 3 patients demonstrated a decreased Treg/CD3 ratio. Using RNA from the same samples we also measured the expression of the Treg specific transcription factor FOXP3 by quantitative PCR. Nineteen of 21 patients showed a marked increase in FOXP3 expression following IL-2 treatment (8.38 median fold increase; range 1.4 to 41.5). Only 2 of 21 patients had lower FOXP3 expression after IL-2 administration. Since IL-2 treatment resulted in the expansion of NK cells as well as Treg, we purified CD56+CD3− NK cells and CD4+ T cells from patient samples collected post-IL-2 treatment, and measured FOXP3 gene expression in both subsets. In 4 analyzed cases, FOXP3 was selectively expressed in CD4+ T cells. Further analysis of purified Treg and NK cells incubated with IL-2 in vitro confirmed that FOXP3 expression was selectively induced in Treg, and also suggested that the in vivo increase in FOXP3 expression resulted from both Treg expansion and up-regulation of gene expression at the single cell level. To study the duration of the IL-2 effect, we analyzed additional samples collected 2 to 8 months after IL-2 treatment was completed. Nine of 10 patient samples tested showed a decrease in the CD4+CD25+/CD3+ ratio (1.39 median fold decrease; range 1.13 to 15.02). Using quantitative PCR, expression of FOXP3 decreased for 6 of 8 patients tested (10.76 median fold decrease; range 1.22 to 88.31). These results indicate that prolonged administration of IL-2 promotes the expansion of CD4+CD25+ Treg in vivo and also has a direct effect on FOXP3 expression. Although administration of IL-2 has previously been used to enhance T and NK cell responses, this study demonstrates that IL-2 therapy predominantly reinforces the regulatory component of the immune response, and may provide a means for controlling immune reactions in vivo.

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.

The Krüppel-Like Factor 4 (KLF4) Modulates Survival and Tissue Distribution of Natural Killer Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 282-282
Author(s):  
Chun Shik Park ◽  
Ping-Hsien Lee ◽  
Takeshi Yamada ◽  
Maksim Mamonkin ◽  
H. Daniel Lacorazza
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Lymph Nodes ◽  
Nk Cells ◽  
Tissue Distribution ◽  
Natural Killer ◽  
Peripheral Blood ◽  
Nk Cell ◽  
Wild Type ◽  
Deficient Mice

Abstract Abstract 282 Natural Killer (NK) cells are important mediators of the innate immune system that could be targeted therapeutically to treat hematologic malignancies and to prevent graft-versus-host disease. Hence, a better understanding of NK cell survival and tissue trafficking at steady state is vital to develop cell-based therapies. Genes that control proliferation are often involved in tissue distribution of lymphocytes, such as KLF2 in T cells. KLF4, another member of the Krüppel-like factor family, can activate and repress genes involved in diverse cellular processes. We recently reported that KLF4 is part of a novel inhibitory pathway that prevents proliferation of naïve T cells during homeostasis and retain memory T cells in lymph nodes (Yamada et al., Nature Immunology, 2009). In this work, we studied the role of KLF4 in the development and maintenance of NK cells by deleting Klf4-floxed gene (fl/fl) using the Mx1-Cre system. The percentage of NK1.1+TCR- cells is significantly reduced in peripheral blood of Klf4-deficient (▪/▪) mice (fl/fl: 3.4±1.1 versus ▪/▪: 1.2±0.1, n=9) and also absolute numbers in spleen (▪/▪: 1.1±1.3 ×106, n=6) due to increased percentage of Annexin V positive cells (fl/fl: 9.2±3.2 versus ▪/▪: 22.9±15.5, n=15). The number of CD49d+TCR- cells was also significantly reduced in peripheral blood and spleen of Klf4-deficient mice. In contrast, the number of NK cells in bone marrow and lymph nodes of Klf4-deficient mice was similar to controls. Deletion of Klf4 gene led to reduced numbers of NK1.1+TCR-CD27+CD11b+ and NK1.1+TCR-CD27-CD11b+ cells, which correlated with increasing apoptosis of these subsets. Yet, the percentages of these NK cell subsets were normal in bone marrow ruling out a developmental defect in this tissue. Transplant of wild type and Klf4-deficient bone marrow cells into wild type mice suggested environmental rather than cell intrinsic defects. NK cells (NK1.1+TCR-) isolated from spleen of Klf4-deficient mice showed to be functional in a cytotoxicity assay using a mixture of differentially CFSE-labeled RMA-S (target) and EL4 (control). In summary, KLF4 plays a key role in the maintenance of mature NK cells in peripheral blood and spleen. Disclosures: No relevant conflicts of interest to declare.

Significant Ex-Vivo Expansion and Functional Activation of Cord Blood (CB) Natural Killer (NK) Cells with A Concomittant Significant Decrease in CB T Cells Following Stimulation with Genetically Engineered K562 Cells (K562-mb15-41BBL).

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 499-499
Author(s):  
Jessica Hochberg ◽  
Janet Ayello ◽  
Carmella VandeVen ◽  
Jeremy Gold ◽  
Evan Cairo ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
K562 Cells ◽  
Fold Increase ◽  
Ex Vivo Expansion ◽  
Genetically Engineered ◽  
Cellular Immunotherapy ◽  
Adoptive Cellular Immunotherapy

Abstract Abstract 499 Introduction: CD56+ NK subsets exhibit differential NK receptors (NKR) such as cytotoxicity profiles including killer-Ig-like receptors (KIR), C-lectin (NKG2) and natural cytotoxicity receptors (NCR) involved with tumor target recognition, which, in part, may play a role in adoptive cellular immunotherapy (ACI) for malignancies (Farag et al Blood, 2002). NK cell activation and NK mediated cytolysis is induced by triggering receptors such as NCR (i.e. NKp46), and NKG2 surface receptors like NKG2D (Moretta et al, Curr Opin in Immunol, 2004, Marcenaro et al, Eur J Immunol, 2003). The major limitations of the use of NK cells in ACI include lack of tumor recognition and/or limited numbers of viable and functionally active NK cells (Shereck/Cairo et al. PBC, 2007). To circumvent these limitations, methods to expand and activate PB NK cells by genetic reengineering have been developed (Imai/Campana et al. Blood, 2005). It has been demonstrated that PB NK cells expanded with modified K562 cells expressing membrane bound IL-15 and 4-1BBL (K562-mb15-41BBL; Imai et al Blood, 2005) are significantly increased in number and maintain heterogeneous KIR expression (Fusaki/Campana et al, BJH, 2009) .We have previously reported the ex-vivo expansion, activation and cytolytic activity of CB NK cells with a cocktail of antibody and cytokines (Ayello/Cairo et al, BBMT, 2006; Ayello/Cairo, Exp Hem, 2009, In Press). Objective: In this study, we compared CB NK expansion and activation following stimulation with genetically engineered K562 cells (K562-mb15-41BBL, generously supplied by D.Campana, St Jude's Children's Hospital, Memphis, TN) with wild-type (WT) K562 cells and NK cell characterization expressing inhibiting and activating KIRs, c-lectin, NCRs and NK cytolytic activation. Methods: Following irradiation with 100Gy, K562-mb15-41BBL or WTK562 were incubated at a 1:1 ratio with fresh CB MNCs at 37C, 5% CO2 for 7 days in RPMI-1640+10IU IL-2. NKR expression (KIR2DS4, NKG2D, NKG2A, CD94, KIR3DL1, KIR2DL2, Nkp46) and LAMP-1 (CD107a) receptor expression and NK cell phenotype (CD56 dim and bright subsets) were determined by flow cytometry. Results: On Day 0, NK cells population was 3.9±1.3%. After 7 days in culture, CB NK cells were significantly increased compared to WTK562 and media alone (72±3.9 vs 43±5.9 vs 9±2.4%, p<0.01). This represented a 35-fold or 3374±385% increase of the input NK cell number. This was significantly increased compared to WTK562 (1771±300%, p<0.05). Concomitantly, there was a significant decrease in CB T cells vs WTK562 or media alone (15±2 vs 36±2 vs 51±7%, p<0.001),respectively. There was a significant increase in CD56bright vs CD56dim populations (67 vs 33%, p<0.01) following stimulation with K562-mb15-41BBL. Also, there was a 10-fold increase in CB NK cells expressing KIR3DL1 following stimulation with K562-mb15-41BBL vs WTK562 (p<0.01) and a 5-fold increase in NK KIR2DS4 expression (p<0.05), respectively. There was a significant increase in the expression of NK activation marker, CD107a, compared to WTK562 (51±0.7 vs 32±1.1,p<0.05). There was no change in CB NK cell expression of the c-lectin receptor, CD94/NKG2A and CD94/NKG2D after stimulation with K562-mb15-41BBL. A standard cryopreserved CB unit (25 ml) contains approximately 750×106 MNC. By using the smaller 5-ml aliquot (20%) of a two-aliquot bag (150×106 MNCs × 3.9%=5.8×106 NK cells), this expansion method would hypothetically yield 200×106 CB NK cells after 7 days stimulation with K562-mb15-41BBL. Conclusion: These results suggest that CB MNC can be ex-vivo expanded with K562-mb15-41BBL resulting in specific expansion of CB NK cells with increased NK KIR expression (KIR2DS4 and KIR3DL1) and NK activation (CD107a), along with a significant decrease in CB T cells. This expansion provides a means to enhance specific CB NK cell expansion for possible use for adoptive cellular immunotherapy in the post UCBT setting Disclosures: No relevant conflicts of interest to declare.

41BBL-Based Activation and Expansion of Autologous Natural Killer Cells Results in Enhanced Activity Against Leukemia Including ALL

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2293-2293
Author(s):  
Ekta Kapadia ◽  
Elad Jacoby ◽  
Mark Kohler ◽  
Waleed Haso ◽  
Christopher Daniel Chien ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Lymphoblastic Leukemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Stem ◽  
Enhanced Activity

Abstract Childhood leukemia is the most common pediatric malignancy. There are now excellent cure rates for these patients, however outcomes remain poor for those with refractory disease and for those who relapse after standard salvage therapies, with a disease recurrence of approximately 50%. Therefore, development of novel cellular therapies is essential to treat these refractory patients. Natural Killer (NK) cells generated from an allograft contribute to improved disease free survival after Hematopoietic Stem Cell Transplantation for leukemia when there is a KIR mismatch. This effect appears to be particularly potent in the setting of Acute Myelogenous Leukemia (AML) with less benefit demonstrated in Acute Lymphoblastic Leukemia (ALL). Preclinical studies have also suggested that activation and expansion of resting NK cells can enhance NK cell cytotoxicity and eliminate the need for KIR mismatch due to up-regulation of activating receptors. We are currently testing this approach in the clinic following a fully matched allogeneic transplant platform for leukemia. Our aim is to explore whether 41BB ligand (41BBL) and recombinant IL-15 (rIL-15) mediated ex vivo expansion of autologous NK cells results in enhanced activity against AML and ALL. The activation/expansion process may allow for the use of autologous NK cell infusions, thus eliminating the need for allogeneic NK cell donors. To test this hypothesis, we ex vivo expanded and activated NK cells derived from C57BL/6J (B6) mice using artificial Antigen Presenting Cells (aAPCs) containing 41BBL and rIL-15 for 7-14 days. NK cells were co-cultured with murine AML cells (C1498) and murine ALL cells (E2A-PBX) – both on B6 background. Controls included YAC cells (murine T-cell lymphoma cell line sensitive to NK cell killing) as well as Phorbol Myristate Acetate (PMA)/ionomycin. All cells were co-cultured for 5 hours prior to functional assessment of NK cells via CD107a degranulation. NK cells cultured with 41BBL aAPCs and rIL-15 had a 30-fold expansion in numbers (Figure 1) and an increase in purity to approximately 95-98% (NK1.1+, CD3–) by Day 7. In the absence of cytokine or aAPCs, cultured NK cells underwent rapid apoptosis. Functionally, although resting NK cells (harvested prior to assessment) expressed CD107a when cultured with YAC cells and PMA, only minimal degranulation was observed in the presence of autologous AML cells or ALL cells. In contrast, activated and expanded autologous NK cells displayed enhanced activity against ALL, AML, as well as YAC cells, while only minimal levels of CD107a were seen in the absence of targets (Figure 2). In vivo experiments with a single injection of activated and expanded NK cells did not result in prolonged survival of mice bearing either AML or ALL. Assessment of adoptively transferred NK cells demonstrated very transient persistence (<2 days) with no in vivo expansion, suggesting that repeated injections may be necessary for leukemia eradication. Future murine experiments will investigate the effect repeated injections of activated/expanded NK cells and/or the administration of rIL-15 will have on survival and leukemia eradication. In addition, the ability to activate and expand NK cells in culture provides an opportunity for lentiviral-based transduction with chimeric antigen receptor (CAR) vectors. We are currently testing this with a murine CD19 CAR. These experiments suggest that autologous activated and expanded NK cells may serve as a viable cellular therapy for pediatric patients with refractory/relapsed leukemia. As demonstrated in these in vitro experiments, autologous activated/expanded NK cells still show increased targeting of mouse AML and ALL cell lines despite the lack of KIR mismatch. Thus, they may serve as a potential platform for leukemia therapy, including ALL, which appear to be poor targets for resting NK cells. In addition, these cells demonstrate transient persistence in vivo, a potential advantage in the context of redirected cytotoxicity using CAR constructs that target antigens with broader expression in the hematopoietic compartment. Figure 1: <![if !vml]><![endif]> Figure 1:. <![if !vml]><![endif]> Figure 2: Figure 2:. Disclosures No relevant conflicts of interest to declare.

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.

A role for interleukin-12/23 in the maturation of human natural killer and CD56+ T cells in vivo

Blood ◽  
2008 ◽  
Vol 111 (10) ◽  
pp. 5008-5016 ◽  
Author(s):  
Sophie Guia ◽  
Céline Cognet ◽  
Ludovic de Beaucoudrey ◽  
Marlowe S. Tessmer ◽  
Emmanuelle Jouanguy ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Memory T Cells ◽  
Effector Memory ◽  
Similar Data ◽  
Effector Memory T Cells ◽  
Ifn Γ

Abstract Natural killer (NK) cells have been originally defined by their “naturally occurring” effector function. However, only a fraction of human NK cells is reactive toward a panel of prototypical tumor cell targets in vitro, both for the production of interferon-γ (IFN-γ) and for their cytotoxic response. In patients with IL12RB1 mutations that lead to a complete IL-12Rβ1 deficiency, the size of this naturally reactive NK cell subset is diminished, in particular for the IFN-γ production. Similar data were obtained from a patient with a complete deficit in IL-12p40. In addition, the size of the subset of effector memory T cells expressing CD56 was severely decreased in IL-12Rβ1– and IL-12p40–deficient patients. Human NK cells thus require in vivo priming with IL-12/23 to acquire their full spectrum of functional reactivity, while T cells are dependent upon IL-12/23 signals for the differentiation and/or the maintenance of CD56+ effector memory T cells. The susceptibility of IL-12/23 axis–deficient patients to Mycobacterium and Salmonella infections in combination with the absence of mycobacteriosis or salmonellosis in the rare cases of human NK cell deficiencies point to a role for CD56+ T cells in the control of these infections in humans.

Sign in / Sign up

Export Citation Format

Share Document