The Proteasome Inhibitor Bortezomib Simultaneously Enhances NK Cell Tumor Cytotoxicity While Paradoxically Reducing Antigen Specific T-Cell Tumor Cytotoxicity.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1789-1789
Author(s):  
Andreas Lundqvist ◽  
Sheila Rao ◽  
Maria Berg ◽  
Aleah Smith ◽  
Su Su ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Cells ◽  
Melanoma Cell ◽  
Nk Cell ◽  
Proteasome Inhibition ◽  
Surface Expression ◽  
Melanoma Cells ◽  
Cytotoxicity Assay ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity

Abstract The proteasome inhibitor bortezomib was recently found to render tumor cells susceptible to natural killer (NK) cell-mediated apoptosis in vitro and in vivo. This sensitization appears to occur as a consequence of this agent up-regulating surface expression of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) on human malignant cells rendering them susceptible to TRAIL-mediated NK cell cytotoxicity. We hypothesized that bortezomib would likewise sensitize tumors to the cytotoxic effects of antigen specific T-cells through similar apoptotic pathways, thereby providing an incentive to use bortezomib as a universal immune-sensitizing agent. The HLA-A2+, gp100+, MART-1+ melanoma cell lines 526 and 624 were treated with 10nM bortezomib for 18 hrs then were analyzed by FACS for expression the cell surface markers (HLA-ABC, MIC-A/B, TRAIL-R1/2 and Fas) and Cr51 cytotoxicity assay for susceptibility to CD8+/HLA-A2+ restricted gp100 and MART-1 specific CTL-mediated lysis. As observed previously, NK cell-mediated apoptosis was significantly higher in tumor cells treated with bortezomib compared to untreated tumor cells. In contrast, an unanticipated and significant reduction in CTL-mediated cytotoxicity was observed in tumors treated with bortezomib compared to untreated tumors; at an effector:target ratio of 3:1, NK cell cytotoxicity increased from 43±2% to 70±2% (p<0.01) while gp100 CTL cytotoxicity decreased from 34±4% to 18±2% (p<0.01) in 624 melanoma cells after exposure to bortezomib (figure). This inhibition in T-cell killing was not due to changes in tumor surface expression of MHC class I, MIC-A/B, TRAIL receptors or Fas. Remarkably, CTL-mediated cytotoxicity was restored to baseline in tumor cells that were pulsed with gp100 antigen following bortezomib treatment, suggesting proteasome inhibition by bortezomib altered or impaired the processing and presentation of the gp100 tumor antigen. Conclusions: Exposure of malignant cells to bortezomib results in simultaneous divergent effects on innate NK cell and adaptive T-cell anti-tumor immunity. While tumors exposed to bortezomib have enhanced susceptibility to NK-cell cytotoxicity, proteasome inhibition appears to disrupt antigen presentation potentially reducing tumor specific CTL effector responses. These findings suggest antigen specific T-cell responses such as graft-vs-host disease, and T-cell mediated graft-vs-tumor effects might be altered when bortezomib is administered following allogeneic hematopoietic cell transplantation. Figure. Melanoma cell line (624) was treated with bortezomib [10 nM] and analyzed for susceptibility to NK cell (left) and gp100-specific CD8+ CTL (middle) - mediated cytotoxicity in a 5h Cr51 cytotoxicity assay. Right - bortezomib-treated and untreated gp100:209 peptide pulsed 624 melanoma cells analyzed for susceptibility to gp100-specific CD8+ CTL-mediated cytotoxicity at a E:T ratio of 4:1 Figure. Melanoma cell line (624) was treated with bortezomib [10 nM] and analyzed for susceptibility to NK cell (left) and gp100-specific CD8+ CTL (middle) - mediated cytotoxicity in a 5h Cr51 cytotoxicity assay. Right - bortezomib-treated and untreated gp100:209 peptide pulsed 624 melanoma cells analyzed for susceptibility to gp100-specific CD8+ CTL-mediated cytotoxicity at a E:T ratio of 4:1

scholarly journals Transient receptor potential melastatin 2 channels are overexpressed in myalgic encephalomyelitis/chronic fatigue syndrome patients

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Cassandra Balinas ◽  
Helene Cabanas ◽  
Donald Staines ◽  
Sonya Marshall-Gradisnik
Keyword(s):  
Nk Cells ◽  
Transient Receptor Potential ◽  
Nk Cell ◽  
Receptor Potential ◽  
Surface Expression ◽  
Chronic Fatigue ◽  
Cell Cytotoxicity ◽  
Fatigue Syndrome ◽  
Transient Receptor Potential Melastatin ◽  
Nk Cell Cytotoxicity

Abstract Background Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is hallmarked by a significant reduction in natural killer (NK) cell cytotoxicity, a mechanism tightly regulated by calcium (Ca2+). Interestingly, interleukin-2 (IL-2) increases NK cell cytotoxicity. Transient receptor potential melastatin 2 (TRPM2) ion channels are fundamental for Ca2+ signalling in NK cells. This pilot investigation aimed to characterise TRPM2 and CD38 surface expression in vitro on NK cells in ME/CFS patients. This investigation furthermore examined the pharmaceutical effect of 8-bromoadenosine phosphoribose (8-Br-ADPR) and N6-Benzoyladenosine-3′,5′-cyclic monophosphate (N6-Bnz-cAMP) on TRPM2 and CD38 surface expression and NK cell cytotoxicity between ME/CFS and healthy control (HC) participants. Methods Ten ME/CFS patients (43.45 ± 12.36) and 10 HCs (43 ± 12.27) were age and sex-matched. Isolated NK cells were labelled with fluorescent antibodies to determine baseline and drug-treated TRPM2 and CD38 surface expression on NK cell subsets. Following IL-2 stimulation, NK cell cytotoxicity was measured following 8-Br-ADPR and N6-Bnz-cAMP drug treatments by flow cytometry. Results Baseline TRPM2 and CD38 surface expression was significantly higher on NK cell subsets in ME/CFS patients compared with HCs. Post IL-2 stimulation, TRPM2 and CD38 surface expression solely decreased on the CD56DimCD16+ subset. 8-Br-ADPR treatment significantly reduced TRPM2 surface expression on the CD56BrightCD16Dim/− subset within the ME/CFS group. Baseline cell cytotoxicity was significantly reduced in ME/CFS patients, however no changes were observed post drug treatment in either group. Conclusion Overexpression of TRPM2 on NK cells may function as a compensatory mechanism to alert a dysregulation in Ca2+ homeostasis to enhance NK cell function in ME/CFS, such as NK cell cytotoxicity. As no improvement in NK cell cytotoxicity was observed within the ME/CFS group, an impairment in the TRPM2 ion channel may be present in ME/CFS patients, resulting in alterations in [Ca2+]i mobilisation and influx, which is fundamental in driving NK cell cytotoxicity. Differential expression of TRPM2 between NK cell subtypes may provide evidence for their role in the pathomechanism involving NK cell cytotoxicity activity in ME/CFS.

In Vitro and In Vivo Sensitization of Malignant Cells to Autologous Natural Killer Cell Cytotoxicity Following Exposure to Bortezomib.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 925-925 ◽  
Author(s):  
Andreas Lundqvist ◽  
Kristy Greeneltch ◽  
Maria Berg ◽  
Shivani Srivastava ◽  
Nanae Harashima ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Nk Cells ◽  
Tumor Cells ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Malignant Cells ◽  
Nk Cell Cytotoxicity ◽  
Tumor Death

Abstract Killer IgG like receptor (KIR) inactivation of NK cells by self HLA molecules has been proposed as a mechanism through which malignant cells evade host NK cell-mediated immunity. To overcome this limitation, we sought to develop a method to sensitize the patient’s tumor to autologous NK cell cytotoxicity. The proteasome inhibitor bortezomib has recently been shown to enhance the activity of tumor death receptors. We found that exposure of a variety of different leukemia, lymphoma and solid tumor cancer cell lines to sub-apoptotic doses of bortezomib sensitized tumor cells in vitro to lysis by allogeneic NK cells. Importantly, this sensitizing effect also occurs with autologous NK cells normally rendered inactive via tumor KIR ligands; NK cells expanded from patients with metastatic renal cell carcinoma were significantly more cytotoxic against the patient’s own autologous tumor cells when pretreated with bortezomib compared to untreated tumors. This sensitization to autologous NK cell killing was also observed in vivo in two different murine tumor models. A significant delay in tumor growth in C57BL/6 mice bearing LLC1 tumors (figure) and a delay in tumor growth and a significant prolongation (p<0.01) in survival were observed in RENCA tumor bearing Balb/c mice treated with bortezomib and syngeneic NK cell infusions compared to untreated mice or animals treated with bortezomib alone or NK cells alone. An investigation into the mechanism through which NK cell cytotoxicity was potentiated revealed bortezomib enhanced the activity of tumor death receptor-dependent and -independent apoptotic pathways. More specifically, bortezomib sensitized human and murine tumor cells to TRAIL and perforin/granzyme mediated NK cell cytotoxicity respectively. These observations suggest that pretreatment of malignant cells with bortezomib could be used as a strategy to override NK cell inhibition via tumor KIR ligands, thus potentiating the activity of adoptively infused autologous NK cells. A clinical trial evaluating the safety and anti-tumor efficacy of adoptively infused autologous NK cells in patients with advanced malignancies with and without tumor sensitization using bortezomib is currently being explored. Figure: Tumor growth in LLC1 bearing C57BL/6 mice. Fourteen days following s.c. injection of 3x105 LLC1 tumor cells, mice received 15μg (i.p) bortezomib and/or an adoptive infusion of 1x106 NK cells from C57BL/6 mice (i.v) given on day 15. Each dot represents the tumor volume of individual mice measured on day 28 post tumor injection. Tumors were significantly smaller in mice treated with bortezomib followed by NK cells compared to controls or mice that received either NK cells alone or bortezomib alone (p<0.04 for all groups). Figure:. Tumor growth in LLC1 bearing C57BL/6 mice. . / Fourteen days following s.c. injection of 3x105 LLC1 tumor cells, mice received 15μg (i.p) bortezomib and/or an adoptive infusion of 1x106 NK cells from C57BL/6 mice (i.v) given on day 15. Each dot represents the tumor volume of individual mice measured on day 28 post tumor injection. Tumors were significantly smaller in mice treated with bortezomib followed by NK cells compared to controls or mice that received either NK cells alone or bortezomib alone (p<0.04 for all groups).

Novel Monoclonal Antibody Enhances Natural Killer (NK) Cell Cytotoxicity against Multiple Myeloma (MM): Interim Phase 1 Trial Results.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2880-2880
Author(s):  
Don Benson ◽  
Craig C. Hofmeister ◽  
Swaminathan Padmanabhan ◽  
Rafat Abonour ◽  
Attaya Suvannasankha ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Dose Escalation ◽  
Nk Cell ◽  
Biological Effects ◽  
Single Agent ◽  
Safety Data ◽  
Cell Maturation ◽  
Cell Cytotoxicity ◽  
Study Results ◽  
Nk Cell Cytotoxicity

Abstract Abstract 2880 Poster Board II-856 Background: MM is increasing in incidence and remains incurable. .NK cells have modest killing activity against MM tumor cells in part because of inhibitory KIR receptors which recognize HLA class 1 antigens on MM tumor cell targets. However, experimental and clinical data in the allogeneic transplant setting suggest that NK cell stimulation by a mismatch between donor KIR and patient KIR ligand may improve outcomes for MM after a reduction of tumor burden by previously administered treatments. To mimic this effect with a pharmaceutical agent, 1-7F9/IPH2101, a fully human IgG4 anti-KIR mAb specific for KIR2DL1/2/3 (HLA-C specific KIRs) was generated (Romagne et al., Blood June, 2009). 1-7F9/IPH 2101 enhances patient NK cell cytotoxicity against autologous MM tumor cells in vitro. We present the interim results of the human phase I trial of this agent in patients with relapsed/refractory MM. Methods: An open-label, single-agent, dose-escalation, multiple dose safety and tolerability study of IPH2101 is being conducted in heavily pre-treated patients with relapsed/refractory MM. Dose escalation with IPH2101 (0.0003, 0.003, 0.015, 0.075, 0.3, 1, 3 mg/kg as IV infusion) is being studied using a 3+3 scheme. Re-dosing criteria (1/month x 4 months) are based on safety data from previous dosing. KIR occupancy, pharmacokinetics (PK), pharmacodynamics, effects on NK cell maturation, and biological effects of IPH 2101 are being monitored in all patients. Results: Currently, dose escalation is entering the final (3 mg/kg) cohort. Data from the first 22 treated patients are available. No Dose Limiting Toxicity (DLT) has been observed. 1 pt (at DL1) has been replaced and 3 additional pts have been enrolled (at DL4) due to an SAE an acute renal failure possibly related to drug. Related Adverse Events were seen in 4/22 patients (18%). 12/22 pts received at least 2 doses (6pts had 2, 1 pt had 3 and 5 pts had 4 cycles-median 2). KIR full occupancy (> 90%) for at least 3 weeks is reached at 1mg /kg. In accordance with the pre-clinical PK/PD model there is a clear relationship between exposure (Cmax) and KIR occupancy. No deleterious effect on NK cell maturation has been seen. IPH 2101 has been well tolerated to date. In the cohorts accrued to date, two heavily pre-treated patients, both with high-risk cytogenetics, showed evidence to suggest disease stabilization while receiving IPH-2101. Conclusions: IPH 2101 improves autologous NK cell killing of MM tumor cells by blocking inhibitory KIR. In the on-going clinical trial, the antibody appears safe and well tolerated at the doses tested. Updated study results will be presented at the time of the meeting This immunotherapeutic approach may hold promise as treatment for MM and further study is warranted. Disclosures: Squiban: Innate pharma: Employment. Marzetto:Innate Pharma: Employment. Andre:Innate Pharma: Employment. Tollier:Innate Pharma: Employment.

Novel monoclonal antibody that enhances natural killer (NK) cell cytotoxicity against multiple myeloma (MM): Preclinical data and interim phase I clinical trial results

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 3032-3032
Author(s):  
D. M. Benson ◽  
F. Romagne ◽  
P. Squiban ◽  
N. Wagtmann ◽  
S. Farag ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Nk Cells ◽  
Tumor Cells ◽  
Nk Cell ◽  
Phase 1 ◽  
Cell Maturation ◽  
Cell Cytotoxicity ◽  
Post Dose ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

3032 Background: MM is increasing in incidence and remains incurable. NK cells have modest killing activity against MM cells in part because of inhibitory signals from HLA class 1 antigens which act via the KIR receptors on NK cells. A novel anti-KIR blocking antibody (1–7F9 named IPH 2101) enhances patient NK cell cytotoxicity against autologous MM tumor cells in vitro and appears safe in an ongoing phase 1 clinical trial. Methods: NK cells from healthy controls or patients were pre-treated with IPH 2101 or IgG4 isotype control and co-cultured with MM cell lines or autologous MM tumor targets. NK cell production of interferon-gamma (IFN-γ) or granzyme B (GrB) were measured by ELISPOT. An open-label, single-agent, phase 1 dose escalation study of IPH 2101 is being conducted in patients with relapsed/refractory MM. KIR binding, pharmacokinetics, pharmacodynamics, effects on NK cell maturation, and biological effects of IPH 2101 are being monitored in all patients. Results: At an effector to target (E:T) ratio of 1:1, IPH 2101 significantly enhances NK cell IFN-γ release against MM targets (mean 33 spots/well ± 12, SEM vs. 11 ± 0.3, p = 0.005). At an E:T ratio of 10:1, IPH 2101 enhances NK cell cytotoxicity, by GrB release, of patient NK cells against autologous MM tumor cells (mean 111 spots/well ± 14, SEM vs 56 ± 10, p = 0.002). By Western blot, IPH 2101 may reduce levels of src, a kinase known to be involved in inhibitory KIR signaling. Dose escalation in the phase 1 study has been completed from 0.0003 mg/kg to 0.075 mg/kg in 14 evaluable patients. At the highest dose tested, KIR occupancy has been detected at a mean 95% ± 1.4 at 2 hours post dose, lasting up to 56% ± 18 during 2 weeks post dose. At this dose level, PK data show good correspondence with previous modeling activity. No deleterious effect on NK cell maturation has been seen. IPH 2101 has been well tolerated to date. Conclusions: IPH 2101 improves autologous NK cell killing of MM tumor cells by blocking inhibitory KIR. In the ongoing clinical trial, the antibody appears safe and well tolerated at the doses tested. This immunotherapeutic approach may hold promise as treatment for MM and further study is warranted. [Table: see text]

scholarly journals A novel immunoregulatory role for NK-cell cytotoxicity in protection from HLH-like immunopathology in mice

Blood ◽  
2015 ◽  
Vol 125 (9) ◽  
pp. 1427-1434 ◽  
Author(s):  
Fernando E. Sepulveda ◽  
Sophia Maschalidi ◽  
Christian A. J. Vosshenrich ◽  
Alexandrine Garrigue ◽  
Mathieu Kurowska ◽  
...  
Keyword(s):  
T Cell ◽  
Cytotoxic Activity ◽  
T Cell Activation ◽  
Cell Activation ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Key Points ◽  
Nk Cell Cytotoxicity ◽  
Deficient Mice

Key Points NK cytotoxic activity limits HLH-like immunopathology in cytotoxic-deficient mice. NK cytotoxic activity reduces T-cell activation and tissue infiltration of macrophages.

Natural Killer Cell Cytotoxicity: A Methods Analysis of Versus Flow Cytometry Chromium Release

2003 ◽  
Vol 5 (2) ◽  
pp. 142-152 ◽  
Author(s):  
Sandra Adams Motzer ◽  
Joyce Tsuji ◽  
Vicky Hertig ◽  
Sandra K. Johnston ◽  
James Scanlan
Keyword(s):  
Flow Cytometry ◽  
Natural Killer ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Killer Cell ◽  
Cytotoxicity Assay ◽  
Cell Cytotoxicity ◽  
Peripheral Blood Mononuclear ◽  
Natural Killer Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity

The purpose of this study is to describe design considerations for the use of flow cytometry (FC) com-pared to51chromium (51Cr)-release assays utilizing cryopreserved peripheral blood mononuclear cells (PBMCs) to detect natural killer (NK) cell cytotoxicity. Subjects were 10 healthy women aged 18 to 39 years. Intra-assay variability between methods differed only at the lowest effector-target ratios evaluated. Interassay variability was wide but did not differ between methods. The relationship of lytic unit-10 between methods was strongly positive. Cytotoxicity detected by51Cr release was higher than that detected by FC for all 10 subjects. Cost was comparable. How-ever, had more assays been performed, technician time would have been greater with flow cytometry. More whole blood was needed to perform the flow cytometry cytotoxicity assay than51Cr-release cytotoxicity assay. The authors found no compelling reason to adopt NK cell cytotoxicity by flow cytometry over51Cr release.

Re-Targeting of an NK Cell Line (NK92) with Specificity for CD19 Efficiently Kills Human B-Precursor Leukemia Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2747-2747 ◽  
Author(s):  
Annette Romanski ◽  
Christoph Uherek ◽  
Gesine Bug ◽  
Tina Muller ◽  
Claudia Rossig ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Nk Cell ◽  
Antibody Fragment ◽  
Surface Expression ◽  
Cytolytic Activity ◽  
Leukemia Cells ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity ◽  
B Lineage

Abstract The continuously growing Natural killer (NK) cell line NK-92 is highly cytotoxic against malignant cells of various origin without affecting normal human cells. It is the only NK cell line that has entered clinical trials to date. Acute lymphoblastic leukemias (ALL) show variable sensitivity towards NK cells including NK-92-lysis. All T-ALL cell lines tested (MOLT-3, MOLT-4 and CEM-T) display moderate sensitivity to NK cytotoxicity with approximately 22±2 – 24±2% killing at an effector to target (E:T) ratio of 10:1, respectively. Comparable results were obtained with primary patient derived T-ALLs (n=4), displaying specific killing rates of 17±5 – 20±2%. In contrast, B lineage ALL cell lines (NALM-6, SEM, REH, JKB, BV173, SupB15, TOM-1, TMD5) and cells derived from patients (n=11) were resistant to NK-92-mediated lysis, with specific killing rates ranging from 2±1% to 13±3% at an E:T ratio of 10:1. Approaches to overcome resistance of B-precursor ALL by re-targeting may shed light on the specific reasonable mechanism conferring resistance and lead to novel therapeutic strategies. Here we have generated genetically modified NK-92 cells expressing a chimeric antigen receptor specific for the pan B cell antigen CD19 which is universally expressed by B lineage leukemia cells. This receptor fragment kindly provided by H. Zola (Child Health Research Institute North Adelaide, Australia) consists of the CD19 specific scFv(CD19) antibody fragment, a flexible hinge region, the CD3 ζ chain and a Myc-tag. Transduced cells were selected with G418, and surface expression of the chimeric scFv(CD19)-ζ construct was verified by FACS analysis using the Myc-tag-specific mAb 9E10. No difference in cytotoxic activity of NK-92 and transduced NK-92-scFv(CD19)-ζ cells towards CD19 negative targets (K562, MOLT-4) was found. In contrast, NK-92-scFv(CD19)-ζ cells specifically and efficiently lysed CD19 expressing B precursor leukemia cells (NALM-6, SEM, B173, SupB15, TOM-1, TMD5) including cells that were completely resistant to cytolytic activity of parental NK-92 cells. Killing of SupB15 and BV173 cells was 10,0±0,8% and 12,0±8,5% with parental NK92 vs. 58,2±14,8% and 52,3±4,1% lysis with NK92 cells expressing the CD19 specific scFv(CD19) antibody fragment. These results demonstrate that efficient retargeting of NK-cell cytotoxicity can be achieved, and might allow the generation of potent cell-based therapeutics. Since the widespread resistance of B precursor ALL blasts to NK cell cytotoxicity is not caused by mechanisms commonly relevant in tumors, this model may allow dissection of possible mechanisms of resistance.

scholarly journals Tumor hypoxia impairs NK cell cytotoxicity through SHP-1-mediated attenuation of STAT3 and ERK signaling pathways

2019 ◽  
Author(s):  
Yanmeng Wang ◽  
Rui Teng ◽  
Nan Lv ◽  
Ramone A. Williamson ◽  
Lei Lei ◽  
...  
Keyword(s):  
Nk Cells ◽  
Tumor Cells ◽  
Nk Cell ◽  
Tyrosine Phosphatase ◽  
Tumor Hypoxia ◽  
Specific Inhibitor ◽  
Dependent Manner ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity ◽  
Anti Tumor Activity

Abstract Natural killer (NK) cells are innate immune effectors with potent anti-tumor activity. Nonetheless, tumor cells have the ability to create an immunosuppressive microenvironment, thereby escaping from immune surveillance. Although accumulating evidence indicates that microenvironmental hypoxia plays an important role in favoring tumor development and immune evasion, it is still unclear how hypoxia directly impairs NK cell anti-tumor activity. In this study, we confirmed that hypoxic NK cells show significantly lower cytotoxicity against tumor cells. Consistent with this, we also found that the reduction in NK cell cytotoxicity resulting from hypoxia is related to the lower expression of granzyme B, IFN-γ, degranulation marker CD107a, as well as killer activation receptors including NKp30, NKp46, and NKG2D on NK cells. More importantly, we further demonstrated that a reduction in the phosphorylation levels of ERK and STAT3 secondary to hypoxia are tightly associated with the attenuated NK cell cytotoxicity. Focusing on the mechanism responsible for reducing phosphorylation levels of ERK and STAT3, we revealed that the activation of protein tyrosine phosphatase SHP-1 (src homology region 2 domain-containing phosphatase-1) following hypoxia may play an essential role in this process. When knocking down SHP-1 or blocking its activity using a specific inhibitor TPI-1, we were able to partially restore NK cell cytotoxicity under hypoxia. Taken together, we demonstrated that hypoxia can impair NK cell cytotoxicity by decreasing the phosphorylation levels of ERK and STAT3 in a SHP-1 dependent manner. Therefore, targeting SHP-1 could provide an approach to enhance NK cell-based tumor immunotherapy.

Natural Killer (NK) or NK/T Cell Lineage Large Granular Lymphocytosis Associated with Dasatinib Therapy for Philadelphia Chromosome Positive Leukemia.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 933-933
Author(s):  
Dong Hwan Kim ◽  
Suzanne Kamel-Reid ◽  
Hong Chang ◽  
Robert Sutherland ◽  
Chul Won Jung ◽  
...  
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Cell Line ◽  
Nk Cell ◽  
Cell Lineage ◽  
Target Cells ◽  
Cell Cytotoxicity ◽  
51Cr Release ◽  
K562 Cell Line ◽  
Nk Cell Cytotoxicity

Abstract Dasatinib, a dual tyrosine kinase inhibitor, is known to modulate or suppress T-cell activation and proliferation. We report a series of patients of chronic peripheral lymphocytosis development, identified as natural killer (NK) cells or NK/T-cells based on their large granular lymphocyte (LGL) morphologies and CD16+CD56+CD3− or CD3+ immunophenotypic profiles during dasatinib therapy. All cases that developed LGL lymphocytosis achieved optimal molecular response (8/8 in LGL+ patients vs 3/10 in LGL− patients, p=0.002). A 51Cr release assay demonstrated that NK cell cytotoxicity has been enhanced in a case of LGL lymphocytosis compared to normal healthy donors (Figure 1), and that NK cell cytotoxicity in dasatinib-responders was superior to that in non-responders (Figure 2). In summary, the present study suggests that NK or NK/T cell lineage LGL lymphocytosis develops associated with dasatinib therapy and that LGL might have a therapeutic effect on Ph+ leukemic cells. Figure 1. Cytotoxicity of NK cells isolated from the patients developing large granular lymphocytosis following dasatinib therapy as assessed by 51Cr release assays using target cells as K562 (A) and T2 cell line (B) as target cells. Figure 1. Cytotoxicity of NK cells isolated from the patients developing large granular lymphocytosis following dasatinib therapy as assessed by 51Cr release assays using target cells as K562 (A) and T2 cell line (B) as target cells. Figure 2. The result of 51Cr release assays comparing cytotoxicity of NK cells isolated from patients responding to dasatinib therapy (responder) and not responding (non-responder) following dasatinib therapy using K562 cell line as target cells. Figure 2. The result of 51Cr release assays comparing cytotoxicity of NK cells isolated from patients responding to dasatinib therapy (responder) and not responding (non-responder) following dasatinib therapy using K562 cell line as target cells.

Mimicking An Induced Self Phenotype by Coating Lymphomas with the Nkp30-Ligand B7-H6 Promotes Antitumoral Natural Killer Cell Cytotoxicity

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 103-103
Author(s):  
Christian Kellner ◽  
Tina Maurer ◽  
Daniela Hallack ◽  
Roland Repp ◽  
Jan G.J. van de Winkel ◽  
...  
Keyword(s):  
Cell Surface ◽  
Fusion Protein ◽  
Nk Cells ◽  
Natural Killer ◽  
Tumor Cells ◽  
Cell Lines ◽  
Surface Density ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity

Abstract Abstract 103 Induced self-expression of ligands for stimulatory receptors facilitates natural killer (NK) cell-mediated elimination of stressed cells. Stimulatory receptors include Natural killer group 2 member D (NKG2D) and Nkp30, which control cytotoxic activities of NK cells and are important in immune surveillance against tumors. Specific modulation of NK cell cytotoxicity by selectively increasing the surface density of activating ligands on tumor cells may therefore represent an innovative approach to develop novel treatment strategies. A novel fusion protein was designed to enhance NK cell-based immune responses against B-lineage lymphomas by increasing the cell surface density of the recently identified Nkp30 ligand B7-H6 on tumor cells. The recombinant protein consisted of the ectodomain of B7-H6 and a CD20-directed human single chain fragment variable (scFv) as targeting device. The resulting fully-human protein designated B7-H6:CD20-scFv was eukaryotically expressed and purified by affinity chromatography. B7-H6:CD20-scFv indeed had bifunctional properties as reflected by its ability to simultaneously bind to the CD20 antigen and to the Nkp30 receptor. CD20-positive lymphoma cells opsonized with B7-H6:CD20-scFv alerted human NK cells as indicated by upregulated surface expression levels of the early inducible activation marker CD69. Activation was accompanied by induced CD107a cell surface exposure indicating enhanced NK cell degranulation. In cytotoxicity assays using human NK cells from healthy donors as effector cells, B7-H6:CD20-scFv triggered killing of lymphoma-derived B-cell lines. B7-H6:CD20-scFv was active in a strictly antigen-specific manner as demonstrated by blocking experiments and was not able to mediate killing of cell lines not expressing the CD20 target antigen. B7-H6:CD20-scFv mediated killing of lymphoma cells in a dose-dependent manner starting at nanomolar concentrations. Target cell death induced by B7-H6:CD20-scFv occurred by apoptosis and involved caspase cleavage. Moreover, B7-H6:CD20-scFv induced NK cell-mediated lysis of fresh tumor cells from 8/8 CLL and 5/5 MCL patients with variable CD20 expression levels. In comparison to ULBP2:CD20-scFv, a similarly constructed fusion protein of the NKG2D ligand ULBP2 and a CD20-directed scFv, the B7-H6:CD20-scFv had a lower potency (EC50 values for B7-H6:CD20-scFv and ULBP2:CD20-scFv were 100 and 4 nM, respectively) but nevertheless achieved similar maximum extents of lysis. Interestingly, when B7-H6:CD20-scFv was added together with ULBP2:CD20-scFv to a mixture of NK cells and target cells, synergistic cytotoxic effects were induced. The combined treatment resulted in a higher percentage of NK cells that responded and exposed the degranulation marker CD107a on the cell surface in comparison to samples containing only one of the two agents. As a consequence a significantly higher extent of lysis was achieved. These results strongly indicate a co-operation between Nkp30 and NKG2D signalling which use different downstream signalling pathways. Thus, mimicking an induced self phenotype of tumors by coating lymphomas with B7-H6:CD20-scFv either alone or in combination with molecules triggering NKG2D may provide an innovative strategy to enhance specific anti-tumoral NK cell cytotoxicity. Disclosures: van de Winkel: Genmab: Employment. Parren:Genmab BV: Employment. Peipp:Genmab: Consultancy.

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