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]

Neutralization of Tumor-Derived Soluble Glucocorticoid-Induced TNF-Related Protein (GITR) Ligand Present in Cancer Patient Sera Increases Anti-Tumor Reactivity of NK Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 314-314 ◽  
Author(s):  
Katrin M. Baltz ◽  
Matthias Krusch ◽  
Tina Baessler ◽  
Anita Bringmann ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Nk Cells ◽  
Tumor Cells ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Related Protein ◽  
Effector Functions ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
Cell Effector

Abstract Glucocorticoid-induced TNF-related protein (GITR) and its ligand (GITRL) are members of the TNF/TNF receptor (TNFR) superfamily, which mediates multiple cellular functions including proliferation, differentiation, and cell death. Recently we reported that NK cells express GITR while tumor cells express GITRL, and GITR-GITRL interaction downregulates NK cell-mediated anti-tumor immunity (Baltz et al., FASEB J 2007). Many TNF family members are released as soluble forms, which affects cell-cell interactions by reduction of ligand density and distally modulates effector cells bearing the respective receptor. Here we report that human tumor cells spontaneously release a soluble form of GITRL (sGITRL), which can be detected in tumor cell culture supernatants by ELISA (detection limit 0.01ng/ml). We demonstrated that NK cell cytotoxicity and IFN-γ production in cocultures with the tumor cell lines SK-Mel (Melanoma), PC-3 (prostate), HCT116 (colon), and LX-1 (lung) were significantly (both p<0.01, Mann-Whitney U-test) and concentration dependently reduced (up to 50%) by tumor-derived sGITRL, and NK cell effector functions could be restored by neutralization of sGITRL using a GITR-Fc fusion protein. While tumor-derived GITRL did not induce apoptosis in NK cells, it diminished nuclear localized RelB indicating that sGITRL negatively modulates NK cell NF-κB activity. Furthermore, we demonstrate that significantly elevated sGITRL levels (mean 0.4ng/ml, range from 0.01 to 3.5ng/ml) were contained in 40 out of 50 sera of patients with various cancers (colon, lung and germ line), while sera of healthy volunteers (n=8) contained no detectable levels of sGITRL. Addition of sGITRL containing patient sera to cocultures of NK cells and GITRL-negative tumor cells significantly reduced NK cell cytotoxicity and IFN-γ production about 30% and 45%, respectively (both p<0.05, Mann-Whitney U-test). Again the inhibitory effects of sGITRL on NK cell effector functions could be completely restored by neutralization of sGITRL with GITR-Fc. The strong correlation of tumor incidence and elevated sGITRL levels clearly suggests that sGITRL is released at significant amounts from malignant cells in vivo and may reduce immune surveillance of human tumors. Our data indicate that determination of sGITRL levels may be implemented as an immunological diagnostic marker in tumor patients, and GITRL-neutralization may be employed in therapeutic strategies like adoptive NK cell transfer.

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&lt;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&lt;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&lt;0.04 for all groups).

IPH2101, a Novel Anti-Inhibitory KIR Monoclonal Antibody, and Lenalidomide Combine to Enhance the Natural Killer (NK) Cell Versus Multiple Myeloma (MM) Effect.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3870-3870 ◽  
Author(s):  
Don Benson ◽  
Courtney E Bakan ◽  
Shuhong Zhang ◽  
Lana Alghothani ◽  
Jing Liang ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Nk Cells ◽  
Tumor Cells ◽  
Nk Cell ◽  
Phase 1 ◽  
Granzyme B ◽  
Cell Activity ◽  
Target Cells ◽  
Nk Cell Activity ◽  
Immune Complex Formation

Abstract Abstract 3870 Poster Board III-806 Background NK cell activity against tumor cells is regulated by a balance of inhibitory and activating signals mediated by receptors on NK cells that recognize inhibitory and activating ligands expressed by cancer cells. IPH2101 (1-7F9) is a novel monoclonal anti-inhibitor KIR blocking antibody that has been shown to augment NK cell function against MM targets. Moreover, lenalidomide has been shown to expand and activate NK cells in vivo and in vitro. We have previously reported that the combination of IPH2101 and lenalidomide enhances NK cell mediated cytotoxicity against MM cells compared to each agent alone (Zhang et al., AACR 2009). We expand our studies to investigate potential mechanisms for the enhancement of NK cell activity by the combination of IPH2101 and lenalidomide. Methods The effects of IPH2101 and lenalidomide alone and in combination were studied using primary human NK cells from healthy donors as well as from MM patients. The MM cell lines U266 and RPMI 8226 as well as primary tumor cells from marrow aspirates of MM patients served as target cells. The effect of lenalidomide on MM activating and inhibitory ligand expression was studied by flow cytometry. NK cell trafficking was investigated with standard transwell plate migration assay. Immune complex formation between NK cell effectors and MM tumor targets was characterized by flow cytometry in control conditions and with NK cells pre-treated with IPH2101 and lenalidomide. The effects of IPH2101 and lenalidomide were studied regarding interferon-gamma and granzyme B production by ELISPOT and target-specific cytotoxicity studies were conducted to complement effector-based assays. Results IPH2101 (30 ug/ml) significantly enhanced cytotoxicity against U266 cells and primary MM tumor cells by both purified NK cells at effector:target (E:T) ratios of 10:1 or less, and also of freshly isolated peripheral blood mononuclear cells (PBMC) at E:T ratios of 60:1 or less, from more than 10 random donors. In addition, treatment of PBMC with 5-10 μmol/L lenalidomide for 72h without interleukin (IL)-2 increased NK cell lysis of U266. Treatment of PBMC from normal donors did not enhance the expression of the NK receptors KIR, NKG2D, NCR, TRAIL, and DNAM-1. Incubation of U266 cells with lenalidomide (5 uM) for 3-5 days resulted in significant enhancement of cytotoxicity by normal donor NK cells. This was associated with upregulation of the activating ligands, MICA, ULBP-2, DR4, and CD112. Using blocking antibodies to NKG2D, TRAIL, and DNAM-1, lenalidomide enhancement of MM cell killing was abrogated indicating the importance of the modulation of the ligands to the latter receptors by lenalidomide. Although IPH2101 and lenalidomide did not significantly increase NK cell migration into normal media, migration was enhanced 2.98-fold (+/− 0.36, p < 0.05) towards U266 cell targets (n= 3, p < 0.05) and MM patient serum 3.2-fold (+/− 0.4, n=3, p < 0.05). IPH2101 and lenalidomide also led to a 2.3-fold (+/− 0.43, p < 0.05) increase in immune complex formation between NK cells and MM tumor cells. IPH2101 and lenalidomide also augmented NK cell interferon gamma production against MM (control mean 303 spots/well +/− 13 versus 525 +/− 83, n=3, p < 0.05) and granzyme B production (control mean 115 +/− 98 versus 449 +/−72, n=3, p < 0.05). Importantly, in all experiments described herein, the effects of IPH2101 and lenalidomide together were greater than either agent alone. Conclusions Taken together, our data suggest that IPH2101 and lenalidomide may exert complementary mechanisms on both effector and target cells to enhance NK cell mediated killing of MM cells. Moreover, these agents have no predicted clinical cross-toxicities. A single-agent phase 1 clinical trial of IPH2101 has shown the mAb to be safe and well tolerated in MM patients. These findings support a phase 1/2 clinical trial of IPH2101 with lenalidomide as a first dual-innate immunotherapy for patients with MM. Disclosures: Andre: Innate Pharma: Employment. Squiban:Innate pharma: Employment. Romagne:Innate Pharma: Employment.

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.

AFM13 Is the Most Advanced Bispecific NK-Cell Engaging Antibody in Clinical Development Substantially Enhancing NK-Cell Effector Function and Proliferation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1764-1764 ◽  
Author(s):  
Jens Pahl ◽  
Uwe Reusch ◽  
Thorsten Gantke ◽  
Anne Kerber ◽  
Joachim Koch ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
Target Cells ◽  
Cell Cytotoxicity ◽  
Cell Receptors ◽  
Cell Responses ◽  
Nk Cell Receptors ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

Abstract Introduction: AFM13 is an NK-cell engaging CD30/CD16A bispecific tetravalent TandAb antibody currently in phase 2 clinical development in Hodgkin lymphoma (HL) and other CD30+ malignancies. It engages NK-cells through CD16A with high affinity and specificity and confers significantly stronger NK-cell activation compared to other therapeutic antibodies. We have previously shown synergistic efficacy when NK-cell activation by AFM13 is combined with check-point modulation such as anti-PD-1 treatment, which is known to unleash T cell and NK-cell activity. The goal of this study was to identify further candidates for combination treatments and biomarkers that potentially indicate NK-cell responses to AFM13 treatment. Methods: AFM13-mediated NK-cell cytotoxicity and IFN-γ production after 4-hour interaction with HL cell lines was measured by 51Cr release assays and flow cytometry, respectively. Expression of NK-cell receptors, NK-cell proliferation (CFSE dilution) and expansion (absolute cell counts) was analyzed by flow cytometry. Results: The interaction of NK-cells with AFM13-coated tumor cells up-regulated the expression of NK-cell receptors such as CD25, CD69, CD137/4-1BB as well as molecules that may serve as NK-cell check-points when compared with the unrelated NK-cell binding TandAb AFM12 that does not bind to target cells. Importantly, CD16A engagement by AFM13 enhanced the proliferation and expansion potential of NK-cells when subsequently incubated with IL-15 or with particularly low doses of IL-2. NK-cell cytotoxicity and IFN-γ production was substantially increased towards CD30+ tumor cells in the presence of AFM13. Even target cells resistant to naïve and IL-2/IL-15-activated NK-cells were susceptible to AFM13-induced NK-cell cytotoxicity. AFM13 concentrations of as low as 10-2 µg/mL resulted in maximal activity while AFM13 was significantly more potent than native anti-CD30 IgG1 antibody. NK-cell activation by IL-2 or IL-15 had a synergistic effect on AFM13-mediated cytotoxicity. Conclusion: AFM13 specifically enhances the cytotoxic, proliferative and cytokine-producing potential of NK-cells. Our data indicate that the distinctive modulation of NK-cell receptors can be utilized to monitor NK-cell responses during AFM13 therapy and provides candidates for therapeutic combination strategies. Moreover, the combination with low doses of IL-2 or with IL-15 may expand the quantity of tumor-reactive NK-cells after AFM13 treatment and promote NK-cell functionality in the tumor microenvironment in cancer patients. Disclosures Reusch: Affimed: Employment, Patents & Royalties: Patents. Gantke:Affimed GmbH: Employment. Kerber:Affimed: Employment. Koch:Affimed: Employment. Treder:Affimed: Employment. Cerwenka:Affimed: Research Funding.

Human plasmacytoid predendritic cells activate NK cells through glucocorticoid-induced tumor necrosis factor receptor-ligand (GITRL)

Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3617-3623 ◽  
Author(s):  
Shino Hanabuchi ◽  
Norihiko Watanabe ◽  
Yi-Hong Wang ◽  
Yui-Hsi Wang ◽  
Tomoki Ito ◽  
...  
Keyword(s):  
Nk Cells ◽  
Tumor Necrosis ◽  
Nk Cell ◽  
Tumor Necrosis Factor Receptor ◽  
Type I ◽  
Cell Cytotoxicity ◽  
Cpg Odn ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
Necrosis Factor

Plasmacytoid dendritic cell precursors (pDCs) are professional type I interferon-producing cells, a critical cell type in regulating innate and adaptive immune responses. By microarray gene expression analysis, we found that pDCs activated by virus or CpG-ODN preferentially express the ligand for the glucocorticoid-induced tumor necrosis factor receptor (GITRL), which was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry analysis. Using the same approaches, we found GITR is expressed by activated natural killer (NK) cells and T cells. We show that pDCs activated by CpG-ODN promote NK cell cytotoxicity and interferon (IFN)-γ production through type I IFNs and GITRL. Using a GITRL-transfected cell line, we further demonstrate that GITRL promotes NK cell cytotoxicity and IFN-γ production in synergy with interleukin-2 (IL-2), IFN-α, and NKG2D triggering. We also demonstrated that pDCs localized in close contact to NK cells in T-cell areas of the tonsils, and a subpopulation of the pDCs expressed GITRL. This study reveals a novel function of GITR/GITRL in pDC-mediated coactivation of NK cells.

Tim-3 expression and function in natural killer cells from advanced melanoma patients.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 8571-8571
Author(s):  
Ines Esteves Domingues Pires Da Silva ◽  
Sonia Jimenez-Baranda ◽  
Anne Gallois ◽  
Vijay Kuchroo ◽  
Iman Osman ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Advanced Melanoma ◽  
Target Cells ◽  
Cell Cytotoxicity ◽  
Healthy Donors ◽  
Melanoma Patients ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
And Function

8571 Background: The concept of CD8+ T cell exhaustion in the context of metastatic cancer has been reinforced by the recent success of immunotherapies targeting the exhaustion markers CTLA-4 and PD-1 in advanced melanoma. T-cell immunoglobulin 3 (Tim-3), another exhaustion marker, is also expressed in natural killer (NK) cells, however its role is still unknown. Recent reports have shown that NK cells, innate immune cells that eliminate tumors through cytotoxicity and IFN-g production, are functionally impaired in advanced melanoma patients, although no receptor has been linked with that phenotype so far. In this study, we characterize the role of Tim-3 in NK cells, particularly in the presence of its natural ligand, Galectin-9 (Gal-9), that is known to be expressed/secreted by some tumor cells including melanoma. Methods: We compared 20 advanced melanoma donors NK cells with 40 healthy donors NK cells as it relates to Tim-3 expression (by flow cytometry) and function (cytotoxicity, IFN-γ production and proliferation). NK cells cytotoxicity was measured by lamp-1 expression, and two different target cells were used: i) K562 cells (Gal-9-) and ii) Gmel Gal-9+ and Gmel Gal-9- sorted melanoma cells. Proliferation was quantified by CFSE after 6 days in the presence of rhIL-2. Recombinant rhGal9 effect was tested in cytotoxicity and IFN-γ production. Results: Melanoma patients NK cells express higher levels of Tim-3 compared to healthy donors NK cells (p<0.05). Melanoma patients NK cells have a defect in cytotoxicity, proliferation and IFN-γ production. Tim-3 expression by itself (without engagement of specific ligands) does not negatively affect NK cell functions (p<0.05). However, when rhGal9 is added to the system, a decrease in NK cell cytotoxicity and IFN-γ production (p<0.05) was observed. Finally, the expression of Gal-9 by the target cells induces a defect in NK cell cytotoxicity (Gmel Gal-9+ vs Gmel Gal-9-). Conclusions: These data suggest that advanced melanoma patients NK cells are exhausted, although it still remains unclear if Tim-3 is involved in this phenotype. In addition,the expression/secretion of Galectin-9, immunosuppressive for NK cells, may be a possible mechanism for tumors to evade immune surveillance.

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.

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.

Impaired NK cell cytotoxicity by high level of interferon-γ in concanavalin A-induced hepatitis

2005 ◽  
Vol 83 (11) ◽  
pp. 1045-1053 ◽  
Author(s):  
Zhongjun Dong ◽  
Cai Zhang ◽  
Haiming Wei ◽  
Rui Sun ◽  
Zhigang Tian
Keyword(s):  
Nk Cells ◽  
Cell Lines ◽  
Nk Cell ◽  
Interferon Γ ◽  
Cell Cytotoxicity ◽  
Wild Mice ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

Unlike T cells, the role of natural killer (NK) cells is not well documented in the concanavalin (ConA)- induced hepatitis model. This study aimed to investigate the regulatory effect of high levels of interferon-γ (IFN-γ) on NK cells in ConA-induced hepatitis. The cytotoxicities of NK cells from ConA-injected mice or NK cell lines (NK92 and NKL) were detected by the 4-h 51Cr release assay. Depletion of NK cells with AsGM1 antibody was used to assess the NK cell role in ConA-induced hepatitis. Expression of NK cell receptors and cytotoxic molecules was measured by reverse transcription – polymerase chain reaction. Twelve hours after ConA injection, serum IFN-γ was significantly increased in wild mice, but not in severe combined immunodeficiency mice, and hepatic NK cells exerted impaired cytotoxicity against YAC-l cells in wild mice. Eight hours after NK cells were incubated in serum from ConA-treated mice, NK cell cytotoxicity was down-modulated and the effect was abolished by pretreatment with neutralizing serum IFN-γ with specific antibody in vitro. A high concentration of IFN-γ (> 1000 U/mL) inhibited the cytotoxicities of 2 NK cell lines in vitro, accompanied with down-regulation of NKG2D transcripts and up-regulation of NKG2A/B and KIR2DL transcripts. The inhibitive role of IFN-γ was not seen in NKG2D ligand negative cells. These results suggest that NK cell cytotoxicity was inhibited by high levels of IFN-γ in ConA-induced hepatitis, which may relate to the dispensable role of NK cells.Key words: cytotoxicity, hepatoimmunology, interferon-γ, liver injury.

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