Direct and Natural Killer Cell-Mediated Anti-Tumor Effects of Low-Dose Bortezomib in Hepatocellular Carcinoma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4181-4181
Author(s):  
Matthias Krusch ◽  
Sorin Armeanu ◽  
Katrin M. Baltz ◽  
Ulrich M. Lauer ◽  
Alexander Steinle ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Nk Cells ◽  
Low Dose ◽  
Nk Cell ◽  
Hepatoma Cell ◽  
Hepatoma Cells ◽  
Cell Cytotoxicity ◽  
Bortezomib Treatment ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

Abstract Background & Aims: Hepatocellular carcinoma (HCC) displays a particular resistance to conventional cytostatic agents. Therefore, alternative treatment strategies focus on novel substances exhibiting anti-neoplastic and/or immunomodulatory activity enhancing for example Natural Killer (NK) cell anti-tumor reactivity. However, the tumor-associated ligands engaging activating NK cell receptors are largely unknown. Exceptions are the NKG2D ligands (NKG2DL) of the MIC and ULBP protein families, which potently stimulate NK cell responses. We studied the consequences of proteasome inhibition with regard to direct and NK cell-mediated effects against HCC. Methods: Primary human hepatocytes (PHH) from different donors, hepatoma cell lines and NK cells were exposed to Bortezomib. Growth and viability of hepatoma cells and PHH as well as immunomodulatory effects including alterations of NKG2DL expression on hepatoma cells, specific induction of NK cell cytotoxicity and IFN-γ production were investigated. Results: Bortezomib treatment inhibited hepatoma cell growth with IC50 values between 2.4 and 7.7 nanomol/liter. These low doses increased MICA/B mRNA levels and total and cell surface protein expression in hepatoma cells, which stimulated cytotoxicity and IFN-γ production of cocultured NK cells. Importantly, while IFN-γ production of NK cells was concentration-dependently reduced, low-dose Bortezomib neither induced NKG2DL expression or cell death in PHH nor altered NK cell cytotoxicity. Conclusions: Low-dose Bortezomib mediates a specific dual anti-tumor effect in HCC by inhibiting tumor cell proliferation and by priming hepatoma cells for NK cell anti-tumor reactivity. Our data suggest the clinical evaluation of Bortezomib treatment in HCC, especially in combination with immunotherapeutic approaches like adoptive NK cell transfer.

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.

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]

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.

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.

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.

Differential Effects of the BCR-ABL-Inhibitors Imatinib, Nilotinib and Dasatinib on NK Cell Reactivity against Chronic Myeloid Leukemia (CML)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3200-3200
Author(s):  
Matthias Krusch ◽  
Julia Salih ◽  
Lothar Kanz ◽  
Helmut R Salih
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Minor Effect ◽  
Cell Cytotoxicity ◽  
Cell Reactivity ◽  
Erk Phosphorylation ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
A Minor

Abstract CML is characterized by the BCR-ABL fusion protein, which mediates the oncogenic signaling. This led to the development of BCR-ABL inhibitors revolutionizing therapy of CML. However, as recently reported for Dasatinib (Schade et al., Blood 111:1366 (2008); Blake et al., Blood 111:4415 (2008)), these agents may impair the activity of immune effector cells like NK cells and T cells. After initiating oncogenic events, development and progression of clinically apparent malignancy is dependent on the evasion of the tumor cells from immunosurveillance. In light of the important role of NK cell reactivity against leukemia we compared the influence of Imatinib, Nilotinib and Dasatinib on the reactivity of both resting and IL-2 activated NK cells against CML cells to identify the compound with the least immuno-compromising side effects. First, the effects of the compounds on NK cell reactivity in concentrations corresponding to plasma peak levels were studied. Dasatinib (200nM) completely abolished NK cell granule mobilization, cytotoxicity and IFN-γ production, while no substantial inhibition was observed with Imatinib (5μM) and Nilotinib (3.6μM) mediated a minor but significant inhibition (p&lt;0.05, Student’s T-test). Presence of the compounds in concentrations corresponding to IC50 levels (Imatinib 600nM, Nilotinib 30nM, Dasatinib 10nM) revealed no influence of Imatinib and Nilotinib, while Dasatinib still significantly reduced NK cell cytotoxicity and IFN-γ production up to 60%. Since Dasatinib, in addition to BCR-ABL, potently inhibits SRC kinases, which are involved in the activation of MAPK pathways and thus crucial for NK cell cytotoxicity, we determined the influence of the compounds on ERK phosphorylation. While no inhibitory effect was observed using Imatinib and Nilotinib, Dasatinib markedly reduced ERK phosphorylation in NK cells. Our data demonstrate that NK cell anti-tumor reactivity is not inhibited by clinically relevant concentrations of Imatinib. While Nilotinib may mediate a minor effect, Dasatinib substantially impairs NK cell reactivity by inhibition of signaling pathways crucial for NK cell effector functions. For a given patient, the choice and dosing of the most suitable BCR-ABL inhibitor may thus require careful consideration of its influence on the immune system, especially in view of the important role of NK cells in the immunesurveillance of residual leukemia.

scholarly journals LncRNA GAS5 enhanced the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3

2019 ◽  
Vol 25 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Peipei Fang ◽  
Luxia Xiang ◽  
Weilai Chen ◽  
Shaoxun Li ◽  
Shanshan Huang ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Nk Cells ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Killing Effect ◽  
Apoptosis Rate ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
Lncrna Gas5

This study aimed to explore the role of lncRNA GAS5 in the regulation of the killing effect of NK cells on liver cancer. Compared with a control group, lncRNA GAS5, RUNX3, and NCR1 were down-regulated in NK cells of patients with liver cancer, whereas miR-544 expression was up-regulated in NK cells of patients with liver cancer. Activated NK cells had higher IFN-γ level. Knockdown of GAS5 in activated NK cells decreased IFN-γ secretion, NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 and Huh7 cells. We also proved the interaction of GAS5 and miR-544, and the negative regulation role of GAS5 on miR-544. GAS5 overexpression in activated NK cells increased RUNX3 expression, IFN-γ secretion, the NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 cells, while miR-544 mimic abolished the promotion effect of GAS5 overexpression. Finally, in vivo experiments indicated an inhibition effect of GAS5 in tumor growth. LncRNA GAS5 overexpression enhances the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3.

scholarly journals NK cell activation in visceral leishmaniasis requires TLR9, myeloid DCs, and IL-12, but is independent of plasmacytoid DCs

2007 ◽  
Vol 204 (4) ◽  
pp. 893-906 ◽  
Author(s):  
Ulrike Schleicher ◽  
Jan Liese ◽  
Ilka Knippertz ◽  
Claudia Kurzmann ◽  
Andrea Hesse ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Nk Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
Dependent Manner ◽  
Cell Cytotoxicity ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

Natural killer (NK) cells are sentinel components of the innate response to pathogens, but the cell types, pathogen recognition receptors, and cytokines required for their activation in vivo are poorly defined. Here, we investigated the role of plasmacytoid dendritic cells (pDCs), myeloid DCs (mDCs), Toll-like receptors (TLRs), and of NK cell stimulatory cytokines for the induction of an NK cell response to the protozoan parasite Leishmania infantum. In vitro, pDCs did not endocytose Leishmania promastigotes but nevertheless released interferon (IFN)-α/β and interleukin (IL)-12 in a TLR9-dependent manner. mDCs rapidly internalized Leishmania and, in the presence of TLR9, produced IL-12, but not IFN-α/β. Depletion of pDCs did not impair the activation of NK cells in L. infantum–infected mice. In contrast, L. infantum–induced NK cell cytotoxicity and IFN-γ production were abolished in mDC-depleted mice. The same phenotype was observed in TLR9−/− mice, which lacked IL-12 expression by mDCs, and in IL-12−/− mice, whereas IFN-α/β receptor−/− mice showed only a minor reduction of NK cell IFN-γ expression. This study provides the first direct evidence that mDCs are essential for eliciting NK cell cytotoxicity and IFN-γ release in vivo and demonstrates that TLR9, mDCs, and IL-12 are functionally linked to the activation of NK cells in visceral leishmaniasis.

scholarly journals The effect of IL-2 stimulation and treatment of TRPM3 on channel co-localisation with PIP2 and NK cell function in myalgic encephalomyelitis/chronic fatigue syndrome patients

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Natalie Eaton-Fitch ◽  
Hélène Cabanas ◽  
Stanley du Preez ◽  
Donald Staines ◽  
Sonya Marshall-Gradisnik
Keyword(s):  
Chronic Fatigue Syndrome ◽  
Nk Cells ◽  
Cell Function ◽  
Nk Cell ◽  
Chronic Fatigue ◽  
Signalling Pathways ◽  
Cell Cytotoxicity ◽  
Fatigue Syndrome ◽  
Intracellular Signalling Pathways ◽  
Nk Cell Cytotoxicity

Abstract Background Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a serious multifactorial disorder. The origin remains ambiguous, however reduced natural killer (NK) cell cytotoxicity is a consistent immunological feature of ME/CFS. Impaired transient receptor potential melastatin 3 (TRPM3), a phosphatidylinositol dependent channel, and impaired calcium mobilisation have been implicated in ME/CFS pathology. This investigation aimed to examine the localisation of TRPM3 at the NK cell plasma membrane and co-localisation with phosphatidylinositol 4,5-bisphosphate (PIP2). The effect of IL-2 priming and treatment using pregnenolone sulfate (PregS) and ononetin on TRPM3 co-localisation and NK cell cytotoxicity in ME/CFS patients and healthy controls (HC) was also investigated. Methods NK cells were isolated from 15 ME/CFS patients and 15 age- and sex-matched HC. Immunofluorescent technique was used to determine co-localisation of TRPM3 with the NK cell membrane and with PIP2 of ME/CFS patients and HC. Flow cytometry was used to determine NK cell cytotoxicity. Following IL-2 stimulation and treatment with PregS and ononetin changes in co-localisation and NK cell cytotoxicity were measured. Results Overnight treatment of NK cells with PregS and ononetin resulted in reduced co-localisation of TRPM3 with PIP2 and actin in HC. Co-localisation of TRPM3 with PIP2 in NK cells was significantly reduced in ME/CFS patients compared with HC following priming with IL-2. A significant increase in co-localisation of TRPM3 with PIP2 was reported following overnight treatment with ononetin within ME/CFS patients and between groups. Baseline NK cell cytotoxicity was significantly reduced in ME/CFS patients; however, no changes were observed following overnight incubation with IL-2, PregS and ononetin between HC and ME/CFS patients. IL-2 stimulation significantly enhanced NK cell cytotoxicity in HC and ME/CFS patients. Conclusion Significant changes in co-localisation suggest PIP2-dependent TRPM3 function may be impaired in ME/CFS patients. Stimulation of NK cells with IL-2 significantly enhanced cytotoxic function in ME/CFS patients demonstrating normal function compared with HC. A crosstalk exists between IL-2 and TRPM3 intracellular signalling pathways which are dependent on Ca2+ influx and PIP2. While IL-2R responds to IL-2 binding in vitro, Ca2+ dysregulation and impaired intracellular signalling pathways impede NK cell function in ME/CFS patients.

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