| 1. |
- Aydin, Ebru, et al.
(author)
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NOX2 inhibition reduces oxidative stress and prolongs survival in murine KRAS-induced myeloproliferative disease
- 2019
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In: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 38:9, s. 1534-1543
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Journal article (peer-reviewed)abstract
- Mutations leading to constitutive RAS activation contribute in myeloid leukemogenesis. RAS mutations in myeloid cells are accompanied by excessive formation of reactive oxygen species (ROS), but the source of ROS and their role for the initiation and progression of leukemia have not been clearly defined. To determine the role of NOX2-derived ROS in RAS-driven leukemia, double transgenic LSL-Kras(G12D) x Mx1-Cre mice expressing oncogenic KRAS in hematopoietic cells (M-Kras(G12D)) were treated with N-alpha-methyl-histamine (NMH) that targeted the production of NOX2-derived ROS in leukemic cells by agonist activity at histamine H-2 receptors. M-Kras(G12D) mice developed myeloid leukemia comprising mature CD11b(+)Gr1(+) myeloid cells that produced NOX2-derived ROS. Treatment of M-Kras(G12D) mice with NMH delayed the development of myeloproliferative disease and prolonged survival. In addition, NMH-treated M-Kras(G12D) mice showed reduction of intracellular ROS along with reduced DNA oxidation and reduced occurence of double-stranded DNA breaks in myeloid cells. The in vivo expansion of leukemia was markedly reduced in triple transgenic mice where KRAS was expressed in hematopoietic cells of animals with genetic NOX2 deficiency (Nox2(-/-) x LSL-Kras(G12D) x Mx1-Cre). Treatment with NMH did not alter in vivo expansion of leukemia in these NOX2-deficient transgenic mice. We propose that NOX2-derived ROS may contribute to the progression of KRAS-induced leukemia and that strategies to target NOX2 merit further evaluation in RAS-mutated hematopoietic cancer.
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| 2. |
- Bernson, Elin, 1987, et al.
(author)
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Impact of killer-immunoglobulin-like receptor and human leukocyte antigen genotypes on the efficacy of immunotherapy in acute myeloid leukemia
- 2017
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In: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551. ; 31:12, s. 2552-2559
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Journal article (peer-reviewed)abstract
- Interactions between killer-immunoglobulin-like receptors (KIRs) and their HLA class I ligands are instrumental in natural killer (NK) cell regulation and protect normal tissue from NK cell attack. Human KIR haplotypes comprise genes encoding mainly inhibitory receptors (KIR A) or activating and inhibitory receptors (KIR B). A substantial fraction of humans lack ligands for inhibitory KIRs (iKIRs), that is, a 'missing ligand' genotype. KIR B/x and missing ligand genotypes may thus give rise to potentially autoreactive, unlicensed NK cells. Little is known regarding the impact of such genotypes in untransplanted acute myeloid leukemia (AML). For this study, NK cell phenotypes and KIR/HLA genotypes were determined in 81 AML patients who received immunotherapy with histamine dihydrochloride and low-dose IL-2 for relapse prevention (NCT01347996). We observed that presence of unlicensed NK cells impacted favorably on clinical outcome, in particular among patients harboring functional NK cells reflected by high expression of the natural cytotoxicity receptor (NCR) NKp46. Genotype analyses suggested that the clinical benefit of high NCR expression was restricted to patients with a missing ligand genotype and/or a KIR B/x genotype. These data imply that functional NK cells are significant anti-leukemic effector cells in patients with KIR/HLA genotypes that favor NK cell autoreactivity.
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| 3. |
- Grauers Wiktorin, Hanna, 1990, et al.
(author)
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Histamine targets myeloid-derived suppressor cells and improves the anti-tumor efficacy of PD-1/PD-L1 checkpoint blockade
- 2019
-
In: Cancer Immunology Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 68:2, s. 163-174
-
Journal article (peer-reviewed)abstract
- Myeloid-derived suppressor cells (MDSCs) are immature monocytes and granulocytes that impede immune-mediated clearance of malignant cells by multiple mechanisms, including the formation of immunosuppressive reactive oxygen species (ROS) via the myeloid cell NADPH oxidase (NOX2). Histamine dihydrochloride (HDC), a NOX2 inhibitor, exerts anti-cancer efficacy in experimental tumor models but the detailed mechanisms are insufficiently understood. To determine effects of HDC on the MDSC compartment we utilized three murine cancer models known to entail accumulation of MDSC, i.e. EL-4 lymphoma, MC-38 colorectal carcinoma, and 4T1 mammary carcinoma. In vivo treatment with HDC delayed EL-4 and 4T1 tumor growth and reduced the ROS formation by intratumoral MDSCs. HDC treatment of EL-4 bearing mice also reduced the accumulation of intratumoral MDSCs and reduced MDSC-induced suppression of T cells ex vivo. Experiments using GR1-depleted and Nox2 knock out mice supported that the anti-tumor efficacy of HDC required presence of NOX2(+) GR1(+) cells in vivo. In addition, treatment with HDC enhanced the anti-tumor efficacy of programmed cell death receptor 1 (PD-1) and PD-1 ligand checkpoint blockade in EL-4- and MC-38-bearing mice. Immunomodulatory effects of a HDC-containing regimen on MDSCs were further analyzed in a phase IV trial (Re:Mission Trial, ClinicalTrials.gov; NCT01347996) where patients with acute myeloid leukemia received HDC in conjunction with low-dose IL-2 (HDC/IL-2) for relapse prevention. Peripheral CD14(+)HLA-DR-/low MDSCs (M-MDSCs) were reduced during cycles of HDC/IL-2 therapy and a pronounced reduction of M-MDSCs during HDC/IL-2 treatment heralded favorable clinical outcome. We propose that anti-tumor properties of HDC may comprise the targeting of MDSCs.
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| 4. |
- Martner, Anna, 1979, et al.
(author)
-
NK cell expression of natural cytotoxicity receptors may determine relapse risk in older AML patients undergoing immunotherapy for remission maintenance.
- 2015
-
In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 6:40, s. 42569-74
-
Journal article (peer-reviewed)abstract
- In a phase IV trial, eighty-four patients (age 18-79) with acute myeloid leukemia (AML) in first complete remission (CR) received cycles of immunotherapy with histamine dihydrochloride (HDC) and low-dose human recombinant interleukin-2 (IL-2) to prevent relapse in the post-consolidation phase. Aspects of natural killer (NK) cell biology were analyzed before and during immunotherapy with focus on outcome in older patients. In younger (<60 years old, n = 37) and older patients (>60 years old, n = 47), treatment with HDC/IL-2 resulted in an expansion of CD56bright and CD16+ NK cells in blood along with an increased NK cell expression of the natural cytotoxicity receptors (NCR) NKp30 and NKp46. In older patients, a high expression of NKp30 or NKp46 on CD16+ NK cells before and during therapy predicted leukemia-free and overall survival. These results suggest that NK cell functions determine relapse risk and survival in older AML patients and point to biomarkers of efficacy in protocols for remission maintenance.
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| 5. |
- Martner, Anna, 1979, et al.
(author)
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Role of natural killer cell subsets and natural cytotoxicity receptors for the outcome of immunotherapy in acute myeloid leukemia
- 2016
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In: Oncoimmunology. - : Informa UK Limited. - 2162-402X. ; 5:1
-
Journal article (peer-reviewed)abstract
- In a phase IV trial, 84 patients (age 18-79) with acute myeloid leukemia (AML) in first complete remission (CR) received cycles of immunotherapy with histamine dihydrochloride (HDC) and low-dose human recombinant interleukin 2 (IL-2) for 18 months to prevent leukemic relapse. During cycles, the treatment resulted in expansion of CD56(bright) (CD3 /16 /56(bright)) and CD16(+) (CD3 /16(+)/56(+)) natural killer (NK) cells in the blood along with increased NK cell expression of the natural cytotoxicity receptors (NCRs) NKp30 and NKp46. Multivariate analyses correcting for age and risk group demonstrated that high CD56(bright) NK cell counts and high expression of NKp30 or NKp46 on CD16(+) NK cells independently predicted leukemia-free survival (LFS) and overall survival (OS). Our results suggest that the dynamics of NK cell subsets and their NCR expression may determine the efficiency of relapse-preventive immunotherapy in AML.
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| 6. |
- Rydström, Anna, 1976, et al.
(author)
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Dynamics of myeloid cell populations during relapse-preventive immunotherapy in acute myeloid leukemia
- 2017
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In: Journal of Leukocyte Biology. - 0741-5400. ; 102:2, s. 467-474
-
Journal article (peer-reviewed)abstract
- Relapse of leukemia in the postchemotherapy phase contributes to the poor prognosis and survival in patients with acute myeloid leukemia (AML). In an international phase IV trial (ClinicalTrials.gov; NCT01347996), 84 patients with AML in first complete remission who had not undergone transplantation received immunotherapy with histamine dihydrochloride (HDC) and low-dose IL-2 with the aim of preventing relapse. The dynamics of myeloid cell counts and expression of activation markers was assessed before and after cycles of immunotherapy and correlated with clinical outcome in terms of relapse risk and survival. During cycles, a pronounced increase in blood eosinophil counts was observed along with a reduction in monocyte and neutrophil counts. A strong reduction of blood monocyte counts during the first HDC/IL-2 treatment cycle predicted leukemia-free survival. The HDC component of the immunotherapy exerts agonist activity at histamine type 2 receptors (H2Rs) that are expressed by myeloid cells. It was observed that the density of H-2 R expression in blood monocytes increased during cycles of immunotherapy and that high monocyte H2R expression implied reduced relapse risk and improved overall survival. Several other activation markers, including HLA-DR, CD86, and CD40, were induced in monocytes and dendritic cells during immunotherapy but did not predict clinical outcome. In addition, expression of HLA-ABC increased in all myeloid populations during therapy. A low expression of HLA-ABC was associated with reduced relapse risk. These results suggest that aspects of myeloid cell biology may impact clinical benefit of relapse-preventive immunotherapy in AML.
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| 7. |
- Sander, Frida Ewald, et al.
(author)
-
Dynamics of cytotoxic T cell subsets during immunotherapy predicts outcome in acute myeloid leukemia
- 2016
-
In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:7, s. 7586-7596
-
Journal article (peer-reviewed)abstract
- Preventing relapse after chemotherapy remains a challenge in acute myeloid leukemia (AML). Eighty-four non-transplanted AML patients in first complete remission received relapse-preventive immunotherapy with histamine dihydrochloride and low-dose interleukin-2 in an international phase IV trial (ClinicalTrials.gov; NCT01347996). Blood samples were drawn during cycles of immunotherapy and analyzed for CD8(+) (cytotoxic) T cell phenotypes in blood. During the first cycle of therapy, a re-distribution of cytotoxic T cells was observed comprising a reduction of T effector memory cells and a concomitant increase of T effector cells. The dynamics of T cell subtypes during immunotherapy prognosticated relapse and survival, in particular among older patients and remained significantly predictive of clinical outcome after correction for potential confounders. Presence of CD8(+) T cells with specificity for leukemia-associated antigens identified patients with low relapse risk. Our results point to novel aspects of T cell-mediated immunosurveillance in AML and provide conceivable biomarkers in relapse-preventive immunotherapy.
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| 8. |
- Sander, Frida Ewald, et al.
(author)
-
Role of regulatory T cells in acute myeloid leukemia patients undergoing relapse-preventive immunotherapy
- 2017
-
In: Cancer Immunology Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 66:11, s. 1473-1484
-
Journal article (peer-reviewed)abstract
- Regulatory T cells - (Tregs) have been proposed to dampen functions of anti-neoplastic immune cells and thus promote cancer progression. In a phase IV trial (Re: Mission Trial, NCT01347996, http://www.clinicaltrials.gov) 84 patients (age 18-79) with acute myeloid leukemia (AML) in first complete remission (CR) received ten consecutive 3-week cycles of immunotherapy with histamine dihydrochloride (HDC) and low-dose interleukin-2 (IL-2) to prevent relapse of leukemia in the post-consolidation phase. This study aimed at defining the features, function and dynamics of Foxp3(+)CD25(high)CD4(+) T-regs during immunotherapy and to determine the potential impact of T-regs on relapse risk and survival. We observed a pronounced increase in T-reg counts in peripheral blood during initial cycles of HDC/IL-2. The accumulating T-regs resembled thymic-derived natural T-regs (nT(regs)), showed augmented expression of CTLA-4 and suppressed the cell cycle proliferation of conventional T cells ex vivo. Relapse of AML was not prognosticated by T-reg counts at onset of treatment or after the first cycle of immunotherapy. However, the magnitude of T-reg induction was diminished in subsequent treatment cycles. Exploratory analyses implied that a reduced expansion of T-regs in later treatment cycles and a short T-reg telomere length were significantly associated with a favorable clinical outcome. Our results suggest that immunotherapy with HDC/IL-2 in AML entails induction of immunosuppressive T-regs that may be targeted for improved anti-leukemic efficiency.
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| 9. |
- Aurelius, Johan, 1980, et al.
(author)
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Anthracycline-based consolidation may determine outcome of post-consolidation immunotherapy in AML
- 2019
-
In: Leukemia & Lymphoma. - : Informa UK Limited. - 1042-8194 .- 1029-2403. ; 60:11, s. 2771-2778
-
Journal article (peer-reviewed)abstract
- Consolidation chemotherapy in acute myeloid leukemia (AML) aims at eradicating residual leukemic cells and mostly comprises high-dose cytarabine with or without the addition of anthracyclines, including daunorubicin. Immunogenic cell death (ICD) may contribute to the efficacy of anthracyclines in solid cancer, but the impact of ICD in AML is only partly explored. We assessed aspects of ICD, as reflected by calreticulin expression, in primary human AML blasts and observed induction of surface calreticulin upon exposure to daunorubicin but not to cytarabine. We next assessed immune phenotypes in AML patients in complete remission (CR), following consolidation chemotherapy with or without anthracyclines. These patients subsequently received immunotherapy with histamine dihydrochloride (HDC) and IL-2. Patients who had received anthracyclines for consolidation showed enhanced frequencies of CD8(+) T-EM cells in blood along with improved survival. We propose that the choice of consolidation therapy prior to AML immunotherapy may determine clinical outcome.
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| 10. |
- Aurelius, Johan, 1980, et al.
(author)
-
NOX2-dependent immunosuppression in chronic myelomonocytic leukemia
- 2017
-
In: Journal of Leukocyte Biology. - 0741-5400 .- 1938-3673. ; 102:2, s. 459-466
-
Journal article (peer-reviewed)abstract
- Chronic myelomonocytic leukemia (CMML) is a myeloproliferative and myelodysplastic neoplasm with few treatment options and dismal prognosis. The role of natural killer (NK) cells and other antileukemic lymphocytes in CMML is largely unknown. We aimed to provide insight into the mechanisms of immune evasion in CMML with a focus on immunosuppressive reactive oxygen species (ROS) formed by the myeloid cell NADPH oxidase-2 (NOX2). The dominant population of primary human CMML cells was found to express membrane-bound NOX2 and to release ROS, which, in turn, triggered extensive PARP-1-dependent cell death in cocultured NK cells, CD8(+) T effector memory cells, and CD8(+) T effector cells. Inhibitors of ROS formation and scavengers of extracellular ROS prevented CMML cell-induced lymphocyte death and facilitated NK cell degranulation toward Ab-coated, primary CMML cells. In patients with CMML, elevation of immature cell counts (CD34(+)) in blood was associated with reduced expression of several NK cell-activating receptors. We propose that CMML cells may use extracellular ROS as a targetable mechanism of immune escape.
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| 11. |
- Aydin, Ebru, et al.
(author)
-
Role of NOX2-Derived Reactive Oxygen Species in NK Cell-Mediated Control of Murine Melanoma Metastasis
- 2017
-
In: Cancer Immunology Research. - : American Association for Cancer Research (AACR). - 2326-6066 .- 2326-6074. ; 5:9, s. 804-811
-
Journal article (peer-reviewed)abstract
- The NADPH oxidase of myeloid cells, NOX2, generates reactive oxygen species (ROS) to eliminate pathogens and malignant cells. NOX2-derived ROS have also been proposed to dampen functions of natural killer (NK) cells and other antineoplastic lymphocytes in the microenvironment of established tumors. The mechanisms by which NOX2 and ROS influence the process of distant metastasis have only been partially explored. Here, we utilized genetically NOX2-deficient mice and pharmacologic inhibition of NOX2 to elucidate the role of NOX2 for the hematogenous metastasis of melanoma cells. After intravenous inoculation of B16F1 or B16F10 cells, lung metastasis formation was reduced in B6.129S6 Cybb(m1DinK) (Nox2-KO) versus Nox2-sufficient wild-type (WT) mice. Systemic treatment with the NOX2-inhibitor histamine dihydrochloride (HDC) reduced melanoma metastasis and enhanced the infiltration of IFN gamma-producing NK cells into lungs of WT but not of Nox2-KO mice. IFN gamma-deficient B6.129S7-Ifngt(m1Ts)/ J mice were prone to develop melanoma metastases and did not respond to in vivo treatment with HDC. We propose that NOX2-derived ROS facilitate metastasis of melanoma cells by downmodulating NK-cell function and that inhibition of NOX2 may restore IFN gamma-dependent, NK cell-mediated clearance of melanoma cells.
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| 12. |
- Bernson, Elin, 1987, et al.
(author)
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Cytomegalovirus Serostatus Affects Autoreactive NK Cells and Outcomes of IL2-Based Immunotherapy in Acute Myeloid Leukemia
- 2018
-
In: Cancer Immunology Research. - : American Association for Cancer Research (AACR). - 2326-6066 .- 2326-6074. ; 6:9, s. 1110-1119
-
Journal article (peer-reviewed)abstract
- Human cytomegalovirus (CMV) infection is reported to promote NK cell differentiation and education. The CMV-induced generation of highly differentiated adaptive-like NK cells has been proposed to affect favorably on the maintenance of remission in patients with acute myeloid leukemia (AML) after allogeneic stem cell transplantation (allo-SCT). The impact of CMV infection and adaptive-like NK cells on relapse and survival of patients with AML not receiving allo-SCT remains unknown. We assayed CMV IgG serostatus to determine past CMV infection in 81 nontransplanted AML patients who were receiving relapse-prevention immunotherapy comprising histamine dihydrochloride and low-dose interleukin-2 (HDC/IL2; NCT01347996). CMV seropositivity correlated negatively with leukemia-free and overall survival of patients receiving HDC/IL2, but did not correlate with outcomes in a contemporary control cohort. Analysis of outcome after stratification of patients based on concordant or discordant killer immunoglobulin-like receptor (KIR) and HLA genotypes implied that the negative impact of CMV seropositivity was restricted to patients lacking a ligand to inhibitory KIRs (iKIR). Previous CMV infection was also associated with fewer NK cells expressing only nonself iKIRs (NS-iKIR). We propose that CMV-driven NK cell education depletes the population of NS-iKIR NK cells, which in turn reduces the clinical benefit of relapse-preventive immunotherapy in AML.
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| 13. |
- Dolatabadi, Soheila, et al.
(author)
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JAK–STAT signalling controls cancer stem cell properties including chemotherapy resistance in myxoid liposarcoma
- 2019
-
In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 145:2, s. 435-449
-
Journal article (peer-reviewed)abstract
- Myxoid liposarcoma (MLS) shows extensive intratumoural heterogeneity with distinct subpopulations of tumour cells. Despite improved survival of MLS patients, existing therapies have shortcomings as they fail to target all tumour cells. The nature of chemotherapy-resistant cells in MLS remains unknown. Here, we show that MLS cell lines contained subpopulations of cells that can form spheres, efflux Hoechst dye and resist doxorubicin, all properties attributed to cancer stem cells (CSCs). By single-cell gene expression, western blot, phospho-kinase array, immunoprecipitation, immunohistochemistry, flow cytometry and microarray analysis we showed that a subset of MLS cells expressed JAK–STAT genes with active signalling. JAK1/2 inhibition via ruxolitinib decreased, while stimulation with LIF increased, phosphorylation of STAT3 and the number of cells with CSC properties indicating that JAK–STAT signalling controlled the number of cells with CSC features. We also show that phosphorylated STAT3 interacted with the SWI/SNF complex. We conclude that MLS contains JAK–STAT-regulated subpopulations of cells with CSC features. Combined doxorubicin and ruxolitinib treatment targeted both proliferating cells as well as cells with CSC features, providing new means to circumvent chemotherapy resistance in treatment of MLS patients. © 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC
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| 14. |
- Grauers Wiktorin, Hanna, 1990, et al.
(author)
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Mutated NPM1 in combination with overexpression of Meis1 or Hoxa9 is not sufficient to induce acute myeloid leukemia
- 2016
-
In: Experimental Hematolgy & Oncology. - : Springer Science and Business Media LLC. - 2162-3619. ; 5
-
Journal article (peer-reviewed)abstract
- Background: Acute myeloid leukemia (AML) carrying nucleophosmin 1 (NPM1) mutations (NPMc(+)) is regarded as a separate entity of myeloid neoplasms due to its distinct biological and clinical features. However, NPMc(+) alone displays low leukemogenic activity and cooperating events appear crucial for AML to develop. Dysregulation of homeobox genes, such as HOXA9 and MEIS1, is a common transcriptional signature of NPMc(+) AML. Furthermore, the pathogenic role for NPMc(+) in AML remains incompletely understood. Aim: To elucidate if NPMc(+) collaborates with Meis1 or Hoxa9 in the evolvement of AML. Methods: Murine bone marrow cells were genetically engineered to express mutated NPM1 variant A in combination with overexpression of Meis1 or Hoxa9. The capacity of the transduced cells to transform in vitro and to cause leukemia in vivo was then assessed. Findings and conclusion: There was no synergy between NPMc(+) and Meis1 or Hoxa9 in causing leukemogenic transformation of murine bone marrow cells, or in inducing AML in a transplantation model. Hence, overexpression of Meis1 or Hoxa9 in combination with NPMc(+) expression was not sufficient to generate an NPMc(+) AML mouse model.
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| 15. |
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| 16. |
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| 17. |
- Hallner, Alexander, 1990, et al.
(author)
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The HLA-B-21 dimorphism impacts on NK cell education and clinical outcome of immunotherapy in acute myeloid leukemia
- 2019
-
In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 133:13, s. 1479-1488
-
Journal article (peer-reviewed)abstract
- Natural killer (NK) cell function is regulated by inhibitory receptors, such as the family of killer immunoglobulin-like receptors (KIRs) and the NKG2A/CD94 heterodimer. These receptors recognize cognate HLA class I molecules on potential target cells, and recent studies imply that an HLA-B dimorphism at position -21 in the gene segment encoding the leader peptide dictates whether NK cell regulation primarily relies on the KIRs or the NKG2A/CD94 receptor. The impact of this HLA-B dimorphism on NK cell-mediated destruction of leukemic cells or on the course of leukemia is largely unknown. In a first part of this study, we compared functions of NK cells in subjects carrying HLA-B -21Mor 21T using interleukin-2 (IL-2)-activated NK cells and leukemic cells from patients with acute myeloid leukemia (AML). Subjects carrying HLA-B -21M harbored better-educated NKG2A1 NK cells and displayed superior capacity to degranulate lytic granules against KIR ligandmatched primary leukemic blasts. Second, we aimed to define the potential impact of HLA-B -21 variation on the course of AML in a phase 4 trial in which patients received IL-2based immunotherapy. In keeping with the hypothesis that 21M may be associated with improved NK cell functionality, we observed superior leukemia-free survival and overall survival in -21M patients than in -21T patients during IL-2based immunotherapy. We propose that genetic variation at HLA-B -21 may determine the antileukemic efficacy of activated NK cells and the clinical benefit of NK cell-activating immunotherapy.
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| 18. |
- Johansson, Junko, 1989, et al.
(author)
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Isolated Limb Perfusion With Melphalan Triggers Immune Activation in Melanoma Patients
- 2018
-
In: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 8
-
Journal article (peer-reviewed)abstract
- Hyperthermic isolated limb perfusion with melphalan (M-ILP) is a treatment option for melanoma patients with metastases confined to the limbs. This study aimed at defining the role of cellular immunity for the clinical response to M-ILP in melanoma patients. It was observed that patients with enhanced cytotoxic CD8(+) T cell reactivity to common antigens (HCMV/EBV/influenza virus) prior to M-ILP were more likely to achieve a complete disappearance of macroscopic tumors (complete response). Following M-ILP treatment, the proportions of CD16(+) intermediate and non-classical monocytes in peripheral blood were significantly enhanced along with induction of HLA-DR on CD4(+) and CD8(+) T cells. For further studies of the mechanism behind melphalan-induced immune activation an in vitro model, aiming at mimicking the clinical M-ILP protocol, was established, where PBMCs were co-cultured with melanoma cells, which had been pre-exposed to melphalan under mild hyperthermia. Upon exposure to melphalan, melanoma cells showed increased expression of immune-related markers including MHC class I and Hsp70. Moreover, when the melphalan-treated melanoma cells were co-cultured with PBMCs, this triggered an increased proportion of CD33(+)CD14(+)CD16(++) non-classical monocytes among the PBMCs. Furthermore, the melphalan-treated melanoma cells stimulated the expansion of CD8(+) T cells in the co-cultured PBMCs. These cells produced enhanced levels of IFN-gamma and granzyme B and were capable of killing melanoma cells. To further verify an immunogenic role of melphalan, mice were vaccinated with melphalan-exposed murine melanoma cells. When challenged with live melanoma cells, vaccinated mice showed reduced tumor growth and enhanced infiltration of tumor-specific T cells into tumors. We conclude that melphalan-exposed melanoma cells trigger expansion of CD16(+) monocytes and activate cytotoxic T cells and that these events may contribute to the antitumoral efficacy of M-ILP.
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| 19. |
- Kiffin, Roberta, et al.
(author)
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Anti-Leukemic Properties of Histamine in Monocytic Leukemia: The Role of NOX2
- 2018
-
In: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 8
-
Journal article (peer-reviewed)abstract
- In patients with acute myeloid leukemia (AML), treatment with histamine dihydrochloride (HDC) and low-dose IL-2 (HDC/ IL-2) in the post-chemotherapy phase has been shown to reduce the incidence of leukemic relapse. The clinical benefit of HDC/ IL-2 is pronounced in monocytic forms of AML, where the leukemic cells express histamine type 2 receptors (H2R) and the NAPDH oxidase-2 (NOX2). HDC ligates to H(2)Rs to inhibit NOX2-derived formation of reactive oxygen species, but details regarding the anti-leukemic actions of HDC remain to be elucidated. Here, we report that human NOX2(+) myelomonocytic/monocytic AML cell lines showed increased expression of maturation markers along with reduced leukemic cell proliferation after exposure to HDC in vitro. These effects of HDC were absent in corresponding leukemic cells genetically depleted of NOX2 (NOX2(-/-)). We also observed that exposure to HDC altered the expression of genes involved in differentiation and cell cycle progression in AML cells and that these effects required the presence of NOX2. HDC promoted the differentiation also of primary monocytic, but not non-monocytic, AML cells in vitro. In a xenograft model, immunodeficient NOG mice were inoculated with wild-type or NOX2(-/-) human monocytic AML cells and treated with HDC in vivo. The administration of HDC reduced the in vivo expansion of NOX2(+/+), but not of NOX2(-/-) human monocytic AML cells. We propose that NOX2 may be a conceivable target in the treatment of monocytic AML.
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| 20. |
- Martner, Anna, 1979, et al.
(author)
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Histamine Promotes the Development of Monocyte-Derived Dendritic Cells and Reduces Tumor Growth by Targeting the Myeloid NADPH Oxidase
- 2015
-
In: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 194:10, s. 5014-5021
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Journal article (peer-reviewed)abstract
- The efficiency of immune-mediated clearance of cancer cells is hampered by immunosuppressive mediators in the malignant microenvironment, including NADPH oxidase-derived reactive oxygen species. We aimed at defining the effects of histamine, an inhibitor of the myeloid NADPH oxidase/NOX2, on the development of Ag-presenting dendritic cells (DCs) from myeloid precursors and the impact of these mechanisms for tumor growth. Histamine was found to promote the maturation of human DCs from monocytes by increasing the expression of HLA-DR and costimulatory molecules, which resulted in improved induction of Th cells with Th0 polarity. Experiments using wild-type and NOX2-deficient myelomonoblastic cells showed that histamine facilitated myeloid cell maturation only in cells capable of generating reactive oxygen species. Treatment of mice with histamine reduced the growth of murine EL-4 lymphomas in parallel with an increment of tumor-infiltrating DCs in NOX2-sufficient mice but not in NOX2-deficient (gp91(phox-/-)) mice. We propose that strategies to target the myeloid NADPH oxidase may facilitate the development of endogenous DCs in cancer.
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| 21. |
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| 22. |
- Martner, Anna, 1979, et al.
(author)
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NOX2 in autoimmunity, tumor growth and metastasis.
- 2019
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In: The Journal of pathology. - : Wiley. - 1096-9896 .- 0022-3417. ; 247:2, s. 151-154
-
Journal article (peer-reviewed)abstract
- Myeloid cell NADPH oxidase isoform 2 (NOX2) generates reactive oxygen species (ROS) that participate in defense against microbial pathogens. Humans with compromised NOX2-mediated ROS formation develop chronic granulomatous disease characterized by recurrent bacterial and fungal infections. Additionally, impaired NOX2 function entails hyperactive lymphocytes and autoimmunity in humans and in murine models. The impact of NOX2 and ROS on cancer development is only partly explored. Recent research published in the Journal of Pathology showed that genetic depletion of any of the NOX2 subunits Cyba, Cybb, Ncf1, Ncf2 and Ncf4 reduced the formation of lung metastases following intravenous injection of murine tumor cells. These findings, together with the role of NOX2 in maintaining self-tolerance, imply that NOX2 is a targetable immune checkpoint in cancer. In particular, the possibility of modulating NOX2 to improve lymphocyte-mediated control of metastatic cells merits further investigation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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| 23. |
- Mukanyangezi, Marie Francoise, et al.
(author)
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Persistence rate of cervical human papillomavirus infections and abnormal cytology in Rwanda
- 2019
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In: HIV Medicine. - : Wiley. - 1464-2662 .- 1468-1293. ; 20:7, s. 485-495
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Journal article (peer-reviewed)abstract
- Objectives In this study, we determined the incidence and persistence of human papillomavirus (HPV) strains and of squamous intraepithelial lesions (SIL) or worse cytology in 237 HIV-positive and HIV-negative Rwandan women and whether the interleukin (IL)-28B single nucleotide polymorphism (SNP) at rs12979860 correlated with susceptibility to and persistence of HPV infection. Methods Cervical samples were collected at baseline and after 9, 18 and 24 months for a 40-HPV DNA screening test and a ThinPrep Pap test. Genotyping of the IL-28B SNP rs12979860 was performed using real-time polymerase chain reaction (PCR). Results Chronic high-risk (HR) HPV infections occurred in 56% of HIV-positive women, while no HIV-negative women developed HPV chronicity. High-grade SIL (HSIL) or cancer was diagnosed in 38% of HIV-positive women with persistent HR-HPV infections. HIV and HR-HPV positivity at baseline were factors associated with an increased risk of HPV persistence. Additionally, HR-HPV positivity at baseline was associated with an increased risk of developing HSIL or worse cytology. The unfavourable T/x genotype at rs12979860 is common among Africans, and women with this genotype were found to be more commonly infected with HPV. Conclusions HPV screening in Rwanda may help to identify women at risk of developing cervical cancer and polymorphism in IL-28B may be associated with risk of contracting HPV infection.
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| 24. |
- Ortiz, M. L., et al.
(author)
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Immature myeloid cells directly contribute to skin tumor development by recruiting IL-17-producing CD4(+) T cells
- 2015
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In: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 212:3, s. 351-367
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Journal article (peer-reviewed)abstract
- Evidence links chronic inflammation with cancer, but cellular mechanisms involved in this process remain unclear. We have demonstrated that in humans, inflammatory conditions that predispose to development of skin and colon tumors are associated with accumulation in tissues of CD33(+)S100A9(+) cells, the phenotype typical for myeloid-derived suppressor cells in cancer or immature myeloid cells (IMCs) in tumor-free hosts. To identify the direct role of these cells in tumor development, we used S100A9 transgenic mice to create the conditions for topical accumulation of these cells in the skin in the absence of infection or tissue damage. These mice demonstrated accumulation of granulocytic IMCs in the skin upon topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA), resulting in a dramatic increase in the formation of papillomas during epidermal carcinogenesis. The effect of IMCs on tumorigenesis was not associated with immune suppression, but with CCL4 (chemokine [C-C motif] ligand 4)-mediated recruitment of IL-17-producing CD4(+) T cells. This chemokine was released by activated IMCs. Elimination of CD4(+) T cells or blockade of CCL4 or IL-17 abrogated the increase in tumor formation caused by myeloid cells. Thus, this study implicates accumulation of IMCs as an initial step in facilitation of tumor formation, followed by the recruitment of CD4(+) T cells.
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| 25. |
- Riise, Rebecca E, 1987, et al.
(author)
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TLR-Stimulated Neutrophils Instruct NK Cells To Trigger Dendritic Cell Maturation and Promote Adaptive T Cell Responses
- 2015
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In: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 195:3, s. 1121-1128
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Journal article (peer-reviewed)abstract
- Polymorphonuclear neutrophils (PMNs) are innate effector cells with pivotal roles in pathogen recognition, phagocytosis, and eradication. However, their role in the development of subsequent immune responses is incompletely understood. This study aimed to identify mechanisms of relevance to the cross talk between human neutrophils and NK cells and its potential role in promoting adaptive immunity. TLR-stimulated PMNs were found to release soluble mediators to attract and activate NK cells in vitro. PMN-conditioned NK cells displayed enhanced cytotoxicity and cytokine production, and responded vigorously to ensuing stimulation with exogenous and endogenous IL-12. The neutrophil-induced activation of NK cells was prevented by caspase-1 inhibitors and by natural antagonists to IL-1 and IL-18, suggesting a role for the NOD-like receptor family pyrin domain containing-3 inflammasome. In addition, PMN-conditioned NK cells triggered the maturation of monocyte-derived dendritic cells, which promoted T cell proliferation and IFN-gamma production. These data imply that neutrophils attract NK cells to sites of infection to convert these cells into an active state, which drives adaptive immune responses via maturation of dendritic cells. Our results add to a growing body of evidence that suggests a sophisticated role for neutrophils in orchestrating the immune response to pathogens.
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| 26. |
- Rugwizangoga, Belson, et al.
(author)
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IFNL4 Genotypes Predict Clearance of RNA Viruses in Rwandan Children With Upper Respiratory Tract Infections
- 2019
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In: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 9
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Journal article (peer-reviewed)abstract
- Polymorphisms in the interferon lambda gene locus (IFNL) such as the IFNL4 genetic variants rs12979860 and rs368234815 are predictive of resolution of hepatitis C virus infection, but information about the impact of these variants in other infections is scarce. This study aimed at determining the potential impact of IFNL4 variation for the clearance of respiratory tract pathogens in Rwandan children (<= 5 years old, n = 480) seeking medical care for acute respiratory infections. Nasopharyngeal swabs were retrieved from all children at the first hospital referral and from 161 children at follow-up visits 2 weeks later. The swabs were analyzed for pathogens by real-time PCR and for host cell IFNL4 genotype at rs12979860 and rs368234815. Approximately 1/3 of the children were homozygous for the rs12979860 T allele and the rs368234815 Delta G allele, which are overrepresented in subjects of African descent. These IFNL4 variants were significantly associated with reduced clearance of RNA viruses. Our results suggest that IFNL4 genotypes that are common among subjects of African descent may determine inefficacious clearance of RNA viruses from the respiratory tract.
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| 27. |
- Skovbjerg, Susann, 1973, et al.
(author)
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Intact Pneumococci Trigger Transcription of Interferon-Related Genes in Human Monocytes, while Fragmented, Autolyzed Bacteria Subvert This Response
- 2017
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In: Infection and Immunity. - 0019-9567. ; 85:5
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Journal article (peer-reviewed)abstract
- A peculiar trait of pneumococci (Streptococcus pneumoniae) is their propensity to undergo spontaneous lysis during stationary growth due to activation of the enzyme autolysin (LytA), which fragments the peptidoglycan cell wall. The fragments that are generated upon autolysis impair phagocytosis and reduce production of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) by human leukocytes in response to intact pneumococci, thereby impeding crucial host defenses. The objective was to identify additional monocyte genes whose transcription is induced by intact pneumococci and subverted by autolyzed bacteria. Monocytes were isolated from healthy blood donors and stimulated for 3 h with UV-inactivated S. pneumoniae (Rx1PLY(-) LytA(+) strain), which is capable of autolyzing, its LytA(-) isogenic autolysin-deficient mutant, or a mixture of the two (containing twice the initial bacterial concentration). Gene expression was assessed by Illumina microarray, and selected findings were confirmed by reverse transcription-quantitative real-time PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and flow cytometry. In all, we identified 121 genes that were upregulated to a significantly higher degree by intact than autolyzed pneumococci. These included IFNB1 and a large set of interferon-induced genes, such as IFIT3, RSAD2, CFCL1, and CXCL10 genes, as well as IL12B and CD40 genes. RT-qPCR revealed that transcription of these genes in response to intact pneumococci diminished when autolyzed pneumococci were admixed and that this pattern was independent of pneumolysin. Thus, transcription of interferon-related genes is triggered by intact pneumococci and subverted by fragments generated by spontaneous bacterial autolysis. We suggest that interferon-related pathways are important for elimination of pneumococci and that autolysis contributes to virulence by extinguishing these pathways.
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| 28. |
- Werlenius, Olle, et al.
(author)
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Reactive oxygen species induced by therapeutic CD20 antibodies inhibit natural killer cell-mediated antibody-dependent cellular cytotoxicity against primary CLL cells
- 2016
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In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:22, s. 32046-32053
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Journal article (peer-reviewed)abstract
- The antibody-dependent cellular cytotoxicity (ADCC) of natural killer (NK) cells is assumed to contribute to the clinical efficacy of monoclonal antibodies (mAbs) in chronic lymphocytic leukemia (CLL) and other hematopoietic malignancies of B cell origin. We sought to determine whether reactive oxygen species (ROS)-producing monocytes regulate the ADCC of NK cells against primary CLL cells using anti-CD20 as the linking antibody. The monoclonal CD20 antibodies rituximab and ofatumumab were found to trigger substantial release of ROS from monocytes. Antibody-exposed monocytes induced NK cell apoptosis and restricted NK cell-mediated ADCC against autologous CLL cells. The presence of inhibitors of ROS formation and scavengers of ROS preserved NK cell viability and restored NK cell-mediated ADCC against primary CLL cells. We propose that limiting the antibody-induced induction of immunosuppressive ROS may improve the anti-leukemic efficacy of anti-CD20 therapy in CLL.
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