| 1. |
- Riise, Rebecca E, 1987, et al.
(författare)
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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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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 195:3, s. 1121-1128
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Akhiani, Aliasghar, 1957, et al.
(författare)
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Idelalisib Rescues Natural Killer Cells from Monocyte-Induced Immunosuppression by Inhibiting NOX2-Derived Reactive Oxygen Species.
- 2020
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Ingår i: Cancer immunology research. - 2326-6074. ; 8:12, s. 1532-1541
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Tidskriftsartikel (refereegranskat)abstract
- The phosphatidylinositol-4,5-bisphosphate-3 kinase-δ (PI3Kδ) inhibitor idelalisib, used alone or in combination with anti-CD20, is clinically efficacious in B-cell lymphoma and chronic lymphocytic leukemia (CLL) by promoting apoptosis of malignant B cells. PI3K regulates the formation of reactive oxygen species (ROS) by the myeloid NADPH oxidase NOX2, but the role of PI3Kδ in myeloid cell-induced immunosuppression is unexplored. We assessed the effects of idelalisib on the spontaneous and IgG antibody-induced ROS production by human monocytes, on ROS-induced cell death of human natural killer (NK) cells, and on tumor cell clearance in an NK cell-dependent mouse model of metastasis. Idelalisib potently and efficiently inhibited the formation of NOX2-derived ROS from monocytes and rescued NK cells from ROS-induced cell death. Idelalisib also promoted NK cell cytotoxicity against anti-CD20-coated primary human CLL cells and cultured malignant B cells. Experiments using multiple PI3K inhibitors implicated the PI3Kδ isoform in regulating NOX2-induced ROS formation and immunosuppression. In B6 mice, systemic treatment with idelalisib significantly reduced the formation of lung metastases from intravenously injected melanoma cells but did not affect metastasis in B6.129S6-Cybbtm1Din (Nox2-/-) mice or in NK cell-deficient mice. Our results imply that idelalisib rescues NK cells from NOX2/ROS-dependent immunosuppression and thus exerts antineoplastic efficacy beyond B-cell inhibition.
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| 3. |
- Akhiani, Aliasghar, 1957, et al.
(författare)
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Role of the ERK Pathway for Oxidant-Induced Parthanatos in Human Lymphocytes
- 2014
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Reactive oxygen species (ROS) are formed by myeloid cells as a defense strategy against microorganisms. ROS however also trigger poly(ADP-ribose) polymerase 1- (PARP-1) dependent cell death (parthanatos) in adjacent lymphocytes, which has been forwarded as a mechanism of immune escape in several forms of cancer. The present study assessed the role of mitogen-activated protein kinases (MAPKs), in particular the extracellular signal-regulated kinase (ERK), in ROS-induced signal transduction leading to lymphocyte parthanatos. We report that inhibitors of ERK1/2 phosphorylation upheld natural killer (NK) cell-mediated cytotoxicity under conditions of oxidative stress and rescued NK cells and CD8(+)T lymphocytes from cell death induced by ROS-producing monocytes. ERK1/2 phosphorylation inhibition also protected lymphocytes from cell death induced by exogenous hydrogen peroxide (H2O2) and from ROS generated by xanthine oxidase or glucose oxidase. Phosphorylation of ERK1/2 was observed in lymphocytes shortly after exposure to ROS. ROS-generating myeloid cells and exogenous H2O2 triggered PARP 1-dependent accumulation of poly ADP-ribose (PAR), which was prevented by ERK pathway inhibitors. ERK1/2 phosphorylation was induced by ROS independently of PARP-1. Our findings are suggestive of a role for ERK1/2 in ROS-induced lymphocyte parthanatos, and that the ERK axis may provide a therapeutic target for the protection of lymphocytes against oxidative stress.
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| 4. |
- Aurelius, Johan, 1980, et al.
(författare)
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Anthracycline-based consolidation may determine outcome of post-consolidation immunotherapy in AML
- 2019
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Ingår i: Leukemia & Lymphoma. - : Informa UK Limited. - 1042-8194 .- 1029-2403. ; 60:11, s. 2771-2778
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Aurelius, Johan, 1980, et al.
(författare)
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Chronic myeloid leukemic cells trigger poly(ADP-ribose) polymerase-dependent inactivation and cell death in lymphocytes.
- 2013
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Ingår i: Journal of leukocyte biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 93:1, s. 155-160
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Tidskriftsartikel (refereegranskat)abstract
- NK cells and T cells are commonly dysfunctional in CML, and their status may determine the course of disease. We aimed to define the molecular mechanisms of leukemia-induced immunosuppression with focus on the role of ROS and the PARP-1 pathway of cell death. Malignant granulocytes from patients with BCR-ABL-positive CML expressed the oxygen radical-producing enzyme NOX, produced large amounts of ROS, and triggered extensive cell death in NK cells. Inhibition of PARP-1 maintained NK cell viability in cocultures with suppressive leukemic cells. Under conditions of oxidative stress, PARP-1 inhibition upheld the capacity of NK cells to kill myeloid leukemic cells, in addition to restoring the proliferation and cytokine production of NK cells and cytotoxic T cells. Our findings are suggestive of a novel pathway of relevance to immunosuppression in CML.
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| 6. |
- Aurelius, Johan, 1980
(författare)
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Mechanisms of leukemia-induced immunosuppression
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aimed to define the role of reactive oxygen species (ROS), produced by the NADPH oxidase of myeloid cells, in the regulation of lymphocyte function with focus on ROS-induced dysfunction of natural killer (NK) cells and T lymphocytes in myeloid leukemia. In Paper I, a novel mechanism is presented by which specifically activated T lymphocytes evade inactivation by ROS after antigen presentation. Antigen-presenting dendritic cells were found to induce ROS-neutralizing thiols on the surface of antigen-specific T cells, but not on T cells that lacked antigen specificity. These findings may explain why antigen-specific T cells remain viable under conditions of oxidative stress. Paper II shows that subsets of leukemic cells recovered from patients with acute myeloid leukemia (AML) produce and release ROS via a membrane-bound NADPH oxidase, and that ROS-producing leukemic cells initiate a PARP-1-dependent pathway of cell death (parthanatos) in NK cells and T cells. The results presented in Paper III demonstrate that treatment of AML patients with a NADPH oxidase inhibitor (histamine dihydrochloride) was preferentially efficacious among patients with monocytic leukemias (FAB classes M4 and M5), in which cells of the leukemic clone expressed a ROS-producing NADPH oxidase and functional histamine H2 receptors. The results presented in Paper IV imply that malignant cells recovered from patients with chronic myeloid leukemia utilize the ROS/PARP-1 axis to induce NK cell parthanatos and that PARP-1 inhibition maintains functions of T cells and NK cells under conditions of oxidative stress. Paper V aimed to define the intracellular pathways of ROS-induced PARP-1 activation with ensuing cell death in lymphocytes. The results suggest that the mitogen-activated protein kinase ERK1/2 is involved in ROS-induced signal transduction and that ERK1/2 is activated upstream of PARP-1 in ROS-dependent lymphocyte parthanatos.
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| 7. |
- Aurelius, Johan, 1980, et al.
(författare)
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Monocytic AML cells inactivate antileukemic lymphocytes: role of NADPH oxidase/gp91(phox) expression and the PARP-1/PAR pathway of apoptosis.
- 2012
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 119:24, s. 5832-7
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Tidskriftsartikel (refereegranskat)abstract
- Dysfunction of T cells and natural killer (NK) cells has been proposed to determine the course of disease in acute myeloid leukemia (AML), but only limited information is available on the mechanisms of lymphocyte inhibition. We aimed to evaluate to what extent human malignant AML cells use NADPH oxidase-derived reactive oxygen species (ROS) as an immune evasion strategy. We report that a subset of malignant myelomonocytic and monocytic AML cells (French-American-British [FAB] classes M4 and M5, respectively), recovered from blood or BM of untreated AML patients at diagnosis, expressed the NADPH oxidase component gp91(phox). Highly purified FAB M4/M5 AML cells produced large amounts of ROS on activation and triggered poly-[ADP-ribose] polymerase-1-dependent apoptosis in adjacent NK cells, CD4(+) T cells, and CD8(+) T cells. In contrast, immature (FAB class M1) and myeloblastic (FAB class M2) AML cells rarely expressed gp91(phox), did not produce ROS, and did not trigger NK or T-cell apoptosis. Microarray data from 207 AML patients confirmed a greater expression of gp91(phox) mRNA by FAB-M4/M5 AML cells than FAB-M1 cells (P < 10(-11)) or FAB-M2 cells (P < 10(-9)). Our data are suggestive of a novel mechanism by which monocytic AML cells evade cell-mediated immunity.
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| 8. |
- Aurelius, Johan, 1980, et al.
(författare)
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NOX2-dependent immunosuppression in chronic myelomonocytic leukemia
- 2017
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Ingår i: Journal of Leukocyte Biology. - 0741-5400 .- 1938-3673. ; 102:2, s. 459-466
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Tidskriftsartikel (refereegranskat)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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| 9. |
- Aurelius, Johan, 1980, et al.
(författare)
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Remission maintenance in acute myeloid leukemia: impact of functional histamine H-2 receptors expressed by leukemic cells
- 2012
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 97:12, s. 1904-1908
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Tidskriftsartikel (refereegranskat)abstract
- Post-consolidation immunotherapy with histamine dihydrochloride and interleukin-2 has been shown to improve leukemia-free survival in acute myeloid leukemia in a phase III trial. For this study, treatment efficacy was determined among 145 trial patients with morphological forms of acute myeloid leukemia as defined by the French-American-British classification. Leukemia-free survival was strongly improved in M4/M5 (myelomonocytic/monocytic) leukemia but not in M2 (myeloblastic) leukemia. We also analyzed histamine H-2 receptor expression by leukemic cells recovered from 26 newly diagnosed patients. H-2 receptors were typically absent from M2 cells but frequently expressed by M4/M5 cells. M4/M5 cells, but not M2 cells, produced reactive oxygen species that triggered apoptosis in adjacent natural killer cells. These events were significantly inhibited by histamine dihydrochloride. Our data demonstrate the presence of functional histamine H2 receptors on human AML cells and suggest that expression of these receptors by leukemic cells may impact on the effectiveness of histamine-based immunotherapy.
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| 10. |
- Bergh Thorén, Fredrik, 1976, et al.
(författare)
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Antitumor properties of histamine in vivo.
- 2011
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Ingår i: Nature medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 17:5
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Tidskriftsartikel (refereegranskat)
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