| 1. |
- Martner, Anna, 1979, et al.
(författare)
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Redox Remodeling by Dendritic Cells Protects Antigen-Specific T Cells against Oxidative Stress
- 2011
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 187:12, s. 6243-8
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Tidskriftsartikel (refereegranskat)abstract
- Microorganisms and microbial products induce the release of reactive oxygen species (ROS) from monocytes and other myeloid cells, which may trigger dysfunction and apoptosis of adjacent lymphocytes. Therefore, T cell-mediated immunity is likely to comprise mechanisms of T cell protection against ROS-inflicted toxicity. The present study aimed to clarify the dynamics of reduced sulfhydryl groups (thiols) in human T cells after presentation of viral and bacterial Ags by dendritic cells (DCs) or B cells. DCs, but not B cells, efficiently triggered intra- and extracellular thiol expression in T cells with corresponding Ag specificity. After interaction with DCs, the Ag-specific T cells acquired the capacity to neutralize exogenous oxygen radicals and resisted ROS-induced apoptosis. Our results imply that DCs provide Ag-specific T cells with antioxidative thiols during Ag presentation, which suggests a novel aspect of DC/T cell cross-talk of relevance to the maintenance of specific immunity in inflamed or infected tissue.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
- Hellstrand, Kristoffer, 1956, et al.
(författare)
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Age-Related Efficacy of Immunotherapy with Histamine Dihydrochloride and Interleukin-2 for Relapse Prevention in Acute Myeloid Leukemia
- 2011
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Ingår i: Annals of Hematology. - : Springer Science and Business Media LLC. - 0939-5555 .- 1432-0584. ; 90:Suppl. 1
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Tidskriftsartikel (refereegranskat)abstract
- Recurrence of leukemia after the completion of induction and consolidation chemotherapy is a significant clinical concern in acute myeloid leukemia (AML). Apart from allogeneic bone marrow transplantation there is no consensus about effective relapse-protective therapy beyond the consolidation phase, and the standard of care for the majority of patients in complete remission (CR) hence is no treatment. Here we present updated results from a phase 3 trial (n=320) evaluating the prevention of relapse in AML patients receiving immunotherapy with histamine dihydrochloride (HDC) and low-dose interleukin-2 (IL-2). This trial was previously reported to meet the primary endpoint of improved leukemia-free survival (LFS) in the primary population of all randomized patients. Our results imply that treatment with HDC/IL-2 prevents relapse in patients 40–70 years old in first CR (p=0.008, leukemia-free survival (LFS), n=190, log rank test) with a more than 80% relative increase in the likelihood of LFS at 3 years. HDC/IL-2 was not significantly efficacious in young patients (<40 years old). Further studies are underway to define the impact of HDC/IL-2 on immune function and the putative efficacy of therapy in genetic subgroups of AML.
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| 8. |
- Lagging, Martin, 1965, et al.
(författare)
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Reply.
- 2014
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Ingår i: Hepatology (Baltimore, Md.). - : Ovid Technologies (Wolters Kluwer Health). - 1527-3350 .- 0270-9139. ; 60:6, s. 2130-1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Martner, Anna, 1979, et al.
(författare)
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Immunotherapeutic strategies for relapse control in acute myeloid leukemia
- 2013
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Ingår i: Blood Reviews. - : Elsevier BV. - 0268-960X. ; 27:5, s. 209-216
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Tidskriftsartikel (refereegranskat)abstract
- Despite that the initial phases of chemotherapy induce disappearance of leukemic cells in many patients with acute myeloid leukemia (AML), the prevention of life-threatening relapses in the post-remission phase remains a significant clinical challenge. Allogeneic bone marrow transplantation, which is available for a minority of patients, efficiently prevents recurrences of leukemia by inducing immune-mediated elimination of leukemic cells, and over the past decades, numerous immunotherapeutic protocols have been developed aiming to mimic the graft-versus-leukemia reaction for the prevention of relapse. Here we review past and present strategies for relapse control with focus on overcoming leukemia-related immunosuppression in AML. We envisage future treatment protocols, in which systemic immune activators, such as vaccines, dendritic cell-based therapies, engineered variants of IL-2, or IL-15, are combined with agents that counter immunosuppression mediated by, e.g., the PD/PDL interaction, CTLA-4, CD200, reactive oxygen species, IDO expression, CXCR4, or the KIR/class I interaction, based on characteristics of the prevailing malignant clone. This combinatorial approach may pave the way for individualized immunotherapy in AML.
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| 10. |
- Martner, Anna, 1979, et al.
(författare)
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Immunotherapy with histamine dihydrochloride for the prevention of relapse in acute myeloid leukemia.
- 2010
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Ingår i: Expert review of hematology. - : Informa UK Limited. - 1747-4094 .- 1747-4086. ; 3:4, s. 381-91
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Tidskriftsartikel (refereegranskat)abstract
- Most patients with acute myeloid leukemia (AML) achieve complete remission (CR) after induction chemotherapy. Despite ensuing courses of consolidation chemotherapy, a large fraction of patients will experience relapses with poor prospects of long-term survival. Histamine dihydrochloride (HDC) in combination with the T-cell-derived cytokine IL-2 was recently approved within the EU as a remission maintenance immunotherapy in AML. HDC reduces myeloid cell-derived suppression of anti-leukemic lymphocytes, and aims to unravel a therapeutic benefit of IL-2 in AML by improving natural killer and T-cell activation. A randomized Phase III trial with 320 AML patients in CR demonstrated a significant reduction of relapse risk after immunotherapy with HDC plus low-dose IL-2 in the post-consolidation phase. HDC is the first approved therapeutic to target the state of immunosuppression in AML; further development in this area may comprise supplementary or alternative counter-suppressive agents with the aim to improve the efficacy of cancer immunotherapy.
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| 11. |
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| 12. |
- Rembeck, Karolina, et al.
(författare)
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Variants of the inosine triphosphate pyrophosphatase gene are associated with reduced relapse risk following treatment for HCV genotype 2/3.
- 2014
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Ingår i: Hepatology (Baltimore, Md.). - : Ovid Technologies (Wolters Kluwer Health). - 1527-3350 .- 0270-9139. ; 59:6, s. 2131-2139
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Tidskriftsartikel (refereegranskat)abstract
- The present study evaluated the impact of variations in the inosine triphosphate pyrophosphatase (ITPase) gene (ITPA) on treatment outcome in patients with hepatitis C virus (HCV) genotype 2/3 infection receiving peginterferon-α2a and lower, conventional 800 mg daily dose of ribavirin. Previous studies using higher, weight-based ribavirin dosing report that patients carrying polymorphisms encoding reduced predicted ITPase activity show decreased risk of ribavirin-induced anemia but increased risk of thrombocytopenia, with no impact on elimination of virus. Three hundred fifty-four treatment naïve HCV genotype 2/3 infected patients, enrolled in a phase III trial (NORDynamIC), were genotyped for ITPA (rs1127354 and rs7270101). Homo- or heterozygosity at Ars1127354 or Crs7270101, entailing reduced ITPase activity, was observed in 37% of patients and was associated with increased likelihood of achieving sustained virological response (SVR) (P=0.0003 in univariate and multivariate analyses) accompanied by a reduced risk of relapse among treatment-adherent patients. The association between ITPA variants and SVR remained significant when patients were subdivided by the 12- and 24-week treatment duration arms, HCV genotype, fibrosis stage and IL28B genotype, and was not secondary to improved adherence to therapy or less pronounced anemia. Gene variants predicting reduced predicted ITPase activity also were associated with decreased risk of anemia (P<0.0001), increased risk of thrombocytopenia (P=0.007), and lower ribavirin concentrations (P=0.02). Conclusion: These findings demonstrate a novel ribavirin-like association between polymorphisms at ITPA and treatment efficacy in chronic hepatitis C mediated by reduced relapse risk. We hypothesize that patients (63%) being homozygous for both major alleles, leading to normal ITPase activity, may benefit more from the addition of ribavirin to present and future treatment regimens for HCV in spite of concomitant increased risk of anemia.
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| 13. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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Gram-positive and gram-negative bacteria induce different patterns of cytokine production in human mononuclear cells irrespective of taxonomic relatedness.
- 2010
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Ingår i: Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research. - New York, USA : Mary Ann Liebert Inc. - 1557-7465 .- 1079-9907. ; 30:1, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- Upon bacterial stimulation, tissue macrophages produce a variety of cytokines that orchestrate the immune response that clears the infection. We have shown that Gram-positives induce higher levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma), and tumor necrosis factor (TNF) from human peripheral blood mononuclear cells (PBMCs) than do Gram-negatives, which instead induce more of IL-6, IL-8, and IL-10. Here, we study whether these patterns follows or crosses taxonomic borders. PBMCs from blood donors were incubated with UV-inactivated bacteria representing 37 species from five phyla. IL-12, TNF, IL-1beta, IL-6, IL-8, and IL-10 were measured in the supernatants after 24 h and IFN-gamma after 5 days. Irrespective of phylogenetic position, Gram-positive bacteria induced much more IL-12 (nine times more on average) and IFN-gamma (seven times), more TNF (three times), and slightly more IL-1beta (1.5 times) than did Gram-negatives, which instead induced more IL-6 (1.5 times), IL-8 (1.9 times), and IL-10 (3.3 times) than did Gram-positives. A notable exception was the Gram-positive Listeria monocytogenes, which induced very little IL-12, IFN-gamma, and TNF. The results confirm the fundamental difference in innate immune responses to Gram-positive and Gram-negative bacteria, which crosses taxonomic borders and probably reflects differences in cell wall structure.
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| 14. |
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