| 1. |
- Betten, Åsa, 1967, et al.
(författare)
-
Oxygen radical-induced natural killer cell dysfunction: role of myeloperoxidase and regulation by serotonin
- 2004
-
Ingår i: J Leukoc Biol. ; 75:6, s. 1111-5
-
Tidskriftsartikel (refereegranskat)abstract
- Natural killer (NK) cells are functionally suppressed and induced to apoptosis by reactive oxygen species (ROS) produced by mononuclear phagocytes (MPs). These inhibitory events are reversed by the biogenic amine serotonin. MPs generate hydrogen peroxide (H(2)O(2)), which is processed further by myeloperoxidase (MPO) to even more toxic compounds. Earlier studies suggest that serotonin scavenges MP-derived oxygen radicals generated by the MPO-H(2)O(2) system. These findings led us to explore the capability of MPO-deficient MPs to induce NK cell dysfunction. We show that MPs recovered from subjects with MPO deficiency trigger inhibition of NK cells. In addition, MPs recovered from healthy subjects conveyed suppression of NK cells in the presence of the MPO inhibitor ceruloplasmin. We conclude that ROS-dependent inhibition of NK cell function is unrestricted by the availability of MPO-derived oxygen radicals and that the protecting properties of serotonin may operate in the absence of functional MPO. Our data suggest a complex mechanism of MP-induced NK cell inhibition, which comprises the generation of interchangeable oxygen radicals.
|
|
| 2. |
- Bylund, Johan, 1975, et al.
(författare)
-
Cytochalasin B triggers a novel pertussis toxin sensitive pathway in TNF-alpha primed neutrophils
- 2004
-
Ingår i: BMC cell biology. - 1471-2121. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cytochalasin B does not directly activate the oxygen-radical-producing NADPH oxidase activity of neutrophils but transfers desensitized G-protein coupled receptors (GPCR) into an active signaling state by uncoupling GCPR from the cytoskeleton. The receptor uncoupling results in respiratory burst activity when signals generated by reactivated formyl peptide receptors trigger the NADPH-oxidase to produce superoxide anions. RESULTS: Tumor necrosis factor alpha (TNF-alpha) primes neutrophils for subsequent activation by cytochalasin B. Pretreatment with TNF-alpha induced mobilization of receptor-storing neutrophil organelles, suggesting that receptor up-regulation significantly contributes to the response, but the receptor mobilization was not sufficient for induction of the cytochalasin B sensitive state. The TNF-alpha primed state resembled that of the desensitized non-signaling state of agonist-occupied neutrophil formyl peptide receptors. The fact that the TNF-alpha primed, cytochalasin B-triggered activation process was pertussis toxin sensitive suggests that the activation process involves a GPCR. Based on desensitization experiments the unidentified receptor was found to be distinct from the C5a receptor as well as the formyl peptide receptor family members FPR and FPRL1. Based on the fact the occupied and desensitized receptors for interleukin-8 and platelet activating factor could not be reactivated by cytochalasin B, also these could be excluded as receptor candidates involved in the TNF-alpha primed state. CONCLUSIONS: The TNF-alpha-induced priming signals could possibly trigger a release of an endogenous GPCR-agonist, amplifying the response to the receptor-uncoupling effect of cytochalasin B. However, no such substance could be found, suggesting that TNF-alpha can transfer G-protein coupled receptors to a signaling state independently of agonist binding.
|
|
| 3. |
- Hellstrand, Kristoffer, 1956, et al.
(författare)
-
Alleviating oxidative stress in cancer immunotherapy: a role for histamine?
- 2000
-
Ingår i: Medical oncology (Northwood, London, England). - 1357-0560. ; 17:4, s. 258-69
-
Tidskriftsartikel (refereegranskat)abstract
- Interleukin-2 is a remarkable activator of lymphocytes with anti-neoplastic properties such as T-cells or natural killer cells, but tumor regression only rarely occurs in interleukin-2-treated cancer patients. In this review, we focus on interactions between monocytes/macrophages and T-cells/natural killer-cells, and in particular the role of such interactions for the outcome of cancer immunotherapy with interleukin-2. We propose that interleukin-2 therapy should be supplemented with compounds that alleviate toxicity inflicted by monocyte/macrophage-derived reactive oxygen metabolites within and around tumors. The hypothesis is founded on data demonstrating that (i) functions of intratumoral lymphocytes in many human malignant tumors are inhibited by reactive oxygen metabolites, generated by neighboring monocytes/macrophages, (ii) interleukin-2 only weakly activates T-cells or natural killer cells in an environment of oxidative stress, and (iii) inhibitors of the formation of reactive oxygen metabolites or scavengers of reactive oxygen metabolites synergize with interleukin-2 to activate these lymphocyte subsets. We also review the preclinical background to the use of histamine dihydrochloride, an inhibitor of reactive oxygen metabolite formation in monocytes/macrophages, as a supplement to cancer immunotherapy with interleukin-2.
|
|
| 4. |
- Hellstrand, Kristoffer, 1956, et al.
(författare)
-
Histamine: a novel approach to cancer immunotherapy
- 2000
-
Ingår i: Cancer investigation. - : Informa UK Limited. - 0735-7907 .- 1532-4192. ; 18:4, s. 347-55
-
Tidskriftsartikel (refereegranskat)abstract
- The functions of intratumoral lymphocytes in many human malignant tumors are inhibited by reactive oxygen species (ROS), generated by adjacent monocytes/macrophages (MO). In vitro data suggest that immunotherapeutic cytokines such as interleukin-2 (IL-2) or interferon-alpha (IFN-alpha) only weakly activate T cells or natural killer (NK) cells in a reconstituted environment of oxidative stress and that inhibitors of the formation of ROS or scavengers of ROS synergize with IL-2 and IFN-alpha to activate T cells and NK cells. In this review, we focus on the immunoenhancing properties of histamine, a biogenic amine. Histamine inhibits ROS formation in MO via H2-receptors; thereby, histamine protects NK cells from MO-mediated inhibition and synergizes with IL-2 and IFN-alpha to induce killing of NK cell-sensitive human tumor cells in vitro. Histamine also optimizes cytokine-induced activation of several subsets of T cells by affording protection against MO-inflicted oxidative inhibition. The putative clinical benefit of histamine as an adjunct to immunotherapy with IL-2 and/or IFN-alpha is currently evaluated in clinical trials in metastatic malignant melanoma and acute myelogenous leukemia.
|
|
| 5. |
|
|
| 6. |
- Ridell, Börje, et al.
(författare)
-
Incidence of chronic myeloproliferative disorders in the city of Göteborg, Sweden 1983-1992.
- 2000
-
Ingår i: European journal of haematology. - 0902-4441. ; 65:4, s. 267-71
-
Tidskriftsartikel (refereegranskat)abstract
- An estimation of the incidence of polycythaemia vera (PV), essential thrombocythaemia (ET) and chronic idiopathic myelofibrosis (CIM) in the city of Göteborg, Sweden during the period 1983-1992 was made from a retrospective case analysis of patients registered as chronic myeloproliferative disorders (CMPD) at the Departments of Medicine and the Department of Pathology of the two major hospitals in the city. A total of 125 cases of PV, 56 males and 69 females were identified. The number of cases as well as the age-specific incidence increased with age. The over all annual gender-specific incidence was 2.69 cases per 10(5) male inhabitants and 3.12 cases per 10(5) female inhabitants. The incidence of PV in relation to the European Standard Population was 2.02 cases per 10(5) inhabitants and year. There were 72 cases, 20 males and 52 females, with ET. The age-specific incidence was in all ages higher for females than for males and increased with age. The annual gender-specific incidence was 0.96 per 10(5) male inhabitants and 2.35 per 10(5) female inhabitants. The incidence of ET in relation to the European Standard Population was 1.28 per 10(5) persons and year. There were 20 cases of CIM, 11 males and 9 females. The annual gender-specific incidence of CIM was 0.53/10(5) male inhabitants and 0.41/10(5) female inhabitants. The incidence of CIM in relation to the European Standard Population was 0.31 per 10(5) persons and year. Seven persons, 2 males and 5 females, had a CMPD that could not be included in any of the above-mentioned groups, but were registered as CMPD, unclassified.
|
|
