| 1. |
- Bergh, Ann-Charlotte, et al.
(författare)
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Silenced B-cell receptor response to autoantigen in a poor-prognostic subset of chronic lymphocytic leukemia
- 2014
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Ingår i: Haematologica. - : Ferrata Storti Foundation. - 0390-6078 .- 1592-8721. ; 99:11, s. 1722-1730
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia B-cells express auto/xeno-antigen-reactive antibodies that bind to self-epitopes and resemble natural IgM antibodies in their repertoire. One of the antigenic structures recognized is oxidation-induced malonedialdehyde present on low-density lipoprotein, apoptotic blebs, and on certain microbes. The poor-prognostic stereotyped subset #1 (Clan I IGHV genes-IGKV1(D)-39) express IgM B-cell receptors that bind oxidized low-density lipoprotein. In this study, we have used for the first time this authentic cognate antigen, since it is more faithful to B-cell physiology than anti-IgM, for analysis of downstream B-cell receptor-signal transduction events. Multivalent oxidized low-density lipoprotein showed specific binding to subset #1 IgM/IgD B-cell receptors, whereas native low-density lipoprotein did not. The antigen-binding induced prompt receptor-clustering, followed by internalization. However, the receptor-signal transduction was silenced, revealing no Ca2+ mobilization or cell-cycle entry, while phosphorylated extracellular-regulated kinase1/2 basal levels were high and could not be elevated further by oxidized low-density lipoprotein. Interestingly, B-cell receptor responsiveness was recovered after 48 hours culture in the absence of antigen in half of the cases. Toll-like receptor 9-ligand was found to breach the B-cell receptor-signaling incompetence in 5 of 12 cases pointing to intra-subset heterogeneity. Altogether, this study supports B-cell receptor-unresponsiveness to cognate self-antigen on its own in poor-prognostic subset #1 chronic lymphocytic leukemia indicating that these cells proliferate by other mechanisms that may override B-cell receptor-silencing brought about in a context of self-tolerance/anergy. These novel findings have implications for the understanding of chronic lymphocytic leukemia pathobiology and therapy.
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| 2. |
- Evaldsson, Chamilly, et al.
(författare)
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4-Thiouridine induces dose-dependent reduction of oedema, leucocyte influx and tumour necrosis factor in lung inflammation
- 2009
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 155:2, s. 330-338
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Tidskriftsartikel (refereegranskat)abstract
- Recent reports demonstrate a role for nucleotides as inflammatory modulators. Uridine, for example, reduces oedema formation and leucocyte infiltration in a Sephadex-induced lung inflammation model. Tumour necrosis factor (TNF) concentration was also reduced. Previous in vivo observations indicated that 4-thiouridine might have similar effects on leucocyte infiltration and TNF release. The aim of this study was thus to investigate the effects of 4-thiouridine in greater detail. We used a Sephadex-induced acute lung inflammation model in Sprague-Dawley rats. The dextran beads were instilled intratracheally into the lungs, which were excised and examined after 24 h. Sephadex alone led to massive oedema formation and infiltration of macrophages, neutrophils and eosinophils. Microgranulomas with giant cell formations were clearly visible around the partially degraded beads. A significant increase in bronchoalveolar lavage fluid (BALF) content of TNF and leukotrienes was also seen. 4-Thiouridine co-administration affected all variables investigated in this model, i.e. oedema, microscopic and macroscopic appearance of lung tissue, total leucocyte and differential leucocyte counts in BALF, TNF and leukotrienes C-4 (LTC4), LTD4 and LTE4 in BALF, indicating a reproducible anti-inflammatory effect. In conclusion, we have demonstrated that 4-thiouridine has anti-inflammatory effects similar to those of uridine. To our knowledge, this is the first demonstration of pharmacological 4-thiouridine effects in vivo. The results suggest nucleoside/nucleotide involvement in inflammatory processes, warranting further studies on nucleoside analogues as attractive new alternatives in the treatment of inflammatory diseases.
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| 3. |
- Evaldsson, Chamilly, 1978-, et al.
(författare)
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Anti-inflammatory effects of exogenous uridine in an animal model of lung inflammation.
- 2007
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Ingår i: International Immunopharmacology. - : Elsevier BV. - 1567-5769 .- 1878-1705. ; 7:8, s. 1025-1032
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Tidskriftsartikel (refereegranskat)abstract
- Nucleosides like adenosine, uridine and their nucleotide derivatives (e.g. ATP and UTP) play important roles in many cellular functions, sometimes by acting as signalling molecules through binding to specific P2 nucleotide receptors. P2 receptors are subdivided into P2X and P2Y subfamilies, the latter of which are G-protein coupled receptors. P2Y receptors and nucleoside transporters have been detected in human and rat lungs, where they mediate effects of interest in airway diseases. The aim of this study was to investigate whether uridine has any anti-inflammatory properties in an asthma-like animal model of lung inflammation. The Sephadex-induced lung inflammation model in Sprague-Dawley rats was chosen mainly due to its localised inflammatory response and uridine's limited oral bioavailability. The dextran beads, with or without the addition of uridine, were instilled intratracheally into the lungs, which were excised and examined after 24 h. Sephadex alone led to massive oedema and infiltration of macrophages, neutrophils and eosinophils. Microgranulomas with giant cell formations were clearly visible around the partially degraded beads. Uridine reduced both the oedema and the infiltration of leukocytes significantly, measured as lung wet weight and leukocyte counts in bronchoalveolar lavage fluid, respectively. Uridine appeared to affect the tumour necrosis factor (TNF) levels, although this could not be statistically confirmed due to large variations within the Sephadex control group. We conclude that uridine has anti-inflammatory effects, and that the exact mechanism(s) of action requires further study.
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| 4. |
- Evaldsson, Chamilly, 1978-, et al.
(författare)
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Isomaltitol exacerbates neutrophilia but reduces eosinophilia : New insights into the Sephadex model of lung inflammation
- 2011
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Ingår i: International Archives of Allergy and Immunology. - : Karger. - 1018-2438 .- 1423-0097. ; 154:4, s. 286-294
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Tidskriftsartikel (refereegranskat)abstract
- We have previously examined isomaltitol in an in vitro static adhesion assay between isolated granulocytes and cultured human umbilical cord vein cells and were interested in investigating whether the potentially anti-inflammatory effects observed there could be reproduced in vivo. The Sephadex-induced lung inflammation model was considered a suitable model due to the significant changes in global inflammatory endpoints, like oedema and leukocyte migration, usually seen upon provocation with Sephadex. Male Sprague-Dawley rats were instilled intratracheally with Sephadex (5 mg/ml), vehicle (0.9% NaCl), isomaltitol (50 mg/ml) or a combination of isomaltitol and Sephadex. After 24 h, the lungs were weighed to measure oedema and preserved for histology. Bronchoalveolar lavage fluid was used for analysis of tumour necrosis factor, cysteinyl leukotrienes, and differential and total leukocyte counts. In addition, blood differential counts and thymus weights were analysed. Contrary to what we expected from in vitro experiments, differential counts showed that isomaltitol increased the neutrophil component while decreasing the eosinophilia. Isomaltitol thus asserted a modulatory role on the usually eosinophil-dominated Sephadex-induced cell profile. Isomaltitol alone also increased several inflammatory parameters, including oedema and cysteinyl leukotrienes, and generally aggravated total inflammation in combination with Sephadex. Although the mechanisms were not investigated in this study, the effects could relate to a combination of isomaltitol's osmotic and structure-specific properties. Our results indicate that isomaltitol can modulate the inflammatory response induced by Sephadex instillation in addition to have pro-inflammatory effects on it its own, and may therefore provide new insights into the mechanisms of this widely used animal model. Sugar alcohols similar to isomaltitol have already been used to aid mucus clearance in cystic fibrosis patients, and it is possible that isomaltitol could also be used for this purpose.
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| 5. |
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| 6. |
- Evaldsson, Chamilly, 1978-
(författare)
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Uridine, 4-thiouridine and isomaltitol in an asthma-like model : Anti-inflammatory and modulating effects
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In chronic inflammatory diseases like asthma or rheumatoid arthritis, erroneous and exaggerated accumulation of leukocytes in a tissue inadvertently causes the body harm. Several efficient anti-inflammatory drugs exist, for example corticosteroids and cyclo-oxygenase inhibitors. However, these drugs have potent and diverse effects and often act by inhibiting events subsequent to initiation of the inflammatory response, leading to more or less severe side-effects, especially when used in high doses for long periods of time. For this reason, strategies aimed at early inhibition of recruitment and activation of leukocytes have been suggested as safer and more specific approaches to reduce inflammation.Leukocyte adhesion to activated endothelium is a prerequisite to the following activation and extravasation, and takes place in the initial phase of inflammation. By using a model that allows leukocytes to adhere to tumour necrosis factor (TNF)-activated endothelial cells, thus mimicking aspects of an inflammatory reaction, we found that uridine, 4-thiouridine and isomaltitol could all reduce adhesion. This suggested that they may have anti-inflammatory potential.We therefore tried the three substances in a Sephadex-induced lung inflammation model and found that uridine and 4-thiouridine have several anti-inflammatory effects, such as being able to reduce leukocyte accumulation, decrease TNF protein levels and partly inhibit the oedema induced by Sephadex. Isomaltitol turned out to have immunomodulating, rather than anti-inflammatory, effects, which could be of interest in diseases where inadequate inflammatory responses are a problem.
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| 7. |
- Rosén, Anders, et al.
(författare)
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Antigens in chronic lymphocytic leukemia--implications for cell origin and leukemogenesis
- 2010
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Ingår i: Seminars in Cancer Biology. - : Elsevier BV. - 1044-579X .- 1096-3650. ; 20:6, s. 400-409
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Forskningsöversikt (refereegranskat)abstract
- Several types of B cell tumors, particularly MALT lymphomas, are known to have an antigen-driven component in tumor development. Over the past two decades substantial data have accumulated regarding the restricted immunoglobulin (IG) gene repertoire in chronic lymphocytic leukemia (CLL) and its potential implications for antigenic drive in the disease development and progression. Herein we discuss how evidence first illustrated a link between certain B cell receptor (BCR) specificities and disease outcome and the subsequent large-scale IG analyses which revealed the extent of "stereotyped" BCRs in CLL. More recent studies on CLL antibody reactivity have gradually provided clues as to which antigens may be involved in the tumor development. Significantly, CLL monoclonal antibodies have been shown to resemble natural antibodies recognizing molecular motifs both on apoptotic cells (e.g. modified cytoskeletal proteins and oxidation-specific epitopes), as well as exogenous bacteria, indicating that CLL clones possibly arise from B cells which have dual function as scavengers of apoptotic debris, while also having the ability to bind conserved bacterial cell structures. Such revelations have led us to re-evaluate both the phenotypic and functional characteristics of the tumor B cells and the pathway by which CLL arises and develops.
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| 8. |
- Rosén, Anders, et al.
(författare)
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Lymphoblastoid cell line with B1 cell characteristics established from a chronic lymphocytic leukemia clone by in vitro EBV infection
- 2012
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Ingår i: Oncoimmunology. - : Informa UK Limited. - 2162-4011 .- 2162-402X. ; 1:1, s. 18-27
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia (CLL) cells express the receptor for Epstein-Barr virus (EBV) and can be infected in vitro. Infected cells do not express the growth-promoting set of EBV-encoded genes and therefore they do not yield LCLs, in most experiments. With exceptional clones, lines were obtained however. We describe a new line, HG3, established by in vitro EBV-infection from an IGHV1-2 unmutated CLL patient clone. All cells expressed EBNA-2 and LMP-1, the EBV-encoded genes pivotal for transformation. The karyotype, FISH cytogenetics and SNP-array profile of the line and the patient's ex vivo clone showed biallelic 13q14 deletions with genomic loss of DLEU7, miR15a/miR16-1, the two micro-RNAs that are deleted in 50% of CLL cases. Further features of CLL cells were: expression of CD5/CD20/CD27/CD43 and release of IgM natural antibodies reacting with oxLDL-like epitopes on apoptotic cells (cf. stereotyped subset-1). Comparison with two LCLs established from normal B cells showed 32 genes expressed at higher levels (> 2-fold). Among these were LHX2 and LILRA. These genes may play a role in the development of the disease. LHX2 expression was shown in self-renewing multipotent hematopoietic stem cells, and LILRA4 codes for a receptor for bone marrow stromal cell antigen-2 that contributes to B cell development. Twenty-four genes were expressed at lower levels, among these PARD3 that is essential for asymmetric cell division. These genes may contribute to establish precursors of CLL clones by regulation of cellular phenotype in the hematopoietic compartment. Expression of CD5/CD20/CD27/CD43 and spontaneous production of natural antibodies may identify the CLL cell as a self-renewing B1 lymphocyte.
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| 9. |
- Szymanowski, Aleksander, et al.
(författare)
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Soluble Fas ligand is associated with natural killer cell dynamics in coronary artery disease
- 2014
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 233:2, s. 616-622
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Apoptosis of natural killer (NK) cells is increased in patients with coronary artery disease (CAD) and may explain why NK cell levels are altered in these patients. Soluble forms of Fas and Fas ligand (L) are considered as markers of apoptosis. Here, we investigated whether plasma levels of Fas and FasL were associated with NK cell apoptosis and NK cell levels in CAD patients. Methods: Fas and FasL in plasma were determined by ELISA in 2 cohorts of CAD patients; one longitudinal study measuring circulating NK cells and apoptotic NK cells by flow cytometry 1 day, 3 months and 12 months after a coronary event and one cross-sectional study measuring NK cell apoptosis ex vivo. Both studies included matched healthy controls. Fas and FasL were also determined in supernatants from NK cells undergoing cytokine-induced apoptosis in cell culture. Results: In the 12-month longitudinal study, plasma FasL increased by 15% (p less than 0.001) and NK cell levels by 31% (p less than 0.05) while plasma Fas did not change. Plasma FasL and NK cell levels were significantly related at 3 months and 12 months, r = 0.40, p less than 0.01. Furthermore, plasma FasL, but not plasma Fas, correlated with NK cell apoptosis ex vivo in CAD patients, r = 0.54, p less than 0.05. In vitro, cytokine-induced apoptosis of NK cells resulted in abundant release of FasL. Conclusion: In CAD patients, FasL in plasma is associated with both apoptotic susceptibility of NK cells and dynamic changes in circulating NK cells. NK cells are also themselves a potential source of soluble FasL. Our findings link NK cell status to a soluble marker with possible atheroprotective effects thereby supporting a beneficial role of NK cells in CAD.
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| 10. |
- Uppugunduri, Srinivas, et al.
(författare)
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Effects of uridine, isomatitol and 4-thiouridine on in vitro cell adhesion and in vivo effects of 4-thiouridine in a lung inflammation model.
- 2004
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Ingår i: International Immunopharmacology. - : Elsevier BV. - 1567-5769 .- 1878-1705. ; 4:9, s. 1241-1248
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Tidskriftsartikel (refereegranskat)abstract
- Since leukocyte adhesion to endothelial cells is crucial for extravasation of leukocytes to sites of inflammation, inhibition of cell-cell adhesion has been suggested as a means to achieve selective modulation of the immune system. We have, using a static in vitro adhesion assay involving adhesion of granulocytes to tumor necrosis factor alpha (TNFalpha)-stimulated human umbilical vein endothelial cells (HUVEC), found three substances--uridine, isomaltitol and 4-thiouridine-that, independently and significantly, reduced leukocyte adhesion by approximately 30-65%. 4-Thiouridine was also tested in an in vivo model of Sephadex (SDX)-induced lung inflammation with Sprague-Dawley rats. Intratracheal instillation of Sephadex (5 mg/kg) alone resulted in a dramatic increase in lung edema and total leukocyte count after 24 h. A differential count of bronchoalveolar lavage (BAL) cells indicated an increased influx of macrophages, eosinophils and neutrophils. Co-administration of 4-thiouridine significantly reduced lung edema by 38%. There was also a significant reduction of the total leukocyte count by 58%. The differential leukocyte count indicated that eosinophil influx alone was reduced by 70%. After Sephadex challenge, we found elevated levels of TNFalpha--an important inflammatory mediator--in the bronchoalveolar lavage fluid (BALF). TNFalpha levels were significantly reduced by more than 80% by co-administration of 4-thoiuridine. These results suggest that uridine, isomaltitol and, especially, 4-thiouridine affect adhesion between leukocytes and activated endothelium, and warrant further in vitro and in vivo studies.
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