Sacha Brigitte Geutskens - Academia.edu (original) (raw)

Papers by Sacha Brigitte Geutskens

Gene Therapy, Aug 1, 2000

The host-immune response against adenoviruses forms a major obstacle for their use as gene therap... more The host-immune response against adenoviruses forms a major obstacle for their use as gene therapy vectors for treatment of genetic defects. None the less, they are the preferred vectors for in vivo gene transfer in experimental gene therapy protocols for cancer. In this article we demonstrate the antitumor efficacy of adenovirus-mediated transfer of human interleukin-2 cDNA in the rat-CC531 model for hepatic metastases of colorectal cancer: intratumoral administration of 10 8 plaque-forming units of the hIL-2-expressing adenoviral vector, AdCAIL-2, resulted in a cessation of tumor growth in 80% of the injected tumors. In control groups receiving AdCnull, a vector with the same viral backbone, but lacking transgene expression, none of the tumors

Journal of Immunology, 1999

αB-crystallin protects the retina during S. aureus induced endophthalmitis (45.2)

Autoimmune insulin-dependent diabetes mellitus Chapter 1 General introduction: Does macrophage ma... more Autoimmune insulin-dependent diabetes mellitus Chapter 1 General introduction: Does macrophage malfunction lead to diabetes? 1.1 Genes and environment: diabetogenic pressure comes from both sides 1.2 From T-cell priming to pathology 1.3 Autoreactive T-cell priming and the process preceding 1.4 Macrophage ontogeny and differentiation 1.5 The target-organ: an innocent bystander? 1.6 Does macrophage malfunction lead to diabetes? 1.7 Aim of this thesis Chapter 2 Dendritic cells and macrophages are essential for the retention of lymphocytes in (peri)-insulitis of the non-obese diabetic mouse: a phagocyte depletion study Chapter 3 Macrophages in the murine pancreas and their involvement in fetal endocrine development in vitro Chapter 4 Extracellular matrix distribution and islet morphology in the early postnatal pancreas: anomalies in the nonobese diabetic mouse Chapter 5 Defective upregulation of CD49d in final maturation of NOD mouse macrophages Chapter 6 Fibronectin receptor defects in NOD mouse leukocytes: Possible consequences for type 1 diabetes Chapter 7 Conclusions, general discussion and future directions 7.1 Conclusions 7.2 General discussion: Matrix-macrophage interactions in NOD mice: miscommunication leads to misconduct 7.2 Future directions Abbreviations Summary Samenvatting voor niet-ingewijden in dutch only Acknowledgements Curriculum vitae List of publications Retention of leukocytes in NOD insulitis

European Journal of Vascular and Endovascular Surgery, Mar 1, 2011

Aim: Monocytes play a significant role in neovascularisation. The stimuli that differentiate mono... more Aim: Monocytes play a significant role in neovascularisation. The stimuli that differentiate monocytes along a pro-angio-/arteriogenic-supporting pathway are currently unclear. We investigated whether pre-stimulation of human monocytes with soluble T-cellderived factors improves revascularisation in murine hind limb ischaemia as a new option for therapeutic angio-and arteriogenesis. Design: Human monocytes were cultured with or without soluble T-cell-derived factors. Unstimulated and pre-stimulated monocytes were transfused after induction of hind limb ischaemia in nude mice.

Immunology Letters, May 1, 1997

Introduction: Patients with Systemic Lupus Erythematosus (SLE) exhibit an increased frequency of ... more Introduction: Patients with Systemic Lupus Erythematosus (SLE) exhibit an increased frequency of in vlvo mutated T cells. This was detem-rined using the Hypoxantin Phosphorfbosyl Transferase (HPRT)-cloning technique based on selection of HPRT mutant cells by culturing in the presence of the selecting agent 6thioguanine. This enhanced frequency of mutant cells is thought to reflect in vivo T cell activation and proliferation in the past; therefore, such mutated T cells may contribute to the disease process in SLE. To characterize these potentially autoreactive T cells, we have made panels of HPRT mutant and non selected clones from SLE patients and control individuals. MaterisIs and Methods: We have studied the TCRBV-family usage of 250 T cell clones from SLE patients and control individuals, comprising non selected and HPRT mutant clones, using RT-PCR with 26 V&sub)family specific primers. CDR3 regions of the clones were compared by direct sequence analysis of the PCR products and the use of probes specific for the junctional region of individual clones.

Journal of Cellular and Molecular Medicine, Jul 29, 2012

Previously, we have shown that CCR5 transcription is regulated by CREB-1. However, the ubiquitous... more Previously, we have shown that CCR5 transcription is regulated by CREB-1. However, the ubiquitous pattern of CREB-1 expression suggests the involvement of an additional level of transcriptional control in the cell type-specific expression of CCR5. In this study, we show that epigenetic changes (i.e. DNA methylation and histone modifications) within the context of the CCR5 P1 promoter region correlate with transcript levels of CCR5 in healthy and in malignant CD4 ϩ T lymphocytes as well as in CD14 ϩ monocytes. In normal naïve T cells and CD14 ϩ monocytes the CCR5 P1 promoter resembles a bivalent chromatin state, with both repressive and permissive histone methylation and acetylation marks. The CCR5-expressing CD14 ϩ monocytes however show much higher levels of acetylated histone H3 (AcH3) compared to the non-CCR5-expressing naïve T cells. Combined with a highly methylated promoter in CD14 ϩ monocytes, this indicates a dominant role for AcH3 in CCR5 transcription. We also show that pharmacological interference in the epigenetic repressive mechanisms that account for the lack of CCR5 transcription in T leukaemic cell lines results in an increase in CREB-1 association with CCR5 P1 chromatin. Furthermore, RNA polymerase II was also recruited into CCR5 P1 chromatin resulting in CCR5 re-expression. Together, these data indicate that epigenetic modifications of DNA, and of histones, contribute to the control of CCR5 transcription in immune effector cells. Keywords: chromatin remodelling • histone modifications • DNA methylation • bivalent chromatin • poised chromatin • CCR5 • T cells • monocytes

Haematologica, Sep 1, 2013

Laboratory Investigation, Jan 17, 2005

Dendritic cells (DC) and macrophages (M/) are present in high numbers in the pancreas of the non-... more Dendritic cells (DC) and macrophages (M/) are present in high numbers in the pancreas of the non-obese diabetic (NOD) mouse during the diabetogenic process from very early stages onwards. In this study, we used clodronate-loaded liposomes to mediate the temporary systemic depletion of these phagocytic cells and monocytic precursors in order to modulate the pancreatic inflammation. Two intraperitoneal injections given with a 2-day interval to 8-week-old NOD mice depleted monocytes from the circulation and monocytes, DC and M/ from the spleen within the first days after the injections. Monocytes, DC and M/ reappeared in the circulation and the spleen within one week and had an unchanged phenotype and antigen presenting function. Interestingly, this treatment caused a delayed disappearance (7-21 days postinjection) of DC and M/ from the endocrine pancreas at a time when monocytes, DC and M/ had already repopulated the circulation and the spleen. The depletion of DC and M/ from the endocrine pancreas was accompanied by a total disappearance of lymphocytes from the pancreas. DC, M/ and lymphocytes reappeared in the pancreatic inflammatory infiltrates in treated mice from 28 days postdepletion onwards. Importantly, the treatment significantly postponed the onset of diabetes, leading to a strongly decreased incidence by 35 weeks of age. Taken together, our data show an essential role of phagocytic cells, that is, DC and M/, in the recruitment of lymphocytes to the pancreatic islets in NOD mice.

Journal of Neuroimmunology, Jul 1, 2000

Various lines of evidence suggest a close relationship between heat shock proteins (hsp) and seve... more Various lines of evidence suggest a close relationship between heat shock proteins (hsp) and several autoimmune diseases such as arthritis, diabetes and multiple sclerosis. While enhanced expression of hsp in autoimmune diseases is often regarded as a non-specific bystander effect of the inflammatory process, surprisingly little is known on hsp regulation by inflammatory mediators such as cytokines. In this study cytokine-induced expression of hsp60, hsp27 and alphaB-crystallin was studied in cultures of primary human adult astrocytes at the mRNA as well as at the protein level. We show differential hsp expression patterns in response to pro-inflammatory and immunoregulatory cytokines. Hsp60 expression was found to be enhanced in response to cytokines as diverse as IL-1beta, TNF-alpha, IL-4, IL-6 and IL-10. Upregulation of hsp27, however, was primarily induced by immunoregulatory cytokines like IL-4, IL-6 and TGF-beta whereas alphaB-crystallin expression was found to be enhanced by the pro-inflammatory cytokine TNF-alpha only. None of the cytokines studied was able to enhance expression of all three hsp simultaneously. These results show that in human astrocytes induced expression of hsp27 and alphaB-crystallin is dependent on the presence of a defined set of stimuli, while induced expression of hsp60 is a much less selective event. This highly differential pattern of hsp expression in response to inflammatory mediators known to play an important role in the pathogenesis of autoimmune diseases indicates that hsp responses are specific rather than non-specific bystander responses.

Haematologica, Jan 24, 2013

Multipotent stromal cells have immunomodulatory capacities and have been used in transplantation ... more Multipotent stromal cells have immunomodulatory capacities and have been used in transplantation and autoimmune diseases. One of the effects of multipotent stromal cells involves the inhibition of dendritic cell differentiation. Since interleukin-6 and interleukin-10 are known to play a role in inhibiting immature dendritic cell differentiation, we hypothesized that these cytokines may also mediate the inhibitory effect of human multipotent stromal cells in immature dendritic cell differentiation. In order to test this hypothesis monocytes were cultured with interleukin-4 and granulocyte-monocyte colony-stimulating factor in the presence or absence of culture-expanded bone marrow-derived multipotent stromal cells. Neutralization and cytokine-depletion strategies were applied to reveal the cellular source and effect of interleukin-6 and interleukin-10. Addition of multipotent stromal cells to monocyte cultures significantly reduced the generation of immature dendritic cells (CD14-CD1a +) and resulted in the generation of CD14 + CD1acells that displayed a significantly reduced immunostimulatory effect. We found that culture supernatants of co-cultures of multipotent stromal cells and monocytes contained higher concentrations of interleukin-6 and interleukin-10. Multipotent stromal cells produced interleukin-6 and neutralizing this interleukin-6 reversed the inhibitory effect of the multipotent cells. Interleukin-10 was not produced by multipotent stromal cells, but exclusively by monocytes after exposure to multipotent stromal cell-produced interleukin-6. In conclusion, through constitutive production of interleukin-6, multipotent stromal cells prevent the differentiation of monocytes towards antigen-presenting immunogenic cells and skew differentiation towards an antiinflammatory interleukin-10-producing cell type.

Journal of Immunology, Dec 15, 2010

Scandinavian Journal of Immunology, Aug 1, 2004

Integrins of the very late antigen (VLA) family mediate leucocyte traffic to lymphoid organs unde... more Integrins of the very late antigen (VLA) family mediate leucocyte traffic to lymphoid organs under physiological conditions and in chronic inflammatory situations such as autoimmunity. Accordingly, the current thinking is of a positive correlation between VLA expression and capability of the generation of autoimmunity. Herein we discuss recent findings on the defective expression of integrin‐type fibronectin receptors α4β1 (VLA‐4) and α5β1 (VLA‐5) in the non‐obese diabetic (NOD) mouse, a murine model of autoimmune insulin‐dependent diabetes mellitus. As compared with normal animals, NOD thymocytes (including the CD4+CD25+ regulatory T cells) exhibit a decrease in the membrane expression of α5β1, resulting in a functional impairment of fibronectin‐mediated interactions, including cell migration. Interestingly, thymocytes that are trapped within the giant perivascular spaces seen in NOD thymus are consistently α5β1 negative, suggesting that the progressive arrest of mature cells can be related to the α5β1 defect. Peripheral T cells also exhibit decreased α5β1 membrane expression and impaired fibronectin‐driven migration. Additionally, we observed a defect in α4β1 fibronectin receptor expression in NOD macrophages. Peritoneal, bone marrow‐derived‐precursor, as well as thymic macrophages of NOD mice showed an impaired upregulation of α4‐integrin chain expression, dependent on the level of macrophage maturation. Overall these data lead to the notion that NOD leucocytes bear distinct fibronectin receptor‐mediated cell migration defects, which may be involved in the pathogenesis and/or pathophysiology of the autoimmune events seen in NOD mice. Further studies will be helpful to define whether or not this concept can be applied for other autoimmune diseases.

Human Immunology, Jun 1, 2015

Monocytes play a key role in immune system function. Chromatin remodeling is crucial for various ... more Monocytes play a key role in immune system function. Chromatin remodeling is crucial for various differentiation and gene regulation processes and is rather well studied in T cells. However, for monocytes not much is known regarding how the epigenetic machinery influences the differentiation into various effector cell types. In the work presented here, we explore the epigenetic underpinnings of monocyte differentiation. By transcriptional profiling we show that transcription of lysine methyltransferases (KMTs) and in particular KMT1c is markedly up regulated after differentiation of monocytes into immature dendritic cells (iDCs). Specifically inhibiting KMT1c function, using the small-molecule inhibitor BIX-01294, changes the transcription levels of the DC marker DC-SIGN, but does not affect surface protein expression. Blocking global KMT activity, using DZNep, does influence monocyte differentiation into iDCs, indicated by a loss of DC-SIGN surface expression. When BIX-01294 and DZNep treatment was combined DC-SIGN expression was almost lost completely. This work shows that the activities of KMTs are required for successful differentiation of monocyte-derived dendritic cells. Furthermore it shows the importance of KMT inhibitors in the field of epigenetic immune therapy, which is still much focused around HDAC inhibitors.

Laboratory Investigation, Feb 1, 2003

The mouse pancreas, an immature organ at birth, reaches its adult size and morphology after weani... more The mouse pancreas, an immature organ at birth, reaches its adult size and morphology after weaning (3 weeks of age). Around this time, apoptotic phenomena and various types of macrophages are normally present. During development, Fas-Fas ligand (FasL) interactions are known to play a role in apoptotic events involved in tissue remodeling and elimination of damaged cells, and macrophages are routinely observed near apoptotic cells. Apoptosis and Fas-FasL interactions are also thought to be involved in the pathogenesis of autoimmune diseases, particularly type 1 diabetes (T1D). Therefore, we used early postnatal mouse pancreata from three control strains (C57BL/6, DBA/2, BALB/c) and from two strains with the nonobese diabetic (NOD)-related genetic background (the spontaneous T1D NOD model and the lymphocyte-deficient NODscid strain) to study apoptotic phenomena together with the molecular and immunohistochemical expression of proapoptosis (Fas, FasL) and antiapoptosis (Bcl-2) proteins. First, although no major difference in the numbers of total pancreatic apoptotic cells was noted among strains, significantly more FasL ϩ expression was detected immunohistochemically in mice with the NOD genetic background than in control pancreata from birth to 1 month of age. Second, FasL ϩ , Fas ϩ , and Bcl-2 ϩ structures seemed to be associated with innervation, regardless of the strain and age. Third, in control and NOD strains, nerves (identified by immunohistochemical labeling of peripherin or neurofilament 200), were often observed in periductular and peri-insular areas. Finally, some peripherin-positive nerves expressed the interferon-inducible protein-10 chemokine, and various types of macrophages were found to be in close proximity. These data highlight an overlooked, innervation-related aspect of normal mouse postnatal pancreas development with possible implications in T1D pathogenesis.

Laboratory Investigation, Aug 1, 2012

Patients whose hematopoietic system is compromised by chemo-and/or radiotherapy require transplan... more Patients whose hematopoietic system is compromised by chemo-and/or radiotherapy require transplantation of hematopoietic stem and progenitor cells (HSPCs) to restore hematopoiesis. Successful homing of transplanted HSPCs to the bone marrow (BM) largely depends on their migratory potential, which is critically regulated by the chemokine CXCL12. In this study, we have investigated the expression and function of Slit proteins and their corresponding Roundabout (Robo) receptors in human HSPC migration. Slit proteins are extracellular matrix proteins that can modulate the (chemoattractant-induced) migration of mature leukocytes. We show that mRNAs for all Slits (Slit1-3) are expressed in primary BM stroma and BM-derived endothelial and stromal cell lines, but not in CD34 þ HSPCs. Human CD34 þ HSPCs expressed mRNAs for all Robos (Robo1-4), but only the Robo1 protein was detected on their cell surface. Functionally, Slit3 treatment increased the in vivo homing efficiency of CD34 þ HSPCs to the BM in NOD/SCID mice, whereas Slit3-exposed HSPC migration in vitro was inhibited. These effects do not appear to result from modulated CXCL12 responsiveness as CXCR4 expression, CXCL12-induced actin polymerization or the basal and CXCL12-induced adhesion to fibronectin or BM-derived endothelial cells of CD34 þ HSPC were not altered by Slit3 exposure. However, we show that Slit3 rapidly reduced the levels of active RhoA in HL60 cells and primary CD34 þ HSPC, directly affecting a pathway involved in actin cytoskeleton remodeling and HSPC migration. Together, our results support a role for Slit3 in human HSPC migration in vitro and homing in vivo and might contribute to the design of future approaches aimed at improving transplantation efficiency of human CD34 þ HSPCs.

Journal of Leukocyte Biology, Jul 21, 2005

Macrophages are a heterogeneous population of cells that belong to the mononuclear phagocyte syst... more Macrophages are a heterogeneous population of cells that belong to the mononuclear phagocyte system. They play an important role in tissue homeostasis and remodeling and are also potent immune regulators. Pancreatic macrophages are critically involved in the development and pathogenesis of autoimmune diabetes. To elucidate the ontogeny of pancreatic macrophages, we characterized in this study the macrophages present in the adult and developing fetal pancreas of normal mice. We additionally examined the presence of local macrophage precursors and the involvement of macrophages in the growth of endocrine tissue in the fetal pancreas. We identified two phenotypically distinct macrophage subsets in the adult pancreas. The majority of macrophages was CD45 ؉ ER-MP23 ؉ MOMA-1 ؉. Under noninflammatory conditions, only a minority (ϳ5%) of the pancreatic macrophages additionally expressed the macrophage marker F4/80. In contrast, in the fetal pancreas, phenotypically, mature macrophages were identified exclusively by their expression of F4/80 and lacked detectable staining with ER-MP23 and MOMA-1 antibodies. In fetal pancreas organ cultures, we could show that macrophages develop from pre-existing precursors, which are present in the fetal pancreas at embryonic age 12.5. Moreover, the number of macrophages increased significantly when macrophagecolony stimulating factor was added to these cultures. It is important that this increase of F4/80positive cells was paralleled by an increase in the number of insulin-producing cells, suggesting that macrophages support the growth of these endocrine cells.

Cell Stress & Chaperones, 2000

We describe a reverse transcriptase-polymerase chain reaction method for the semiquantitative det... more We describe a reverse transcriptase-polymerase chain reaction method for the semiquantitative detection of mRNAs encoding the human heat shock proteins alphaB-crystallin, Hsp27, and Hsp60. The method involves the coamplification of cellular mRNA-derived cDNA with a dilution series of a competitor fragment (internal standard), using 1 primer pair common to both templates. Internal standards were based on cellular-derived cDNA engineered to be slightly smaller to differentiate between the target and the standard on electrophoretic separation. Initial cDNA quantitations can be corrected for possible variations during cDNA synthesis by standardizing to the levels of beta-actin-encoding cDNA. We show that the coamplified templates accumulate in a parallel manner with the cellular-derived cDNA throughout both the exponential and the nonexponential phase of amplification. Furthermore, we illustrate the utility of this technique by quantifying increased expression of alphaB-crystallin, Hsp27, and Hsp60 mRNA in astroglioma cells on heat shock.

Cytotherapy, Apr 1, 2014

Stemcel biology/Regenerative medicine (incl. bloodtransfusion

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.