Mesenchymal stromal cells (MSCs) are currently under investigation for the treatment of inflammatory disorders, including Crohn's disease. MSCs are pluripotent cells with immunosuppressive... Show moreMesenchymal stromal cells (MSCs) are currently under investigation for the treatment of inflammatory disorders, including Crohn's disease. MSCs are pluripotent cells with immunosuppressive properties. Recent data suggest that resting MSCs do not have significant immunomodulatory activity, but that the immunosuppressive function of MSCs has to be elicited by interferon-gamma (IFN-gamma). In this article, we assessed the effects of IFN-gamma prestimulation of MSCs (IMSCs) on their immunosuppressive properties in vitro and in vivo. To this end, we pretreated MSCs with IFN-gamma and assessed their therapeutic effects in dextran sodium sulfate (DSS)- and trinitrobenzene sulfonate (TNBS)-induced colitis in mice. We found that mice treated with IMSCs (but not MSCs) showed a significantly attenuated development of DSS-induced colitis. Furthermore, IMSCs alleviated symptoms of TNBS-induced colitis. IMSC-treated mice displayed an increase in body weight, lower colitis scores, and better survival rates compared with untreated mice. In addition, serum amyloid A protein levels and local proinflammatory cytokine levels in colonic tissues were significantly suppressed after administration of IMSC. We also observed that IMSCs showed greater migration potential than unstimulated MSCs to sites within the inflamed intestine. In conclusion, we show that prestimulation of MSCs with IFN-gamma enhances their capacity to inhibit Th1 inflammatory responses, resulting in diminished mucosal damage in experimental colitis. These data demonstrate that IFN-gamma activation of MSCs increases their immunosuppresive capacities and importantly, their therapeutic efficacy in vivo. STEM CELLS 2011;29:1549-1558 Show less
BACKGROUND AND AIMS Mesenchymal stromal cells (MSC) have both multilineage differentiation capacity and immunosuppressive properties. Promising results with MSC administration have been obtained in... Show moreBACKGROUND AND AIMS Mesenchymal stromal cells (MSC) have both multilineage differentiation capacity and immunosuppressive properties. Promising results with MSC administration have been obtained in experimental colitis. Clinical application of MSC for the treatment of inflammatory bowel disease (IBD) is currently under investigation in phase I-III trials in patients with past or concurrent immunomodulating therapy. However, little is known about MSC interactions with these immunosuppressive drugs. To address this issue we studied the combined effect of MSC and IBD drugs in in vitro functionality assays. METHODS The effects of azathioprine, methotrexate, 6-mercaptopurine and anti-tumor necrosis factor (TNF)-α on MSC phenotype, survival, differentiation capacity and immunosuppressive capacity were studied. RESULTS MSC exposed to physiologically relevant concentrations of IBD drugs displayed a normal morphology and fulfilled phenotypic and functional criteria for MSC. Differentiation into adipocyte and osteocyte lineages was not affected and cells exhibited normal survival after exposure to the various drugs. MSC suppression of peripheral blood mononuclear cell (PBMC) proliferation in vitro was not hampered by IBD drugs. In fact, in the presence of 6-mercaptopurine and anti-TNF-α antibodies, the inhibitory effect of this drug alone was enhanced, suggesting an additive effect of pharmacotherapy and MSC treatment. CONCLUSIONS This study demonstrates that, in vitro, MSC phenotype and function are not affected by therapeutic concentrations of drugs commonly used in the treatment of IBD. These findings are important for the potential clinical use of MSC in combination with immunomodulating drugs and anti-TNF-α therapy. Show less
Background and aims. Mesenchymal stromal cells (MSC) have both multilineage differentiation capacity and immunosuppressive properties. Promising results with MSC administration have been obtained... Show moreBackground and aims. Mesenchymal stromal cells (MSC) have both multilineage differentiation capacity and immunosuppressive properties. Promising results with MSC administration have been obtained in experimental colitis. Clinical application of MSC for the treatment of inflammatory bowel disease (IBD) is currently under investigation in phase I-III trials in patients with past or concurrent immunomodulating therapy. However, little is known about MSC interactions with these immunosuppressive drugs. To address this issue we studied the combined effect of MSC and IBD drugs in in vitro functionality assays. Methods. The effects of azathioprine, methotrexate, 6-mercaptopurine and anti-tumor necrosis factor (TNF)-alpha on MSC phenotype, survival, differentiation capacity and immunosuppressive capacity were studied. Results. MSC exposed to physiologically relevant concentrations of IBD drugs displayed a normal morphology and fulfilled phenotypic and functional criteria for MSC. Differentiation into adipocyte and osteocyte lineages was not affected and cells exhibited normal survival after exposure to the various drugs. MSC suppression of peripheral blood mononuclear cell (PBMC) proliferation in vitro was not hampered by IBD drugs. In fact, in the presence of 6-mercaptopurine and anti-TNF-alpha antibodies, the inhibitory effect of this drug alone was enhanced, suggesting an additive effect of pharmacotherapy and MSC treatment. Conclusions. This study demonstrates that, in vitro, MSC phenotype and function are not affected by therapeutic concentrations of drugs commonly used in the treatment of IBD. These findings are important for the potential clinical use of MSC in combination with immunomodulating drugs and anti-TNF-alpha therapy. Show less
Background: Immune suppressant medications such as thiopurines and anti-tumor necrosis factor agents are important for maintaining disease control in most patients with inflammatory bowel diseases ... Show moreBackground: Immune suppressant medications such as thiopurines and anti-tumor necrosis factor agents are important for maintaining disease control in most patients with inflammatory bowel diseases (IBDs); however, their use has been associated with the development of malignant lymphoma. The purpose of this Dutch nationwide study was to estimate the relative risk of malignant lymphoma in IBD patients. Methods: IBD patients who developed a lymphoma between 1997 and 2004 were identified using the Dutch National Database of PALGA. Data from confirmed cases were collected from individual hospitals, including data on Epstein Barr virus (EBV). The age-adjusted 8-year incidence of malignant lymphoma in the Netherlands was retrieved from the Central Bureau of Statistics. Results: Forty-two hospitals were visited and 285 matches evaluated in the total cohort of 17,834 IBD patients. Forty-four lymphomas were observed, resulting in a relative risk of 1.27 (95% confidence interval [CI]: 0.92-1.68). Only 19 of 44 patients (43%) were exposed to azathioprine/6-mercaptopurine (AZA/6-MP). Remarkably, 92% of patients (11/12) with EBV-positive lymphoma used AZA/6-MP, in contrast to only 19% patients (4/21) with EBV-negative lymphoma, suggesting a strong relation between EBV-positive lymphoma and thiopurine use. Conclusions: This nationwide study does not suggest a significant overall increased risk for lymphoma in IBD patients. A distinct correlation between EBV-positive lymphoma and AZA/6-MP use was observed. Show less
De resultaten beschreven in dit proefschrift verschaffen nieuwe inzichten in verschillende aspecten van de behandeling van inflammatoire darmziekten. Uit grote studies is gebleken dat mutaties in... Show moreDe resultaten beschreven in dit proefschrift verschaffen nieuwe inzichten in verschillende aspecten van de behandeling van inflammatoire darmziekten. Uit grote studies is gebleken dat mutaties in genen die betrokken zijn bij het autofagie proces (autophagos: __zelf-eten__), geassocieerd zijn met de ziekte van Crohn. In dit proefschrift wordt beschreven hoe deze mutatie in dendritische cellen leidt tot hyperactivatie van het immuunsysteem. Dit mechanisme kan mogelijk een nieuw aangrijpingspunt verschaffen voor nieuwe therapie voor pati_nten die een mutatie hebben in dit gen. Anti-tumor-necrosis-factor-alpha (anti-TNF_) therapie neemt een steeds belangrijkere plaats in in de behandeling van IBD; het werkingsmechanisme is echter niet geheel duidelijk. In dit proefschrift wordt beschreven hoe regulatoire macrophagen met immuunsuppressieve en wondgenezende eigenschappen ge_nduceerd worden door anti-TNF_ therapie. Dit werkingsmechanisme kan nieuwe aangrijpingspunten verschaffen voor toekomstige therapie_n. Tevens wordt in dit proefschrift een experimentele behandeling van Crohn met mesenchymale stamcellen (MSCs) beschreven. Deze behandeling is haalbaar en veilig gebleken, hetgeen aanleiding geeft tot verder onderzoek naar de effectiviteit van MSCs in de behandeling van Crohn. Tot slot werd het v__rkomen van kwaadaardige lymfomen onderzocht in IBD pati_nten in Nederland. Deze lymfomen bleken niet vaker voor te komen in de totale groep IBD pati_nten vergeleken met gezonde mensen, wel werd een verhoogde incidentie gezien in bepaalde leeftijdsgroepen. Daarnaast bleek het ontstaan van een EBV positief lymfoom (epstein Barr virus) sterk geassocieerd te zijn met het gebruik van azathioprine, een ander immuunsuppressieve therapie. Samenvattend beschrijft dit proefschrift verschillende aspecten van IBD therapie, en worden nieuwe inzichten en aangrijpinspunten verschaft Show less
Vos, A.C.W.; Wildenberg, M.E.; Duijvestein, M.; Verhaar, A.P.; Brink, G.R. van den; Hommes, D.W. 2011
BACKGROUND & AIMS: Anti-tumor necrosis factor (TNF)alpha antibodies are effective in treating patients with Crohn's disease whereas soluble TNF alpha receptors have not shown clinical efficacy;... Show moreBACKGROUND & AIMS: Anti-tumor necrosis factor (TNF)alpha antibodies are effective in treating patients with Crohn's disease whereas soluble TNF alpha receptors have not shown clinical efficacy; the mechanism that underlies these different effects is not clear. We examined the immunosuppressive effects of different anti-TNF alpha reagents on activated T cells. METHODS: We studied the effects of anti-TNF alpha antibodies infliximab and adalimumab, the soluble TNF alpha receptor etanercept, the pegylated F(ab') fragment certolizumab, and certolizumab-immunoglobulin (Ig)G on primary activated T cells. T cells were grown in isolation or in a mixed lymphocyte reaction (MLR). Proliferation was measured by H-3 thymidine incorporation and apoptosis was examined using Annexin V labeling and a colorimetric assay for activated caspase-3. Macrophage phenotypes were assayed by flow cytometry and cytokine secretion. RESULTS: Infliximab and adalimumab reduced T-cell proliferation in an MLR whereas etanercept and certolizumab did not; this effect was lost after Fc receptors were blocked. The infliximab F(ab') 2 fragment did not inhibit proliferation whereas certolizumab-IgG did inhibit proliferation. In the MLR, the antibodies against TNF induced formation of a new population of macrophages in an Fc region-dependent manner; these macrophages had an immunosuppressive phenotype because they inhibit proliferation of activated T cells, produce anti-inflammatory cytokines, and express the regulatory macrophage marker CD206. CONCLUSIONS: Regulatory macrophages have immunosuppressive properties and an important role in wound healing. Antibodies against TNF induce regulatory macrophages in an Fc region-dependent manner. These functions of anti-TNFs might contribute to the resolution of inflammation. Show less
Background and aim Mesenchymal stromal cells (MSCs) are pluripotent cells that have immunosuppressive effects both in vitro and in experimental colitis. Promising results of MSC therapy have been... Show moreBackground and aim Mesenchymal stromal cells (MSCs) are pluripotent cells that have immunosuppressive effects both in vitro and in experimental colitis. Promising results of MSC therapy have been obtained in patients with severe graft versus host disease of the gut. Our objective was to determine the safety and feasibility of autologous bone marrow derived MSC therapy in patients with refractory Crohn's disease. Patients and intervention 10 adult patients with refractory Crohn's disease (eight females and two males) underwent bone marrow aspiration under local anaesthesia. Bone marrow MSCs were isolated and expanded ex vivo. MSCs were tested for phenotype and functionality in vitro. 9 patients received two doses of 1-2x10(6) cells/kg body weight, intravenously, 7 days apart. During follow-up, possible side effects and changes in patients' Crohn's disease activity index (CDAI) scores were monitored. Colonoscopies were performed at weeks 0 and 6, and mucosal inflammation was assessed by using the Crohn's disease endoscopic index of severity. Results MSCs isolated from patients with Crohn's disease showed similar morphology, phenotype and growth potential compared to MSCs from healthy donors. Importantly, immunomodulatory capacity was intact, as Crohn's disease MSCs significantly reduced peripheral blood mononuclear cell proliferation in vitro. MSC infusion was without side effects, besides a mild allergic reaction probably due to the cryopreservant DMSO in one patient. Baseline median CDAI was 326 (224-378). Three patients showed clinical response (CDAI decrease >= 70 from baseline) 6 weeks post-treatment; conversely three patients required surgery due to disease worsening. Conclusions Administration of autologous bone marrow derived MSCs appears safe and feasible in the treatment of refractory Crohn's disease. No serious adverse events were detected during bone marrow harvesting and administration. Show less
