Robert Deans

University Hospital Regensburg, Regensburg, Bavaria, Germany

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Publications (50)173.48 Total impact

  • Nature Biotechnology 08/2014; · 32.44 Impact Factor
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    ABSTRACT: Acute respiratory distress syndrome (ARDS) is the most common cause of respiratory failure among critically ill subjects, sepsis and severe bacterial pneumonia being its most common causes. The only interventions that have proven beneficial are protective ventilation strategies and fluid conservation approaches. New therapies are needed to address this common clinical problem. Others and we have previously shown the beneficial effect of infusion of exogenous adult stem cells in different pre-clinical models of ARDS. In the present study endotoxin was infused intravenously into 14 sheep from which 6 received different doses of adult stem cells by intrabronchial delivery to evaluate the effect of stem cell therapy. After administration of endotoxin, there was a rapid decline in oxygenation to hypoxemic values, indicative of severe-to-moderate ARDS. None of the animals treated with saline solution recovered to normal baseline values during the 6 hours that the animals were followed. In contrast, sheep treated with a dose of 40 million adult stem cells returned their levels of oxygen in their blood to baseline two hours after the cells were infused. Similarly, improvements in carbon dioxide (CO2) clearance, pulmonary vascular pressures and inflammation were observed and confirmed by histology and by the decrease in lung edema. We concluded that instillation of adult non-hematopoietic stem cells can diminish the impact of endotoxin and accelerate recovery of oxygenation, CO2 removal and inflammation in the ovine model, making the use of adult stem cells a real alternative for future therapies for ARDS.
    Stem Cell Research & Therapy 03/2014; 5(2):42. · 3.65 Impact Factor
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    ABSTRACT: Introduction: Early reports demonstrated the safety of adherent mesenchymal stromal cell (MSC) infusions in the hematopoietic stem cell transplantation (HCT) setting, as well as clinical efficacy for treatment of steroid refractory acute graft-versus-host disease (GVHD); however, two large, Phase III randomized, placebo-controlled trials of MSC for initial therapy or steroid refractory GVHD failed to meet their primary endpoints of durable complete response. Subset analyses demonstrated efficacy in selected patient populations, contributing to recent approvals of MSC for pediatric patients in Canada and New Zealand. Areas covered: In this review, we discuss the biologic and immunomodulatory properties of MSC and potential mechanisms involved. We review the results of prior clinical trials incorporating MSC for GVHD treatment or prophylaxis, the recent approvals in Canada and New Zealand, as well as future directions in the field. Expert opinion: The role of MSC infusions, in the prophylaxis and/or treatment of GVHD after HCT, continues to be under active investigation. Whether, and how, to incorporate MSC infusions is unclear, and ongoing questions include the source tissue type and culture methods, the timing and dosage of MSC product infusions, as well as the optimal clinical trial design and endpoints for assessment of clinical response.
    Expert opinion on biological therapy 02/2014; 14(2):231-46. · 3.22 Impact Factor
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    ABSTRACT: The mesenchymal stromal cell (MSC) field continues to rapidly progress with a number of clinical trials initiated and completed, with some reported successes in multiple clinical indications, and a growing number of companies established. The field nevertheless faces several challenges. Persistent issues include the definition of a MSC and comparability between MSC cell preparations. This is because of inherent cell heterogeneity, absence of markers unique to MSCs, and the difficulty in precisely defining them by developmental origin. Differences in the properties of MSCs also depend on the site of tissue harvest, phenotypic and genotypic characteristics of the donor and the isolation, storage and expansion methods used. These differences may be sufficient to ensure that attributes of the final MSC product could differ in potentially significant ways. As there are currently no gold standards, we propose using a reference material to establish methods of comparability amongst MSC preparations. We suggest four possible "ruler scenarios" and a method for global distribution. We further suggest that critical to establishing a reference material is the need to define protocols for comparing cells. The main purpose of this manuscript is to solicit input in establishing a consensus-based comparison. A comparative approach will be critical to all stages of translation to better clarify mechanisms of MSC actions, define optimal cell manufacturing process, ensure best practice clinical investigations, extend the use of a MSC product for new indications, protect a MSC product from imitators, and develop uniform reimbursement policies. Importantly, a reference material may enable a consensus on a practical definition of MSCs.
    Stem cells and development 01/2014; · 4.15 Impact Factor
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    ABSTRACT: Targeted recruitment of leukocytes to sites of inflammation is a crucial event in normal host defense against pathogens, and attachment to and rolling on activated endothelial cells is a prerequisite first step for eventual leukocyte extravasation into sites of inflammation. These key events are mediated by interactions between glycosylated ligands expressed on leukocytes and selectins expressed on activated endothelium. Cell surface expression of selectin ligands on leukocytes is regulated by the rate-limiting enzyme fucosyltransferase VII (Fut7), and in its absence extravasation of leukocytes is severely inhibited. Multipotent adult progenitor cells (MAPCs) are an adherent cell population isolated from adult bone marrow. Intravenous administration of MAPCs provided functional improvement in multiple pre-clinical models of injury or disease, but the mechanisms by which these outcomes were achieved remain poorly understood. In vitro cell analysis studies including fluorescence-activated cell sorting, messenger RNA analysis, T-cell proliferation assays and endothelial cell binding assays were performed. The in vitro cell analysis studies characterized the ability of MAPCs to secrete factors that transcriptionally attenuate expression of Fut7 in T cells, blocking the terminal fucosylation event in the biosynthesis of selectin ligands and reducing T-cell binding to endothelial cells. This study presents the first example of a distinct regulatory mechanism involving transcriptional down-regulation of Fut7 by MAPCs that could modulate the trafficking behavior of T cells in vivo.
    Cytotherapy 10/2013; · 3.06 Impact Factor
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    ABSTRACT: Multipotent adult progenitor cells (MAPCs) are adult adherent stromal stem cells currently being assessed in acute graft versus host disease clinical trials with demonstrated immunomodulatory capabilities and the potential to ameliorate detrimental autoimmune and inflammation-related processes. Our previous studies documented that MAPCs secrete factors that play a role in regulating T-cell activity. Here we expand our studies using a proteomics approach to characterize and quantify MAPC secretome components secreted over 72 hours in vitro under steady-state conditions and in the presence of the inflammatory triggers interferon-γ and lipopolysaccharide, or a tolerogenic CD74 ligand, RTL1000. MAPCs differentially responded to each of the tested stimuli, secreting molecules that regulate the biological activity of the extracellular matrix (ECM), including proteins that make up the ECM itself, proteins that regulate its construction/deconstruction, and proteins that serve to attach and detach growth factors from ECM components for redistribution upon appropriate stimulation. MAPCs secreted a wide array of proteases, some detectable in their zymogen forms. MAPCs also secreted protease inhibitors that would regulate protease activity. MAPCs secreted chemokines and cytokines that could provide molecular guidance cues to various cell types, including neutrophils, macrophages, and T cells. In addition, MAPCs secreted factors involved in maintenance of a homeostatic environment, regulating such diverse programs as innate immunity, angiogenesis/angiostasis, targeted delivery of growth factors, and the matrix-metalloprotease cascade.
    Stem cells translational medicine. 08/2013;
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    ABSTRACT: Multipotent adult progenitor cells (MAPCs) are an adherent stem cell population that belongs to the mesenchymal-type progenitor cell family. Although MAPCs are emerging as candidate agents for immunomodulation after solid organ transplantation, their value requires further validation in a clinically relevant cell therapy model using an organ donor- and organ recipient-independent, third-party cell product. We report that stable allograft survival can be achieved following third-party MAPC infusion in a rat model of fully allogeneic, heterotopic heart transplantation. Furthermore, long-term accepted heart grafts recovered from MAPC-treated animals can be successfully retransplanted to naïve animals without additional immunosuppression. This prolongation of MAPC-mediated allograft acceptance depends upon a myeloid cell population since depletion of macrophages by clodronate abrogates the tolerogenic MAPC effect. We also show that MAPC-mediated allograft acceptance differs mechanistically from drug-induced tolerance regarding marker gene expression, T regulatory cell induction, retransplantability, and macrophage dependence. MAPC-based immunomodulation represents a promising pathway for clinical immunotherapy that has led us to initiate a phase I clinical trial for testing safety and feasibility of third-party MAPC therapy after liver transplantation.
    Stem cells translational medicine. 07/2013;
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    ABSTRACT: The Fourth Expert Meeting of the Mesenchymal Stem Cells in Solid Organ Transplantation (MiSOT) Consortium took place in Barcelona on October 19 and 20, 2012. This meeting focused on the translation of preclinical data into early clinical settings. This position paper highlights the main topics explored on the safety and efficacy of mesenchymal stem cells as a therapeutic agent in solid organ transplantation and emphasizes the issues (proper timing, concomitant immunossupression, source and immunogenicity of mesenchymal stem cells, and oncogenicity) that have been addressed and will be followed up by the MiSOT Consortium in future studies.
    Transplantation 06/2013; · 3.78 Impact Factor
  • Robert Deans
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    ABSTRACT: Robert Deans speaks to Alexandra Hemsley, Commissioning Editor Robert Deans has led Athersys Inc.'s (OH, USA) regenerative medicine research and development activities since February 2003 and has served as Vice President of Regenerative Medicine since October 2003. He was named Executive Vice President of Regenerative Medicine in April 2011. Deans is highly regarded as an expert in stem cell therapeutics, with over 20 years of experience in this field. From 2001 to 2003, Deans worked for early-stage biotechnology companies. Deans was formerly the Vice President of Research at Osiris Therapeutics, Inc. (MD, USA), a biotechnology company, from 1998 to 2001 and Director of Research and Development with the Immunotherapy Division of Baxter International, Inc. (IL, USA), a global healthcare company, from 1992 to 1998. Deans was also previously on the faculty at University of Southern California Medical School in Los Angeles (CA, USA) between 1981 and 1998, in the departments of microbiology and neurology at the Norris Comprehensive Cancer Center. Deans was an undergraduate at Massachusetts Institute of Technology, received his PhD at the University of Michigan and did his post-doctoral work at University of California in Los Angeles, CA, USA. Aside from his Athersys responsibilities, Deans has a very active role within the International Society for Cellular therapy, specifically in Chairing the Commercialization Committee, and the Alliance for Regenerative Medicine, where he is co-chair of the Science and Technology committee.
    Regenerative Medicine 05/2013; 8(3):251-6. · 3.87 Impact Factor
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    ABSTRACT: A major goal of immunotherapy remains the control of pathogenic T cell responses that drive autoimmunity and allograft rejection. Adherent progenitor cells, including mesenchymal stromal cells (MSCs) and multipotent adult progenitor cells (MAPCs), represent attractive immunomodulatory cell therapy candidates currently active in clinical trials. MAPCs can be distinguished from MSCs on the basis of cellular phenotype, size, transcriptional profile, and expansion capacity. However, despite their ongoing evaluation in autoimmune and allogeneic solid organ transplantation settings, data supporting the immune regulatory potential of clinical-grade MAPCs are limited. In this study, we used allogeneic islet transplantation as a model indication to assess the ability of clinical-grade MAPCs to control T cell responses that drive immunopathology in human autoimmune disease and allograft rejection. MAPCs suppressed T cell proliferation and Th1 and Th17 cytokine production while increasing secretion of IL-10 and were able to suppress effector functions of bona fide autoreactive T cells from individuals with type 1 diabetes mellitus, including killing of human islets. Furthermore, MAPCs favored the proliferation of regulatory T cells during homeostatic expansion driven by γ-chain cytokines and exerted a durable, yet reversible, control of T cell function. MAPC suppression required licensing and proceeded via IDO-mediated tryptophan catabolism. Therefore, the common immune modulatory characteristics of clinical-grade MAPCs shown in this study suggest that they can be regarded as an alternative source of adult progenitor cells with similar clinical usefulness to MSCs. Taken collectively, these findings may guide the successful deployment of both MSCs and MAPCs for the amelioration of human autoimmunity and allograft rejection.
    The Journal of Immunology 04/2013; · 5.52 Impact Factor
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    ABSTRACT: Multipotent adult progenitor cells (MAPCs) are bone marrow-derived nonhematopoietic stem cells with a broad differentiation potential and extensive expansion capacity. A comparative study between human mesenchymal stem cells (hMSCs) and human MAPCs (hMAPCs) has shown that hMAPCs have clearly distinct phenotypical and functional characteristics from hMSCs. In particular, hMAPCs express lower levels of MHC class I than hMSCs and cannot only differentiate into typical mesenchymal cell types but can also differentiate in vitro and in vivo into functional endothelial cells. The use of hMSCs as cellular immunomodulatory stem cell products gained much interest since their immunomodulatory capacities in vitro became evident over the last decade. Currently, the clinical grade stem cell product of hMAPCs is already used in clinical trials to prevent graft-versus-host disease (GVHD), as well as for the treatment of acute myocardial infarct, ischemic stroke, and Crohn’s disease. Therefore, we studied the immune phenotype, immunogenicity, and immunosuppressive effect of hMAPCs in vitro. We demonstrated that hMAPCs are nonimmunogenic for T-cell proliferation and cytokine production. In addition, hMAPCs exert strong immunosuppressive effects on T-cell alloreactivity and on T-cell proliferation induced by mitogens and recall antigens. This immunomodulatory effect was not MHC restricted, which makes off-the-shelf use promising. The immunosuppressive effect of hMAPCs is partially mediated via soluble factors and dependent on indoleamine 2,3-dioxygenase (IDO) activity. At last, we isolated hMAPCs, the clinical grade stem cell product of hMAPCs, named MultiStem, and hMSCs from one single donor and observed that both the immunogenicity and the immunosuppressive capacities of all three stem cell products are comparable in vitro. In conclusion, hMAPCs have potent immunomodulatory properties in vitro and can serve as a valuable cell source for the clinical use of immunomodulatory cellular stem cell product.
    Cell Transplantation 01/2013; 22(10). · 4.42 Impact Factor
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    ABSTRACT: BACKGROUND: Cellular therapy after organ transplantation is emerging as an intriguing strategy to achieve dose reduction of classical immunosuppressive pharmacotherapy. Here, we introduce a new scoring system to assess treatment-emergent adverse events (TEAEs) of adherent stem cell therapies in the clinical setting of allogeneic liver transplantation (for example, the MiSOT-I trial Eudract CT: 200901779525). METHODS: The score consists of three independent modalities (set of parameters) that focus on clinically relevant events early after intravenous or intraportal stem cell infusion: pulmonary toxicity, intraportal-infusional toxicity, and systemic toxicity. For each modality, values between 0 (no TEAE) and 3 (severe TEAE) were defined. The score was validated retrospectively on a cohort of n=187 recipients of liver allografts not receiving investigational cell therapy between July 2004 and December 2010. These patients represent a control population for further trials. Score values were calculated for days 1, 4, and 10 after liver transplantation. RESULTS: Grade 3 events were most commonly related to the pulmonary system (3.5% of study cohort on day 4). Almost no systemic-related TEAEs were observed during the study period. The relative frequency of grade 3 events never exceeded 5% over all modalities and time points. A subgroup analysis for grade 3 patients provided no descriptors associated with severe TEAEs. CONCLUSION: The MiSOT-I score provides an assessment tool to score specific adverse events that may occur after adherent stem cell therapy in the clinical setting of organ transplantation and is thus a helpful tool to conduct a safety study.
    Trials 11/2012; 13(1):211. · 2.21 Impact Factor
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    ABSTRACT: Clinical results from acute myocardial infarction (AMI) patients treated with MultiStem®, a large-scale expanded adherent multipotent progenitor cell population (MAPC), have demonstrated a strong safety and benefit profile for these cells. The mechanism of benefit with MAPC treatment is a result, in part, of its ability to induce neovascularization through trophic support. Production of clinical-grade stem cell products requires the development of lot-release criteria based on potency assays that directly reflect the fundamental mechanistic pathway underlying the therapeutic response to verify manufacturing process consistency and product potency. Using an in vitro endothelial tube formation assay, a potency assay has been developed that reflects MAPC pro-angiogenic activity. Serum-free conditioned media collected from MAPC culture induced endothelial tube formation. A proteomic survey of angiogenic factors produced by the cells in vitro revealed candidate factors linked to angiogenic potency. Three cytokines, chemokine (C-X-C motif) ligand 5 (CXCL5), interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF), were required for this angiogenic activity. Depletion of any of these factors from the media prevented tube formation, while adding back increasing amounts of these cytokines into the depleted serum-free conditioned media established the lower limits of each of the cytokines required to induce angiogenesis. A necessary threshold of angiogenic factor expression was established using an in vitro angiogenesis assay. By correlating the levels of the cytokines required to induce tube formation in vitro with levels of the factors found in the spent media from manufacturing production runs, detection of these factors was identified as a surrogate potency assay with defined pass/fail criteria.
    Cytotherapy 06/2012; 14(8):994-1004. · 3.06 Impact Factor
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    ABSTRACT: Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the CNS for which only partially effective therapies exist. Intense research defining the underlying immune pathophysiology is advancing both the understanding of MS as well as revealing potential targets for disease intervention. Mesenchymal stromal cell (MSC) therapy has the potential to modulate aberrant immune responses causing demyelination and axonal injury associated with MS, as well as to repair and restore damaged CNS tissue and cells. This article reviews the pathophysiology underlying MS, as well as providing a cutting-edge perspective into the field of MSC therapy based upon the experience of authors intrinsically involved in MS and MSC basic and translational science research.
    Immunotherapy 05/2012; 4(5):529-47. · 2.39 Impact Factor
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    ABSTRACT: Mucopolysaccharidosis type I (MPS-I; Hurler syndrome) is an inborn error of metabolism caused by lack of the functional lysosomal glycosaminoglycan (GAG)-degrading enzyme α-L-iduronidase (IDUA). Without treatment, the resulting GAG accumulation causes multisystem dysfunction and death within the first decade. Current treatments include allogeneic hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy. HSCT ameliorates clinical features and extends life but is not available to all patients, and inadequately corrects the most devastating features of the disease including mental retardation and skeletal deformities. Recent developments suggest that stem cells can be used to deliver needed enzymes to the central nervous system. To test this concept, we transplanted bone marrow derived normal adult human MultiStem® cells into the cerebral lateral ventricles of immunodeficient MPS-I neonatal mice. Transplanted cells and human-specific DNA were detected in the hippocampal formation, striatum, and other areas of the central nervous system. Brain tissue assays revealed significant long-term decrease in GAG levels in the hippocampus and striatum. Sensorimotor testing 6 months after transplantation demonstrated significantly improved Rotarod performance of transplanted mice in comparison to nontransplanted and sham-transplanted control animals. These results suggest that a single injection of MultiStem cells into the cerebral ventricles of neonatal MPS-I mice induces sustained reduction in GAG accumulation within the brain, and modest long-term improvement in sensorimotor function.
    Cell Transplantation 04/2012; · 4.42 Impact Factor
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    ABSTRACT: Multipotent, bone marrow-derived stromal cells (BMSCs, also known as mesenchymal stem cells [MSCs]), are culture-expanded, nonhematopoietic cells with immunomodulatory effects currently being investigated as novel cellular therapy to prevent and to treat clinical disease associated with aberrant immune response. Emerging preclinical studies suggest that BMSCs may protect against infectious challenge either by direct effects on the pathogen or through indirect effects on the host. BMSCs may reduce pathogen burden by inhibiting growth through soluble factors or by enhancing immune cell antimicrobial function. In the host, BMSCs may attenuate pro-inflammatory cytokine and chemokine induction, reduce pro-inflammatory cell migration into sites of injury and infection, and induce immunoregulatory soluble and cellular factors to preserve organ function. These preclinical studies provide provocative hints into the direction MSC therapeutics may take in the future. Notably, BMSCs appear to function as a critical fulcrum, providing balance by promoting pathogen clearance during the initial inflammatory response while suppressing inflammation to preserve host integrity and facilitate tissue repair. Such exquisite balance in BMSC function appears intrinsically linked to Toll-like receptor signaling and immune crosstalk.
    Blood 02/2012; 119(8):1801-9. · 9.78 Impact Factor

Publication Stats

1k Citations
173.48 Total Impact Points

Institutions

  • 2011–2013
    • University Hospital Regensburg
      • Klinik für Chirurgie
      Regensburg, Bavaria, Germany
    • Case Western Reserve University
      • Department of Neurosciences
      Cleveland, OH, United States
  • 2005–2013
    • Athersys Inc.
      Cleveland, Ohio, United States
  • 2010
    • Erasmus MC
      • Department of Internal Medicine
      Rotterdam, South Holland, Netherlands
  • 2008
    • Peninsula Cancer Institute
      Williamsburg, Virginia, United States
  • 2006–2008
    • Georgia Health Sciences University
      • Department of Neurology
      Augusta, GA, United States