Low autocrine interferon beta production as a gene therapy approach for AIDS: Infusion of interferon beta-engineered lymphocytes in macaques chronically infected with SIVmac251

BACKGROUND: The aim of this study was to evaluate gene therapy for AIDS based on the transduction of circulating lymphocytes with a retroviral vector giving low levels of constitutive macaque interferon β production in macaques chronically infected with a pathogenic isolate of SIVmac251. RESULTS: Two groups of three animals infected for more than one year with a pathogenic primary isolate of SIVmac251 were included in this study. The macaques received three infusions of their own lymphocytes transduced ex vivo with the construct encoding macaque IFN-β (MaIFN-β or with a vector carrying a version of the MaIFN-β gene with a deletion preventing translation of the mRNA. Cellular or plasma viremia increased transiently following injection in most cases, regardless of the retroviral construct used. Transduced cells were detected only transiently after each infusion, among the peripheral blood mononuclear cells of all the animals, with copy numbers of 10 to 1000 per 10(6 )peripheral mononuclear cells. CONCLUSION: Long-term follow-up indicated that the transitory presence of such a small number of cells producing such small amounts of MaIFN-β did not prevent animals from the progressive decrease in CD4(+ )cell count typical of infection with simian immunodeficiency virus. These results reveal potential pitfalls for future developments of gene therapy strategies of HIV infection

Toward the creation of 2D or 3D clusters of cells in acoustic levitation

International audienceIntroduction Today, three-dimensional (3D) cell cultures tend to replace 2D conventional method because of their more relevant tissue-mimicking characteristics. Indeed, the 3D cell architecture (spheroïd, organoïd, etc) and the microenvironment is closer to In Vivo physiological behaviour [1, 2]. The main difficulties remain in creating a scaffold compatible with the targeted cells and tissues. Bioprinting is one the great objective for tissue engineering. For instance, stereolithography is a 3D printing technology where the freestanding object is built layer by layer with a photosensitive polymer resin through the projection of a UV image in the top plane. In recent promising work, stereolithography has been applied to create 3D hydrogel structures to guide cells like hepatocytes [3]. Nevertheless, ideally, scaffold-free methods are needed. We propose a new method combining microfluidic channels and the acoustic radiation force (ARF) to structure and to control the shape of stem-cells aggregates

Toward the creation of 2D or 3D clusters of cells in acoustic levitation

International audienceIntroduction Today, three-dimensional (3D) cell cultures tend to replace 2D conventional method because of their more relevant tissue-mimicking characteristics. Indeed, the 3D cell architecture (spheroïd, organoïd, etc) and the microenvironment is closer to In Vivo physiological behaviour [1, 2]. The main difficulties remain in creating a scaffold compatible with the targeted cells and tissues. Bioprinting is one the great objective for tissue engineering. For instance, stereolithography is a 3D printing technology where the freestanding object is built layer by layer with a photosensitive polymer resin through the projection of a UV image in the top plane. In recent promising work, stereolithography has been applied to create 3D hydrogel structures to guide cells like hepatocytes [3]. Nevertheless, ideally, scaffold-free methods are needed. We propose a new method combining microfluidic channels and the acoustic radiation force (ARF) to structure and to control the shape of stem-cells aggregates

Mesenchymal Stromal Cells (MSC) : phenotypical and functional characterizations as tools for immunomodulation in Myasthenia Gravis

International audienceSeveral autoimmune diseases are mediated by antibodies produced after deregulations of the immune system and directed against self antigens. Myasthenia Gravis (MG) is a rare disease in which pathogenicity is due to autoantibodies directed against the neuromuscular endplate. MG is not really cured, corticosteroids and azathioprin are commonly used, however they trigger severe side-effects, mandating the setup of novel therapies. Mesenchymal Stromal/Stem Cells (MSC) are multipotent progenitor cells that can be isolated from various human tissues and can modulate the immune system via soluble mediators and cell-cell contacts. Our team has recently validated a new animal model of MG, in which we demonstrated that the transfer of MSC conditioned by peripheral blood mononucleated cells (PBMC) improved the clinical status of the animals (Sudres et al., JCI Insight 2017). To develop this immunomodulating approach in clinical perspective, we compared the phenotypes of research-grade (RG) and clinical-grade (CG) MSC testing a series of 60 antibodies (Ab) directed against surface antigens by flow cytometry. We evaluated the variations introduced by different conditioning treatments (activation by gamma-interferon, cross-stimulation by PBMC or monocytes). Markers involved in immunomodulation (recognition, activation, function of complement, co-stimulation, immune checkpoints) were increased or decreased depending on treatment. Adhesion molecules and receptors were also differentially modified (integrins, selectins, cell-cell adhesion molecules, growth factor receptors, tetraspanins). These results suggest that the conditioning regimens act through different pathways. From this panel, we derived a second one of 31 Ab allowing simultaneous labeling of MSC at single cell level by mass cytometry (CyTOF). We defined MSC clusters which were modulated upon activation. In parallel, we evaluated the functional activity of resting or conditioned CG MSC through a cell proliferation assay, and through the quantification by ELISA of secreted immunomodulating products. The conditioning regimens differentially modulated the secretion of Prostaglandin E2 and TGFbeta1, and inhibited PBMC proliferation. This work unveiled phenotypic and functional markers of MSC along with their modulations according to different treatments, and will contribute to validate a cell therapy product for immunomodulation purposes

Banking or Bankrupting: Strategies for Sustaining the Economic Future of Public Cord Blood Banks

International audienceCord blood is an important source of stem cells. However, nearly 90% of public cord blood banks have declared that they are struggling to maintain their financial sustainability and avoid bankruptcy. The objective of this study is to evaluate how characteristics of cord blood units influence their utilization, then use this information to model the economic viability and therapeutic value of different banking strategies. Retrospective analysis of cord blood data registered between January 1st, 2009 and December 31st, 2011 in Bone Marrow Donor Worldwide. Data were collected from four public banks in France, Germany and the USA. Samples were eligible for inclusion in the analysis if data on cord blood and maternal HLA typing and biological characteristics after processing were available (total nucleated and CD34+ cell counts). 9,396 banked cord blood units were analyzed, of which 5,815 were Caucasian in origin. A multivariate logistic regression model assessed the influence of three parameters on the CBU utilization rate: ethnic background, total nucleated and CD34+ cell counts. From this model, we elaborated a Utilization Score reflecting the probability of transplantation for each cord blood unit. We stratified three Utilization Score thresholds representing four different banking strategies, from the least selective (scenario A) to the most selective (scenario D). We measured the cost-effectiveness ratio for each strategy by comparing performance in terms of number of transplanted cord blood units and level of financial deficit. When comparing inputs and outputs over three years, Scenario A represented the most extreme case as it delivered the highest therapeutic value for patients (284 CBUs transplanted) along with the highest financial deficit (USD 5.89 million). We found that scenario C resulted in 219 CBUs transplanted with a limited deficit (USD 0.98 million) that charities and public health could realistically finance over the long term. We also found that using a pre-freezing level of 18 x 108 TNC would be the most cost-effective strategy for a public bank. Our study shows that a swift transition from strategy A to C can play a vital role in preventing public cord blood banks worldwide from collapsing

A phase I/II clinical trial of autologous myoblast transplantation in facioscapulohumeral muscular dystrophy

International audienceFacioscapulohumeral muscular dystrophy type 1 (FSHD1) is one of the most frequent adult myopathies (1/20.000), with selective involvement of specific groups of muscles : facial, scapular fixator, anterior foreleg muscles, abdominal and humeral muscles. Vastus lateralis (VL) is usually spared clinically until late stages of the disease, and myoblasts grown from VL have similar behaviour in vivo and in vitro than myoblasts from control patients-> Proposal:Transplantation of autologous myoblast from spared muscle (VL) into an affected muscle as the Tibialis anterior (TA) muscle could locally improve the muscle’s regenerative capacities. Results and discussion: Cell productions were feasible but the quality of the initial muscle biopsy is important. Cell administrations were feasible and clinically well tolerated by all patients but one. The control of local cell distribution may be improved by echographic monitoring. Results show slight increases in twitch response and slight decrease in fatigue in the 3rd group. The combination of cell type (myoblasts) and of the modality (dense multisite injections) may have positively affected the TA muscle, BUT: No clinically significant gain of function perceived by FSHD patients, and no significant changes were noted at MRI and PET-Scan.The local FSHD1 degenerated muscle environment may be detrimental to the stability of the fibers or of the niches, and muscle regeneration may have been inefficient, too transitory, aborted or too unstable.The slight muscle strength increase may not be clinically significant for FSHD patients, but may improve the quality of life of patients with more advanced muscle loss (e.g. DMD patients) in other indications

Autologous Myoblast Transplantation for Oculopharyngeal Muscular Dystrophy: a Phase I/Iia Clinical Study

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A clinical‐grade acellular matrix for esophageal replacement

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Bone marrow sites differently imprint dormancy and chemoresistance to T-cell acute lymphoblastic leukemia

International audienceT-cell acute lymphoblastic leukemia (T-ALL) expands in various bonemarrow (BM) sites of the body. We investigated whether different BM sites could differently modulate T-ALL propagation using in vivo animal models. We observed that mouse and human T-ALL develop slowly in the BM of tail vertebrae compared with the BM from thorax vertebrae. T-ALL recovered from tail BM displays lower cell-surfacemarker expression and decreased metabolism and cell-cycle progression, demonstrating a dormancy phenotype. Functionally, tailderived T-ALL exhibit a deficient short-term ex vivo growth and a delayed in vivo propagation. These features are noncell-autonomous because T-ALL fromtail and thorax shares identical genomic abnormalities and functional disparities disappear in vivo and in prolonged in vitro assays. Importantly tail-derived T-ALL displays higher intrinsic resistance to cell-cycle-related drugs (ie, vincristine sulfate and cytarabine). Of note, T-ALL recovered from gonadal adipose tissues or from cocultures with adipocytes shares metabolic, cell-cycle, and phenotypic or chemoresistance features, with tail-derived T-ALL suggesting adipocytes may participate in the tail BM imprints on T-ALL. Altogether these results demonstrate that BM sites differentially orchestrate T-ALL propagation stamping specific features to leukemic cells such as quiescence and decreased response to cell-cycle-dependent chemotherapy

CBU inclusion criteria.

<p>CBU inclusion criteria.</p