Abstract Serologic testing results are one of the major reasons for discarding donor corneas. This study assessed the prevalence of serologic markers and the times of preanalytic steps. The ...prevalence of serologic markers in 705 cornea donors of the Lorraine region was studied. One hundred forty-one (20%) corneas were discarded on the basis of serologic testing. In a subsample of 180 consecutive cornea donors, data concerning the time of death, sampling, and serology testing were collected. When the time between death and sampling did not exceed 8 h ( n = 122), immediate decantation (separation of serum from clot) led to less discarding of corneas than delayed decantation (2/46 4.3% discarded in the group with immediate decantation versus 13/76 17.1% discarded in the group with delayed decantation P = 0.038). For blood samples collected within 8 h of death, the rate of reactive results is significantly lower if samples are immediately decanted.
Abstract Background Epstein-Barr virus (EBV) infection is a major cause of morbidity following hematopoietic stem cell transplantation. EBV-infected B cells may not respond to rituximab treatment and ...may lead to a life-threatening post-transplantation lymphoproliferative disorder. Adoptive cellular immunotherapy using EBV-lymphoblastoid cell lines (LCL) as stimulating antigen has proved effective in restoring specific immunity. However, EBV presents several immunodominant antigens, and developing a swift and effective clinical-grade immunotherapy relies on the definition of a Good Manufacturing Practices (GMP) universal stimulating antigen. Methods Peripheral blood mononuclear cells (PBMCs) from six donors with a cellular immune response against EBV were immunoselected after stimulation with a new EBV antigen associated with an EBNA3 peptide pool. Results After immunoselection, a mean of 0.53 ± 0.25 × 106 cells was recovered consisting of a mean of 24.77 ± 18.01% CD4+ -secreting interferon (IFN)-γ and 51.42 ± 26.92% CD8+ -secreting IFN-γ. The T memory stem cell sub-population was identified. EBV-specific T cells were expanded in vitro , and their ability to secrete IFN-γ and to proliferate after re-stimulation with EBV antigen was confirmed. A specific lysis was observed against autologous target cells pulsed with EBV peptide pools (57.6 ± 11.5%) and against autologous EBV-LCL (18.3 ± 7.3%). A mean decrease of 94.7 ± 3.3% in alloreactivity against third-party donor mononuclear cells with EBV-specific T cells was observed compared with PBMCs before selection. Conclusions Our results show that a combination of peptide pools including EBNA3 is needed to generate EBV-specific T cells with good specific cytotoxicity and devoid of alloreactivity, but as yet GMP grade is not fully achieved.
Adenovirus (ADV) infections are one of the major causes of morbidity and mortality after hematopoietic stem cell transplantation, despite new antiviral treatment strategies. We describe here a ...complete clinical-grade generation of human anti-ADV cytotoxic T cells to propose an adoptive immunotherapy. Peripheral blood mononuclear cells (PBMC) from 7 healthy donors, known for their good cellular immunity against ADV, were stimulated for 6 hours with a synthetic peptide pool covering the ADV5 Hexon protein interferon-gamma (IFN-gamma) secreting cells were isolated on a clinical device. After immunoselection, a mean number of 1.01 +/- 0.84 x 10(6) total nucleated cells was obtained. The isolated ADV-specific T cells were mainly CD4+ (mean=56% +/- 20.8%, yield=51% +/- 32.4%) but also CD8+ (mean=42% +/- 27%, yield = 56% +/- 39.3%). Isolated T lymphocytes (CTL) were expanded to carry out functional tests. Ability of the expanded CTL to secrete IFN-gamma and to proliferate after restimulation with the ADV peptide pool was confirmed. A high cytotoxicity against autologous target cells loaded with ADV antigens was observed but not against nonloaded target cells. We observed a decrease of 1.27 log of the allogeneic reaction against non HLA identical healthy donor PBMC with CTL compared with the PBMC before selection. Clinical-grade generation of ADV-specific T cells was achieved with a synthetic antigen. This technology has the advantage of being fast, and is sufficiently reactive to be proposed for immunotherapy if antiviral treatment fails.
Abstract A young boy with a confirmed complete DiGeorge Syndrome (cDGS) underwent a peripheral blood mononuclear cell transplantation (PBMCT) from his HLA-identical sister at 4.5 years of age, ...without a conditioning regimen. Eight years later, he is healthy with good immunological functions in the presence of a stable mixed T-cell chimerism. Absence of recent thymic emigrants is confirmed. We observe an inverted CD4+/CD8+ ratio, related to the CD8 subset expansion, a skewing of the TCR repertoire, especially on the CD8+ subset and a telomere loss on the CD8+ cells compared to the donor. However, these anomalies do not seem to have an impact on functional immunity. PBMCT in cDGS using an HLA-matched sibling donor provides good long-lasting immunity and is an easy alternative to bone marrow transplantation and to thymic transplantation.
Adoptive antiviral cellular immunotherapy by infusion of virus-specific T cells (VSTs) is becoming an alternative treatment for viral infection after hematopoietic stem cell transplantation. The T ...memory stem cell (TSCM) subset was recently described as exhibiting self-renewal and multipotency properties which are required for sustained efficacy in vivo. We wondered if such a crucial subset for immunotherapy was present in VSTs. We identified, by flow cytometry, TSCM in adenovirus (ADV)-specific interferon (IFN)-γ+ T cells before and after IFN-γ-based immunomagnetic selection, and analyzed the distribution of the main T-cell subsets in VSTs: naive T cells (TN), TSCM, T central memory cells (TCM), T effector memory cell (TEM), and effector T cells (TEFF). In this study all of the different T-cell subsets were observed in the blood sample from healthy donor ADV-VSTs, both before and after IFN-γ-based immunomagnetic selection. As the IFN-γ-based immunomagnetic selection system sorts mainly the most differentiated T-cell subsets, we observed that TEM was always the major T-cell subset of ADV-specific T cells after immunomagnetic isolation and especially after expansion in vitro. Comparing T-cell subpopulation profiles before and after in vitro expansion, we observed that in vitro cell culture with interleukin-2 resulted in a significant expansion of TN-like, TCM, TEM, and TEFF subsets in CD4IFN-γ T cells and of TCM and TEM subsets only in CD8IFN-γ T cells. We demonstrated the presence of all T-cell subsets in IFN-γ VSTs including the TSCM subpopulation, although this was weakly selected by the IFN-γ-based immunomagnetic selection system.
Most human tissues do not regenerate spontaneously, which is why "cell therapy" are promising alternative treatments. The Principe is simple: patients' or donors' cells are collected and introduced ...into the injured tissues or organs directly or in a porous 3D material, with or without modification of their properties. This concept of regenerative medicine is an emerging field which can be defined as "the way to improve health and quality of life by restoring, maintaining, or enhancing tissue and organ functions".There is an extraordinarily wide range of opportunities for clinical applications: artheropathies, diabetes, cartilage defects, bone repair, burns, livers or bladder regeneration, organs reconstruction (lung, heart, liver ...) neurodegenerative disorders, sepsis ... Different stem cells (SC) with different potential can be used and characterised (totipotent, mesenchymal of different origins, especially those present in tissues...). Today it is undeniable that cells like bone marrow, adipose tissue or Wharton Jelly stem cells, are of potential interest for clinical applications because they are easily separated and prepared and no ethical problems are involved in their use.In this paper some potential clinical applications in the vascular field are considered: peripheral arteriopathy in diabetic patients, cardiac insufficiency, traitment of erectile dysfunction, or organ regeneration with liver as example. But the regeneration of tissue or organ is and will remain a challenge for the future development of cell therapy. Many problems remain to be solved that could lead to the development of innovative strategies to facilitate cell differentiation, increase the yield of cells and ensure a standardised product, overcome the risks of teratogenic effects and/or immune reactions, enable grafting via direct cell or biotissue transplantation and avoid legal issues involved in national regulations.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
This study investigated the gene expression profile of human mesenchymal stem cells seeded in collagen sponge for 28 days in three different mediums: (1) basal medium as control containing ITS alone, ...(2) ITS+TGF-β1 alone or (3) ITS 1% supplemented sequentially by TGF-β1 (D3-D14) followed by BMP-2 (D15-D28). Differential expression of 84 genes implicated in chondrogenic and osteogenic differentiation of MSCs was analyzed at D28 by real-time RT-PCR array technology. TGF-β1 alone down-regulated two genes, CD36 and cathepsin K. Sixteen genes were significantly up-regulated, notably type 2 and type 10 collagens, COMP and Sox9. The sequential combination of TGF-β1 and BMP-2 produced a similar profile with prominent expression of type 2 collagen and the alkaline phosphatase gene. Interestingly, in this in vitro condition, RUNX2 was not up-regulated, suggesting that the sequential combination of TGF-β1/BMP2 enhances the hypertrophic chondrogenic profile without turning towards the osteoblastic pathway.
Celotno besedilo
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In 1997, the Joint Accreditation Committee ISCT & EBMT (JACIE) was created. The following year, it approved the first edition of standards for haemopoietic progenitor cell collection, processing and ...transplantation. The purpose of the standards is to ensure a minimal level of quality, alertness and homogeneity in the implementation of autologous and allogeneic haemopoietic stem cell transplantation (HSCT) programme in onco-hematology. The acquisition of accreditation is based upon the system of examination by trained medical professionals according to countries endorsements with the national regulation obligations applicable to HSCT. In 2008, the fourth edition has been launched. The range of application of the standards comprises both donors and recipients, and all phases of collection, processing, storage and administration of haemopoietic progenitor cells. Among the accredited processing facilities, a few have been integrated JACIE standards into their existing management quality system which is inspected by national health authority. In France, the comparison between JACIE standards and the good manufacturing practices of cellular therapy product reveals some common points and some differences to apply.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Injuries to articular cartilage are one of the most challenging issues of musculoskeletal medicine due to the poor intrinsic ability of this tissue for repair. Despite progress in orthopaedic ...surgery, cell-based surgical therapies such as autologous chondrocyte transplantation (ACT) have been in clinical use for cartilage repair for over a decade but this approach has shown mixed results. Moreover, the lack of efficient modalities of treatment for large chondral defects has prompted research on cartilage tissue engineering combining cells, scaffold materials and environmental factors. This paper focuses on the main parameters in tissue engineering and in particular, on the potential of mesenchymal stem cells (MSCs) as an alternative to cells derived from patient tissues in autologous transplantation and tissue engineering. We discussed the prospects of using autologous chondrocytes or MSCs in regenerative medicine and summarized the advantages and disadvantages of these cells in articular cartilage engineering.
The aim of this study was first, to analyze the post-thaw progenitor assays usually performed on peripheral blood stem cell autografts and second, to achieve standardization with improved flow ...cytometric and CFU-GM assays.
In the first part of the study (n=79), recovery and Intraclass Correlation Coefficient (ICC) of total nucleated cells, CD34 and CFU-GM were analyzed before and after cryopreservation. In the second part (n=20), evaluation methods were modified : the washing step was suppressed in the flow cytometric method and 500 CD34 were plated compared to 4×10(4) total nucleated cells in the CFU-GM assay. The recovery rates were analyzed and the CFU-GM results were regarded as reliable when 30-100 colonies were observed, according to the manufacturer recommendation.
The analysis of the first part showed an ICC that was perfect for total nucleated cells (0.93), substantial for CD34 (0.67) and fair for CFU-GM (0.25). Median CD34 recovery was 112.6% (29.9-222%). The CFU-GM median recovery was 31.7% (0.19-142%) leading to reliable results for 27 grafts. In the second part, the median CD34 recovery was 85.75% (54-99%). No recovery over 100% was observed. The CFU-GM assay led to 18 out of 20 evaluable autografts when 500 CD34 were seeded, compared to 10 out of 20 when total nucleated cell were seeded.
Avoiding cell washing in the flow cytometric method limited the overestimate of the CD34 percentage. Plating 500 thawed CD34 improved reliability of the results and allowed a better standardization of the assay.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
