Search results for " stem cell transplantation"

Non-cognate bystander cytolysis by clonal epitope-specific CTL lines through CD28-CD80 interaction inhibits antibody production: A potential caveat t…

2015

Abstract Adoptive transfer of virus epitope-specific CD8 T cells is an immunotherapy option to control cytomegalovirus (CMV) infection and prevent CMV organ disease in immunocompromised solid organ transplantation (SOT) and hematopoietic cell transplantation (HCT) recipients. The therapy aims at an early, selective recognition and cytolysis of infected cells for preventing viral spread in tissues with no adverse immunopathogenic side-effects by attack of uninfected bystander cells. Here we describe that virus epitope-specific, cloned T-cell lines lyse target cells that present the cognate antigenic peptide to the TCR, but simultaneously have the potential to lyse uninfected cells expressing…

2017

Better identification of severe acute graft-versus-host disease (GvHD) may improve the outcome of this life-threatening complication of allogeneic hematopoietic stem cell transplantation. GvHD induces tissue damage and the release of damage-associated molecular pattern (DAMP) molecules. Here, we analyzed GvHD patients (n = 39) to show that serum heat shock protein glycoprotein 96 (Gp96) could be such a DAMP molecule. We demonstrate that serum Gp96 increases in gastrointestinal GvHD patients and its level correlates with disease severity. An increase in Gp96 serum level was also observed in a mouse model of acute GvHD. This model was used to identify complement C3 as a main partner of Gp96 i…

Stem cell therapy. Old challenges and new solutions

2020

Stem cell therapy (SCT), born as therapeutic revolution to replace pharmacological treatments, remains a hope and not yet an effective solution. Accordingly, stem cells cannot be conceivable as a "canonical" drug, because of their unique biological properties. A new reorientation in this field is emerging, based on a better understanding of stem cell biology and use of cutting-edge technologies and innovative disciplines. This will permit to solve the gaps, failures, and long-term needs, such as the retention, survival and integration of stem cells, by employing pharmacology, genetic manipulation, biological or material incorporation. Consequently, the clinical applicability of SCT for chro…

Wharton's Jelly Mesenchymal Stromal Cells as a Feeder Layer for the Ex Vivo Expansion of Hematopoietic Stem and Progenitor Cells: a Review

2016

In recent years, umbilical cord blood (UCB) has been widely used as an alternative source to bone marrow (BM) for transplantation of hematopoietic stem and progenitor cells (HSPCs) in a variety of hematological and non-hematological disorders. Nevertheless, the insufficient number of UCB-HSPCs for graft represents a major challenge. HSPCs ex vivo expansion prior to transplantation is a valid strategy to overcome this limit. Several attempts to optimize the expansion conditions have been reported, including the use of mesenchymal stromal cells (MSCs) as feeder layer. Wharton's Jelly (WJ), the main component of umbilical cord (UC) matrix, is especially rich in MSCs, which are considered ideal…

Treatment strategies for lysosomal storage disorders.

2017

Over the past several years the number of treatments available for patients with lysosomal storage disorders has rapidly increased. Haematopoietic stem cell transplantation, enzyme replacement therapy, substrate reduction, and chaperone therapies are currently available, and gene therapies and other treatments are rapidly advancing. Despite remarkable advances, the efficacy of most of these therapies is limited, particularly because the treatments are usually initiated when organ damage has already occurred. To circumvent this limitation, screening in newborn infants for lysosomal storage disorders has been introduced in many countries. However, this screening is complicated by the broad cl…

Modulating endothelial adhesion and migration impacts stem cell therapies efficacy

2020

Abstract Background Limited knowledge of stem cell therapies` mechanisms of action hampers their sustainable implementation into the clinic. Specifically, the interactions of transplanted stem cells with the host vasculature and its implications for their therapeutic efficacy are not elucidated. We tested whether adhesion receptors and chemokine receptors on stem cells can be functionally modulated, and consequently if such modulation may substantially affect therapeutically relevant stem cell interactions with the host endothelium. Methods We investigated the effects of cationic molecule polyethylenimine (PEI) treatment with or without nanoparticles on the functions of adhesion receptors a…

Mouse Model of Cytomegalovirus Disease and Immunotherapy in the Immunocompromised Host: Predictions for Medical Translation that Survived the “Test o…

2018

Human Cytomegalovirus (hCMV), which is the prototype member of the β-subfamily of the herpesvirus family, is a pathogen of high clinical relevance in recipients of hematopoietic cell transplantation (HCT). hCMV causes multiple-organ disease and interstitial pneumonia in particular upon infection during the immunocompromised period before hematopoietic reconstitution restores antiviral immunity. Clinical investigation of pathomechanisms and of strategies for an immune intervention aimed at restoring antiviral immunity earlier than by hematopoietic reconstitution are limited in patients to observational studies mainly because of ethical issues including the imperative medical indication …

Extravascular coagulation in hematopoietic stem and progenitor cell regulation

2018

Abstract The hemostatic system plays pivotal roles in injury repair, innate immunity, and adaptation to inflammatory challenges. We review the evidence that these vascular-protective mechanisms have nontraditional roles in hematopoietic stem cell (HSC) maintenance in their physiological bone marrow (BM) niches at steady-state and under stress. Expression of coagulation factors and the extrinsic coagulation initiator tissue factor by osteoblasts, tissue-resident macrophages, and megakaryocytes suggests that endosteal and vascular HSC niches are functionally regulated by extravascular coagulation. The anticoagulant endothelial protein C receptor (EPCR; Procr) is highly expressed by primitive …

Exogenous TNFR2 activation protects from acute GvHD via host T reg cell expansion

2015

Activation of TNFR2 with a novel agonist expands T reg cells in vivo and protects allo-HCT recipients from acute GvHD while sparing antilymphoma and antiinfectious properties of transplanted donor T cells.

Transfer of minimally manipulated CMV-specific T cells from stem cell or third-party donors to treat CMV infection after allo-HSCT.

2017

Cytomegalovirus (CMV) infection is a common, potentially life-threatening complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). We assessed prospectively the safety and efficacy of stem cell-donor-or third-party-donor-derived CMV-specific T cells for the treatment of persistent CMV infections after allo-HSCT in a phase I/IIa trial. Allo-HSCT patients with drugrefractory CMV infection and lacking virus-specific T cells were treated with a single dose of ex vivo major histocompatibility complex-Streptamer-isolated CMV epitope-specific donor T cells. Forty-four allo-HSCT patients receiving a T-cell-replete (D+ repl; n = 28) or T-cell-depleted (D+ depl; n = 16) …