Innovations in Stem Cell Transplantation

This book documents the increased number of stem cell related research, basic and clinical applications as well as views for the future. The book covers a wide range of issues related to new developments and innovations in cell-based therapies containing basic and clinical chapters from the respected authors involved in stem cell studies and research around the world. It thereby complements and extends the basic coverage of stem cells such as immunogenetics, neuron replacement therapy, cover hematopoietic stem cells, issues related to clinical problems, advanced HLA typing, alternative donor sources as well as gene therapy that employs novel methods in this field. Clearly, the treatment of various malignancies and biomedical engineering will depend heavily on stem cells, and this book is well positioned to provide comprehensive coverage of these developments

New Advances in Stem Cell Transplantation

This book documents the increased number of stem cell-related research, clinical applications, and views for the future. The book covers a wide range of issues in cell-based therapy and regenerative medicine, and includes clinical and preclinical chapters from the respected authors involved with stem cell studies and research from around the world. It complements and extends the basics of stem cell physiology, hematopoietic stem cells, issues related to clinical problems, tissue typing, cryopreservation, dendritic cells, mesenchymal cells, neuroscience, endovascular cells and other tissues. In addition, tissue engineering that employs novel methods with stem cells is explored. Clearly, the continued use of biomedical engineering will depend heavily on stem cells, and this book is well positioned to provide comprehensive coverage of these developments

In vitro expanded human CD4+CD25+ regulatory T cells suppress effector T cell proliferation.

Regulatory T cells (Tregs) have been shown to be critical in the balance between autoimmunity and tolerance and have been implicated in several human autoimmune diseases. However, the small number of Tregs in peripheral blood limits their therapeutic potential. Therefore, we developed a protocol that would allow for the expansion of Tregs while retaining their suppressive activity. We isolated CD4+CD25 hi cells from human peripheral blood and expanded them in vitro in the presence of anti-CD3 and anti-CD28 magnetic Xcyte Dynabeads and high concentrations of exogenous Interleukin (IL)-2. Tregs were effectively expanded up to 200-fold while maintaining surface expression of CD25 and other markers of Tregs: CD62L, HLA-DR, CCR6, and FOXP3. The expanded Tregs suppressed proliferation and cytokine secretion of responder PBMCs in co-cultures stimulated with anti-CD3 or alloantigen. Treg expansion is a critical first step before consideration of Tregs as a therapeutic intervention in patients with autoimmune or graft-versus-host disease

The mononuclear phagocyte system in Graft-versus-host-disease

PhD ThesisThe human mononuclear phagocyte system of monocytes, macrophages and dendritic cells participates in both innate and adaptive immune responses. However, the accurate identities, functions and inter-relationships of these crucial immune cells during inflammation are poorly defined. Two inflammatory settings were examined in this work: the skin in acute Graft-versus-Host Disease and the lung during experimental inflammation induced by LPS inhalation. The purpose of this enquiry was to characterize inflammatory mononuclear phagocytes in tissue, investigate their origins and explore their contribution to disease pathogenesis. In the skin GvHD study, shave biopsies were obtained from 73 individuals on presentation with acute rash following bone marrow transplantation (BMT). Controls were obtained from 19 BMT recipients at matched time points without rash and 26 healthy individuals undergoing plastic surgery. Tissue was digested and the leukocyte composition analysed by flow cytometry/ sorting. Sorted populations were used in functional assays or in gene expression experiments performed using NanoString technology. An in vitro equivalent of CD14-expressing mononuclear phagocytes (MPs) was developed using HLA-matched mixed leukocyte reactions. Gene expression was measured and the function of these equivalents in a skin explant model of GvHD was tested. GvHD lesional skin was characterized by expansion of CD14-expressing MPs (GVH14) and a reduction in CD1c-expressing MPs. GVH14 were identified as donor monocyte-derived macrophages. Functionally, GVH14 could produce chemokines to recruit T lymphocytes to lesions. They were capable of activating and expanding T lymphocytes in vitro. GVH14 equivalents could damage basal keratinocytes of the epidermis without the presence of T cells. This characterization has identified a novel pathogeneic role for macrophages in acute GvHD. In the LPS inhalation study, 13 healthy individuals received saline (0.9% sodium chloride) and 13 received LPS (0.9% sodium chloride with 2mg LPS from E.coli 026:B6) by dosimeter nebulizer. Blood samples were obtained at 2, 4, 6 and 24 hours following inhalation. Between 7 and 8 hours post-inhalation, bronchoalveolar ! V! lavage (BAL) of a sub-segment of the right middle lobe was performed. BAL fluid supernatant chemokines and cytokines were analysed by multiplexed ELISA. The cellular component of BAL was analysed by flow cytometry/ sorting. Sorted populations were used in functional assays or in gene expression experiments performed using NanoString technology. Seven distinct MPs were identified in steady state (i.e. following saline inhalation). Following LPS inhalation, neutrophils, CD14-expressing MPs and CD1c-expressing MPs were expanded. Phenotypically, CD1c expressing MPs resembled blood cDC2. Both subsets of blood cDC2 were recruited to the airspace but their distinct functions and gene expression profiles converged upon recruitment. This analysis provides the first detailed characterization of BAL fluid MPs. As such it provides a foundation for studying MPs in human lung diseases, including the Idiopathic Pneumonia Syndrome occurring after BMT. It detailed the surprising observation that blood cDC2 can be recruited to tissue in inflammation, challenging the dogma that inflammatory MPs must be monocyte-derived.Wellcome Trust Clinical Research Training Fellowshi

Hematopoietic stem cell transplantation for neurological disorders: a focus on inborn errors of metabolism

Copyright © 2022 de Vasconcelos and Lacerda. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Hematopoietic stem cells have been investigated and applied for the treatment of certain neurological disorders for a long time. Currently, their therapeutic potential is harnessed in autologous and allogeneic hematopoietic stem cell transplantation (HSCT). Autologous HSCT is helpful in immune-mediated neurological diseases such as Multiple Sclerosis. However, clinical benefits derive more from the immunosuppressive conditioning regimen than the interaction between stem cells and the nervous system. Mainly used for hematologic malignancies, allogeneic HSCT explores the therapeutic potential of donor-derived hematopoietic stem cells. In the neurological setting, it has proven to be most valuable in Inborn Errors of Metabolism, a large spectrum of multisystem disorders characterized by congenital deficiencies in enzymes involved in metabolic pathways. Inborn Errors of Metabolism such as X-linked Adrenoleukodystrophy present with brain accumulation of enzymatic substrates that result in progressive inflammatory demyelination. Allogeneic HSCT can halt ongoing inflammatory neural destruction by replacing hematopoietic-originated microglia with donor-derived myeloid precursors. Microglia, the only neural cells successfully transplanted thus far, are the most valuable source of central nervous system metabolic correction and play a significant role in the crosstalk between the brain and hematopoietic stem cells. After transplantation, engrafted donor-derived myeloid cells modulate the neural microenvironment by recapitulating microglial functions and enhancing repair mechanisms such as remyelination. In some disorders, additional benefits result from the donor hematopoietic stem cell secretome that cross-corrects neighboring neural cells via mannose-6-phosphatase paracrine pathways. The limitations of allogeneic HSCT in this setting relate to the slow turnover of microglia and complications such as graft-vs.-host disease. These restraints have accelerated the development of hematopoietic stem cell gene therapy, where autologous hematopoietic stem cells are collected, manipulated ex vivo to overexpress the missing enzyme, and infused back into the patient. With this cellular drug vehicle strategy, the brain is populated by improved cells and exposed to supraphysiological levels of the flawed protein, resulting in metabolic correction. This review focuses on the mechanisms of brain repair resulting from HSCT and gene therapy in Inborn Errors of Metabolism. A brief mention will also be made on immune-mediated nervous system diseases that are treated with this approach.info:eu-repo/semantics/publishedVersio

Computational analysis of innate and adaptive immune responses

Both innate and adaptive immune processes rely on the activation of differentiated haematopoietic stem cell lineages to affect an appropriate response to pathogens. This thesis employs a largely network biology focused approach to better understand the specificity of immune cell responses in two distinct cases of pathogenic challenge. In the context of adaptive immunity, I studied the transcriptional responses of T cells during Graft-versus-Host Disease (GvHD). GvHD represents one of the major complications to arise following allogeneic hematopoietic stem cell transplantation and yet why only particular organs are damaged as a result of this pathology is still unclear. To investigate whether key GvHD transcriptional signatures seen in effector CD8+ T cells compared to naïve T cells are triggered in target organs or the secondary lymphoid organs, a module-based association test was developed to combine the output of gene clustering algorithms with that of differential expression analysis. This methodology significantly aided the identification of skin specific effector T cell transcriptional programs believed to drive murine GvHD pathogenesis at this site. Turning to the innate immune response, I investigated the transcriptional profiles of resting and activated macrophages in the setting of Tuberculosis (TB), the second leading cause of death from infectious disease worldwide. Regression-based analyses and clustering of macrophage expression data provided insight into the variations in gene expression profiles of naïve macrophages compared to those infected with Mycobacterium tuberculosis (MTB) or a vaccine strain of mycobacteria (BCG). The availability of genotype data as part of the macrophage dataset facilitated an expression quantitative trait loci (eQTL) study which highlighted a novel association between the cytoskeleton gene BCAR1 and TB risk, together with a previously undescribed trans-eQTL module specific to MTB infected macrophages. Potential genetic variants impacting expression of the aforementioned GvHD specific T cell transcriptional signatures were additionally investigated using external trans-eQTL datasets

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown