Lau Fung Yi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 107-130). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

The first transplantable hematopoietic stem cells (HSC) arise in the aorta-gonad mesonephros region (AGM) during early stages of embryo development. Specifically, ventral aspect of embryonic dorsal aorta (DA) contains HSC that upon transplantation into irradiated recipients can reconstitute all lineages of the haematopoietic system [Medvinsky et al. 1993; Muller and Medvinsky, 1994; Medvinsky and Dzierzak, 1996; Cumano et al., 1996; Tavian et al., 1996; Peault and Tavian, 2003; Taoudi and Medvinsky, 2007; Ivanovs et al., 2011, 2014]. The ventral aspect of DA bears so-called intra-aortic cell clusters (IAC), the appearance of which coincides with the emergence of HSC [Babovic and Eaves, 2014; Bhatia, 2007; Boisset et al., 2010, 2011; Bollerot et al., 2005; de Bruijin et al., 2002; Bertrand et al., 2010]. According to recent reports, HSC are a heterogeneous population of cells [Dykstra et al., 2007; Seita and Weissman, 2010; Muller-Sieburg et al., 2012]. It is unclear whether all HSC precursors originate from the same location, for example, DA lining, IAC or sub-aortic tissues; or HSC precursors migrate into DA lining from other parts of the embryo [Tavian et al., 1999; Yoder et al., 1997; Oberlin et al., 2002; Peault and Tavian, 2003; Dzierzak, 2003; Samokhvalov et al., 2007; Medvinsky et al., 2011]. To elucidate ontogeny of early HSC precursors (pro-HSC), two approaches were applied in this PhD project. First, we mapped potential pro-HSC in pre-circulation mouse embryos (embryonic day 6-8.5, E6-E8.5). We defined potential pro-HSC as cells co-expressing the transcription factor Runx1, endothelial markers (VE-Cad or CD31) and/or haematopoietic markers (CD45, CD41) [Oberlin et al., 2002; de Bruijn and Dzierzak, 2012; Liakhovitskaia et al., 2009, 2014]. In E6-E8 mouse embryo, prospective pro-HSC were found to be located in chorionic plate, yolk sac and in allantoic core domain. In early somitic mouse embryo (E8-8.5) cells with pro-HSC phenotype (Runx1+CD31+CD41+) were found to be in cell clusters in forming vessel of confluence and in nascent dorsal aortae lining. Pro-HSC are not directly transplantable [Cumano et al., 1996., 2001; Godin et al., 1993; 1995; Batta et al., 2016; Matsuoka et al., 2001; Nishikawa et al., 1998]. Therefore, cells and tissues containing prospective pro-HSC were initially matured using several in-vitro culture systems. According to our results, E8 mouse embryo pro-HSC are only preserved in explant cultures, but not in co-aggregate cultures with stroma cells. After culture, cells were transplanted into sub-lethally irradiated recipients. Six weeks after transplantation 19 out of 82 transplanted recipients had donor derived blood cells' chimerism at the level of 0.1-0.3%. Forty six percent of these grafts were derived from rostral part of the embryo tissues (head, heart, upper somites). Only one out of 82 recipients had donor cells contribution above 1% (1.2 %). This recipient was engrafted with cells derived from the E8 mouse embryo head and heart region. Recipients having blood chimerism at the range of 0.1-0.3% had mainly lymphoid donor derived cells in their peripheral blood. The only recipient showing the high donor cells contribution (1.2%) had contribution mainly to myeloid lineage. Recorded low levels of blood chimersims are in line with those reported by Rybtsov et al. (2014) for early E9 mouse embryos. Donor derived cells formed clearly distinguishable populations on cytometry plots. This population of cells were absent from control engraftment experiments with carrier cells only. Previously, lymphoid potential was detected in paraaortic spnanchnopleura (P-Sp) of E8.5-9 mouse embryos, but not in E8 mouse embryos (0-5 somites, pre-circulation) and later in yolk sac [Cumano et al., 1996; Nishikawa et al., 1998; Fraser et al., 2002; Yokota et al., 2006]. However, prior works used different criteria to establish recipient reconstitution. Therefore, it is possible that recipients repopulated with E8 derived cells at the level of 0.1% were not considered as repopulated and hence, presence of lymphoid lineage precursors was overlooked in early somitic mouse embryos. The only recipient showing substantial myeloid cells contribution (73% Mac1+Gr1+ cells of donor derived cells) received engrafted cells from an older (6-13 sp) embryo and therefore potentially has yolk sac derived myeloid cells. Yolk sac cell contribution to myeloid lineage, specifically to the brain microglia was reported in prior works [Samokhvalov et al., 2007]. Our data show that early E8 AGM cells do not expand in in vitro conditions. While in AGM, cells from E9 mouse embryo expand in culture [Rybtsov et al., 2014]. We have analysed Runx1 expression pattern and dorsal aorta morphology at the time when E9 HSC precursors acquire ability to expand in in vitro culture. Runx1 expression becomes clearly polarised at the time point (22-26 sp), when paired dorsal aortae fusion is initiated. We envision that intimate connection between DA fusion events and induction of pro-HSC maturation exists. According to prior reports, Bmp, Shh and VEGF signalling regulate DA fusion [Garriock et al., 2010]. Thereofore, to enhance in vitro HSC maturation system, DA fusion triggers (for example, Bmp4) might be added to culture. Since, pro-HSC maturation methods established to date are not efficient to expand and differentiate E8 pro-HSC into potent HSC, another approach had to be implemented to study HSC ontogeny. The second approach we utilized was to trace the origin of HSC in chicken embryo, starting from the very beginning of cell fate specification, i.e. from gastrulation stages. Chick embryo haematopoiesis is similar in both human and mouse: precursors of HSC arise in the embryo proper in AGM, and IAC are formed in DA ventral aspect [Dieterlen-Lièvre, 1975; Dieterlen-Lièvre and Martin, 1981; Dieterlen-Lièvre and Jaffredo, 2009; Jaffredo et al., 2000; Le Douarin and Dieterlen-Lièvre, 2013]. In contrast to mammals, chick embryo develops ex vivo, making direct labelling and cell tracing possible. We aimed to identify cells giving rise to regions of DA that produce IAC. Therefore, segments of primitive streak (PS) were labelled with lipophilic dyes or by substituting segments of host PS with PS sections derived from transgenic (GFP+) stage matched chicken embryos. Our results show that in an 18-25h chicken embryo (Hamburger and Hamilton developmental stage 4-6, HH4-6) cells giving rise to DA ingress through the wide region of PS (35-60% of its length) [Hamburger and Hamilton, 1951]. We identified that the section of DA producing HSC is formed by cells ingressing through PS in region of 40-55% of its length at 18-25h of chick embryo development. Regardless of the embryo development stage (HH4-6), in chimeras grafted at 40-55% of PS length, GFP+ cells contributed to DA and to the IAC. Within GFP+ labelled areas, we observed clusters consisting entirely of GFP+ and clusters having a mixture of GFP+ and GFP- cells. Entirely GFP+ clusters were found in the stretch of DA that had the entire aortic endothelial lining labelled. Clusters formed on the mosaic (GFP+/GFP-) aortic endothelium also had mosaic nature. According to our data, multiple descendants of PS contribute to the same stretch of dorsal aorta. This explains mosaicity of dorsal aorta lining and IAC labelling. Since we encountered clusters with mixture of GFP+ and GFP- cells, we conclude that IAC are not clonal formations. Mosaicity of IAC also does not exclude a scenario when cells migrate in and out of a cluster. Further tracing experiments are required to establish HSC nature of cells within a cluster.

Lam Audrey Carmen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 166-195). / Abstracts in English and Chinese. / Acknowledgements --- p.vi / Publications --- p.vii / Abbreviations --- p.x / Abstract --- p.xiii / Chapter Chapter One - --- Introduction --- p.1 / Chapter Section 1.1 --- Hematopoietic Stem Cells --- p.1 / Chapter 1.1.1 --- Hematopoiesis --- p.1 / Chapter 1.1.2 --- Hematopoietic Stem and Progenitor Cells --- p.1 / Chapter Section 1.2 --- Stem Cell Transplantation --- p.4 / Chapter 1.2.1 --- Stem Cell Transplantation --- p.4 / Chapter 1.2.2 --- Sources of Hematopoietic Stem Cells for Transplantation --- p.4 / Chapter 1.2.3 --- Cord Blood as a Source of Hematopoietic Stem Cells --- p.6 / Chapter 1.2.3.1 --- Advantages of Cord Blood Transplant --- p.6 / Chapter 1.2.3.2 --- Disadvantages of Cord Blood Transplant --- p.7 / Chapter Section 1.3 --- Ex Vivo Expansion --- p.8 / Chapter 1.3.1 --- Optimization of Expansion Conditions --- p.10 / Chapter 1.3.1.1 --- CD34+ Cell Selection --- p.10 / Chapter 1.3.1.2 --- Cytokines --- p.11 / Chapter 1.3.1.2.1 --- Thrombopoietin --- p.12 / Chapter 1.3.1.2.2 --- Stem Cell Factor --- p.14 / Chapter 1.3.1.2.3 --- Flt-3 Ligand --- p.15 / Chapter 1.3.1.2.4 --- Granulocyte-Colony Stimulating Factor --- p.16 / Chapter 1.3.1.2.5 --- Interleukin-3 --- p.17 / Chapter 1.3.1.2.6 --- Interleukin-6 --- p.18 / Chapter 1.3.1.2.7 --- Comparison of Flt-3 Ligand and Stem Cell Factor --- p.20 / Chapter 1.3.1.3 --- Culture Medium --- p.20 / Chapter 1.3.2 --- Mannose-Binding Lectin --- p.22 / Chapter 1.3.3 --- Ex Vivo Expansion for Clinical Transplantation --- p.23 / Chapter Section 1.4 --- Non-Obese Diabetic/Severe Combined Immunodeficient Mouse Transplantation Model --- p.29 / Chapter Chapter Two - --- Objectives --- p.32 / Chapter Chapter Three - --- Materials and Methodology --- p.34 / Chapter Section 3.1 --- Collection of Cord Blood Samples / Chapter Section 3.2 --- Cryopreservation and Thawing of Cord Blood --- p.34 / Chapter Section 3.3 --- Enrichment of CD34+ Cells --- p.35 / Chapter Section 3.4 --- Ex Vivo Expansion --- p.38 / Chapter 3.4.1 --- Effects of Flt-3 Ligand and stem Cell Factor on the Expansion of Megakaryocytic Progenitor Cells --- p.39 / Chapter 3.4.1.1 --- Ex Vivo Expansion of Cord Blood CD34+ Cells with Flt-3 Ligand or Stem Cell Factor --- p.39 / Chapter 3.4.1.2 --- Flt-3 Receptor Assay --- p.40 / Chapter 3.4.2 --- Effects of Mannose-Binding Lectin on the Ex Vivo Expansion of Hematopoietic Stem and Progenitor Cells --- p.41 / Chapter 3.4.2.1 --- Ex Vivo Expansion of Cord Blood CD34+ Cells with Mannose-Binding Lectin --- p.41 / Chapter 3.4.2.2 --- Effects of Mannose-Binding Lectin on the Preservation of Early Stem and Progenitor Cells --- p.41 / Chapter 3.4.2.3 --- Transplantation of Expanded Cells into NOD/SCID Mice --- p.42 / Chapter 3.4.3 --- "Optimization of Culture Duration, Culture Media, Autologous Plasma and Cytokine Combinations for the Preclinical Ex Vivo Expansion of Hematopoietic Stem and Progenitor Cells" --- p.42 / Chapter 3.4.3.1 --- "Comparison of Culture Duration, Culture Media and Cytokine Combinations" --- p.42 / Chapter 3.4.3.2 --- Effects of Autologous Cord Blood Plasma --- p.43 / Chapter 3.4.3.3 --- Effects of Flt-3 Ligand and Dosage of Thrombopoietin and Stem Cell Factor --- p.43 / Chapter 3.4.3.4 --- Transplantation of Expanded Cells into NOD/SCID Mice --- p.44 / Chapter Section 3.5 --- Progenitor Colony-Forming Assays --- p.44 / Chapter 3.5.1 --- Colony-Forming Unit Assay --- p.44 / Chapter 3.5.2 --- Colony Forming Unit Megakaryocyte --- p.46 / Chapter 3.5.3 --- Calculations of CFU --- p.46 / Chapter Section 3.6 --- Flow Cytometry Analysis --- p.47 / Chapter Section 3.7 --- Transplantation of Non-Obese Diabetic/Severe Combined Immunodeficient Mice --- p.48 / Chapter Section 3.8 --- Assessment of Human Cell Engraftment in Transplanted NOD/SCID Mice --- p.49 / Chapter 3.8.1 --- Flow Cytometry Analysis --- p.49 / Chapter 3.8.2 --- PCR Analysis --- p.50 / Chapter Section 3.9 --- Statistical Analysis --- p.52 / Chapter Chapter Four - --- Effects of Flt-3 Ligand and Stem Cell Factor on the Expansion of Megakaryocytic Progenitor Cells --- p.53 / Chapter Section 4.1 --- Results --- p.53 / Chapter 4.1.1 --- Ex Vivo Expansion of CD34+ Cells --- p.53 / Chapter 4.1.2 --- Identification of Flt-3 Receptors --- p.55 / Chapter Section 4.2 --- Discussion --- p.55 / Chapter Chapter Five- --- Effects of Mannose-Binding Lectin on the Ex Vivo Expansion of Hematopoietic Stem and Progenitor Cells --- p.68 / Chapter Section 5.1 --- Results --- p.68 / Chapter 5.1.1 --- Ex Vivo Expansion of CD34+ Cells with Mannose-Binding Lectin --- p.68 / Chapter 5.1.2 --- Effects of Mannose-Binding Lectin on the Preservation of Early Stem and Progenitor Cells --- p.72 / Chapter 5.1.3 --- Transplantation of Expanded Cells into NOD/SCID Mice --- p.75 / Chapter Section 5.2 --- Discussion --- p.76 / Chapter Chapter Six - --- "Optimization of Culture Duration, Culture Media, Autologous Plasma and Cytokine Combinations for the Preclinical Ex Vivo Expansion of Hematopoietic Stem and Progenitor Cells" --- p.111 / Chapter Section 6.1 --- Results --- p.111 / Chapter 6.1.1 --- Kinetics of Expansion --- p.111 / Chapter 6.1.2 --- Assessment of Culture Media --- p.113 / Chapter 6.1.3 --- Effects of Autologous Cord Blood Plasma --- p.115 / Chapter 6.1.4 --- Effects of Granulocyte-Colony Stimulating Factor --- p.117 / Chapter 6.1.5 --- Effects of Interleukin-6 --- p.118 / Chapter 6.1.6 --- Effects of Increased Dosage of Thrombopoietin and Stem Cell Factor --- p.119 / Chapter 6.1.7 --- Effects of Flt-3 Ligand --- p.120 / Chapter 6.1.8 --- Transplantation of Expanded Cells into NOD/SCID Mice --- p.121 / Chapter Section 6.2 --- Discussion --- p.123 / Chapter Chapter Seven- --- General Discussion and Conclusion --- p.163 / Bibliography --- p.166

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: stem cells, cytokines. Includes bibliographical references (p. 79-83).

In recent years, great advances have been made in the field of stem cell differentiation. Seminal insights in the area of developmental biology and tissue regeneration have made ex vivo differentiated cells a realistic alternative for transplantation applications. The recent application of these murine-based insights to human systems has paved new paths in autoimmune disease, chemotherapy, and immuno-deficiency research. Such strides would eliminate the hurdles associated with adoptive transfer including limited availability of transplantable cells, site morbidity, difficulties in cell isolation and expansion lag time. Current approaches in ex vivo hematopoiesis and T cell differentiation have begun to explore the effects of biomaterials on differentiation efficiency. These approaches, however, have not fully studied the quantitative effects of biomaterials and their properties on hematopoietic and T cell differentiation generation. Our goal was to design biomaterials whose properties could be tailored to improve differentiation efficiencies in T cell differentiation. Our work is dedicated to fabricating and characterizing Notch ligand functionalized microbeads for T cell differentiation applications. Our work has shown stable functionalization of Notch ligands on microbeads that can be quantitatively varied to achieve optimal Notch signaling. We have also demonstrated limited cellular toxicity and effective Notch signaling upon exposure to Notch ligand functionalized beads. Finally, we have successfully differentiated T cell progenitors from hematopoietic stem cells using the functionalized microbeads. As a side study, we have fabricated and characterized polymeric PLA scaffolds that were systematically varied and studied for their effects on hematopoietic differentiation efficiency. Insights gained from these studies should provide a better understanding of the microenvironmental signals in hematopoiesis and aid in the development of efficient technologies for the production of hematopoietic progenitors and T cells for therapeutic applications.

published_or_final_version / Medicine / Master / Doctor of Medicine

Η μη επαγόμενη και η επαγόμενη παραγωγή των GM-CSF, G-CSF, IL-3, IL-6, SCF, IL-1β, TNF-α , TNF-β, IFN-γ και του TGF-β προσδιορίστηκαν μετά από καλλιέργεια μονοπύρηνων κυττάρων αίματος 22 ασθενών με βαριά β-θαλασσαιμία που υποβάλλονταν σε κανονικό πρόγραμμα μεταγγίσεων, 5 ασθενών με ενδιάμεση β- θαλασσαιμία που δεν υποβάλλονταν σε κανονικό πρόγραμμα μεταγγίσεων και 9 φυσιολογικών ατόμων. Ένα διακριτό πρότυπο παραγωγής κυτταροκινών διαπιστώθηκε στους β-θαλασσαιμικούς ασθενείς. Συγκεκριμένα παρατηρήθηκε μειωμένη μη επαγόμενη παραγωγή όλων των κυτταροκινών και σημαντική αύξηση της επαγόμενης παραγωγής των IFN-γ, TNF-α και της IL-1β. Αυτές οι διαταραχές ήταν περισσότερο εμφανείς στους μεγαλύτερους σε ηλικία ασθενείς, που έχουν υποβληθεί στις περισσότερες μεταγγίσεις. Η αυξημένη παραγωγή των παραπάνω κυτταροκινών, συνήθως χαρακτηρίζει την οξεία απόκριση σε μολυσματικούς παράγοντες και ασκεί αρνητική επίδραση στην ερυθροποίηση. Αυτό μπορεί να εξηγεί την επιδείνωση της αναιμίας στους θαλασσαιμικούς ασθενείς, κατά τη διάρκεια οξείων λοιμώξεων. / The unstimulated and induced production of granulocyte-macrofage colonystimulating factor (GM-CSF), granulocyte colony –stimulating factor (G-CSF), IL-3, IL-6, stem cell factor (SCF), IL-1β, tumour necrosis factor-alpha (TNF-a), TNF-β, interferon-gamma (IFN-γ) and transforming growth factor-beta (TGF-β) was determined after culture of blood mononuclear cells from 22 patients with severe β- thalassaemia in a regular transfusion programme, five non-regularly transfused patients with β-thalassaemia intermedia and nine normal persons. A distinct pattern of cytokine production in thalassaemic patients was detected, namely a low unstimulated production of all cytokines and a significant increase in the stimulated production of IFN-γ, TNF-a and IL-1β; these abnormalities were more pronounced in the more heavily transfused older patients. The increased production of the above cytokines, which usually characterize the acute response to infectious agents and have a negative effect on erythropoiesis, may explain the deterioration of anaemia found in thalassaemic patients during acute infections.

Thesis (MAppSc (Medical Laboratory Science)) --University of South Australia, 1993

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 7 uppsatser.