Transient uterine Natural Killer (uNK) cells are the predominant leukocytes of early gestational human and murine uteri. Murine uNK cells promote changes in endometrial structure including initiation of perivascular smooth muscle reduction in spiral arteries. Less is known about human uNK cell functions due to sampling constraints. Xenogeneic engraftment of human lymphocyte progenitors to alymphoid mice has been useful in understanding human lymphocyte functions in vivo. Irradiation of recipients is required to create a niche for successful humanization of the mice but renders recipient mice sterile. The goal of my thesis was to develop a protocol enabling engraftment of human hematopoietic stem cells in alymphoid mice that would permit differentiation of functional human uNK cells. I then planned to evaluate human uNK cell functions and their regulation in vivo. Neonatal Rag2-/-Il2rg-/- mice, which lack T cells, B cells and NK cells were preconditioned with 5-fluorouracil and inoculated with syngeneic mouse bone marrow cells. As adults, inoculated female mice conceived and differentiated functional mouse uNK cells. In contrast, neonatally-preconditioned Rag2-/-Il2rg-/- mice inoculated with human cord blood hematopoietic stem cells conceived but differentiated non-lymphoid cells in sites normally occupied by uNK cells. Weekly injections of human IL-15, which is required for NK cell differentiation, proliferation and survival, did not promote uNK cell differentiation. Rather, treatment with IL-15 altered gestational uteri, even in mice receiving neither preconditioning nor hematopoietic stem cells. I was successful in developing a protocol that enables hematopoietic stem cell engraftment in neonatal mice without compromising mouse fertility. However, this model is apparently not suitable for in vivo studies of human uNK cell functions. / Thesis (Master, Anatomy & Cell Biology) -- Queen's University, 2010-08-30 16:27:07.522

Sertoli cells (SCs) are somatic cells located in the testes. They are the only cells in direct contact with germ cells and play a key role in process of spermatogenesis. New insights in the biology of SCs are highlighting the immunological function of these cells: germ cells protection by maintaining the immunoprotective niche, creating the blood- testis barrier and local modulation of the immune response to spermatic cells. Immunomodulatory activity of SCs is preserved after their allo- and xenogeneic transplantation, and thus SCs prolongs survival not only of themselves but also of cells transplanted with them. The aim of this thesis was to study the survival and migration of SCs precursors (TSC) in mice recipients. The project is employing the neonatal tolerance phenomenon and evolutionary distinct donor organism, Xenopus tropicalis, to monitor conserved mechanisms of immune system (IS) modulation using SCs. SCs were detectable in the lungs and thymus 7 days after transplantation. The phenotype of immune cells was not altered 30 days after transplantation, however we detected changes in cytokine environment, namely increased levels of cytokines typical for Th2 and Treg immune responses. In vitro experiments further confirmed IS modulation by SCs - changing the phenotype of macrophages to alternatively...

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23368号 / 医博第4737号 / 新制||医||1051(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川口 義弥, 教授 妹尾 浩, 教授 稲垣 暢也 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Yes / Current nerve tissue engineering applications are adopting xenogeneic nerve tissue as potential nerve grafts to help aid nerve regeneration. However, there is little literature that describes the exact location, anatomy and physiology of these nerves to highlight their potential as a donor graft. The aim of this study was to identify and characterise the structural and extracellular matrix (ECM) components of porcine peripheral nerves in the hind leg. Methods included the dissection of porcine nerves, localisation, characterisation and quantification of the ECM components and identification of nerve cells. Results showed a noticeable variance between porcine and rat nerve (a commonly studied species) in terms of fascicle number. The study also revealed that when porcine peripheral nerves branch, a decrease in fascicle number and size was evident. Porcine ECM and nerve fascicles were found to be predominately comprised of collagen together with glycosaminoglycans, laminin and fibronectin. Immunolabelling for nerve growth factor receptor p75 also revealed the localisation of Schwann cells around and inside the fascicles. In conclusion, it is shown that porcine peripheral nerves possess a microstructure similar to that found in rat, and is not dissimilar to human. This finding could extend to the suggestion that due to the similarities in anatomy to human nerve, porcine nerves may have utility as a nerve graft providing guidance and support to regenerating axons.

No description available.

La réaction du greffon contre l’hôte (GvHD) est une complication majeure de la transplantation de cellules souches hématopoïétiques (HSCT). Les traitements de prophylaxie contre le développement de la GvHD reposent essentiellement sur l’utilisation d’agents immunosuppresseurs, ce qui contribue à ralentir la reconstitution immunitaire post-greffe et à prolonger la durée de l’état immunosupprimé des patients. Le développement de prophylaxie pour la GvHD à base d’agents immunomodulateurs est ainsi privilégié. À l’aide d’un modèle murin xénogénique chez les souris NOD/scid-IL2rγ-/- (NSG), on a étudié le potentiel immunomodulateur des immunoglobulines intraveineuses (IVIG) dans la prévention de la GvHD, ainsi que leurs effets sur la qualité et la cinétique de la reconstitution immunitaire. On a déterminé qu’un traitement hebdomadaire d’IVIG peut effectivement réduire l’incidence de la GvHD, ainsi que la mortalité qui y est reliée, avec une efficacité similaire à celle obtenue avec la cyclosporine A, un immunosuppresseur couramment utilisé dans la prophylaxie de la GvHD. Par ailleurs, on a déterminé que le mécanisme d’action des IVIG dans la réduction de la GvHD est distinct de celui des immunosuppresseurs. De plus, on a démontré que les IVIG induisent l’expansion et l’activation des cellules NK présentes au sein du greffon, lesquelles sont nécessaires pour l’obtention de l’effet protecteur des IVIG contre le développement de la GvHD, et sont dépendantes de la présence de lymphocytes T activés. Grâce à un modèle murin humanisé, on a également démontré que le traitement hebdomadaire d’IVIG induit un délai transitoire de la reconstitution humorale, ce qui n’affecte toutefois pas la qualité globale de la reconstitution immunitaire. Ces résultats mettent cependant en doute la pertinence de l’utilisation des IVIG dans les protocoles cliniques de prophylaxie de la GvHD, puisque les immunosuppresseurs seront toujours utilisés, et qu’on a démontré que les IVIG ont besoin de lymphocytes T activés afin de prévenir efficacement le développement de la GvHD. / Graft-versus-Host Disease (GvHD) is a major complication following hematopoietic stem cell transplantation (HSCT). Prophylactic treatments for the prevention of GvHD rely mostly on the use of immunosuppressors, which contribute to inhibit the patient’s immune reconstitution and prolong their immunosuppressed state. Development of immunomodulator-based prophylactic treatments is therefore preferred. Using NOD/scid-IL2rγ-/- mice, we developed a xenogeneic mouse model to assess the immunomodulatory potential of intravenous immunoglobulins (IVIG) for the prevention of GvHD, along with assessing their effect on the kinetics and the quality of the immune reconstitution in mice. We determined that weekly IVIG treatments reduced the incidence of GvHD and its related mortality. The effectiveness of IVIG for the prevention of GvHD was similar to that of cyclosporine A, an immunosuppressive drug routinely used for the prophylactic treatment of GvHD. Furthermore, we demonstrated that IVIG has a mechanism of action that is different from that of immunosuppressors. IVIG induce the expansion and activation of NK cells from the graft, which is mandatory for the preventive effect of IVIG on GvHD development. Furthermore, this IVIG-induced expansion and activation of NK cells require the presence of activated T lymphocytes. Using our humanized mouse model, we have also demonstrated that weekly IVIG treatments cause a transient delay of the humoral reconstitution, but do not affect the overall quality of the immune reconstitution. We have demonstrated that activated T lymphocytes are mandatory for the effective expansion and activation of NK cells, which in turn are essential to the IVIG-induced prevention of GvHD, and immunosuppressors will always be part of the prophylactic regimen of GvHD, therefore shining a doubt on the usefulness of adding IVIG to the prophylactic treatments for the prevention of GvHD.