Etude des Treg dans la physiopathologie du syndrome de Wiskott-Aldrich et étude de la reconstitution des Treg dans les greffes de cellules souches hématopoïétiques après un conditionnement nonmyéloablateur.

Through the recruitment of immunologic mechanisms, allogeneic hematopoeitic cell transplantation (HCT) has been establiched as a curative treatment for various hematologic diseases. The most convenient source to obtain hematopoietic progenitor cells are peripheral blood stem cells (PBSCs) which are harvested from the donor via leukapheresis after mobilization with granulocyte-colony stimulating factors. With the introduction of reduced intensity condition (RIC), the curative potential of allogeneic HCT became accessible to older and/or frail patients otherwise ineligible for HCT. However, new challenges arise as the increasing age of patients is inevitably accompanied by a comparable increase in the age of donors. Safety considerations of collecting PBSCs might attain new dimensions. Data to potential risks in elderly donors are lacking. Moreover, the impact of donor’s age on the feasibility of PBSCs collection and on the quality of the harvest in terms of stem cells (CD34+) and natural killer (NK)-cells has not been studied. It is also unknown whether PBSCs obtained from donors above 50 years would negatively influence engraftment or the incidence of graft-versus-host disease (GVHD) in the recipient. These questions were explored in a retrospective study including 167 recipients of an allogeneic HCT (52.7% after RIC) from a matched related sibling. Median donors’ age was 47 years [67 (40%) donors were > 50 years including 34 donors > 60 years]. Safety of mobilization and leukapheresis was age independent. Adequate PBSCs were collected from all donors though a higher CD34+-cell count was seen in donors < 50 years (p<0.0005), whereas harvests from donors > 60 years contained a higher NK-cell count (p=0.003). Engraftment in the recipient occurred after a median of 12 days and was not affected by an advanced donor age. Similarly, a higher incidence of GVHD was not seen in recipients of harvests from older donors. For the first time, we show that donor’s age, even beyond 60 years, does not preclude successful collection of PBSCs from siblings, does not jeopardize the short-term safety of the donor, and is not associated with deleterious sequels for the recipient in terms of engraftment or GVHD. As NK-cells have been implicated in the suppression of GVHD, and the mediation of a graft versus leukemia effect, the impact of the higher number of NK-cells in harvests from elderly donors on relapse of hematologic malignancies in the recipient warrants further studies.

Through the recruitment of immunologic mechanisms, allogeneic hematopoeitic cell transplantation (HCT) has been establiched as a curative treatment for various hematologic diseases. The most convenient source to obtain hematopoietic progenitor cells are peripheral blood stem cells (PBSCs) which are harvested from the donor via leukapheresis after mobilization with granulocyte-colony stimulating factors. With the introduction of reduced intensity condition (RIC), the curative potential of allogeneic HCT became accessible to older and/or frail patients otherwise ineligible for HCT. However, new challenges arise as the increasing age of patients is inevitably accompanied by a comparable increase in the age of donors. Safety considerations of collecting PBSCs might attain new dimensions. Data to potential risks in elderly donors are lacking. Moreover, the impact of donor’s age on the feasibility of PBSCs collection and on the quality of the harvest in terms of stem cells (CD34+) and natural killer (NK)-cells has not been studied. It is also unknown whether PBSCs obtained from donors above 50 years would negatively influence engraftment or the incidence of graft-versus-host disease (GVHD) in the recipient. These questions were explored in a retrospective study including 167 recipients of an allogeneic HCT (52.7% after RIC) from a matched related sibling. Median donors’ age was 47 years [67 (40%) donors were > 50 years including 34 donors > 60 years]. Safety of mobilization and leukapheresis was age independent. Adequate PBSCs were collected from all donors though a higher CD34+-cell count was seen in donors < 50 years (p<0.0005), whereas harvests from donors > 60 years contained a higher NK-cell count (p=0.003). Engraftment in the recipient occurred after a median of 12 days and was not affected by an advanced donor age. Similarly, a higher incidence of GVHD was not seen in recipients of harvests from older donors. For the first time, we show that donor’s age, even beyond 60 years, does not preclude successful collection of PBSCs from siblings, does not jeopardize the short-term safety of the donor, and is not associated with deleterious sequels for the recipient in terms of engraftment or GVHD. As NK-cells have been implicated in the suppression of GVHD, and the mediation of a graft versus leukemia effect, the impact of the higher number of NK-cells in harvests from elderly donors on relapse of hematologic malignancies in the recipient warrants further studies.

Cellular therapies rely on the delivery of therapeutic cells into patients, but their safety can be compromised by the manipulation of cells ex vivo or their placement outside of their natural context in vivo. Cell Fate Control Gene Therapy (CFCGT) offers the possibility of establishing pharmacological controls over gene-modified cells (GMCs) with regards to their proliferation, differentiation, or function. In its simplest form, 'suicide' gene therapy (SGT), stable introduction of a 'suicide' gene that can activate a non-toxic prodrug establishes control over the survival of GMCs. Current SGT modalities are sub-optimal in clinical setting. To overcome the many limitation of current strategies, we have developed a next-generation CFCGT approach based on the active site-engineered variants of human deoxyCytidine Kinase (dCK), which enable robust activation of multiple Nucleoside Analogue (NA)-based prodrugs, act early in the pathway enabling rapid accumulation of activated NAs in target cells, and also provide the capabilities for the direct imaging of GMCs. Stable introduction of dCK variants into target cells by means of Lentiviral (LV) gene transfer significantly increases their sensitivity to multiple prodrugs. Our dCK variant with only two active site amino acid substitutions is expected to be non-immunogenic yet capable of specifically activating deoxythymidine- and deoxyuridine-based NAs that are not substrates for the wild-type enzyme, such as bromovinyldeoxyuridine (BVdU) and L-deoxythymidine (LdT). We show here that dCK can be used for controlling the survival of GMCs, in cell lines and primary cells in vitro and in a murine xenogeneic transplant models in vivo. To characterize dCK/prodrug-mediated killing mechanisms in GMCs, we have examined the levels of active metabolites in cells and the cellular pathways they antagonize. We describe here the experimental basis for the application of this novel CFCGT in bone marrow transplantation for management of Graft-versus-Host Disease (GvHD) and in enhancing chemotherapy in direct treatment of tumors. In summary, we have developed a novel and robust strategy for effective CFCGT that addresses the many shortcomings of existing modalities. Future studies will validate this novel system in a variety of primary cells and animal disease models, including models of hematopoietic transplantation and ES/iPS-based cell therapies.

Cellular therapies rely on the delivery of therapeutic cells into patients, but their safety can be compromised by the manipulation of cells ex vivo or their placement outside of their natural context in vivo. Cell Fate Control Gene Therapy (CFCGT) offers the possibility of establishing pharmacological controls over gene-modified cells (GMCs) with regards to their proliferation, differentiation, or function. In its simplest form, 'suicide' gene therapy (SGT), stable introduction of a 'suicide' gene that can activate a non-toxic prodrug establishes control over the survival of GMCs. Current SGT modalities are sub-optimal in clinical setting. To overcome the many limitation of current strategies, we have developed a next-generation CFCGT approach based on the active site-engineered variants of human deoxyCytidine Kinase (dCK), which enable robust activation of multiple Nucleoside Analogue (NA)-based prodrugs, act early in the pathway enabling rapid accumulation of activated NAs in target cells, and also provide the capabilities for the direct imaging of GMCs. Stable introduction of dCK variants into target cells by means of Lentiviral (LV) gene transfer significantly increases their sensitivity to multiple prodrugs. Our dCK variant with only two active site amino acid substitutions is expected to be non-immunogenic yet capable of specifically activating deoxythymidine- and deoxyuridine-based NAs that are not substrates for the wild-type enzyme, such as bromovinyldeoxyuridine (BVdU) and L-deoxythymidine (LdT). We show here that dCK can be used for controlling the survival of GMCs, in cell lines and primary cells in vitro and in a murine xenogeneic transplant models in vivo. To characterize dCK/prodrug-mediated killing mechanisms in GMCs, we have examined the levels of active metabolites in cells and the cellular pathways they antagonize. We describe here the experimental basis for the application of this novel CFCGT in bone marrow transplantation for management of Graft-versus-Host Disease (GvHD) and in enhancing chemotherapy in direct treatment of tumors. In summary, we have developed a novel and robust strategy for effective CFCGT that addresses the many shortcomings of existing modalities. Future studies will validate this novel system in a variety of primary cells and animal disease models, including models of hematopoietic transplantation and ES/iPS-based cell therapies.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12980号 / 論医博第2106号 / 新制||医||1012(附属図書館) / 32450 / (主査)教授 髙橋 良輔, 教授 鈴木 茂彦, 教授 高橋 淳 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24830号 / 医博第4998号 / 新制||医||1067(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 後藤, 慎平, 教授 河本, 宏, 教授 羽賀, 博典 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

A doença falciforme constitui um grupo de hemoglobinopatias hereditárias caracterizadas por uma mutação de ponto na cadeia da globina ?, que resulta em uma hemoglobina anormal denominada HbS. Apesar de sua importância para a saúde pública mundial e seu grande impacto social, a doença falciforme ainda apresenta muitas questões fisiopatológicas não esclarecidas e desafios terapêuticos. Paralelamente, existe a necessidade da descoberta de novos biomarcadores fisiopatológicos da doença falciforme e de biomarcadores de resposta terapêutica. O objetivo desse trabalho foi quantificar, em amostras de soro de indivíduos sadios (N=19) e de pacientes com doença falciforme sem tratamento (N=14) ou tratados com hidroxiuréia (N=15), transfusão crônica (N=15) ou transplante alogênico de células-tronco hematopoéticas (N=21), biomarcadores de ativação endotelial (VCAM-1, ICAM-1, E-selectina, P-selectina, HGF, FGF, VEGF-A, endothelina-1, CXCL4/PF4, TGF-? e óxido nítrico), biomarcadores de ativação plaquetária (von Willebrand e trombomodulina), biomarcadores de inflamação (IL-1?, pentraxina-3, IL-18, IL-6, IL-8, IL-2, IL-17A, TNF-?, INF-?, CCL2/MCP-1, CCL4/MIP-1?, IL-12p70, IL-33, IL-27, GM-CSF, CD163, osteopontina, BAFF, APRIL e heme) e biomarcadores relacionados à imunomodulação (arginase-1 e IL-10). De acordo com os resultados obtidos e as análises de correlação, os pacientes com doença falciforme sem tratamento, tratados com transfusão crônica ou transplante apresentaram perfis mais inflamatórios que os pacientes tratados com hidroxiuréia. Os tratamentos com transfusão crônica e transplante não foram capazes de diminuir os níveis séricos dos biomarcadores de inflamação, de ativação endotelial e plaquetária para níveis similares aos dos indivíduos sadios. Os pacientes tratados com transfusão crônica apresentaram o perfil mais inflamatório de todos os grupos analisados. Apesar dos pacientes tratados com hidroxiuréia apresentarem os menores níveis séricos de biomarcadores de inflamação e de ativação endotelial e plaquetária, estes continuaram apresentando níveis séricos elevados de heme e da citocina pró-inflamatória IL-18. Os pacientes transplantados apresentaram perfil inflamatório intenso, com níveis elevados de P-selectina, trombomodulina e IL-8 (relacionados à ativação endotelial, ativação plaquetária e inflamação, respectivamente) em comparação com todos os grupos analisados. Porém, os pacientes transplantados apresentaram níveis séricos de IL-18 significativamente menores que os pacientes com doença falciforme sem tratamento. Os pacientes transplantados apresentaram níveis séricos da citocina anti-inflamatória IL-10 similares aos de indivíduos sadios, porém, significativamente maiores que os pacientes tratados com hidroxiuréia. Os resultados obtidos nesse trabalho podem direcionar estudos futuros para o monitoramento laboratorial de respostas terapêuticas aos diferentes tratamentos atualmente utilizados para doença falciforme e para o desenvolvimento de novos tratamentos ou de terapias complementares às que estão atualmente disponíveis. / Sickle cell disease is a group of hereditary hemoglobinopathies characterized by a point mutation in the ? globin chain, which results in an abnormal hemoglobin named HbS. Despite its importance for global public health and its great social impact, sickle cell disease still presents many unclarified pathophysiological issues and therapeutic challenges. In parallel, there is a need for the discovery of new pathophysiological biomarkers of sickle diseases and biomarkers of therapeutic response. The aim of this study was to quantify serum samples from healthy subjects (N = 19) and patients with sickle cell disease (N = 14) or treated with hydroxyurea (N = 15), chronic transfusion (N = 15) or allogeneic hematopoietic stem cell transplantation (N = 21) endothelial activation biomarkers (VCAM-1, ICAM-1, E-selectin, P-selectin, HGF, FGF, VEGF-A, endothelin-1, CXCL4 / PF4, TGF-? and nitric oxide), platelet activation biomarkers (von Willebrand and thrombomodulin), inflammatory biomarkers (IL-1?, pentraxin-3, IL-18, IL-6, IL-8, IL-2, IL-17A, TNF-?, INF-?, CCL2/MCP-1, CCL4/MIP-1?, IL-12p70, IL-33, IL-27, GM-CSF, CD163, osteopontin, BAFF, APRIL and heme) and immunomodulatory biomarkers (arginase-1 and IL-10). According to the obtained results and correlation analyzes, patients with sickle disease without treatment, treated with chronic transfusion or transplantation presented more high inflammatory profiles than patients treated with hydroxyurea. Patients treated with chronic transfusion and transplantation were not able to decrease the elevated serum biomarkers of inflammation and endothelial and platelet activation similar to healthy subjects levels. Patients treated with chronic transfusion presented the most inflammatory profile of all groups analyzed. Although patients treated with hydroxyurea had the lowest serum levels of inflammatory and endothelial/platelet activation biomarkers, they continued to have high serum levels of heme and proinflammatory cytokine IL-18. Transplanted patients presented a high inflammatory profile, with elevated levels of P-selectin, thrombomodulin and IL-8 (related to endothelial activation, platelet activation and inflammation, respectively) compared to all groups analyzed. However, transplant patients had significantly lower serum IL-18 levels than patients with untreated sickle cell disease. Notably, transplanted patients had levels of the anti-inflammatory cytokine IL-10 similar to those of healthy subjects, but significantly higher than patients treated with hydroxyurea. The results obtained in this study may pave the way for future studies for the laboratory monitoring of therapeutic responses to different sickle cell disease treatments and for the development of new or complementary treatments to the currently available therapies.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Enxertos ósseos homólogos congelados têm sido documentados apresentando bons resultados clínicos como substituto ao material autógeno nas reconstruções alveolares. Entretanto, dados referentes à incorporação e remodelação destes enxertos não estão disponíveis na literatura. Este estudo tem por objetivo determinar um período ótimo de espera para instalação de implantes em rebordos reconstruídos com enxertos ósseos homólogos em bloco no que se refere à incorporação e reabsorção. 24 pacientes foram submetidos à reconstrução alveolar óssea homóloga previamente à instalação de implantes. Os indivíduos foram alocados randomicamente em um de 3 grupos de acordo com o tempo de espera para o segundo estágio cirúrgico (4, 6 e 8 meses). Análises tomográficas, histológicas e histomorfométricas foram utilizadas a fim de determinar o grau de reabsorção e incorporação dos enxertos nos diferentes intervalos de tempo para cada grupo. Os dados de reabsorção sofrida pelos enxertos demonstraram diferenças estatisticamente significativas para os três intervalos de espera. Da mesma forma, parâmetros histomorfométricos como contagem de osteócitos e quantificação de remanescentes de osso homólogo nas biópsias apresentaram diferenças significativas entre os grupos. De acordo com os dados do presente trabalho, no que diz respeito à remodelação e incorporação, o período mais favorável à instalação dos implantes a curto prazo após recontruções com enxertos homólogos é de 4 meses. / Fresh-frozen homologous bone grafts have been reported achieving good clinical results as a substitute for autogenous bone in alveolar reconstruction. However, data regarding the incorporation and remodeling of these grafts are not available in the literature. The aim of this study is to determine the optimal period for the implant placement in alveolar ridges reconstructed with bone block allografts. 24 patients underwent alveolar ridge reconstruction with homologous bone prior to implant placement. Subjects were randomly assigned into one of three groups according to the waiting time for the second surgical stage (4, 6 and 8 months). Tomographic, histological and histomorphometric analisys were used to determine the rates of grafts resorption and incorporation at different time intervals for each group. Data from graft resorption showed statistically significant differences for the three healing intervals. Similarly, histomorphometric parameters as: osteocytes count and quantification of remaining graft in the biopsies showed significant differences between groups. According to this work, with regard to the remodeling and incorporation, the most favorable the short term period to implant placement after fresh-frozen block allografts ridge reconstruction is 4 months.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Enxertos ósseos homólogos congelados têm sido documentados apresentando bons resultados clínicos como substituto ao material autógeno nas reconstruções alveolares. Entretanto, dados referentes à incorporação e remodelação destes enxertos não estão disponíveis na literatura. Este estudo tem por objetivo determinar um período ótimo de espera para instalação de implantes em rebordos reconstruídos com enxertos ósseos homólogos em bloco no que se refere à incorporação e reabsorção. 24 pacientes foram submetidos à reconstrução alveolar óssea homóloga previamente à instalação de implantes. Os indivíduos foram alocados randomicamente em um de 3 grupos de acordo com o tempo de espera para o segundo estágio cirúrgico (4, 6 e 8 meses). Análises tomográficas, histológicas e histomorfométricas foram utilizadas a fim de determinar o grau de reabsorção e incorporação dos enxertos nos diferentes intervalos de tempo para cada grupo. Os dados de reabsorção sofrida pelos enxertos demonstraram diferenças estatisticamente significativas para os três intervalos de espera. Da mesma forma, parâmetros histomorfométricos como contagem de osteócitos e quantificação de remanescentes de osso homólogo nas biópsias apresentaram diferenças significativas entre os grupos. De acordo com os dados do presente trabalho, no que diz respeito à remodelação e incorporação, o período mais favorável à instalação dos implantes a curto prazo após recontruções com enxertos homólogos é de 4 meses. / Fresh-frozen homologous bone grafts have been reported achieving good clinical results as a substitute for autogenous bone in alveolar reconstruction. However, data regarding the incorporation and remodeling of these grafts are not available in the literature. The aim of this study is to determine the optimal period for the implant placement in alveolar ridges reconstructed with bone block allografts. 24 patients underwent alveolar ridge reconstruction with homologous bone prior to implant placement. Subjects were randomly assigned into one of three groups according to the waiting time for the second surgical stage (4, 6 and 8 months). Tomographic, histological and histomorphometric analisys were used to determine the rates of grafts resorption and incorporation at different time intervals for each group. Data from graft resorption showed statistically significant differences for the three healing intervals. Similarly, histomorphometric parameters as: osteocytes count and quantification of remaining graft in the biopsies showed significant differences between groups. According to this work, with regard to the remodeling and incorporation, the most favorable the short term period to implant placement after fresh-frozen block allografts ridge reconstruction is 4 months.