Dissertation (Ph.D.)--University of South Florida, 2008. / Includes vita. Includes bibliographical references.

Typescript (Photocopy) / Bibliography: leaves 170-198. / xx, 198 leaves, 1 leaf of col. plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1991

Dendritic cells (DC) are antigen-presenting cells that are critical for the initiation and regulation of the immune response. Several DC subtypes within mouse spleen have previously been characterised and these include the plasmacytoid (pDC), and conventional DC (cDC) of the CD8+ and CD8- subtypes. Each subtype appears to have a specialised role in the various arms of immunity and tolerance. Less clear is the process by which these DC develop from haematopoietic precursors, of the precursor stages and branch points from bone marrow (BM) stem cells to each of the peripheral DC subtypes. The research described herein had the aim of identifying and isolating some of the intermediate precursors of DC, downstream of stem cells, and determining whether these differed in the steady-state versus inflammation. Particular was given to DC of the spleen. Experiments that sought the identity of such precursors involved both i) transfer of cell fractions that contained DC precursors into steady-state or inflamed recipient mice to assess their in vivo development at later times, and ii) analysis of an in vitro culture system to question whether it reflected development of the steady-state DC subtypes.

Thesis (Ph.D. in Toxicology) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 224-253). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 298-310).

Thesis (Ph.D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed on June 29, 2009). Includes bibliographical references.

Thèse (M.Sc.) -- Université Laval, 1998. / Bibliogr.: f. 74-87. Publié aussi en version électronique.

During our lifetime, our bones constantly go through remodelling to maintain the skeletal system. This is done by osteoblasts that deposit new bone tissue, osteoclasts that remove the bone matrix and mechanosensing osteocytes. In case of bone implants, increased resorption by osteoclasts due to inflammation (inflammatory osteolysis) leads to aseptic implant loosening. This study focuses on how to detect these inflammatory resorbing cells at an early stage and prevent their activity with appropriate medication. To achieve this, we differentiated classical monocytes into macrophage-like cells, osteoclasts(OCs) and foreign body giant cells (FBGC) and their secretome was studied to identify specific biomarkers. Previously, tartrate resistant acid phosphatase (TRAP) was studied as an important biomarker for OCs and macrophages. An ELISA to separate and quantitate the two TRAP isoforms was used to distinguish the resorbing OCs from inflammatory FBGCs on the basis of the isoform ratio. This assay gave high levels of 5b isoform for osteoclastic stimulation and high 5a levels for the inflammatory stimulation. Also, different aminothiazole inhibitors were tested which were shown to be efficient drugs in inhibiting inflammatory osteolysis by reducing osteoclast formation and resorption in sub-micromolar concentration. Further to apply this study to patient samples, an immunoassay panel can be developed which will help detect TRAP and multiple biomarkers like CTX specific to aseptic loosening simultaneously. This will help in early, efficient and accurate diagnosis of inflammatory osteolytic bone loss and provide us with an accurate diagnosis and sufficient time for appropriate treatment.

Changes to the composition and function of the gut mononuclear phagocyte (MNP) compartment are associated with the development of intestinal inflammation. Much work has focused on the role of MNPs in gut-associated lymphoid tissue in maintaining homeostasis, however little is known regarding the roles of MNPs during colitis. We have investigated MNPs in the large intestinal lamina propria during the steady state and inflammation. One of our primary aims was to determine the contribution of MNP subsets to intestinal pathology. For our studies of inflammation, we focused mainly on the Helicobacter hepaticus infection + anti-IL-10R model, which induces inflammation of the colon and caecum (typhlocolitis). We defined the composition of the MNP compartment alongside intestinal pathology scores throughout Hh + anti-IL-10R typhlocolitis. Peak pathology, 2-3 weeks after induction of colitis, coincided with peak frequencies of CX₃CR1^int Ly6C^+ MNPs. Having observed the accumulation of CX₃CR1^int CD64^+ monocyte/macrophage MNPs in the inflamed lamina propria, we conducted comparative whole genome microarray analysis of these cells isolated from the large intestine three weeks after Hh + anti-IL-10R treatment. CX₃CR1^int CD64^+ MNPs selectively expressed a variety of pro- and anti-inflammatory genes, including a number of genes which individually can both promote and negatively regulate inflammation. IL-23 is essential for Hh + anti-IL-10R-induced intestinal pathology. We investigated the role of MNPs as a source of IL-23 which drives Hh + anti-IL-10R colitis. Unexpectedly, our results indicate that normally hyporesponsive CX₃CR1^hi macrophages may act as the initial source of IL-23, which induces development of colitis. Recruitment of Ly6C^+ MHCII^+ MNPs to the lamina propria was IL-23-dependent, and these cells also expressed IL-23, which may establish a positive feedback loop of immune cell recruitment, activation and IL-23 production. Finally, we also examined how MNPs might be recruited to the colonic lamina propria during inflammation. Our studies support the conclusion that CCR6 is not required for accumulation of monocyte-derived populations in the inflamed intestine. We cannot rule out a role for CCR2, however preliminary data from the Hh + anti-IL-10R colitis model suggest a potential role for CCR1 or its close relation CCRL2. Such pathways could represent new therapeutic targets in inflammatory bowel disease.

A tese encontra-se em formato de artigos conforme norma do Programa de Pós-graduação em Genética e Bioquímica da Universidade Federal de Uberlândia. Esta tese é composta por 4 capítulos, sendo o primeiro capítulo a revisão bibliografica a qual foi escrita em português de acordo com as normas da ABNT e os demais capítulos refere-se a artigos científicos os quais estão em inglês e obdecem as normas das revistas científicas as quais serão submetidos. / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / A sepse é uma síndrome clínica grave responsável por grande parte dos óbitos nas Unidades de Terapia Intensiva. Há uma diversidade de causas primárias que podem evoluir para um quadro clínico de sepse o que dificulta o diagnóstico precoce e a descoberta de drogas eficientes para tratamento. Os altos custos dos tratamentos e as taxas de letalidade mundial demonstram a necessidade de uma melhor compreensão desta síndrome. Este estudo buscou avaliar a expressão gênica dos Receptores de Peptídeos Formilados (FPR) em leucócitos totais, análise de marcadores sistêmicos e o perfil proteínas globais dos monócitos para averiguar as alterações presentes no organismo do indivíduo com a síndrome da sepse. Foi realizado a caracterização das alterações sistêmicas responsáveis pelo óbito de pacientes com sepse através da quantificação simultânea de 27 biomarcadores; verificou-se o silenciamento da expressão gênica do FPR1 e o FPR2 em pacientes com sepse e choque, relatando as possíveis disfunções imunológicas provocadas pela ausência desses FPRs; e a análise proteômica dos monócitos de pacientes com choque séptico permitiu averiguar a contribuição dessa célula no colapso desta síndrome, sua influência na lesão vascular, endotoxemia, inflamação e trombose. Esta investigação identificou pela primeira vez alvos biológicos relevantes os quais podem desempenhar papeis importantes no diagnóstico, prognóstico e terapêutica. / Sepsis is a serious clinical syndrome responsible for most of the deaths in the Intensive Care Units. There are a number of primary causes that may develop for a clinical picture of sepsis, making it difficult to diagnose early and find effective treatment medications. The high costs of treatments and global lethality rates demonstrate the need for a better understanding of this syndrome. This study aimed to evaluate the gene expression of Formulated Peptide Receptors (FPR) in total leukocytes, analysis of systemic markers and the profile of monocyte global proteins to ascertain the changes present in the body of the individual with sepsis syndrome. The characterization of the systemic changes responsible for the death of patients with sepsis was carried out through the simultaneous quantification of 27 biomarkers. The silencing of the gene expression of FPR1 and FPR2 in patients with sepsis and septic shock, reporting as possible immunological dysfunctions caused by the absence of these FPRs. The proteomic analysis of the monocytes of patients with septic shock allowed us to investigate the contribution of this cell in the collapse of this syndrome, its influence on vascular injury, endotoxemia, inflammation and thrombosis. This research identified for the first time, what is more important for the diagnosis, prognosis and therapeutics. / Tese (Doutorado)