Much of this thesis describes the use of immunohistochemical methods on salivary glands from patients with Sjogren's syndrome (SS) to quantify the position, nature and proliferative activity of the inflammatory cell infiltrate, deposition of cell matrix proteins and glandular expression of TGFp. Studies are also undertaken on glands from an experimental animal model and from patients with two associated conditions, benign lymphoepithelial lesion (BLEL) and systemic sclerosis (SSc). Initially a rat model of SS was examined and changes in salivary glands quantified at different stages after autoimmunisation. Immunohistochemically there were similarities to SS, in that class II antigen was expressed by glandular epithelium and the early lesions contained T lymphocytes. However, B lymphocytes were rare, the cell infiltrate contained large populations of macrophages and neutrophils, and there was evidence of increased elaboration of fibrous connective tissue. These results indicate that this animal model is of doubtful use for the study of Sjogren's syndrome. Studies on human tissue showed that the lymphocyte infiltrate in BLEL patients was more extensive than SS and that T cells predominated in small foci, whereas B cells were the dominant lymphocyte type in larger foci. In areas of extensive lymphocyte infiltration, B cells were closely associated with ducts or present in germinal centre-like structures with T cells being found elsewhere. A previously unreported feature of BLEL was the presence of intra-epithelial (and intra-lumenal) B cells, many of which were proliferating. The remaining duct walls in BLEL appeared to be under pressure due to this population of B lymphocytes and "holes" were observed both in the basement membrane and at the lumenal surface that may facilitate migration of lymphocytes from glandular stroma into duct lumens. There was significantly more tenascin and fibronectin in BLEL glands (p<0.01) compared to normal parotid controls which contained minimal amounts of these proteins. By contrast, both proteins were expressed in normal labial glands with no significant increase in glands from SS and SSc patients. As both tenascin and fibronectin are important in cell migration, increased levels may be a factor facilitating lymphoid infiltration in BLEL. Absorbance measurements demonstrated that ductal expression of TGFI differed between control, SS and BLEL salivary glands. SS glands showed an increase in expression of all isoforms of TGFß with the increase for TGFP2 and TGFP3 being significant (p=0.02 & p<0.002). By contrast, ductal expression of all isoforms of TGFI in BLEL was reduced in both confluent (p<0.0001) and minimally infiltrated (p<0.005) areas of gland. Thus reduced glandular expression of TGFJ may be important in allowing the high levels of lymphocyte and epithelial cell proliferation detected in BLEL which are rarely seen in SS. Salivary glands from SSc and Raynaud's phenomenon (RP) patients contained small, predominately T cell foci with few proliferating B cells and a significantly increased mast cell population (p<0.005). Fibrosis within the glands was variable and not associated with increased deposition of fibronectin or tenascin. Subjectively, the most obvious difference in TGFI expression in SSc compared to controls was exhibited by fibroblasts. Cell counts revealed no differences in fibroblast expression of TGFßI or TGFß receptors. However, the percentage of TGFß2-positive fibroblasts was significantly higher in SSc glands compared to controls (p<0.004). RP glands showed an intermediate level of expression. By contrast, a lower percentage of RP fibroblasts expressed TGF(33 compared to controls, with SSc glands showing an intermediate level of expression. The results indicate that both SSc and RP are associated with an increased salivary gland mast cell population and changes in expression of TGFß2 and ß3 isoforms by glandular fibroblasts. The final section of this thesis describes an investigation of antioxidant levels in saliva from healthy individuals and patients with SS or periodontal disease. The results demonstrated that in SS there was an increase in the concentration of antioxidants in unstimulated saliva but a reduced rate of production. This diminished output of salivary gland antioxidants may be of significance to the oral health of these patients. In periodontal disease there was a reduction in antioxidant levels in stimulated saliva that may have been the result of local depletion by reactive oxygen species, produced by chronic inflammation within the gingival tissues. Alternatively, these patients may have intrinsically reduced levels of antioxidants and therefore be more susceptible to periodontal disease.

Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2014 (Department of Endodontics). / Includes bibliographic references: leaves 41-49. / Sjogren's syndrome (SS) is a chronic, multisystem inflammatory disorder of multifactorial etiology resulting in loss of secretory function in the exocrine glands including salivary and lacrimal. Even though the pathophysiology progression of SS has been subject to great amount of research, the roles of different mechanisms remain inconclusive. The main dogma is that immune system pathology drives SS; however, there is no straightforward pathogenesis theory as there are multiple autoantibodies and changing proportions of different T-cell subsets with the progression of the disease along with many other different contributors. Interestingly, increasing evidence points to structural defects, including defective E-cadherin adhesion, to be involved in the etiology of SS. Recently, the Hippo signaling pathway has emerged as one of the main pathways regulating size of the organs and proliferation/ differentiation of cells, in part via interaction with E-cadherin junctions. Despite this, the role of Hippo signaling in the ... [TRUNCATED]

Hokkaido University (北海道大学) / 博士 / 医学

Thesis (Ph. D.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 152 pages. Includes Vita. Includes bibliographical references.

Diss. (sammanfattning) Linköping : Univ., 2002. / Härtill 4 uppsatser.

published_or_final_version / abstract / Dentistry / Doctoral / Doctor of Philosophy

O HTLV-1 (human T-cell lymphotropic virus type 1) foi o primeiro retrovírus humano a ser identificado. O HTLV-1 tem a capacidade de ativar e gerar uma intensa resposta inflamatória, podendo levar a alterações em diversos tecidos que mimetizam uma doença autoimune. Do complexo de doenças associadas ao HTLV-1, a Síndrome de Sjögren (SS) figura entre as mais estudadas. No entanto, nenhuma relação definitiva foi ainda estabelecida. Este trabalho propõe-se a investigar indícios da presença do HTLV-1 em glândulas salivares menores de pacientes infectados por esse retrovírus e comparar as alterações morfológicas em glândulas salivares menores de pacientes com HTLV-1 e de pacientes com SS não infectados. Amostras de glândula salivar menor foram coletadas de 14 pacientes HTLV+ que apresentavam síndrome seca (grupo de estudo) e 5 pacientes diagnosticados com SS e negativos para o HTLV (grupo controle). No grupo de estudo, o infiltrado inflamatório visto era composto principalmente por linfócitos T CD4+, no grupo controle a população majoritária foi de linfócitos B CD20+. Alterações morfológicas como fibrose e infiltração gordurosa foram mais comumente vistas nas amostras do grupo de estudo, sendo a diferença estatisticamente significativa (p=0,038 e 0,033 respectivamente). Na análise por PCR 11 (78,57%) dos casos do grupo de estudo foi detectado o gene tax e/ou rex do HTLV-1, no entanto 4 (80%) das amostras do grupo controle também foram positivas. O HTLV-1 mostra indícios de estar presente nas glândulas salivares de indivíduos com síndrome seca, no entanto pacientes HTLV-1+ apresentam alterações morfológicas em padrões diferentes dos vistos em pacientes com SS, denotando uma provável diferença no processo de ativação imunológica. / Human T-cell lymphotropic virus type I (HTLV-1) was the first human retrovirus to be discovered. HTLV-1 has the ability to activate and generate an intense inflammatory response, which can lead to changes in several tissues that mimic an autoimmune disease Of the complex of diseases associated with HTLV-1, Sjögren\'s Syndrome (SS) is among the most studied. The aim of this study is to investigate the presence of HTLV-1 in the minor salivary glands of patients infected with this retrovirus and to compare the morphological alterations in the salivary glands of patients with HTLV-1 and patients with SS uninfected. Minor salivary gland samples were obtained from 14 HTLV + patients with dry syndrome (study group) and 5 patients diagnosed with SS and HTLV negative (control group). In the study group, the inflammatory infiltrate was mainly composed of CD4+ T lymphocytes, in the control group the majority population was of CD20+ B lymphocytes. Morphological changes such as fibrosis and adipose tissue infiltration were more common in the study group, the difference was statistically significant (p = 0.038 and 0.033, respectively). The HTLV-1 tax and/or rex genes were detected by PCR in 11 (78.57%) patients of the study group, but 4 (80%) samples from the control group were also positive. HTLV-1 shows signs of being present in the salivary glands of individuals with dry syndrome however, HTLV-1+ patients present morphological alterations in different patterns from those observed in SS patients, denoting a probable difference in the immunological activation process.

BAFF, «facteur d'activation des lymphocytes B (LB) » contribue à l'expansion des LB autoréactifs de faible affinité lors de la mise en place de la tolérance. Cependant, les mécanismes menant à la surexpression de BAFF dans les maladies auto-immunes ne sont pas compris. Nous avons découvert un nouveau variant de BAFF, 4BAFF (dans lequel l'exon 4 est épissé), qui agit comme un facteur de transcription de son propre gène et participe à sa régulation. Ainsi, 4BAFF est préférentiellement observé dans les cellules isolées de patients atteints de maladies auto-immunes. De plus, 4BAFF régule un grand nombre de gènes associés à la réponse immunitaire innée et à la régulation de l’apoptose. Une autre constatation importante est que 4BAFF est un élément clé pour comprendre l’activité des LB régulateurs. Notre travail présente un concept entièrement nouveau suggérant qu'une cytokine peut être régulée par l'activité de l'un de ses variants d'épissage. Par ailleurs, nous avons observé que les cellules épithéliales expriment le récepteur de BAFF : BR3. Le blocage de BR3 se traduit par la translocation nucléaire de PKC et l'apoptose des cellules épithéliales. Par un effet autocrine, nous démontrons que seules certaines formes de BAFF participent à la survie des cellules épithéliales. Enfin , nous avons étudié les conséquences de l'expression du TLR9 à la surface des LB et démontrons que ce TLR9 membranaire ne fixe pas le CpG et agit comme un co-récepteur négatif du BCR. En effet, l'activation des LB par le CpG capté au niveau endosomal, est inhibée par l’action d’un anticorps anti-TLR9 se fixant au niveau membranaire. Tous ces résultats contribuent à une meilleure compréhension des mécanismes impliqués dans l'immunopathologie des maladies autoimmunes avec des applications potentielles en thérapeutique. / Elevated expression of ‘B cell activating factor’ (BAFF), a potent B cell survival factor contributes to the expansion of low-affinity self-reactive B cells during the establishment of tolerance. However, mechanisms leading to BAFF over-expression in autoimmune diseases are not understood. We reported the discovery of a new variant for BAFF, 4BAFF in humans (in which exon 4 is excised) or 5BAFF in mice (in which exon 5 is excised), which acts as a transcription factor of the full-length form of BAFF, and which is preferentially found in cells isolated from patients with autoimmune diseases. When transfected in human B cells, D4BAFF upregulates a large number of genes associated with immune response and especially innate immunity and regulation of apoptotis. Furthermore D4BAFF acts, in association with p50 from the NF- B pathway, as a transcription factor for its own parent gene. Another important finding is that 4BAFF is an important component of the efficacy of regulatory B cell activity. Our work introduces an entirely novel concept in biology suggesting that a human cytokine gene can be transcriptionally regulated by the activity of one of its own splice variants.We have also tried to understand the complexity of the various forms of BAFF. We observed that epithelial cells expressed BAFF-receptor (BR3) and produce BAFF suggesting autocrine properties. Blocking BR3 results in nuclear translocation of PKC promoting epithelial cell apoptosis.Furthermore, only some forms of BAFF are required for epithelial cell survival. Finally, we studied the consequences of the expression of TLR9 on the B cell surface and demonstrated that TLR9 acts as a co-receptor of the B cell receptor to influence B cell fate independently of CpG binding. We show that CpG activation of B cells, acting synergistically with BCR signals, was inhibited by anti-TLR9 stimulation. Induction of CD25 expression and proliferation of B cells were thus down-regulated by engagement of cell surface TLR9. Overall, our results indicate that TLR9 expressed on B cell plasma membrane might be a negative regulator of endosomal TLR9, and could provide a novel control by which activation of autoreactive B cells is restrained. All these findings contribute to a better understanding on immunopathology of autoimmune diseases with potential applications in therapy.

O HTLV-1 (human T-cell lymphotropic virus type 1) foi o primeiro retrovírus humano a ser identificado. O HTLV-1 tem a capacidade de ativar e gerar uma intensa resposta inflamatória, podendo levar a alterações em diversos tecidos que mimetizam uma doença autoimune. Do complexo de doenças associadas ao HTLV-1, a Síndrome de Sjögren (SS) figura entre as mais estudadas. No entanto, nenhuma relação definitiva foi ainda estabelecida. Este trabalho propõe-se a investigar indícios da presença do HTLV-1 em glândulas salivares menores de pacientes infectados por esse retrovírus e comparar as alterações morfológicas em glândulas salivares menores de pacientes com HTLV-1 e de pacientes com SS não infectados. Amostras de glândula salivar menor foram coletadas de 14 pacientes HTLV+ que apresentavam síndrome seca (grupo de estudo) e 5 pacientes diagnosticados com SS e negativos para o HTLV (grupo controle). No grupo de estudo, o infiltrado inflamatório visto era composto principalmente por linfócitos T CD4+, no grupo controle a população majoritária foi de linfócitos B CD20+. Alterações morfológicas como fibrose e infiltração gordurosa foram mais comumente vistas nas amostras do grupo de estudo, sendo a diferença estatisticamente significativa (p=0,038 e 0,033 respectivamente). Na análise por PCR 11 (78,57%) dos casos do grupo de estudo foi detectado o gene tax e/ou rex do HTLV-1, no entanto 4 (80%) das amostras do grupo controle também foram positivas. O HTLV-1 mostra indícios de estar presente nas glândulas salivares de indivíduos com síndrome seca, no entanto pacientes HTLV-1+ apresentam alterações morfológicas em padrões diferentes dos vistos em pacientes com SS, denotando uma provável diferença no processo de ativação imunológica. / Human T-cell lymphotropic virus type I (HTLV-1) was the first human retrovirus to be discovered. HTLV-1 has the ability to activate and generate an intense inflammatory response, which can lead to changes in several tissues that mimic an autoimmune disease Of the complex of diseases associated with HTLV-1, Sjögren\'s Syndrome (SS) is among the most studied. The aim of this study is to investigate the presence of HTLV-1 in the minor salivary glands of patients infected with this retrovirus and to compare the morphological alterations in the salivary glands of patients with HTLV-1 and patients with SS uninfected. Minor salivary gland samples were obtained from 14 HTLV + patients with dry syndrome (study group) and 5 patients diagnosed with SS and HTLV negative (control group). In the study group, the inflammatory infiltrate was mainly composed of CD4+ T lymphocytes, in the control group the majority population was of CD20+ B lymphocytes. Morphological changes such as fibrosis and adipose tissue infiltration were more common in the study group, the difference was statistically significant (p = 0.038 and 0.033, respectively). The HTLV-1 tax and/or rex genes were detected by PCR in 11 (78.57%) patients of the study group, but 4 (80%) samples from the control group were also positive. HTLV-1 shows signs of being present in the salivary glands of individuals with dry syndrome however, HTLV-1+ patients present morphological alterations in different patterns from those observed in SS patients, denoting a probable difference in the immunological activation process.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2010. / Härtill 4 uppsatser.