O objetivo dessa tese foi avaliar a expressão de citocinas Th1 (IL-12 e INF), citocinas Th2 (IL-4, IL-6 e IL-10) e das citocinas pró-inflamatórias IL-18, IL-1 e TNF no fluido gengival de pacientes com periodontite crônica portadores da doença de Crohn (DC), de retocolite ulcerativa idiopática (RCUI) e em indivíduos saudáveis (o grupo controle, GC). Como objetivo secundário, avaliamos a função dos neutrófilos no fluido gengival desses pacientes através da mensuração das metaloproteinases da matriz -8, -9 (MMP-8 e MMP-9) e da atividade da elastase. Quinze pacientes com DC (idade média 38.2 11.4 anos), 15 pacientes com RCUI (idade média 45.0 10.5 anos) e 15 pacientes saudáveis (idade média 42.1 7.8 anos) participaram desse estudo. Todos os dentes presentes, com exceção dos terceiros molares, foram examinados. Profundidade de bolsa (PB), nível de inserção clínica (NI), presença de placa e de sangramento a sondagem foram avaliados em seis sítios por dente. Em cada paciente, o fluido de 4 sítios com periodontite (PB  5 mm e NI 3mm) e de 4 sítios com gengivite (PB 3 mm e NI  1 mm) foram coletados através de pontas de papel absorvente pré-fabricadas. O sistema LUMINEX foi utilizado na mensuração das IL-1, IL-4, IL-6, IL-10, IL-12p70, TNF, INF, MMP-8 e MMP-9. A IL-18 foi analisada através do ensaio ELISA e a atividade de elastase através de uma reação enzimática. O soro desses pacientes também foi analisado e o coeficiente de correlação de Pearson foi utilizado na análise da correlação entre as citocinas no soro e no fluido gengival. Nos sítios com gengivite, a quantidade total de IL-4 foi significativamente menor no grupo RCUI do que no grupo GC (p=0.016). Nos sítios com periodontite, a quantidade total de IL-4 foi significativamente menor no grupo DC do que no grupo GC (p=0.029). A quantidade total da IL-6 (p=0.028) assim como sua concentração (p=0.044) foram significativamente maiores no grupo RCUI do que no grupo GC. No soro, os níveis da IL-18 foram significativamente mais altos nos grupos DC (p=0.011) e RCUI (p=0.019) do que no grupo GC. No grupo RCUI, a IL-18 do soro se correlacionou positivamente com a IL-1 do fluido gengival (r=0. 667, p=0.01). Concluindo, nos pacientes com doença inflamatória intestinal, os níveis da IL-4 estavam mais baixos no fluido gengival e os níveis da IL-18 estavam aumentados no soro quando comparados aos controles. A função dos neutrófilos foi similar entre os pacientes com doença inflamatória intestinal e os controles. Com exceção da correlação positiva entre a IL-18 sérica e a IL-1 no fluido gengival dos pacientes com retocolite ulcerativa idiopática, não houve correlação entre as diversas citocinas mensuradas no soro e as citocinas mensuradas no fluido gengival nos controles nem nos pacientes com doença inflamatória intestinal. Não houve a caracterização de um padrão de resposta Th1 ou Th2 no fluido gengival dos pacientes com doença inflamatória intestinal. / The aim of this thesis was to evaluate the expression of Th1 cytokines (IL-12 and INF-γ), Th2 cytokines (IL-4, IL-6 and IL-10) and the pro-inflammatory cytokines IL-18, IL-1 and TNF-α in the gingival crevicular fluid (GCF) from Crohns disease (CD) patients, ulcerative colitis (UC) patients and healthy individuals (control group, CG) who had chronic periodontitis. Besides, we measured elastase activity, matrix metalloproteinase -8 and -9 (MMP-8 and -9) to address the neutrophil function in the GCF. Fifteen CD patients (mean age 38.2  11.4 years), 15 UC patients (mean age 45.0  10.5 years) and 15 systemically healthy controls (mean age 42.1  7.8 years) were enrolled in this study. All the present teeth, except for the third molars were examined. Probing pocket depth (PPD), clinical attachment loss (CAL), presence of plaque and presence of bleeding on probing were assessed in six sites per tooth. In every subject, GCF from 4 gingivitis sites (PPD  3mm and CAL  1mm) and from 4 periodontitis sites (PPD  5mm and CAL 3mm) were collected with filter strips. The data were reported as total amount and concentration. IL-1, IL-4, IL-6, IL-10, IL-12p70, TNFα, INFγ, MMP-8 and MMP-9 were analyzed by the Luminex analyzer. IL-18 was analyzed using a commercially available ELISA assay and the elastase activity by an enzymatic reaction. The serum was also analysed and the correlations between the cytokines in the GCF and in the serum were calculated by Pearson correlation analysis. In gingivitis sites, the total amount of IL-4 was significantly lower in the UC group than in the CG group (p=0.016). In periodontitis sites, the total amount of IL-4 was significantly lower in CD group than in the CG group (p=0.029). The total amount of IL-4 was lower in UC group than in CD group (p=0.077). Similarly, IL-4 concentrations in both CD (p=0.096) and UC (p=0.064) groups were lower than in CG group. IL-6 total amount (p=0.028) and IL-6 concentration (p=0.044) were significantly higher in the UC group than in the CG group. In the serum, IL-18 levels were significantly higher in CD (p=0.011) and UC (p=0.019) groups than in the CG group. In UC group, there was a positive correlation between serum IL-18 levels and IL-1 in the GCF (r=0. 667, p=0.01). In conclusion, IBD patients had lower IL-4 levels in the GCF and higher IL-18 levels in the serum than healthy controls. The neutrophil function in IBD patients is similar to controls. Except for the positive correlation between IL-18 in the serum and IL-1 in the GCF, there was no correlation between the cytokines in serum and in the GCF either in IBD patients or in controls. There was not a Th1 or Th2 polarization in the GCF from IBD patients.

O objetivo dessa tese foi avaliar a expressão de citocinas Th1 (IL-12 e INF), citocinas Th2 (IL-4, IL-6 e IL-10) e das citocinas pró-inflamatórias IL-18, IL-1 e TNF no fluido gengival de pacientes com periodontite crônica portadores da doença de Crohn (DC), de retocolite ulcerativa idiopática (RCUI) e em indivíduos saudáveis (o grupo controle, GC). Como objetivo secundário, avaliamos a função dos neutrófilos no fluido gengival desses pacientes através da mensuração das metaloproteinases da matriz -8, -9 (MMP-8 e MMP-9) e da atividade da elastase. Quinze pacientes com DC (idade média 38.2 11.4 anos), 15 pacientes com RCUI (idade média 45.0 10.5 anos) e 15 pacientes saudáveis (idade média 42.1 7.8 anos) participaram desse estudo. Todos os dentes presentes, com exceção dos terceiros molares, foram examinados. Profundidade de bolsa (PB), nível de inserção clínica (NI), presença de placa e de sangramento a sondagem foram avaliados em seis sítios por dente. Em cada paciente, o fluido de 4 sítios com periodontite (PB  5 mm e NI 3mm) e de 4 sítios com gengivite (PB 3 mm e NI  1 mm) foram coletados através de pontas de papel absorvente pré-fabricadas. O sistema LUMINEX foi utilizado na mensuração das IL-1, IL-4, IL-6, IL-10, IL-12p70, TNF, INF, MMP-8 e MMP-9. A IL-18 foi analisada através do ensaio ELISA e a atividade de elastase através de uma reação enzimática. O soro desses pacientes também foi analisado e o coeficiente de correlação de Pearson foi utilizado na análise da correlação entre as citocinas no soro e no fluido gengival. Nos sítios com gengivite, a quantidade total de IL-4 foi significativamente menor no grupo RCUI do que no grupo GC (p=0.016). Nos sítios com periodontite, a quantidade total de IL-4 foi significativamente menor no grupo DC do que no grupo GC (p=0.029). A quantidade total da IL-6 (p=0.028) assim como sua concentração (p=0.044) foram significativamente maiores no grupo RCUI do que no grupo GC. No soro, os níveis da IL-18 foram significativamente mais altos nos grupos DC (p=0.011) e RCUI (p=0.019) do que no grupo GC. No grupo RCUI, a IL-18 do soro se correlacionou positivamente com a IL-1 do fluido gengival (r=0. 667, p=0.01). Concluindo, nos pacientes com doença inflamatória intestinal, os níveis da IL-4 estavam mais baixos no fluido gengival e os níveis da IL-18 estavam aumentados no soro quando comparados aos controles. A função dos neutrófilos foi similar entre os pacientes com doença inflamatória intestinal e os controles. Com exceção da correlação positiva entre a IL-18 sérica e a IL-1 no fluido gengival dos pacientes com retocolite ulcerativa idiopática, não houve correlação entre as diversas citocinas mensuradas no soro e as citocinas mensuradas no fluido gengival nos controles nem nos pacientes com doença inflamatória intestinal. Não houve a caracterização de um padrão de resposta Th1 ou Th2 no fluido gengival dos pacientes com doença inflamatória intestinal. / The aim of this thesis was to evaluate the expression of Th1 cytokines (IL-12 and INF-γ), Th2 cytokines (IL-4, IL-6 and IL-10) and the pro-inflammatory cytokines IL-18, IL-1 and TNF-α in the gingival crevicular fluid (GCF) from Crohns disease (CD) patients, ulcerative colitis (UC) patients and healthy individuals (control group, CG) who had chronic periodontitis. Besides, we measured elastase activity, matrix metalloproteinase -8 and -9 (MMP-8 and -9) to address the neutrophil function in the GCF. Fifteen CD patients (mean age 38.2  11.4 years), 15 UC patients (mean age 45.0  10.5 years) and 15 systemically healthy controls (mean age 42.1  7.8 years) were enrolled in this study. All the present teeth, except for the third molars were examined. Probing pocket depth (PPD), clinical attachment loss (CAL), presence of plaque and presence of bleeding on probing were assessed in six sites per tooth. In every subject, GCF from 4 gingivitis sites (PPD  3mm and CAL  1mm) and from 4 periodontitis sites (PPD  5mm and CAL 3mm) were collected with filter strips. The data were reported as total amount and concentration. IL-1, IL-4, IL-6, IL-10, IL-12p70, TNFα, INFγ, MMP-8 and MMP-9 were analyzed by the Luminex analyzer. IL-18 was analyzed using a commercially available ELISA assay and the elastase activity by an enzymatic reaction. The serum was also analysed and the correlations between the cytokines in the GCF and in the serum were calculated by Pearson correlation analysis. In gingivitis sites, the total amount of IL-4 was significantly lower in the UC group than in the CG group (p=0.016). In periodontitis sites, the total amount of IL-4 was significantly lower in CD group than in the CG group (p=0.029). The total amount of IL-4 was lower in UC group than in CD group (p=0.077). Similarly, IL-4 concentrations in both CD (p=0.096) and UC (p=0.064) groups were lower than in CG group. IL-6 total amount (p=0.028) and IL-6 concentration (p=0.044) were significantly higher in the UC group than in the CG group. In the serum, IL-18 levels were significantly higher in CD (p=0.011) and UC (p=0.019) groups than in the CG group. In UC group, there was a positive correlation between serum IL-18 levels and IL-1 in the GCF (r=0. 667, p=0.01). In conclusion, IBD patients had lower IL-4 levels in the GCF and higher IL-18 levels in the serum than healthy controls. The neutrophil function in IBD patients is similar to controls. Except for the positive correlation between IL-18 in the serum and IL-1 in the GCF, there was no correlation between the cytokines in serum and in the GCF either in IBD patients or in controls. There was not a Th1 or Th2 polarization in the GCF from IBD patients.

Th17 cells are pro-inflammatory cells that are characterized by the production of their signature cytokine, IL-17. Although they are thought to have arisen to protect against extracellular bacteria and fungi they have been shown to mediate autoimmune diseases such as EAE and psoarisis. Notch protein is a cell-surface receptor that has been widely conserved among species. It plays an essential role in determining multiple cell fates. More recently, it has been implicated in regulating peripheral CD4+ T-cell responses. In these studies, we report that blockade of Notch signaling significantly down-regulates the production of IL-17 and associated cytokines in both mouse and human in-vitro polarized Th17 cells, suggesting an intrinsic requirement for Notch during Th17 differentiation in both species. We also present evidence, using promoter reporter assays, knockdown studies as well as chromatin immunoprecipitation, that IL-17 and RORt are direct transcriptional targets of Notch signaling in Th17 cells, with Notch 1 being the responsible Notch family member important in regulating the differentiation of human Th17 cells. In-vivo inhibition of Notch signaling reduced IL-17 production and Th17 mediated disease progression in experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. In addition, by using Notch1 and Notch3 knockout mice, we have shown that Notch 3 is the Notch family member that is essential for murine Th17 differentiation. We have also investigated noncanonical Notch signaling in Th17 cells by using CD4+ T-cells from CSL/RBP-Jk knockout mice. Based on data obtained, we have concluded that canonical Notch signaling is dispensable in Th17 responses. Thus, this study highlights the importance of different Notch family members in Th17 differentiation and indicates that selective targeted therapy against Notch may be an important tool to treat autoimmune disorders, including multiple sclerosis.

Les mastocytes sont des cellules immunitaires présentes dans tous les tissus de l'organisme. Ils ont été depuis longtemps associés aux réponses allergiques, mais ces cellules sont aussi des acteurs majeurs de la réponse inflammatoire. La dégranulation des mastocytes, ou exocytose des granules sécrétoires, est un mécanisme d'action important de ces cellules. Au laboratoire, nous avons mis au point une méthode innovante qui nous permet de suivre en temps réel la dynamique de cette dégranulation. Cette méthode repose sur l'utilisation de l'avidine couplé à un fluorochrome qui se lie spécifiquement à la matrice des granules. Nous avons recherché les modalités de la dégranulation lorsque les mastocytes sont activés par un ligand cellulaire comme des cellules cibles recouvertes d'anticorps. Nous avons pu mettre en évidence, de façon surprenante, que les mastocytes dégranulent de manière polarisée contre une cellule cible opsonisée avec des anticorps de type IgE ou IgG en mettant en place un nouveau mécanisme que nous avons nommé ADDS (Antibody Dependent Degranulatory Synapse). L'ADDS est caractérisée par une signalisation du récepteur RFc et une dépolymérisation du cytosquelette cortical d'actine locales. De plus, cette synapse peut aussi avoir lieu lorsque le mastocyte est au contact d'un parasite opsonisé comme Toxoplasma Gondii, et induit la mort du parasite et la libération de cytokines et chimiokines pro-inflammatoires. Nous avons ensuite analysé la dynamique de la dégranulation à l'échelle " single cell " et sa régulation par des facteurs inflammatoires. Grâce à une approche de " cell barcoding " et de cytométrie en flux en temps réel, nous avons pu mettre en évidence que la dégranulation induite par l'agrégation des RFc?I était contrôlée par deux mécanismes : un premier qui règle le nombre de mastocytes qui dégranulent et un second qui régule l'intensité de la dégranulation. L'interleukine 33 peut finement potentialiser ces deux mécanismes en augmentant le pourcentage de mastocytes qui dégranulent et l'intensité de la dégranulation. L'IL-33 induit ainsi l'émergence de cellules hautement inflammatoires. Dans un second axe de recherche, nous avons étudié quel pouvait être l'impact des prostaglandines dans le dialogue entre mastocytes et lymphocytes T CD4+ Helper (TH). Nos résultats indiquent un rôle insoupçonné de la prostaglandine D2 et la prostaglandine E2 comme des acteurs importants pour la production d'interleukine 17 par les LTH. En conclusion, mon travail de thèse nous a permis de révéler l'existence de la synapse dégranulatoire des mastocytes, de nouveaux mécanismes contrôlant la dégranulation et d'identifier les mastocytes comme une source importante de prostaglandines impliquées dans la polarisation des LTH. / Mast cells are tissue-resident immune cells particularly enriched in regions exposed to the external environment. They have been associated, for a long time, with allergic disorders but these cells are also major effectors of inflammatory response. The degranulation process, or granule exocytosis, is one of the main effector functions of mast cells and it has been implicated in various biological processes. In our laboratory, we have developed a new method to monitor live mast cell degranulatory response. This approach is based on fluorescent avidin that binds selectively mast cell granule matrix. Thanks to this method, we have investigated the degranulatory response following mast cell activation by cell bound antigens. We have shown that mast cells can undergo polarized degranulation toward IgE- or IgG-opsonized cells in a new mechanism we named ADDS (Antibody Dependent Degranulatory Synapse). The ADDS is characterized by a local signaling of FcR receptors and cortical actin depolymerisation. Moreover, this synapse takes place when mast cells are triggered by opsonized parasite Toxoplasma Gondii. It leads to the death of the parasite and the release of pro-inflammatory cytokines and chemokines. We next analyzed the mast cell degranulatory response dynamics at the single cell level and its regulation by alarmin IL-33. Using cutting-edge "cell barcoding" approach and live flow cytometry, we showed that Fc?RI mediated degranulatory response is controlled by two mechanisms: a first one that sets the frequency of degranulated mast cells and a second one that regulates the magnitude of the degranulation. The IL-33 fine tunes these two mechanisms by augmenting both the frequency of degranulated mast cells and the extent of individual mast cell degranulation. Our results indicate that interleukin 33 induces the emergence of high inflammatory mast cells. In a second axis of research, we analysed the influence of prostaglandins during the cooperation between mast cells and CD4+ T helper cells. Our results indicate that prostaglandin D2 and E2 produced by mast cells are important inducers of interleukin 17 by CD4+ T helper cells. Taken together, my thesis work revealed that mast cells can form degranulatory synapses, new mechanisms that control the degranulatory response and identified mast cells as a source of pro-IL-17 prostaglandins during their cooperation with CD4+ T helper cells.

The present work concerns the regulation of B cell activation, growth and terminal differentiation of helper T cells. T cell dependent (TD) B cell activation requires physical cell to cell contact between competent helper T cells (TH) and B cells and the recognition of MHC Class II antigens. The involvement of immunoglobulin receptors in TD B cell induction and maturation of B cells to plasma cells, however, are still unclear. Long term helper T cell lines and clones were raised against naturally expressed minor transplantation antigens. Using such antigen specific TH lines and clones, the mechanisms controlling growth and maturation of B cells to plasma cells were studied. Specific TH cells against both H-Y and C3H/Tif "minor" antigens were able to polyclonally induce small, resting B lymphocytes to proliteration and high rate antibody secretion. This observation definitively excludes an obligatory role of membrane immunoglobulin molecules in TD B cell triggering. In contrast to other similarly derived TH clones, a variant clone, was isolated which was fully competent to activate B cells to proliferation but did not induce PFC in T cell depleted "target" spleen cells. This defect could, however, be fully reconstituted by cell culture supernatants derived from competent TH clones (but not from the variant clone). These results indicated the presence of two distinct factors in such supernatants, controlling either growth or maturation in TD B cell responses, and lead to further efforts in their characterization. A B cell growth factor (BSF-pI) derived from such supernatants, with a Mr of 15-20 kD, displayed no mitogenicity on small, resting B lymphocytes and failed to induce PFC in prol iterating B cells. On the other hand, two distinct species of B cell maturation factors (BMA) were separated from the supernatants with Mr of 60 kD and 30 kD, respectively. These factors induced PFC of several antibody isotypes in assays were only maturation activity was limiting, but only the 60 kD species induced Ig-secretion, in pure populations of lymphoma cells (WEHI-279.1). Finally, neonatal B cells were shown to be inducible to growth but not to immunoglobulin secretion by competent TH cells, in the absence of suppressive effects in the neonatal spleen cell population. These results suggest that "early" B lymphocytes are intrinsically defective in the reception or processing of maturation signals. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1984, härtill 5 uppsatser</p> / digitalisering@umu