A determinação dos marcadores sorológicos P-ANCA (anticorpo perinuclear contra estruturas citoplasmáticas do neutrófilo) e ASCA (anticorpo anti-Saccharomyces cerevisiae) auxilia de forma menos invasiva no diagnóstico da doença inflamatória intestinal (DII). O padrão de associação mais relacionado à retocolite ulceratica inespecífica (RCUI) ocorre com ASCA- (negativo) e P-ANCA + (positivo). Na doença de Crohn (DC) ocorre o contrário, ou seja, ASCA+ e P-ANCA-. O P-ANCA é determinado por imunofluorescência indireta usando neutrófilos fixados em etanol, e o ASCA através de ELISA. De forma geral, a prevalência do P-ANCA em pacientes com RCUI tem variado entre 50 e 80% e em pacientes com DC entre 10 e 30%. Controles sadios têm revelado prevalência menor que 4% e controles patológicos em torno de 8%. Alguns trabalhos mostraram ampla variação nos resultados, sugerindo além de variação genéticas, variações metodológicas de acordo com a população estudada. Foram realizadas análises no soro de 200 pacientes para pesquisa de P-ANCA e ASCA, sendo 98 com RCUI e 102 com DC. O grupo controle foi representado por 54 indivíduos sadios. Os pacientes com DII foram oriundos do ambulatório de Gastroenterologia ? Grupo de Intestino do Hospital das Clínicas Faculdade da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP). A prevalência encontrada do P-ANCA na RCUI, DC e grupo controle correspondeu a 61,2%, 16,7% e 5,6% respectivamente, enquanto que a do ASCA para a DC, RCUI e grupo controle correspondeu a 52,9%, 27,6% e 5,6% respectivamente. A sensibilidade e especificidade encontrada com o padrão ASCA+/P-ANCA- para DC foi de 45,1% e 89,% respectivamente, enquanto que para o padrão P-ANCA+/ASCA- para RCUI foi de 43,9% e 91,2% respectivamente. No que diz respeito às características clínicas e demográficas, nenhuma associação com a presença dos anticorpos foi estabelecida no presente estudo, exceto quando avaliado o uso de drogas imunossupressoras e infliximab em pacientes com DC e ASCA+ , a qual se mostrou aumentada (p=0,008). Assim sendo, a determinação dos anticorpos P-ANCA e ASCA na DII possui baixa sensibilidade, mas níveis elevados de especificidade como demonstrado em outros estudos publicados. A correlação dos anticorpos P-ANCA e ASCA com características clínicas ainda permanece controversa. / The determination of serologic markers P-ANCA (perinuclear antineutrophil cytoplasmic autoantibodies) and ASCA (anti-Saccharomyces cerevisiae mannan antibodies) assists as non-invasive way on the inflammatory bowel disease (IBD) diagnosis. The most associated pattern to ulcerative colitis (UC) occurs with ASCA- (negative) and P-ANCA + (positive). In the Crohns disease (CD) is the opposite, that is, ASCA+ and P-ANCA-. Determination of P-ANCA is performed by an indirect immunofluorescence assay, using ethanol-fixed neutrophil slides and ASCA is measured by ELISA. Usually, the prevalence of P-ANCA in patients with UC has varied between 50 and 80% and in patients with CD between 10 and 30%. Healthy controls have disclosed lesser prevalence than 4% and pathological controls around 8%. Some studies had shown a wide variation in the results, suggesting both genetic and methodologic variations, according to the studied population. Serum samples were obtained from 200 patients for analysis of P-ANCA and ASCA, being 98 with UC and 102 with CD. The control group was represented by 54 healthy individuals. Patients with IBD were selected from the Department of Gastroenterology - Intestine Group of the Hospital das Clínicas of the University of São Paulo (HCFMUSP). P-ANCA prevalence found in UC, CD and control group were 61,2%, 16,7% e 5,6%, respectively, but ASCA prevalence in UC, CD and control group were 52,9%, 27,6% e 5,6%, respectively. Sensitivity and specificity achieved using ASCA+/P-ANCA- pattern for CD were 45,1% e 89,%, respectively, but P-ANCA+/ASCA- pattern for UC were 43,9% e 91,2% respectively. In this study, the current data did not support a relationship between the serological markers and clinical and demographic characteristics, except when evaluated the use of immunosuppresive drugs and infliximab in patients with CD and ASCA+, which were increased (p=0,008). Thus, the determination of antibodies P-ANCA and ASCA in the IBD gets low sensitivity, but high levels of especificity as demonstrated in other published reports. The correlation of antibodies P-ANCA and ASCA with clinical characteristics appears to be limited.

Die Präeklampsie ist eine schwangerschaftsspezifische Bluthochdruck-Erkrankung, die im Allgemeinen nach der 20. Schwangerschaftswoche auftritt. Neben der Hypertonie sind die Proteinurie und die Ödembildung charakteristische Symptome der Präeklampsie. Obwohl heute die Pathophysiologie der Präeklampsie zum großen Teil verstanden ist, ist die Ätiologie dieser Erkrankung noch unklar. 1999 konnten wir in den Seren von Präeklampsie-Patientinnen agonistische Autoantikörper, die gegen den Angiotensin II AT1-Rezeptor gerichtet sind (AT1-AAK), nachweisen. Diese AT1-AAK gehören zur Antikörpersubklasse IgG3.<br /> Die AT1-AAK führen in Kulturen neonataler Rattenkardiomyozyten AT1-Rezeptor spezifisch zu einem positiv chronotropen Effekt. Mittels Immunpräzipitation wurde gezeigt, dass AT1-AAK spezifisch den AT1-Rezeptor präzipitieren. Kontrollproben, aus denen die AT1-AAK entfernt wurden, führen zu keiner Präzipitation des AT1-Rezeptors. Die Präzipitation des AT1-Rezeptors bleibt ebenfalls aus, wenn die AT1-AAK mit einem Peptid, welches der Aminosäuresequenz des zweiten extrazellulären Loops des humanen AT1-Rezeptors entspricht, behandelt wurden. Eine Langzeitbehandlung der Kulturen neonataler Rattenherzzellen mit AT1-AAK vermindert die funktionelle Ansprechbarkeit der Zellen auf einen erneuten AT1-Rezeptor-Stimulus.<br /> Eine veränderte AT1-Rezeptorexpression wurde nicht nachgewiesen. In guter Übereinstimmung mit den in vitro-Expressionsdaten wurde gezeigt, dass die plazentare AT1-Rezeptorexpression bei Präeklampsie-Patientinnen nicht verschieden von der plazentaren AT1-Rezeptorexpression gesunder Schwangerer mit nicht pathogen verändertem Blutdruck ist. Im Zellsystem der neonatalen Rattenherzzellen führen die AT1-AAK zur Aktivierung von Gi-Proteinen und zu verringerten intrazellulären cAMP-Spiegeln.<br /> Des Weiteren wurde gezeigt, dass die AT1-AAK in Kulturen neonataler Rattenherzzellen die Transkriptionsfaktoren AP-1 und NFkB aktivieren. Die Aktivierung des Transkriptionsfaktors NFkB wurde vornehmlich in den Nicht-Myozyten der Rattenherzzellkultur nachgewiesen. Generell wurde festgestellt, dass sich die AT1-AAK pharmakologisch wie der natürliche Agonist des AT1-Rezeptors, Angiotensin II, verhalten.<br /> Erste Daten dieser Arbeit deuten auf einen eventuellen Einfluss der AT1-AAK auf die Expression von Komponenten der extrazellulären Matrix bzw. assoziierter Faktoren (Kollagen III, MMP-2, TIMP-2, Colligin) hin. In allen in dieser Arbeit untersuchten Seren von klinisch diagnostizierten Präeklampsie-Patientinnen wurden agonistische AT1-AAK nachgewiesen. Wir vermuten daher, dass die AT1-AAK möglicherweise bedeutend in der Pathogenese der Präeklampsie sind. / Preeclampsia is a serious, pregnancy-specific disorder that usually occurs after week 20 of gestation and is characterized by hypertension, proteinuria, and oedema. While the pathophysiology is clear, little is known about etiology of preeclampsia.<br /> In 1999, we showed that sera from preeclamptic patients contain autoantibodies directed against angiotensin II AT1 receptor (AT1-AAB). These autoantibodies are immunoglobuliens of the IgG3 subclass.<br /> AT1-AAB accelerate the beating rate of neonatal rat cardiomyocytes. The agonistic effect can be blocked with the AT1 receptor blocker losartan.<br /> Co-immunoprecipitation studies have shown that AT1-AAB specifically precipitate the AT1 receptor while control samples lacking AT1-AAB do not. The AT1 receptor could not be precipitated following neutralization of the AT1-AAB by a peptide corresponding to the AT1 receptors second extracellular loop. In further studies on neonatal rat heart cells, we showed long-term stimulation of the AT1 receptor whereby AT1-AAB down-regulated the AT1 receptor-mediated response to a second agonistic receptor-stimulation.<br /> After long-term stimulation of neonatal rat heart cells, no changes in AT1 receptor expression could be identified. Corresponding to these in vitro-expression data, no difference was seen in placental AT1 receptor expression between patients with preeclampsia and healthy pregnant women. Next, we tested if the AT1-AAB lead to activation of AT1 receptor signaling in angiotensin II fashion. In neonatal rat heart cell cultures, AT1-AAB lead to activation of Gi-protein with reduced cAMP levels. AT1-AAB are able to activate the transcription factors AP-1 and NFkB in this cell system. In all observations, the agonistic AT1-AAB behave pharmacologically in a similar fashion to angiotensin II.<br /> Initial data suggest that AT1-AAB may have an effect on extracellular matrix components (ECM).<br /> We have found AT1-AAB in all women meeting the clinical criteria of preeclampsia and, therefore, suggest that AT1-AAB may be important to the pathogenesis of the disease.

A determinação dos marcadores sorológicos P-ANCA (anticorpo perinuclear contra estruturas citoplasmáticas do neutrófilo) e ASCA (anticorpo anti-Saccharomyces cerevisiae) auxilia de forma menos invasiva no diagnóstico da doença inflamatória intestinal (DII). O padrão de associação mais relacionado à retocolite ulceratica inespecífica (RCUI) ocorre com ASCA- (negativo) e P-ANCA + (positivo). Na doença de Crohn (DC) ocorre o contrário, ou seja, ASCA+ e P-ANCA-. O P-ANCA é determinado por imunofluorescência indireta usando neutrófilos fixados em etanol, e o ASCA através de ELISA. De forma geral, a prevalência do P-ANCA em pacientes com RCUI tem variado entre 50 e 80% e em pacientes com DC entre 10 e 30%. Controles sadios têm revelado prevalência menor que 4% e controles patológicos em torno de 8%. Alguns trabalhos mostraram ampla variação nos resultados, sugerindo além de variação genéticas, variações metodológicas de acordo com a população estudada. Foram realizadas análises no soro de 200 pacientes para pesquisa de P-ANCA e ASCA, sendo 98 com RCUI e 102 com DC. O grupo controle foi representado por 54 indivíduos sadios. Os pacientes com DII foram oriundos do ambulatório de Gastroenterologia ? Grupo de Intestino do Hospital das Clínicas Faculdade da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP). A prevalência encontrada do P-ANCA na RCUI, DC e grupo controle correspondeu a 61,2%, 16,7% e 5,6% respectivamente, enquanto que a do ASCA para a DC, RCUI e grupo controle correspondeu a 52,9%, 27,6% e 5,6% respectivamente. A sensibilidade e especificidade encontrada com o padrão ASCA+/P-ANCA- para DC foi de 45,1% e 89,% respectivamente, enquanto que para o padrão P-ANCA+/ASCA- para RCUI foi de 43,9% e 91,2% respectivamente. No que diz respeito às características clínicas e demográficas, nenhuma associação com a presença dos anticorpos foi estabelecida no presente estudo, exceto quando avaliado o uso de drogas imunossupressoras e infliximab em pacientes com DC e ASCA+ , a qual se mostrou aumentada (p=0,008). Assim sendo, a determinação dos anticorpos P-ANCA e ASCA na DII possui baixa sensibilidade, mas níveis elevados de especificidade como demonstrado em outros estudos publicados. A correlação dos anticorpos P-ANCA e ASCA com características clínicas ainda permanece controversa. / The determination of serologic markers P-ANCA (perinuclear antineutrophil cytoplasmic autoantibodies) and ASCA (anti-Saccharomyces cerevisiae mannan antibodies) assists as non-invasive way on the inflammatory bowel disease (IBD) diagnosis. The most associated pattern to ulcerative colitis (UC) occurs with ASCA- (negative) and P-ANCA + (positive). In the Crohns disease (CD) is the opposite, that is, ASCA+ and P-ANCA-. Determination of P-ANCA is performed by an indirect immunofluorescence assay, using ethanol-fixed neutrophil slides and ASCA is measured by ELISA. Usually, the prevalence of P-ANCA in patients with UC has varied between 50 and 80% and in patients with CD between 10 and 30%. Healthy controls have disclosed lesser prevalence than 4% and pathological controls around 8%. Some studies had shown a wide variation in the results, suggesting both genetic and methodologic variations, according to the studied population. Serum samples were obtained from 200 patients for analysis of P-ANCA and ASCA, being 98 with UC and 102 with CD. The control group was represented by 54 healthy individuals. Patients with IBD were selected from the Department of Gastroenterology - Intestine Group of the Hospital das Clínicas of the University of São Paulo (HCFMUSP). P-ANCA prevalence found in UC, CD and control group were 61,2%, 16,7% e 5,6%, respectively, but ASCA prevalence in UC, CD and control group were 52,9%, 27,6% e 5,6%, respectively. Sensitivity and specificity achieved using ASCA+/P-ANCA- pattern for CD were 45,1% e 89,%, respectively, but P-ANCA+/ASCA- pattern for UC were 43,9% e 91,2% respectively. In this study, the current data did not support a relationship between the serological markers and clinical and demographic characteristics, except when evaluated the use of immunosuppresive drugs and infliximab in patients with CD and ASCA+, which were increased (p=0,008). Thus, the determination of antibodies P-ANCA and ASCA in the IBD gets low sensitivity, but high levels of especificity as demonstrated in other published reports. The correlation of antibodies P-ANCA and ASCA with clinical characteristics appears to be limited.

The α7 subunit of the nicotinic receptor, a ligand gated ion channel with an affinity for nicotine, has long been implicated in the pathophysiology of schizophrenia due to the extremely high rate of smoking within the patient population. However, the exact role of the receptor has never fully been determined. In the following studies, various functions the receptor may assume in disease state are evaluated. There is a strong relationship between the immune system and schizophrenia, with the α7 subunit possibly serving as the link between the two. One of the following studies looks at the possibility of the receptor functioning as antigen in an autoimmune response. Blood sera of schizophrenic patients, as well as controls, were analyzed for the presence of antibodies to the α7 subunit of the nicotinic receptor. A sensitive ligand-based assay revealed schizophrenic patients could possess a pathogenic level of antibody that may exacerbate the degenerative nature of the disease, allowing for the possibility that receptor antibodies may serve as a contributing factor in the etiology of the disorder in at least a subset of patients. In other studies, the expression of the α7 receptor was investigated. Recombinant α7 receptor production has eluded researchers in non-mammalian species and this was the focus of our initial studies. In general, the lack of sufficient molecular recombinant techniques utilizing the receptor makes characterization of the α7 receptor and it's specific protein interactions difficult to evaluate. The regulatory mechanisms of the nicotinic receptor α7 subunit production and receptor formation have yet to be completely elucidated. Results in this investigation found a relationship between a functional CRE-element in the promoter region.

INTRODUÇÃO: A Urticária Crônica é caracterizada pelo aparecimento de pápulas eritematosas, pruriginosas recorrentes e transitórias que duram por mais de seis semanas. Na maioria dos pacientes a causa é indeterminada, definida como idiopática (UCI), entretanto, um sub-grupo apresentam autoanticorpos contra a cadeia alfa do receptor de alta afinidade para IgE (FceRI), que são expressos na superfície de mastócitos e basófilos, tornando-os células alvo nesta doença. OBJETIVOS: Avaliar em pacientes com UCI, submetidos ao teste intradérmico de soro autólogo (ASST), o perfil de ativação dos basófilos, pela intensidade de expressão de marcadores de ativação/desgranulação e pela capacidade dos basófilos em responder aos estímulo com a IL-3 e anticorpo anti-IgE. Além disto, a presença de fator liberador de histamina foi avaliado nos soros dos pacientes. METODOLOGIA: Pacientes com UCI (n= 37) foram selecionados no Ambulatório de Urticária do Departamento de Dermatologia do Hospital das Clínicas da Faculdade de Medicina da USP e submetidos ao ASST. O grupo controle foi constituído por indivíduos saudáveis (n=38). A análise da expressão de FceRI, CD63, CD123 e CD203c em basófilos de sangue periférico foi realizada por citometria de fluxo. No ensaio in vitro de estimulação dos basófilos com anti-IgE, as células foram previamente incubadas com IL-3. O ensaio de liberação de histamina mediada por soros de pacientes com UCI foi realizado com três diferentes doadores de leucócitos e a histamina liberada dosada por ELISA de competição. RESULTADOS: Há um baixo número de basófilos no sangue periférico nos pacientes com UCI, coincidente com o baixo nível sérico de histamina. Os escassos basófilos no sangue periférico mostram elevada expressão de FceRI e uma regulação positiva da expressão de CD203c e CD63, independentemente do ASST. A análise funcional dos basófilos, mostra que somente a incubação com IL-3 recombinante já induz aumento significante da expressão de CD203c e da liberação de histamina dos basófilos de pacientes com UCI, que são intensificados com o estímulo por anticorpos anti-IgE após 15 e 40 minutos em relação ao grupo controle. Já a expressão de CD63 em basófilos após estímulo com anti-IgE, aumentou somente nos basófilos de indivíduos sadios, uma vez que os níveis de expressão basal estavam previamente aumentados. A presença de autoanticorpos liberadores de histamina foi analisada nos soros de pacientes com UCI. Três experimentos independentes foram realizados, evidenciando a ocorrência de 17% de positividade. CONCLUSÕES: Os resultados mostram que na UCI, os basófilos são sensibilizados in vivo, por fatores além dos autoanticorpos anti-FceRI e que funcionalmente, estão hiper-reativos a estímulos imunológicos. A presença de fatores séricos liberadores de histamina, independente do ASST, enfatiza que o teste intradérmico é sugestivo de autorreatividade e não de autoimunidade na UC / INTRODUCTION: Chronic Urticaria is characterized by recurrent, transitory, pruritic and erythematous wheals present for at least six weeks. In most patients the cause is unknown, defined as idiopathic (CIU), however, a sub-group has autoantibodies against the alfa chain of the high affinity IgE receptor (FceRIa) expressed on mast cells and basophils surface making it the target cells in this disease. OBJECTIVES: To evaluate in CIU patients, undergone autologous serum skin test (ASST), the activation profile of the basophils assessed by the expression of activation/degranulation markers and by the ability to release histamine in response to IL-3 priming and cross-linking with anti-IgE antibodies. Furthermore, the presence of histamine releasing factor in sera of patients was evaluated. METHODS: CIU patients (n = 37) were selected from the Dermatological Outpatient Clinic of the Hospital das Clínicas de São Paulo (HC-FMUSP) and submitted to the ASST. The control group consisted of healthy subjects (n=38). The analysis of the expression of FceRI, CD63, CD123 and CD203c on basophils from peripheral blood was assessed by flow cytometry. For the in vitro stimulation with anti-IgE antibodies, the cells were previously primed with human recombinant IL-3. The histamine release assay mediated by sera from patients with CIU was performed with three different donors of leukocytes and released histamine measured by competition ELISA. RESULTS: There is a low number of basophils in peripheral blood of patients with CIU, reflecting a low serum levels of histamine. The scarce basophils in peripheral blood show high expression of FceRI and an up-regulation of CD203c and CD63 marker expression, independently of the ASST. The functional analysis of basophils, revealed that recombinant IL-3 per se induces a significant increase in CD203c expression and the histamine release from basophils of patients with CIU, which are enhanced followed for 15 and 40 minutes of anti-IgE estimulation. The expression of CD63 in basophils upon anti-IgE stimulation, increased only in basophils of healthy individuals, since the baseline levels of CD63 expression on basophils of patients was already up-regulated. The presence of histamine release factors was examined in sera from CIU patients. Three independent experiments were performed, showing the occurrence of 17% of positivity. CONCLUSION: The results show that in CIU, the basophils are primed in vivo due to factor other than autoantibodies anti-FceRI and they have an hyperactive status to the immunological stimuli. The presence of serum histamine releasing factors, independent of the ASST, emphasizes that the intradermal test is suggestive of autorreactivity and not for autoimmunity in UC

INTRODUÇÃO: A Urticária Crônica é caracterizada pelo aparecimento de pápulas eritematosas, pruriginosas recorrentes e transitórias que duram por mais de seis semanas. Na maioria dos pacientes a causa é indeterminada, definida como idiopática (UCI), entretanto, um sub-grupo apresentam autoanticorpos contra a cadeia alfa do receptor de alta afinidade para IgE (FceRI), que são expressos na superfície de mastócitos e basófilos, tornando-os células alvo nesta doença. OBJETIVOS: Avaliar em pacientes com UCI, submetidos ao teste intradérmico de soro autólogo (ASST), o perfil de ativação dos basófilos, pela intensidade de expressão de marcadores de ativação/desgranulação e pela capacidade dos basófilos em responder aos estímulo com a IL-3 e anticorpo anti-IgE. Além disto, a presença de fator liberador de histamina foi avaliado nos soros dos pacientes. METODOLOGIA: Pacientes com UCI (n= 37) foram selecionados no Ambulatório de Urticária do Departamento de Dermatologia do Hospital das Clínicas da Faculdade de Medicina da USP e submetidos ao ASST. O grupo controle foi constituído por indivíduos saudáveis (n=38). A análise da expressão de FceRI, CD63, CD123 e CD203c em basófilos de sangue periférico foi realizada por citometria de fluxo. No ensaio in vitro de estimulação dos basófilos com anti-IgE, as células foram previamente incubadas com IL-3. O ensaio de liberação de histamina mediada por soros de pacientes com UCI foi realizado com três diferentes doadores de leucócitos e a histamina liberada dosada por ELISA de competição. RESULTADOS: Há um baixo número de basófilos no sangue periférico nos pacientes com UCI, coincidente com o baixo nível sérico de histamina. Os escassos basófilos no sangue periférico mostram elevada expressão de FceRI e uma regulação positiva da expressão de CD203c e CD63, independentemente do ASST. A análise funcional dos basófilos, mostra que somente a incubação com IL-3 recombinante já induz aumento significante da expressão de CD203c e da liberação de histamina dos basófilos de pacientes com UCI, que são intensificados com o estímulo por anticorpos anti-IgE após 15 e 40 minutos em relação ao grupo controle. Já a expressão de CD63 em basófilos após estímulo com anti-IgE, aumentou somente nos basófilos de indivíduos sadios, uma vez que os níveis de expressão basal estavam previamente aumentados. A presença de autoanticorpos liberadores de histamina foi analisada nos soros de pacientes com UCI. Três experimentos independentes foram realizados, evidenciando a ocorrência de 17% de positividade. CONCLUSÕES: Os resultados mostram que na UCI, os basófilos são sensibilizados in vivo, por fatores além dos autoanticorpos anti-FceRI e que funcionalmente, estão hiper-reativos a estímulos imunológicos. A presença de fatores séricos liberadores de histamina, independente do ASST, enfatiza que o teste intradérmico é sugestivo de autorreatividade e não de autoimunidade na UC / INTRODUCTION: Chronic Urticaria is characterized by recurrent, transitory, pruritic and erythematous wheals present for at least six weeks. In most patients the cause is unknown, defined as idiopathic (CIU), however, a sub-group has autoantibodies against the alfa chain of the high affinity IgE receptor (FceRIa) expressed on mast cells and basophils surface making it the target cells in this disease. OBJECTIVES: To evaluate in CIU patients, undergone autologous serum skin test (ASST), the activation profile of the basophils assessed by the expression of activation/degranulation markers and by the ability to release histamine in response to IL-3 priming and cross-linking with anti-IgE antibodies. Furthermore, the presence of histamine releasing factor in sera of patients was evaluated. METHODS: CIU patients (n = 37) were selected from the Dermatological Outpatient Clinic of the Hospital das Clínicas de São Paulo (HC-FMUSP) and submitted to the ASST. The control group consisted of healthy subjects (n=38). The analysis of the expression of FceRI, CD63, CD123 and CD203c on basophils from peripheral blood was assessed by flow cytometry. For the in vitro stimulation with anti-IgE antibodies, the cells were previously primed with human recombinant IL-3. The histamine release assay mediated by sera from patients with CIU was performed with three different donors of leukocytes and released histamine measured by competition ELISA. RESULTS: There is a low number of basophils in peripheral blood of patients with CIU, reflecting a low serum levels of histamine. The scarce basophils in peripheral blood show high expression of FceRI and an up-regulation of CD203c and CD63 marker expression, independently of the ASST. The functional analysis of basophils, revealed that recombinant IL-3 per se induces a significant increase in CD203c expression and the histamine release from basophils of patients with CIU, which are enhanced followed for 15 and 40 minutes of anti-IgE estimulation. The expression of CD63 in basophils upon anti-IgE stimulation, increased only in basophils of healthy individuals, since the baseline levels of CD63 expression on basophils of patients was already up-regulated. The presence of histamine release factors was examined in sera from CIU patients. Three independent experiments were performed, showing the occurrence of 17% of positivity. CONCLUSION: The results show that in CIU, the basophils are primed in vivo due to factor other than autoantibodies anti-FceRI and they have an hyperactive status to the immunological stimuli. The presence of serum histamine releasing factors, independent of the ASST, emphasizes that the intradermal test is suggestive of autorreactivity and not for autoimmunity in UC

Alzheimers sjukdom (AD, eng. Alzheimer’s disease) upptäcktes för 111 år sedan av Alois Alz-heimer. Idag är det den ledande orsaken till demens hos äldre, och incidencen förväntas öka med befolkningens ökande livslängd. År 2050 förutspås antalet patienter med AD nå 10 miljoner personer [1]. Det har gjorts många försök att angripa AD via dess främsta kännetäcken, såsom plack av beta-amyloid (Aβ), Aβ-oligomerer, och ansamlingar av tau-protein, kallat tau-trassel. Trots att forskning om AD bedrivits i flera årtionden är dess orsak alltjämt okänd.På sistone har det funnits ett fokus på de inflammatoriska komponenterna inom AD. Det finns en utbredd aktivering av immunförsvaret i det centrala nervsystemet hos patienter med AD, men varken dess orsak eller dess roll inom AD är känd. Däremot finns det tydliga tecken på att inflammationen är av autoimmun art. Med detta i åtanke är det tydligt att det finns ett stort behov att utröna auto-immunitetens roll inom AD. I denna forskningsstudie användes proteomik-metoder för att bestämma autoantikroppsprofilerna inom plasma och cerebrospinalvätska (CSF, eng. cerebrospinal fluid) hos AD-patienter och en frisk kontrollgrupp.I denna studie användes par av plasma- och CSF-prover från 23 friska individer och 49 patien-ter. Dessutom inkluderades 2 plasmaprover och 18 CSF-prover från patienter. En 380-faldig och en 314-faldig riktad analys gjordes med hjälp utav suspension bead array-teknologi (SBA). Varje SBA bestod av färgkodade, magnetiska mikrosfärer i suspension, med antigen immobiliserade på kulornas yta. Denna analysmetod användes för att undersöka autoantikropssprofilerna i alla prover. Resul-taten visade en ökad respons från autoantikroppar mot antigenen SLC17A6 (Solute Carrier Family 17 Member 6), MAP1A (Microtubule Associated Protein 1A), och MAP2 (Microtubule Associated Protein 2) i patiener gentemot friska individer. Dock har dessa antigen uppvisat en bred reaktivitet i tidigare, opublicerade studier. Därför behövs ytterligare forskning för att fastställa deras roll inom AD.Dessutom användes paren av plasma- och CSF-prover för att undersöka autoantikroppsprofilernas överrensstämmelse inom varje patient. Det visade sig att korrelationen följde en normalfördelning, med starkare korrelation inom antigen med starkare reaktivitet mot den motsvarande autoantikroppen. Denna studie utgör en av de första storskaliga forskningsstudierna av överrensstämmelsen mellan autoantikroppsprofilerna inom plasma och CSF. / Alzheimer’s disease (AD) was discovered 111 years ago by Alois Alzheimer. Today, it is the leading cause of dementia in elderly, and incidence is expected to increase with life expectancy. By 2050, the number of a˙ected individuals is predicted to reach 10 million [1]. There have been numerous attempts to describe AD by its primary hallmarks, including amyloid plaques, amyloid beta (Aβ) oligomers, and tau tangles. However, despite several decades of intense research, the cause of AD remains unknown.Recently, there has been a focus on the inflammatory components of AD. There is an extensive activation of the immune system within the CNS of AD patients, but neither its cause nor its role in AD is known. However, there are strong indications that the inflammation has an autoimmune character. Considering this, there is an imperative need to examine autoimmunity within AD. In the present study, a proteomic approach was used to determine the autoantibody profiles within plasma and cerebrospinal fluid (CSF) within AD patients and healthy controls.Paired plasma and CSF samples from 23 healthy controls and 49 patients were included in the present study. In addition, 2 plasma samples and 18 CSF samples from patients were included (not paired). One 380-plex and one 314-plex targeted suspension bead array (SBA), each consisting of color-coded magnetic microspheres with immobilized antigens, were used to analyze autoantibody profiles in all samples. The resulting data revealed an increased autoantibody response towards anti-gens SLC17A6 (Solute Carrier Family 17 Member 6), MAP1A (Microtubule Associated Protein 1A), and MAP2 (Microtubule Associated Protein 2) in patients compared to healthy controls. However, as these antigens have displayed wide reactivities in previous, unpublished studies, they require further investigation to determine their role in AD.Furthermore, the paired CSF and plasma samples were used to investigate the correlation of autoantibody profiles within patients. The correlation was found to follow a normal distribution, with correlation being higher in antigens displaying stronger autoantibody reactivity. This work represents one of the first large-scale studies on the correlation of autoantibody profiles in plasma and CSF.

Le costimulateur inductible (ICOS) est un récepteur costimulatoire des cellules T crucial pour l’immunité humorale. Chez l’humain, une déficience de ICOS est associée à des infections récurrentes dû à des défauts de différentiation des lymphocytes T auxiliaires folliculaires (Tfh) et un manque d’anticorps protecteurs. Paradoxalement, certains patients déficients en ICOS développent des signes d’autoimmunité causés par des autoanticorps. Ces observations sont en accord avec des résultats suggérant que ICOS joue un double rôle dans la promotion des fonctions de cellules T effectrices et de cellules T régulatrices. L’arthrite rhumatoïde (RA) est une maladie autoimmune caractérisée par l’inflammation articulaire et la destruction progressive des os. Dans la première étude présentée au Chapitre 2, nous avons démontré que ICOS est requis pour l’initiation et la maintenance de l’arthrite induite par le collagène (CIA), un modèle murin de la RA. Nous avons démontré que des événements clés de l’initiation de la CIA incluant la production d’anticorps contre le collagène et la prolifération de cellules T inflammatoires sont dépendants de la voie de signalisation ICOS-PI3K. Aussi, nous avons trouvé que la signalisation par ICOS-PI3K promouvoit le maintien de la CIA. De plus, nous avons établi que l’inhibition de la glycolyse réduit la sévérité de la CIA, ce qui suggère un chevauchement entre la signalisation ICOS-PI3K et le métabolisme du glucose dans la pathogenèse de l’arthrite autoimmune. Dans la deuxième étude présentée au Chapitre 3, nous avons utilisé des souris dont les cellules T régulatrices sont déficientes en ICOS (ICOS FC) pour évaluer l’impact de ICOS dans les cellules Tfr. Nous avons trouvé que les souris ICOS FC possèdent un taux réduit de cellules Tfr, mais aucune diminution des cellules T régulatrices (Treg) précurseurs. De plus, les souris ICOS FC ont un taux élevé de cellules B du centre germinatif (GC) non-spécifiques ainsi qu’une production accrue d’anticorps anti-nucléaires. Nous avons aussi observé une perturbation des réponses anti-virales et de la production d’anticorps spécifiques dans les souris ICOS FC ce qui suggère des rôles non-régulateurs pour les cellules Tfr. Nous avons effectué une analyse de transcriptome de cellule unique avec des Tregs et nous avons observé une accumulation de précurseurs de Tfr dans les souris ICOS FC, ce qui suggère un défaut de la transition Treg à Tfr. Nos données suggèrent que ICOS participe à la différentiation des cellules Tfr en régulant KLF2 et NFAT2, ce qui contribue à l’établissement de traits folliculaires. En résumé, nous avons démontré que ICOS promouvoit le développement de l’arthrite autoimmune en soutenant les fonctions des cellules T inflammatoires par la voie de signalisation ICOS-PI3K. De plus, nos résultats prouvent que ICOS peut prévenir la production d’autoanticorps en supportant la différentiation des cellules Tfr. Notre travail contribue à l’avancement des connaissances en ce qui concerne le rôle double de ICOS dans l’immunité cellulaire et humorale et fournit des paramètres importants à considérer lors de la recherche de nouvelles cibles thérapeutiques. / The inducible costimulator (ICOS) is a T cell costimulatory receptor crucial for humoral immunity. In humans, ICOS deficiency is associated with recurrent infections due to defects in T follicular helper (Tfh) differentiation and lack of protective antibodies. Paradoxically, some ICOS-deficient patients were found to exhibit signs of antibody-mediated autoimmunity. These observations are congruent with findings suggesting that ICOS plays a dual role in promoting T effector and T regulatory cell functions. Due to this ambivalence, the role of ICOS in autoimmunity remains unresolved. Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and progressive bone destruction. The number of ICOS+ T cells in the synovial tissues of RA patients was found to be elevated, suggesting a potential involvement of ICOS signaling in the pathogenesis of RA. In the first study presented in Chapter 2, we showed that ICOS is required for the initiation and maintenance of collagen-induced arthritis (CIA), a murine model of RA. We found that key CIA initiation events such as anti-collagen antibody production and inflammatory T cell proliferation were dependent on ICOS-PI3K signaling. Further, we found that ICOS-PI3K signaling promotes maintenance of established CIA. Additionally, we show that glycolysis inhibition ameliorates CIA, thus suggesting potential overlaps between ICOS-PI3K signaling and glucose metabolism in the pathophysiology of autoimmune arthritis. The initiation of autoimmunity depends on the action of autoimmune effector cells, but also on a failure of regulatory cells. Amongst the latter, T follicular regulatory (Tfr) cells are thought to prevent autoantibody production. In the second study presented in Chapter 3, we used regulatory T cell-specific ICOS knockout (ICOS FC) mice to investigate the impact of ICOS signaling in Tfr cells. We found that ICOS FC mice display a significant reduction in Tfr cell numbers, but no depletion of their T regulatory (Treg) precursors. Further, ICOS FC mice exhibited a rise of extraneous germinal center (GC) B cells numbers and increased production of anti-nuclear antibodies. We also observed disruptions of anti-viral responses and antigen-specific antibody production in ICOS FC mice, suggesting non-regulatory roles for Tfr cells. We performed single-cell transcriptome analysis of regulatory T cells and observed an accumulation of Tfr precursors in ICOS FC mice suggestive of a Treg-to-Tfr transition defect. Mechanistically, we found that ICOS participates in Tfr differentiation by regulating KLF2 and NFAT2, thereby contributing to the establishment of follicular T cell traits. In sum, we demonstrate that ICOS promotes the development of autoimmune arthritis by fostering inflammatory T cell responses in a PI3K-dependent manner. In addition, our work shows that ICOS can prevent autoantibody production by supporting Tfr differentiation. Thus, we contribute insights into the dual role of ICOS in the cellular and humoral arms of autoimmunity, providing important parameters to be considered when searching for novel therapeutic targets.

Beeinträchtigungen der humanen Immunantwort durch primäre Immundefekte (PID) oder Immundysfunktionen können zu einer lebensbedrohlichen Anfälligkeit für Infektionen führen. Der erste Abschnitt dieser Arbeit umfasst die Charakterisierung einer unbekannten IKBKG-Mutation, die zu einer bisher unbeschriebenen NEMO-Defekt-Variante führt. NEMO-Defekte wurden bislang den Defekten der angeborenen Immunität zugeordnet. Die Mutation verursachte jedoch einen zusätzlichen schweren T-Zelldefekt, infolgedessen der Patient in seinem ersten Lebensjahr vermehrt an schweren bakteriellen Infektionen litt. Die Analyse der NEMO-kodierenden Sequenz ergab, dass die Mutation zu einem Exon-Verlust und somit zu einem verkürzten, funktionell-eingeschränkten Protein führte. Im Vergleich mit vorbeschriebenen NEMO-Defekten wurde deutlich, dass das Spektrum der Erkrankungen durch IKBKG-Mutationen breiter als bisher angenommen und die frühzeitige Charakterisierung der Immunantwort zur Abschätzung der individuellen Prognose essentiell ist. Der zweite Abschnitt umfasst die Charakterisierung von anti-Interleukin (IL)-6-Autoantikörpern (AAk) in Patienten, die an mindestens einer schweren bakteriellen Infektion erkrankt waren. 0,6 % dieser Patienten wiesen neutralisierende AAk gegen IL-6 auf, während 0,4 % einer Patientenkohorte mit Autoimmunerkrankungen, 0 % einer Patientenkohorte mit mykobakteriellen Infektionen und 0,1 % von Individuen ohne schwere bakterielle Infektionen anti-IL-6-AAk präsentierten. Des Weiteren wurden drei bislang gesunde Frauen mit neutralisierenden AAk identifiziert. Das Epitop-Mapping zeigte Bindungsstellen, die für die Bildung des IL-6-Rezeptorkomplexes notwendig sind. Die Verlaufsanalyse der Titer ergab, dass trotz persistentem bzw. abfallendem Titer keine weiteren Infektionen eintraten. Zusammenfassend führen anti-IL-6-AAk einerseits zu einer erhöhten Anfälligkeit für bakterielle Infektionen, andererseits ist diese Anfälligkeit nicht in dem Maße ausgeprägt wie bei einem PID. / Disturbances of the human immune response in the form of primary immunodeficiencies (PID) or immune dysfunctions can lead to life-threatening infections. The first chapter of this work refers to the analysis of an unknown IKBKG mutation resulting in an undescribed variant of NEMO-deficiency. These defects have been previously assigned to immunodeficiencies of the innate immunity. However, the mutation additionally leads to a severe T-cell defect, whereupon the patient suffered from several severe bacterial infections in his first year of life. Analysis of the NEMO-coding sequence indicated that the mutation leads to an exon skipping and a shortened, functionally restricted protein. The range of diseases caused by IKBKG mutations is broader than previously presumed when compared to other NEMO-deficiencies. Therefore, the early characterization of the immune response is essential for the assessment of the individual prognosis. The second chapter comprises the characterization of anti-IL-6-autoantibodies in a cohort of patients who suffered from at least one severe bacterial infection. 0.6 % of these patients presented neutralizing autoantibodies against IL-6 whereas 0.4 % of patients with autoimmune diseases, 0 % of patients with mycobacterial infections and 0.1 % of individuals without severe infections demonstrated neutralizing autoantibodies against IL-6. In addition, three so far healthy women with neutralizing anti-IL-6-autoantibodies were identified. Analysis of the binding characteristics identified IL-6-binding sites that are essential for the formation of the IL-6 signaling complex. The examination over several years revealed that, despite persistent or decreasing antibody titers, no further or new infections occurred. In summary, anti-IL-6-autoantibodies seem to have an extenuated predisposition to severe infections, but this susceptibility is not as severe as in PID.

La sclérose systémique (ScS) est une maladie auto-immune d’origine inconnue qui est caractérisée par des atteintes vasculaires, des dérèglements cellulaire et immunitaire. La majorité des patients atteints de ScS possède des auto-anticorps dirigés contre des protéines nucléaires. Ces auto-anticorps sont associés à des manifestations cliniques spécifiques favorisant la classification et le diagnostic de la ScS. Les anti-ADN topoisomérase I (antitopo) sont l’un des principaux auto-anticorps retrouvés dans la ScS. Ils sont associés à la forme la plus grave de la maladie, soit la forme diffuse. Celle-ci se caractérise par une importante fibrose progressant vers une atteinte viscérale. La fibrose résulte d’une production excessive et dérégulée de matrice extracellulaire par les fibroblastes. Bien que les anti-topo soient associés à un très mauvais pronostic et qu’ils corrèlent avec l’activité et la sévérité de la maladie, leur rôle dans la pathogenèse de la ScS n’est pas élucidé. Toutefois, depuis que certains auto-antigènes ont démontré des fonctions additionnelles lorsque retrouvés dans le milieu extracellulaire, leur contribution suscite un intérêt marqué. En effet, ces auto-antigènes, dits bifonctionnels, influencent la physiologie de certaines cellules en se liant à leur surface. Ainsi, la détermination du rôle de ces autoantigènes ouvre la voie pour l’exploration du rôle potentiellement pathogène de leurs autoanticorps. Tout d’abord, nous avons démontré que l’auto-antigène topo, ciblée par les antitopo, pouvait influencer la physiologie du fibroblaste suite à l’activation de voies de signalisations intracellulaires stimulant la migration cellulaire. Nos résultats suggèrent fortement que la topo stimule le fibroblaste suite à son interaction avec le CCR7, un récepteur de chimiokine, présent à sa surface. Nous avons également démontré que la topo utilisait les protéoglycans à chaînes d’héparanes sulfates (HSPG) à titre de corécepteurs. Il avait été démontré que la topo liée à la surface des fibroblastes entraînait le recrutement d’anti-topo, l’adhésion et l’activation monocytaires. Nous avons ici démontré que la présence d’anticorps anti-topo entraîne l’amplification de la liaison de la topo au niveau des HSPG. De ce fait, le complexe immun à la surface des fibroblastes pourrait contribuer à l’initiation d’une cascade inflammatoire propice au développement d’une fibrose, caractéristique de la ScS. En dernier lieu, nos résultats nous ont permis de suggérer l’utilisation de l’héparine et des héparines de bas poids moléculaires comme approche thérapeutique pour la ScS puisqu’elles permettent autant de prévenir la liaison du complexe immun topo/anti-topo au niveau des HSPG que de le dissocier une fois lié. En résumé, notre étude soutient d’abord le rôle actif de l’auto-antigène dans la physiologie des fibroblastes mais également le rôle pathogène des anti-topo en présence de la topo dans la ScS. Finalement, les résultats de notre étude permettent de proposer une approche thérapeutique potentielle pour inhiber le développement d’une cascade inflammatoire et pro-fibrotique. / Systemic sclerosis (SSc) is an autoimmune disease of unknown etiology characterized by vascular damage, cellular and immunological disorders. The vast majority of patient sera are characterized by the presence of autoantibodies directed against nuclear proteins. The autoantibodies are associated with specific clinical manifestations and thus useful for diagnostic and classification of the disease. One of the major autoantibody groups are the anti-DNA topoisomerase I (anti-topo). They are associated with the diffuse form of the disease which is characterized by extensive cutaneous and visceral fibrosis. Increased extracellular matrix synthesis and deposition by fibroblast result in the development of fibrosis. Although anti-topo are associated with the worst form of the disease, correlated with the activity and the severity of SSc, their exact role in the pathogenesis of SSc is controversial and still unravelled. On the other hand, there is now strong evidence for active contribution of autoantigens, targeted by autoantibodies, in autoimmune diseases. Indeed, numerous cells have been shown to be influenced by the interaction of autoantigens with their cognate receptors present on their surface. These autoantigens display cytokine-like effects toward their target cell and are called bifunctional autoantigen. Hence, determination of the exact role of these autoantigens and characterization of their interaction with their target cell may open up research perspectives for the elucidation of the potential pathogenic role of their autoantibodies. In our study, we demonstrated that topo activates intracellular signaling pathways leading to the stimulation of fibroblast migration. We undertook experiments to characterize the interaction of the autoantigen topo with fibroblasts responsible of these cellular effects. Our results strongly suggest a direct interaction of topo with CCR7, a chemokine receptor, present on the surface of fibroblasts. Heparan sulfate proteoglycans (HSPG), abundantly present on fibroblast surfaces, were found to act as coreceptors for topo binding. Previous work has demonstrated that once bound to fibroblast surfaces, topo recruits anti-topo autoantibodies, which subsequently lead to adhesion and activation of monocytes. Here, we demonstrated that anti-topo autoantibodies from SSc sera lead to the amplification of topo binding to HSPG on fibroblast surfaces. The binding of topo/anti-topo IC could mediate the initiation and maintenance of an inflammatory cascade and further fibrosis development. Hence, perturbing the binding of topo/anti-topo immune complexes to HSPG became an interesting therapeutic approach. Heparin and low molecular weight heparins were found to prevent the binding of topo and topo/anti-topo immune complexes to the fibroblast surfaces. Moreover, topo/anti-topo immune complexes could be dissociated from fibroblast surfaces by these molecules. Hence, the prevention of topo/anti-topo immune complexes binding to HS chains could result in the absence of the inflammatory cascade initiation. Overall, our results support an active role for topo as a bifunctional autoantigen toward fibroblasts and a pathogenic role for anti-topo autoantibodies in SSc. Finally, a potential therapeutic approach is proposed which could target inflammatory and fibrotic development characteristic of SSc.