Les lymphocytes T Vgamma9Vdelta2 humains constituent la sous-population majoritaire de lymphocytes Tgammadelta dans le sang chez l'adulte sain et représentent 1% à 4% des cellules mononucléées du sang périphérique (PBMC). Ce sont des lymphocytes T non conventionnels activés par des antigènes non peptidiques, les phosphoantigènes (PAgs) sans nécessité de restriction par les molécules du CMH. Ils jouent un rôle essentiel dans l'immunité anti-infectieuse et antitumorale, notamment en sécrétant des cytokines pro-inflammatoires et des molécules lytiques au contact de leurs cellules cibles. L'efficacité des lymphocytes T Vgamma9Vdelta2 en immunothérapie anticancéreuse est aujourd'hui démontrée mais reste fortement limitée en raison de la grande toxicité de l'IL-2 requise pour leur expansion. Toutes les cytokines de la famille de l'IL-2 possèdent la même toxicité intrinsèque, en raison de la chaîne gamma commune à tous les récepteurs de cette famille. Il est donc nécessaire de trouver une molécule alternative à l'IL 2, moins toxique mais tout aussi efficace, dont la transduction du signal ne dépend pas de la chaîne gamma. L'IL-33 est une cytokine de la famille de l'IL-1 appartenant au groupe des alarmines, dont le récepteur ST2/IL-1 RAcP est gamma chain-indépendant. Elle est naturellement présente dans le microenvironnement tumoral et son récepteur ST2 est exprimé sur de nombreuses cellules de l'immunité innée et adaptative. L'IL-33 est une cytokine pluripotente, pouvant induire à la fois des réponses immunitaires de type Th2 ou Th1. Néanmoins, aucune donnée n'était disponible quant à la bioactivité de l'IL-33 sur les lymphocytes T Vgamma9Vdelta2. Mes travaux de thèse ont donc consisté à déterminer si l'IL-33 pouvait potentialiser les fonctions anticancéreuses des lymphocytes T Vgamma9Vdelta2. Au cours de cette étude, nous avons montré que l'IL-33 associée à un PAg induit la prolifération et l'amplification des lymphocytes T Vgamma9Vdelta2 au sein des PBMC. Après amplification, les lymphocytes T Vgamma9Vdelta2 induits avec de l'IL-33 sécrètent des cytokines de type Th1 INF-gamma et TNF-alpha et ont une activité cytotoxique semblable à ceux induits avec de l'IL-2. De plus, nous avons mis en évidence que la prolifération des lymphocytes T Vgamma9Vdelta2 induite par l'IL-33 est issue d'un mécanisme complexe dépendant d'une interaction avec les lymphocytes T CD4. L'ensemble de ces résultats suggère que l'IL-33 pourrait représenter une bonne alternative à l'IL-2 dans les protocoles d'immunothérapie anticancéreuse impliquant des lymphocytes T Vgamma9Vdelta2. / Human Vgamma9Vdelta2 T cells represent the most prominent subset of gammadelta T cells in the blood of healthy adults, representing 1 to 4% of peripheral blood mononuclear cells (PBMC). These cells are non-conventional lymphocytes activated by non peptidic antigens, the phosphoantigens (PAgs), without restriction by MHC molecules. They are very important actors of anti-infectious and antitumor immune responses. Indeed, their activation upon a contact with their target cells lead them to secrete pro-inflammatory cytokines and lytic granules mediating cell cytotoxicity. Their efficacy in cancer immunotherapy is now demonstrated but appears strongly limited by the toxicity of IL-2 which is essential for their expansion. All the cytokines of the IL-2 family have the same toxicity owing to the gamma chain shared by all the receptors of the family. Therefore, it appears crucial to find as effective but safer alternative to IL-2 which signaling does not depend on the gamma chain. IL-33 is a member of IL-1 family belonging to the alarmins which its receptor ST2/IL-1RAcP does not require the gamma chain. It is naturally present in the tumor microenvironment and ST2 is expressed on numerous innate and adaptive immune cells. IL 33 is a multipotent cytokine able to sustain both Th2 and Th1 immune responses. However, its bioactivity on Vgamma9Vdelta2 T cells has never been studied. The aim of my PhD thesis consisted in determining if IL-33 could promote Vgamma9Vdelta2 T cell anticancer functions. We found that IL-33 enhances the proliferation and the amplification of PAg-activated Vgamma9Vdelta2 T cells. Moreover, we found that IL-33-induced Vgamma9Vdelta2 T cells display the same anticancer functions than those induced by IL-2, through their secretion of Th1 type cytokines and to their cytotoxic activity towards cancer cells. Interestingly, we found that Vgamma9Vdelta2 T cell proliferation induced by IL-33 is due to a complex mechanism requiring interaction with CD4 T cells. Altogether, these results suggest that IL-33 represents a potential alternative to IL-2 in Vgamma9Vdelta2 T cell-based immunotherapies.

Regulatorische Foxp3+CD4+ T-Zellen sind essentiell für das Gleichgewicht des intestinalen Immunsystems. Eine Einschränkung ihrer Suppressionsfunktion wird bei Patienten mit Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX)-Syndrom beobachtet und führt im Tiermodell zu lymphoproliferativen Erkrankungen und intestinalen Entzündungen. Von entscheidender Bedeutung für Homöostase und Suppressionsfunktion regulatorischer T-Zellen ist das Signalmolekül Interleukin-2 (IL-2). Im Gegensatz zu Effektor-T-Zellen exprimieren Foxp3+CD4+ T-Zellen den hochaffinen IL-2-Rezeptor αβγ konstitutiv. IL-2 wird von regulatorischen T-Zellen nicht in relevanten Mengen exprimiert. Sie sind somit auf von anderen Zellen sezerniertes IL-2 angewiesen. In der vorliegenden Arbeit wird gezeigt, dass im Tiermodell regulatorische Foxp3+CD4+ T-Zellen durch Applikation eines IL-2/anti-IL-2-Antikörperkomplex nicht nur in mesenterialen Lymphknoten und Milz, sondern auch lokal in der Lamina propria mucosae des Kolons der Versuchstiere expandiert werden. Als relevante Quelle von IL-2 in situ könnten aktivierte proliferierende T-Zellen dienen. Um dies näher zu untersuchen, wurde die Proteinexpression proliferierender Einzelzellen mittels Matrix assisted laser desorption/ionisation-Time of flight-Massenspektrometrie-Imaging (MALDI-Imaging) analysiert. Es gelang die Identifikation präferentiell in lymphoiden Geweben exprimierter Peptidmassen. Obwohl die Einzelzellanalyse mittels MALDI-Imaging prinzipiell möglich erscheint, ist ein Nachweis von Zytokinen wie IL-2 derzeit aufgrund fehlender Sensitivität im Proteinmassebereich zwischen 10kDa und 20kDa nicht möglich. Die therapeutischen Möglichkeiten der Expansion regulatorischer Foxp3+ T-Zellen durch stabile IL-2-Rezeptor-Agonisten und die Rolle von IL-2 für die intestinale Immunregulation sollten weiter untersucht werden.:Bibliographische Beschreibung 3 Inhaltsverzeichnis 4 Abkürzungsverzeichnis 7 1. Einleitung 9 1.1. Störung der Barrierefunktion des intestinalen Immunsystems als Ursache chronisch entzündlicher Darmerkrankungen 9 1.2. Foxp3+ regulatorische T-Zellen 10 1.3. Die Rolle von Interleukin-2 für regulatorische T-Zellen 11 1.4. Signaltransduktion in regulatorischen T-Zellen als Grundlage ihrer selektiven Expansion und Induktion 12 1.5. Möglichkeiten der präferentiellen Expansion regulatorischer T-Zellen 15 1.5.1. Expansion regulatorischer T-Zellen durch Agonisten des hochaffinen IL-2-Rezeptors 15 1.5.2. Induktion regulatorischer T-Zellen durch TGF-β 16 1.5.3. Expansion regulatorischer T-Zellen durch Rapamycin (Sirolimus) 17 1.5.4. Expansion regulatorischer T-Zellen durch UVB-Bestrahlung bzw. Vitamin D-Rezeptor-Agonisten 18 1.5.5. Expansion regulatorischer T-Zellen durch Histon-Deacetylaseinhibitoren 19 1.6. Suppression von Effektor-T-Zellen durch regulatorische T-Zellen 20 1.6.1. Zellkontaktabhängige Mechanismen 20 1.6.2. Zellkontaktunabhängige Mechanismen 22 1.7. Matrix assisted laser desorption ionisation-Time of flight-Massenspektromie (MALDI-TOF-MS): Bedeutung und Funktion 23 1.8. Zielstellung 25 2. Materialien und Methoden 26 2.1. Versuchstiere 26 2.2. IL-2/IgG2b-Fusionsprotein-Vorexperiment 26 2.2.1. Induktion von 2,4,6-Trinitrobenzensulfonsäure (TNBS)-Kolitis 26 2.2.2. Durchführung des IL-2/IgG2b-Fusionsprotein-Vorexperimentes 26 2.3. Durchführung des IL-2/anti-IL-2-Antikörperkomplex-Experiments 27 2.4. Durchflusszytometrie 27 2.5. Histologische Färbungen 28 2.5.1. Probenvorbereitung 28 2.5.2. Hämatoxylin/Eosin (HE) Färbung 29 2.5.3. Immunfluoreszenz-Färbungen 29 2.5.4. Ki67-Schnellfärbung 30 2.5.5. Mikroskopie und Photographie 30 2.6. Histologische Auswertungen 31 2.6.1. Kolitis-Score 31 2.6.2. Bildanalyse 31 2.6.3. Validierung der automatischen Bildanalyse mittels CellProfiler 33 2.7. MALDI-Imaging 35 2.7.1. Probenvorbereitung für MALDI-Imaging 35 2.7.2. Analyse der Peptidexpression in Gewebeschnitten mittels MALDI-Imaging 36 2.8. Statistische Auswertungen 36 2.8.1. Statistische Tests 36 2.8.2. Berechnung der zu erwartenden Zahl von Kontakten zwischen Ki67+ und Foxp3+ Zellen 36 3. Ergebnisse 38 3.1. Design des IL-2/anti-IL-2-Antikörperkomplex Experimentes 38 3.2. Mit IL-2/anti-IL-2-Antikörperkomplex behandelte Tiere zeigen Splenomegalie und Lymphadenomegalie 40 3.3. Behandlung mit einem IL-2/anti-IL-2-Antikörperkomplex führt zur präferentiellen Expansion regulatorischer T-Zellen in mesenterialen Lymphknoten und Milz 41 3.4. Behandlung mit IL-2/anti-IL-2-Antikörperkomplex führt nicht zu Kolitis 43 3.5. Behandlung mit IL-2/anti-IL-2-Antikörperkomplex führt zur präferentiellen Expansion regulatorischer T-Zellen in der Lamina propria mucosae 45 3.6. IL-2/anti-IL-2-Antikörperkomplex steigert die Proliferation regulatorischer T-Zellen in der Lamina propria mucosae und lymphoiden Follikeln des Kolons 47 3.7. Regulatorische T-Zellen sind nach Behandlung mit IL-2/anti-IL-2-Antikörperkomplex weiter mit proliferierenden Zellen assoziiert. 50 3.8. MALDI-Imaging als Möglichkeit der Proteinexpressionsanalyse in situ 52 3.8.1. Vergleich der Proteinexpression in verschiedenen Geweben von Ileum und Zäkum mit der Expression in Thymus und mesenterialem Lymphknoten 55 3.8.2. MALDI-Imaging nach Schnellfärbung Ki67+ Zellen mit Streptavidin 63 3.8.3. Analyse der Massenspektren von Einzelzellen mittels MALDI-Imaging 66 4. Diskussion 68 4.1. Applikation von IL-2/anti-IL-2-Antikörperkomplex hat keine fatalen Nebenwirkungen 68 4.2. IL-2/anti-IL-2-Antikörperkomplex führt zur präferentiellen Expansion regulatorischer T-Zellen in mesenterialen Lymphknoten, Milz und Kolon 70 4.3. IL-10 als wichtiger Vermittler der Suppressionsaktivität durch IL-2/anti-IL-2-Antikörperkomplex expandierter regulatorischer T-Zellen 71 4.4. Expansion regulatorischer T-Zellen beim Menschen: Voraussetzungen und Chancen 72 4.5. Regulatorische T-Zellen akkumulieren an proliferierenden Zellen 73 4.6. Nachweis spezifischer Massen in Gewebe und Einzelzellen mittels MALDI-Imaging 74 5. Zusammenfassung 80 Literaturverzeichnis 83 Publikationen 90 Erklärung über die eigenständige Abfassung der Arbeit 97 Lebenslauf 98 Danksagungen 99

Background: Diminished cytokine production in infancy has been associated with an increased risk for allergen sensitization and early-life wheeze. Objective: We sought to assess the effect of low cytokine production in the first year of life on the development of wheeze through age 13 years. Methods: Cytokine production (IFN-γ and IL-2) by mitogen-stimulated mononuclear cells was determined from peripheral blood samples (9.4 months, n = 118) in a subset of healthy infants enrolled in the Tucson Children's Respiratory Study. The occurrence of wheeze during the previous year was ascertained at ages 2, 3, 6, 8, 11, and 13 years by means of questionnaire. Relative risk for wheeze was computed with generalized estimating equations. Results: The risk of wheezing between 2 and 13 years was significantly higher for subjects with low 9-month IFN-γ production (relative risk, 2.29; 95% CI, 1.35-3.89) and borderline significant for those with intermediate IFN-γ production (relative risk, 1.59; 95% CI, 0.95-2.68) compared with those who produced high levels of IFN-γ (P value for linear association = .002). Nine-month IL-2 production was unrelated to wheeze. In relation to complex wheezing phenotypes, 9-month IFN-γ production was inversely related to toddler wheeze (occurring only before age 6 years, P = .03) and chronic wheeze (occurring before and after age 6 years, P = .007) but not school-age wheeze (occurring only after age 6 years, P = .06). Conclusion: The results suggest that characteristics of the immune system present during the first year of life can anticipate the likelihood of development of episodes of airway obstruction characterized by wheezing. Clinical implications: Immune susceptibility to asthma is established very early during postnatal life.

A ulceração aftosa recorrente (UAR) é considerada a doença ulcerativa mais frequente da cavidade bucal. Sua etiopatogenia ainda não está plenamente esclarecida, embora inúmeros fatores locais e sistêmicos já tenham sido a ela associados. Recentemente, a resposta imune anormal do tipo celular tem sido considerada a responsável pela lesão bucal na UAR, favorecendo uma resposta imunológica pró-inflamatória do tipo Th1, em conjunto com alterações em linfócitos T regulatórios. Sendo assim, o objetivo do presente estudo foi realizar análise da expressão gênica da FOXP3, MIP-3? e Interleucinas 2, 10 e 35 em pacientes com ulceração aftosa recorrente, por meio de estudo caso-controle. Os pacientes do grupo caso apresentavam quadros frequentes de UAR com pelo menos um ano de manifestação de surtos ulcerativos e história negativa de condições sistêmicas ou locais interferentes com a expressão das UAR. Estes foram submetidos a biópsia de lesão ulcerativa recente para a análise molecular. Os pacientes do grupo controle apresentavam história negativa de UAR, mucosa clinicamente saudável, e doaram voluntariamente fragmento de mucosa saudável para análise molecular, quando submetidos a procedimentos cirúrgicos como exodontia de terceiros molares ou biópsias ósseas. Todos os pacientes foram incluídos no grupo de pesquisa apenas após anuência com termo de consentimento livre e esclarecido. Submeteram-se a exame clínico, realizaram exames complementares para controle da saúde geral e suporte diagnóstico. Onze pacientes UAR e três controles voluntários compuseram a casuística estudada, sendo submetidos a biópsia de lesões de UAR ou de mucosa de revestimento sadia. As amostras de tecido bucal foram submetidas aos procedimentos laboratoriais de extração do RNA e análise da expressão gênica da FOXP3, MIP-3? e Interleucinas 2, 10 e 35 por meio da técnica de RT-PCR em tempo real. Não houve diferença significativa na expressão dos genes estudados entre as amostras de portadores de UAR e controles sadios. Concluímos que os genes aqui avaliados não parecem desempenhar papel distintivo na fase ulcerativa inicial das UAR, entretanto estudos adicionais são recomendados a fim de se verificar a real participação desses agentes da inflamação na expressão da doença. / Recurrent aphthous ulcers (RAU) is the most common ulcerative disease of the oral cavity. Its pathogenesis is poorly understood yet, although numerous local and systemic factors have been associated with it. Recently, abnormal immune response of cellular type has been considered responsible for the RAU oral lesions, promoting a pro-inflammatory immune response Th1-type, in conjunction with changes in regulatory T cells. Thus, the aim of this study was to analyze the gene expression of FOXP3, MIP-3? and interleukins 2, 10 and 35 in patients with recurrent aphthous ulceration through a case-control study. The case group of patients presented frequent RAU bouts with at least one year of manifestation of ulcerative outbreaks and negative history of local or systemic conditions interfering with the RAU expression. These patients were submitted to a biopsy procedure of a recent ulcerative lesion for molecular analysis. Patients in the control group presented no history of RAU, and agreed with a donation of a healthy mucosa fragment for molecular analysis when undergoing surgical procedures such as extraction of third molars or bone biopsies. All patients were included in the research group only after agreement with an informed consent. All subjects underwent clinical examination and were submitted to additional lab tests to check overall health and support diagnosis. Eleven RAU patients and three control volunteers composed the sample size and undergone biopsy of RAU lesions or healthy mucosal lining. The oral tissue samples were submitted to the laboratory procedures of RNA extraction and analysis of gene expression of FOXP3, MIP-3? and interleukins 2, 10, 35 by real time RT-PCR. There was no significant difference in gene expression between the studied samples of patients with RAU and healthy controls. It was concluded that the genes evaluated do not seem to play distinctive role in the initial ulcerative phase of RAU, however further studies are recommended in order to verify the actual participation of these inflammation agents in RAU expression.

Durante a ativação policlonal induzida pelo P. chabaudi a maior fonte de IL-2 são as células CD4+ ativadas, além disso, acorre a expansão de células Treg. No dia 7 após a infecção, a ausência de células Treg leva a uma exacerbação da ativação de células CD4+, além de altos níveis de anticorpos anti-P.chabaudi e auto-anticorpos. A neutralização da IL-2, com Mab anti-IL-2 JES6-1, na fase aguda da infecção leva a uma redução no número de células Treg. No dia 20 de infecção, a freqüência de células CD4+ ativadas esteve elevada e as células Treg voltaram aos níveis basais. Experimentos in vitro mostraram que a neutralização da IL-2 não altera a proliferação antígeno-específica de células CD4+ da fase aguda da infecção, porém, em tempos tardios da infecção houve um drástico aumento na freqüência de células CD4+ que proliferam em resposta a eritrócitos parasitados. Podemos concluir que a IL-2 e as células Treg são capazes de limitar a ativação policlonal induzida pelo P. chabaudi ainda que com cinéticas distintas. / Polyclonal activation during P. chabaudi infection results on a huge IL-2 production by activated CD4+ T cells, besides a considerable expansion of Treg cells. At day 7 after infection in the absence of Treg cells there is an enhanced response of activated CD4+ T cells, an increase of Abs anti-P.chabaudi and autoantibody production. Neutralization of IL-2 with Mab anti-IL2 JES6-1 during acute infection reveals a markedly reduction in Treg-cells number. At day 20 of infection we can observe an increase on activated CD4+ T cells frequency. Moreover, Treg cells return to values similar to controls. IL-2 in vitro assays during acute infection results on Ag-specific CD4+ T cells proliferation, on the other hand, at the late infection, we observed a huge increase of CD4+ T cells frequency that strongly response to PRBC. Our findings suggest that IL-2 and Treg cells are capable of restricting PLA during P.chabaudi infection, although with different kinetics.

A ulceração aftosa recorrente (UAR) é considerada a doença ulcerativa mais frequente da cavidade bucal. Sua etiopatogenia ainda não está plenamente esclarecida, embora inúmeros fatores locais e sistêmicos já tenham sido a ela associados. Recentemente, a resposta imune anormal do tipo celular tem sido considerada a responsável pela lesão bucal na UAR, favorecendo uma resposta imunológica pró-inflamatória do tipo Th1, em conjunto com alterações em linfócitos T regulatórios. Sendo assim, o objetivo do presente estudo foi realizar análise da expressão gênica da FOXP3, MIP-3? e Interleucinas 2, 10 e 35 em pacientes com ulceração aftosa recorrente, por meio de estudo caso-controle. Os pacientes do grupo caso apresentavam quadros frequentes de UAR com pelo menos um ano de manifestação de surtos ulcerativos e história negativa de condições sistêmicas ou locais interferentes com a expressão das UAR. Estes foram submetidos a biópsia de lesão ulcerativa recente para a análise molecular. Os pacientes do grupo controle apresentavam história negativa de UAR, mucosa clinicamente saudável, e doaram voluntariamente fragmento de mucosa saudável para análise molecular, quando submetidos a procedimentos cirúrgicos como exodontia de terceiros molares ou biópsias ósseas. Todos os pacientes foram incluídos no grupo de pesquisa apenas após anuência com termo de consentimento livre e esclarecido. Submeteram-se a exame clínico, realizaram exames complementares para controle da saúde geral e suporte diagnóstico. Onze pacientes UAR e três controles voluntários compuseram a casuística estudada, sendo submetidos a biópsia de lesões de UAR ou de mucosa de revestimento sadia. As amostras de tecido bucal foram submetidas aos procedimentos laboratoriais de extração do RNA e análise da expressão gênica da FOXP3, MIP-3? e Interleucinas 2, 10 e 35 por meio da técnica de RT-PCR em tempo real. Não houve diferença significativa na expressão dos genes estudados entre as amostras de portadores de UAR e controles sadios. Concluímos que os genes aqui avaliados não parecem desempenhar papel distintivo na fase ulcerativa inicial das UAR, entretanto estudos adicionais são recomendados a fim de se verificar a real participação desses agentes da inflamação na expressão da doença. / Recurrent aphthous ulcers (RAU) is the most common ulcerative disease of the oral cavity. Its pathogenesis is poorly understood yet, although numerous local and systemic factors have been associated with it. Recently, abnormal immune response of cellular type has been considered responsible for the RAU oral lesions, promoting a pro-inflammatory immune response Th1-type, in conjunction with changes in regulatory T cells. Thus, the aim of this study was to analyze the gene expression of FOXP3, MIP-3? and interleukins 2, 10 and 35 in patients with recurrent aphthous ulceration through a case-control study. The case group of patients presented frequent RAU bouts with at least one year of manifestation of ulcerative outbreaks and negative history of local or systemic conditions interfering with the RAU expression. These patients were submitted to a biopsy procedure of a recent ulcerative lesion for molecular analysis. Patients in the control group presented no history of RAU, and agreed with a donation of a healthy mucosa fragment for molecular analysis when undergoing surgical procedures such as extraction of third molars or bone biopsies. All patients were included in the research group only after agreement with an informed consent. All subjects underwent clinical examination and were submitted to additional lab tests to check overall health and support diagnosis. Eleven RAU patients and three control volunteers composed the sample size and undergone biopsy of RAU lesions or healthy mucosal lining. The oral tissue samples were submitted to the laboratory procedures of RNA extraction and analysis of gene expression of FOXP3, MIP-3? and interleukins 2, 10, 35 by real time RT-PCR. There was no significant difference in gene expression between the studied samples of patients with RAU and healthy controls. It was concluded that the genes evaluated do not seem to play distinctive role in the initial ulcerative phase of RAU, however further studies are recommended in order to verify the actual participation of these inflammation agents in RAU expression.

Durante a ativação policlonal induzida pelo P. chabaudi a maior fonte de IL-2 são as células CD4+ ativadas, além disso, acorre a expansão de células Treg. No dia 7 após a infecção, a ausência de células Treg leva a uma exacerbação da ativação de células CD4+, além de altos níveis de anticorpos anti-P.chabaudi e auto-anticorpos. A neutralização da IL-2, com Mab anti-IL-2 JES6-1, na fase aguda da infecção leva a uma redução no número de células Treg. No dia 20 de infecção, a freqüência de células CD4+ ativadas esteve elevada e as células Treg voltaram aos níveis basais. Experimentos in vitro mostraram que a neutralização da IL-2 não altera a proliferação antígeno-específica de células CD4+ da fase aguda da infecção, porém, em tempos tardios da infecção houve um drástico aumento na freqüência de células CD4+ que proliferam em resposta a eritrócitos parasitados. Podemos concluir que a IL-2 e as células Treg são capazes de limitar a ativação policlonal induzida pelo P. chabaudi ainda que com cinéticas distintas. / Polyclonal activation during P. chabaudi infection results on a huge IL-2 production by activated CD4+ T cells, besides a considerable expansion of Treg cells. At day 7 after infection in the absence of Treg cells there is an enhanced response of activated CD4+ T cells, an increase of Abs anti-P.chabaudi and autoantibody production. Neutralization of IL-2 with Mab anti-IL2 JES6-1 during acute infection reveals a markedly reduction in Treg-cells number. At day 20 of infection we can observe an increase on activated CD4+ T cells frequency. Moreover, Treg cells return to values similar to controls. IL-2 in vitro assays during acute infection results on Ag-specific CD4+ T cells proliferation, on the other hand, at the late infection, we observed a huge increase of CD4+ T cells frequency that strongly response to PRBC. Our findings suggest that IL-2 and Treg cells are capable of restricting PLA during P.chabaudi infection, although with different kinetics.

This thesis describes generation and characterization of Affibody molecules with future applications in proteomics research, protein structure determinations, therapeutic treatment of disease and medical imaging for in vivo diagnostics. Affibody molecules are engineered affinity proteins developed by combinatorial protein engineering from the 58-residue protein A-derived Z domain scaffold. Novel Affibody molecules targeting human proteins were selected from a combinatorial library using phage display technology. In the first two investigations, an Affibody molecule specifically targeting the high abundant human serum protein transferrin was generated. The intended future use of this Affibody ligand would be as capture ligand for depletion of transferrin from human samples in proteomics analysis. Strong and highly specific transferrin binding of the selected Affibody molecule was demonstrated by biosensor technology, dot blot analysis and affinity chromatography. Efficient Affibody-mediated depletion of transferrin in human plasma and cerebrospinal fluid (CSF) was demonstrated in combination with IgG and HSA removal. Furthermore, depletion of five high abundant proteins including transferrin from human CSF gave enhanced identification of proteins in a shotgun proteomics analysis. Two studies involved the selection and characterization of Affibody molecules recognizing Alzheimer’s amyloid beta (Abeta) peptides. Future prospect for the affinity ligands would primarily be for therapeutic applications in treatment of Alzheimer’s disease. The developed A-binding Affibody molecules were found to specifically bind to non-aggregated forms of Abeta and to be capable of efficiently and selectively capture Abeta peptides from spiked human serum. Interestingly, the Abeta-binding Affibody ligands were found to bind much better to Abeta as dimeric constructs, and with impressive affinity as cysteine-bridged dimers (KD~17 nM). NMR spectroscopy studies revealed that the original helix one, of the two Affibody molecules moieties of the cysteine-bridged dimers, was unfolded upon binding, forming intermolecular β-sheets that stabilized the Abeta peptide, enabling a high resolution structure of the peptide. Furthermore, the Abeta-binding Affibody molecules were found to inhibit Abeta fibrillation in vitro. In the last study, Affibody molecules directed to the interleukin 2 (IL-2) receptor alpha (CD25) were generated. CD25-binding Affibody molecules could potentially have a future use in medical imaging of inflammation, and possibly in therapeutic treatment of disease conditions with CD25 overexpression. The selected Affibody molecules were demonstrated to bind specifically to human CD25 with an apparent affinity of 130-240 nM. Moreover, the CD25-targeting Affibody molecules were found to have overlapping binding sites with the natural ligand IL-2 and an IL-2 blocking monoclonal antibody. Furthermore, the Affibody molecules demonstrated selective binding to CD25 expressing cells. / QC 20100729

Tyrimo tikslas buvo įvertinti sensitizaciją ŽLA antigenais, inksto transplantatų recipientams, kurie greta standartinės imunosupresijos vartojo monokloninius antikūnus prieš IL-2 receptorių ir monokloninių antikūnų nevartojusiems recipientams. Tyrime dalyvauja VULSK pacientai, kuriems 2000-2005 metais imtinai buvo atliktos inkstų transplantacijos (Tx), bei kurie prieš ir po Tx buvo tirti dėl teigiamai su limfocitų panele reaguojančių antikūnų skaičiaus, išreikšto procentais (PRA). Iš viso tyrime dalyvauja 189 recipientai. Dalis jų (n=83) greta standartinės imunosupresijos vartojo monokloninius antikūnus prieš IL-2 receptorių (basiliksimabą ar daklizumabą), kiti (n=106) gavo tik standartinę imunosupresiją. Pagrindiniai sensitizaciją ŽLA antigenais lemiantys veiksniai abiejose grupėse pasiskirstė nevienodai. Didesnė monokloninius antikūnus vartojusių dalis gavo kraujo perpylimus (72% vs. 57,3%), šioje grupėje taip pat daugiau buvo pakartotinų Tx (9,6% vs. 7,5%), tik gimdžiusių moterų skaičius didesnis buvo monokloninių antikūnų nevartojusioje grupėje (47,7% vs. 30,8%). Tirtos ligonių grupės palygintos taikant &#967;² kriterijų, skirtumas laikytas statistiškai reikšmingas, kai p<0,05. Išanalizavus recipientų sensitizaciją prieš Tx paaiškėjo, kad dauguma (58%; 110/189) buvo nesensitizuoti (PRA 0-10%), likę 42% (79/189) - sensitizuoti, iš kurių 14% (11/189) – labai sensitizuoti (PRA 50-100%). Po Tx monokloninius antikūnus vartojusių recipientų grupėje (n=83) 2% padaugėjo... [toliau žr. visą tekstą] / The aim of this study was to evaluate the sensitization with HLA antigens in kidney transplant recipients, who received induction therapy with monoclonal antibodies against IL-2R and in the group of patients, who were only under the triple drug therapy. This study comprises recipients, who received kidney transplant in the year 2000-2005, and who were tested for panel reactive antibody test before and after transplantation (Tx). The total number of 189 kidney transplant recipients takes part in this study. 83 received monoclonal antibodies against IL-2R (basiliximab or daclizumab), others (n=106) – did not. These groups were unequal in comparison to the main factors causing sensitization with HLA antigens. The group of patients, who received induction therapy with monoclonal antibodies had more blood transfuzions (72% vs. 57,3%), and previous transplantations (9,6% vs. 7,5%), in comparison with the other group. Only the number of pregnancies was higher in the group of patients who were only under the triple drug therapy (47,7% vs. 30,8%). Statistical analyses were caried out using chi-square test, differences were considered significant at p<0,05. 58% (110/189) of kidney transplant recipients were unsensitized (PRA 0-10%) before Tx, the rest 42% (79/189) were sensitized, from which 14% (11/189) were highly sensitized (PRA 50-100%). After Tx the number of medium sensitized (PRA 11-50%) kidney transplant recipients, who received induction therapy by monoclonal antibodies... [to full text]

L’endométriose est une pathologie chronique, bénigne, caractérisée par la présence de tissu endométrial (glande et stroma) en dehors de l’utérus. La forte prévalence de cette maladie, sa symptomatologie invalidante et son coût annuel considérable en font un véritable enjeu de santé publique. Le traitement de l’endométriose comprend un volet chirurgical, potentiellement délabrant, et un volet médical, basé sur des produits anti-gonadotropes en première intention. L’endométriose est d’origine multifactorielle. Sa physiopathologie demeure mal connue. Alors que le reflux menstruel via les trompes semble être le primum movens, plusieurs étapes sont nécessaires à la formation des lésions d’endométriose : l’adhésion et l’implantation des cellules endométriales au mésothélium péritonéal, la prolifération cellulaire soutenue par un phénomène d’angiogenèse et enfin, la réaction inflammatoire. Ces étapes sont dépendantes de facteurs génétiques, immunologiques et environnementaux. L’inflammation joue un rôle clef dans la pathogénie de l’endométriose. Nous avons montré dans un premier temps, à l’aide d’une double approche de PCR quantitative et d’immunohistochimie, la surexpression du récepteur de la LH (LHCGR) dans les tissus endometriosiques ectopiques. A l’aide d’un modèle in vitro, nous avons démontré que la stimulation du LHCGR par l’hCG activait les MAPK (avec une augmentation du rapport pERK/ERK), exerçait une effet prolifératif et enfin, induisait la surexpression de nombreux gènes cibles : CYP19A1, NR5A1, INSL3, VEGFA et PTGS2. Ensuite, nous avons étudié les principaux acteurs de la voie des prostaglandines. Nous avons montré une nette perturbation de cette voie en faveur d’une augmentation de l’inflammation avec une surexpression de la PTGS2 ainsi que des récepteurs des prostaglandines PTGER2, 3 et 4 dans l’endomètre des patientes endométriosiques. Nous avons ensuite étudié la voie des sphingosines en analysant l’expression de ses acteurs clef (SPHK1-2, SGPP1-2, SGPL1, SPHAKAP, S1PR1-5). Nous avons mis en évidence pour la première fois l’existence d’une profonde dérégulation de l’expression des enzymes et des récepteurs de cette voie en faveur d’une diminution du catabolisme du Sphingosine-1phosphate. Cette perturbation est à l’origine de la réaction inflammatoire qui participe à l’entretien de la prolifération et de la croissance des cellules endométriosiques. Dans un deuxième temps, nous avons exploré le retentissement systémique de l’endométriose à l’aide du modèle d’une interleukine pro-inflammatoire et fibrosante, l’IL-33, et de deux interleukines anti-inflammatoires l’IL-19 et l’IL-22. L’IL-33 est significativement plus élevée dans le sérum des patientes endométriosiques en particulier en cas d’endométriose profonde. Nous avons également mis en évidence l’existence d’une corrélation significative avec le nombre et la sévérité des lésions profondes. En opposition, les interleukines anti-inflammatoires IL-19 et IL-22 sont significativement diminuées dans le sérum des patientes endométriosiques. En conclusion, nous avons montré l’existence d’une perturbation des voies inflammatoires : la voie de la PTGS2 et de celle des sphingosines ainsi que le rôle pro-inflammatoire du LCGHR. Nous avons également mis en évidence le déséquilibre de la balance des cytokines systémiques inflammatoires et anti-inflammatoires dans l’endométriose. Ainsi, ces médiateurs de l’inflammation pourraient être considérés comme de potentiels marqueurs évolutifs de l’endométriose. Leur utilisation pourrait permettre d’effectuer un diagnostic plus précoce, et d’envisager de nouvelles thérapeutiques ciblées. / Pas de résumé en anglais