La transformation génétique naturelle est un mode de transfert horizontal de gènes chez les bactéries, qui contribue au maintien et à l'évolution de leurs génomes. C’est un mécanisme clé pour l’adaptation des bactéries, qui pourrait être responsable de la transmission des résistances aux antibiotiques observée en clinique chez certaines espèces pathogènes (S. pneumoniae, H. pylori,…). La transformation naturelle s’effectue par l’internalisation d’ADN exogène à travers la membrane, puis par sa prise en charge jusqu’à son intégration dans le chromosome bactérien par recombinaison homologue. Le processus de prise en charge fait intervenir la protéine DprA, très conservée dans le monde bactérien, impliquée dans la protection de l’ADN entrant contre les nucléases, et dans le recrutement de la recombinase universelle RecA sur l’ADNsb. DprA joue donc un rôle majeur et a récemment été décrite comme étant impliquée dans d’autres aspects de la transformation génétique naturelle, comme la fermeture de la compétence via une interaction directe avec le régulateur de réponse ComE, ou la levée de la barrière du système de restriction-modification afin de faciliter la transformation. Chez H. pylori, DprA est en opéron avec DprB, suggérant l’implication de ces 2 protéines dans une même voie et une interaction directe entre elles. DprA apparaît donc comme étant au cœur d’un véritable réseau d’interaction, protéique et nucléique. / The natural genetic transformation is a mode of horizontal gene transfer that contributes to the maintenance and to the evolution of the genomes in bacteria. It is a key mechanism for their adaptation which could be responsible for the transmission of antibiotic resistances observed clinically for some pathogenic species (S. pneumoniae, H. pylori...). Natural transformation is performed by internalizing exogenous DNA followed by its processing and its integration into the bacterial chromosome by homologous recombination. The DNA processing involves the highly conserved DprA protein for the protection of the incoming DNA against nucleases and the recruitment of the universal recombinase RecA on ssDNA. DprA plays a key role and has recently been suggested to be involved in other aspects of the natural genetic transformation, such as the shut-off of the competence via a direct interaction with the response regulator ComE, or removal of the restriction-modification barrier system in order to facilitate the processing. In H. pylori, the dprA gene is in operon with dprB, whose function is unknown, suggesting their involvement in the same pathway and their likely direct interaction. DprA appears to be central in protein/nucleic acid interactions network.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O carcinoma gÃstrico à a segunda causa de morte por cÃncer no mundo. No Cearà à o segundo mais freqÃente entre os homens e o terceiro entre as mulheres. Dos cÃnceres gÃstricos os adenocarcinomas representam em torno de 95%. A doenÃa tem sido associada a fatores genÃticos e ambientais sendo demonstrada Ãntima relaÃÃo com a infecÃÃo por Helicobacter pylori, principalmente associada à presenÃa do gene cagA e genÃtipos vacAs1m1. Entretanto, apesar dos mecanismos pelos quais a bactÃria promove a carcinogÃnese gÃstrica ainda nÃo estarem esclarecidos, uma das hipÃteses seria atravÃs da inativaÃÃo de supressores tumorais. O objetivo do presente trabalho foi verificar, em adenocarcinomas gÃstricos, se a presenÃa de H. pylori, e de seus genes cagA e vacA, està relacionada com a mutaÃÃo e/ou alteraÃÃo na expressÃo protÃica dos supressores tumorais p53 e p27. Neste estudo, 74 amostras de pacientes foram analisadas quanto à presenÃa de H. pylori, cagA+ e os genÃtipos de vacA, pela reaÃÃo em cadeia da polimerase (PCR). A anÃlise mutacional do gene p53 foi realizada por PCR-SSCP e a detecÃÃo da mutaÃÃo/superexpressÃo do p53 e expressÃo da proteÃna p27 pelo mÃtodo imunohistoquÃmico. A bactÃria foi detectada em 95% das amostras, das quais 63% eram cagA(+). Dentre os alelos de vacA, observou-se predomÃnio de s1 (74%) e m1 (82%), associados em 69% dos casos. Na anÃlise mutacional do p53 verificou-se que 72% dos casos exibiram alteraÃÃo no padrÃo de mobilidade eletroforÃtica, sendo esta associada significativamente à presenÃa do gene cagA. Por outro lado, apenas 29% dos casos apresentaram detecÃÃo pelo mÃtodo imunohistoquÃmico, nÃo sendo encontrada associaÃÃo com a H. pylori. A proteÃna p27 demonstrou acentuada reduÃÃo em sua expressÃo (detectada em apenas 19% dos casos), nÃo demonstrando atividade compensatÃria em relaÃÃo à proteÃna p53 mutada e sem associaÃÃo estatÃstica dos casos negativos com a presenÃa da H. pylori. Finalmente, os resultados sugerem que estes supressores simultaneamente inativados podem ser o ponto chave da desregulaÃÃo do ciclo celular que, associados a outros fatores, favoreÃam o desenvolvimento e progressÃo dos adenocarcinomas gÃstricos. Hà indÃcios de que a presenÃa bacteriana, e dos seus genes cagA(+) e vacA/s1m1, possam influenciar, de forma nÃo esclarecida, as alteraÃÃes moleculares ocorridas nos supressores tumorais p53 e p27. / Gastric carcinoma is the second cause of death by cancer in the world. On State of Ceara-Brazil is the second most frequent type of cancer in men and third in women. Adenocarcinomas account for approximately 95% of all malignant gastric neoplasms. It has been associated to genetic and environmental factors and a intimate relationship between the infection by the bacteria Helicobacter pylori and the gastric carcinoma have been related. The presence of the cagA gene and specific genotypes (s1m1) of the gene vacA have been detected in more pathogenic strains. Although the precise molecular mechanisms by which H. pylori could promote the process of gastric carcinogenesis are under investigation, one hypothesized mechanism involves the tumor supressor genes inactivation. The aim of the present study was to verify if the presence of Helicobacter pylori, cagA and vacA genes is related to mutations in the tumor supressor gene p53 and altered expression of p53 and p27 proteins in gastric adenocarcinomas. Seventy-four (74) samples were analyzed to detect the presence of H. pylori, cagA and genotypes of vacA by Polymerization Chain Reaction (PCR). The mutational analysis of p53 gene was performed by PCR-SSCP (Polymerization Chain Reaction for analysis of the Single-strand Conformation Polymorphism). Analysis of mutation or overexpression of p53 protein and p27 expression was detected by the immunohistochemical method. The bacteria was detected in 95% of the samples, 63% was cagA(+). Among the vacA allele it was observed prevalence of s1 (74%) and m1 (82%), associated in 69% of the cases. Mutation analysis of p53 demonstrated 72% of the cases with altered electrophoretic mobility; The alterations were significatively more frequent in the presence of the cagA gene. Immunohistochemical analysis detected only 29% of cases with the expression of p53 protein. The protein p27 showed accentuated reduction in its expression (detected in only 19% of the cases), it has not demonstrated compensatory activity in relation to the p53 altered protein, neither association to H. pylori presence. Finally, these data suggest that simultaneous inactivation of these tumor suppressors genes may be the key point of deregulation of the cellular cycle that, associated to the other factors, favor the development and progression of the gastric cancer. There is some evidence that the bacterial presence, cagA and vacA/s1m1 genes, may influence, in a not understood way, the alterations observed in the tumor suppressors p53 and p27.

Atualmente, muitas são as diretrizes na literatura quanto à influência do Helicobacter pylori na Doença do Refluxo Gastroesofágico. Alguns autores acreditam que o H. pylori poderia ter um efeito protetor para o desenvolvimento na DRGE e outros até mesmo concluem que o agente possa ser um fator agravante na doença. Muitas publicações nos alertam para o desenvolvimento de sintomas da DRGE, ou mesmo da esofagite, em uma porcentagem razoável de pacientes erradicados pelo esquema tríplice para tratar o H. pylori, sendo que aproximadamente 10% teriam DRGE. Na verdade, por essas dúvidas, ainda não foi estabelecido um consenso quanto à importância do H. pylori na etiopatogenia da DRGE e suas complicações. Fato também discutido, seria a importância das cepas para a formação da esofagite em pacientes submetidos à erradicação. Talvez as mais virulentas, assim como a presença da “ilha de patogenicidade"(cagA) ou algumas cepas vacuolizantes (vacA), teriam uma maior relação com a prevenção da esofagite. Outro mecanismo importante, apontado por muitos, para a formação da esofagite em pacientes erradicados seria a elevação do índice de Massa Corpórea nesse grupo de pacientes erradicados associados ou não à presença da hérnia hiatal e justificados pela melhor qualidade de vida após melhora dos sintomas depois da erradicação. Em nosso estudo, 148 pacientes com úlcera péptica ativa ou cicatrizada receberam esquema tríplice de erradicação para o Helicobacter pylori e foram submetidos a exame endoscópico e ao teste histopatológico das amostras colhidas por biópsias de corpo e antro, teste respiratório com Carbono 14 e urease, antes e após o tratamento. Realizamos a genotipagem do agente, através do PCR, separando amostras de corpo e de antro, para determinar as cepas do agente. Os pacientes foram seguidos ambulatorialmente por um ano e avaliados quanto à melhora ou piora dos sintomas relacionados a DRGE (pirose) e sintomas considerados inespecíficos como a dor epigástrica; também procuramos quantificar o ganho ou perda do IMC. Encontramos 28 pacientes (18,9%) com esofagite erosiva (24 grau A e 4 grau B de Los Angeles) endoscópica após o tratamento do agente. Deste grupo, somente 3 pacientes que não tinham sintomas desenvolveram pirose (2%). A grande maioria dos pacientes se beneficiou com o tratamento, mostrando que 69 46,6%) melhoraram da pirose e outra grande maioria melhorou dos sintomas inespecíficos. Em 18 pacientes ulcerosos com esofagite, a análise de fragmentos de corpo foi cagA positiva (64,3%) e em amostras de antro 21 eram cagA positivos (75%). Assim como no grupo geral, as cepas vacuolizantes s1b/m1 e s1b foram, respectivamente, as mais encontradas no grupo da esofagite endoscópica. Houve ligeiro aumento nos Índices de Massa Corpórea em pacientes com e sem esofagite, sendo estatisticamente mais significativo nos 120 pacientes sem esofagite. Apesar do aparecimento da esofagite erosiva endoscópica em número razoável de pacientes, a sintomatologia não foi fator determinante, pois muitos melhoraram dos sintomas após o tratamento, e a erradicação não foi importante para determinar o grau de esofagite erosiva. Não foi encontrada nenhuma relação entre a genotipagem do agente e o desenvolvimento de esofagite endoscópica. O aumento de IMC, também não justifica, em nosso estudo a esofagite em pacientes ulcerosos tratados contra o H. pylori. / Nowadays, there are many directrixes in literature as to the influence of Helicobacter pylori, in the Disease of Gastroesophagic reflux. Some authors believe that H. pylori could have a protective effect to the development of GERD, and others even conclude that the agent may be an aggravating factor in the disease. Many publications allert us to the development of symptoms of GERD, or even the esophagitis,in a reasonable percentage of erradicated patients by the triplicit scheme to treat H. pylori, and 10%, approximately, would have GERD. In fact, due to these doubts, a consensus has not been established yet to the importance of H. pylori in the GERD’s etiopathogenic and its complications. The strains importance to the formation of esophagitis in patients submitted to erradication is another fact that has also been discussed. Maybe the most virulent ones, as the presence of “pathogenical island"(cagA) or some other vacuolating cytotoxin (vacA), would have a larger relation in the esophagitis prevention. Another important mechanism, pointed by many, to the formation of esophagitis in erradicated patients would be the elevation of Body Mass Index in this group of eradicated patients associated or not to the presence of hiatal hernia and justified by a better quality of life due to symptoms’ improvement after erradication. In our studies, 148 patients with active or healed peptic ulcer received triplicit scheme of erradication to the Helicobacter pylori and were submitted to endoscopic exams and histopathologic test of gathered samples by body and antro biopsies, respiratory test with carbon 14 and ureasis, before and after treatment. We have done the agent genotyping, through the PCR, separating samples of body and antro, to determine the agent Cepas. The patients have been followed ambulatorially for a year and evaluated as to the improvement or worsening of the symptoms related to GERD (pyrosis) and symptoms considered non-specific as epigastric pain; we have also tried to quantify the gain or loss of Body Mass Index. We found 28 patients(18.9%) with endoscopic erosive esophagitis (24 degree A and 4 degree B of Los Angeles) after agent’s treatment. In this group, only three patients who had no symptoms developed pyrosis (2%). Most of the patients benefitted from treatment showing that 69 (46.6%) presented improvement in pyrosis and another great majority improved non-specific symptoms. In 18 ulcered patients with esophagitis, the body analysis fragments was positive cagA (64.3%)and in antro samples of 21 were positive cagA (75%). As in the general group, the vacuolizing cepas slb/ml and slb were, respectivelly, the most found in the endoscopic esophagitis group. There was a slight raise in the BMI in patients with and without esophagitis, and it is, statistically more meaningful in the 120 patients without esophagitis. Even though there was the appearance of endoscopic erosive esophagitis in a reasonable number of patients, the symptmology was not a determining factor, because many have got better after the treatment, and erradication was not important to determine the erosive esophagitis. It was not found any relation between the agent genotyping and the development of endoscopic esophagitis. The raise of BMI does not justify in our study the esophagitis in ulcered patients treated against H. pylori.

Die kontinuierliche Rezirkulation von Immunzellen durch periphere und sekundäre lymphatische Organe (SLOs) ist Bestandteil der Immunüberwachung und wichtig für die Aufrechterhaltung und Funktionsbereitschaft des Immunsystems. Der homöostatische Chemokinrezeptor CCR7 vermittelt dabei nicht nur die Rezirkulation von Lymphozyten durch SLOs, sondern scheint auch an der homöostatischen Rezirkulation von Lymphozyten durch nicht-lymphoide periphere Gewebe beteiligt zu sein. Im Rahmen dieser Arbeit wurde mithilfe von CCR7-defizienten Mäusen die funktionale Bedeutung von CCR7 für die homöostatische Rezirkulation von Lymphozyten durch das Peritoneum untersucht und nachgewiesen, dass CCR7 der dominante Chemokinrezeptor ist, der unter physiologischen Bedingungen die Transitzeit von Lymphozyten durch das Peritoneum festlegt. Die gestörte Rezirkulation von Lymphozyten begünstigte außerdem die Entstehung von tertiären lymphoiden Organen (TLOs) in der Magenschleimhaut von CCR7-defizienten Mäusen. Untersuchungen zur zellulären und molekularen Grundlage dieser und weiterer pathomorphologischer Veränderungen in der Magenschleimhaut von CCR7-defizienten Mäusen verdeutlichten die Funktion von CCR7 für die Etablierung von zentraler und peripherer Toleranz gegenüber gastrischen Antigenen. Fehlt CCR7, dann entwickelten Mäuse eine spontane Autoimmungastritis, welche durch gastritogene CD4+ T-Zellen verursacht wurde, deren Aktivierung auch unabhängig von Lymphknoten und TLOs erfolgte. Die Entstehung von TLOs wird auch bei einer durch Helicobacter pylori ausgelösten chronischen Gastritis beobachtet. Die Expression des homöostatischen Chemokinrezeptors CXCR5 und seines Liganden CXCL13 ist mit der Entwicklung dieser TLOs korreliert worden. Unter Verwendung eines Mausmodells für H. pylori-induzierte chronische Gastritis konnte gezeigt werden, dass CXCR5 die Ausbildung von TLOs vermittelt und eine Rolle für die Induktion von H. pylori-spezifischen T-Zell- sowie humoralen Immunantworten spielt. / Homeostatic recirculation of immune cells through peripheral and secondary lympoid organs (SLOs) is required for immune surveillance and the maintenance and functionality of the immune system. The homeostatic chemokine receptor CCR7 controls not only lymphoid cell trafficking to and within SLOs, but also seems to be involved in the homeostatic recirculation of lymphocytes through non-lymphoid peripheral tissues. Within the scope of this work we investigated the functional relevance of CCR7 for the homeostatic recirculation of lymphocytes through the peritoneal cavity and could show, that CCR7 is the dominant chemokine receptor which defines the transit time of lymphocytes in the peritoneal cavity under physiological conditions. Impaired recirculation of lymphocytes also promoted the development of tertiary lymphoid organs (TLOs) in the gastric mucosa of CCR7-deficient mice. Analysis of the cellular and molecular mechanisms underlying these and other pathomorphological alterations in the gastric mucosa of CCR7-deficient mice provided further evidence regarding the function of CCR7 for the establishment of central and peripheral tolerance towards gastric antigens. Mice that lack CCR7 spontaneously developed autoimmune gastritis, which was caused by gastritogenic CD4+ T-cells. Such autoreactive T cell responses were also initiated in the absence of lymph nodes and TLOs in CCR7/LT-alpha double-deficient mice. Development of TLOs is also observed during chronic gastritis induced by Helicobacter pylori. The expression of the homeostatic chemokine receptor CXCR5 and its ligand CXCL13 has been correlated with the development of these TLOs. Using a mouse model for H. pylori-induced chronic gastritis, we could show that CXCR5 is responsible for the development of TLOs and also plays a role for the induction of H. pylori-specific T and B cell responses.

No description available.

Made available in DSpace on 2015-02-24T17:42:52Z (GMT). No. of bitstreams: 1 ThalesRFP_DISSERT.pdf: 5363462 bytes, checksum: 16f2d3a123870a2d8c63de00ac4bf689 (MD5) Previous issue date: 2014-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Helicobacter pylori is the main cause of gastritis, gastroduodenal ulcer disease and gastric cancer. The most recommended treatment for eradication of this bacteria often leads to side effects and patient poor compliance, which induce treatment failure. Magnetic drug targeting is a very efficient method that overcomes these drawbacks through association of the drug with a magnetic compound. Such approach may allow such systems to be placed slowed down to a specific target area by an external magnetic field. This work reports a study of the synthesis and characterization of polymeric magnetic particles loaded with the currently used antimicrobial agents for the treatment of Helicobacter pylori infections, aiming the production of magnetic drug delivery system by oral route. Optical microscopy, scanning electron microscopy, transmission electron microscopy, x-ray powder diffraction, nitrogen adsorption/desorption isotherms and vibrating sample magnetometry revealed that the magnetite particles, produced by the co-precipitation method, consisted of a large number of aggregated nanometer-size crystallites (about 6 nm), creating superparamagnetic micrometer with high magnetic susceptibility particles with an average diameter of 6.8 ? 0.2 μm. Also, the polymeric magnetic particles produced by spray drying had a core-shell structure based on magnetite microparticles, amoxicillin and clarithromycin and coated with Eudragit? S100. The system presented an average diameter of 14.2 ? 0.2 μm. The amount of magnetite present in the system may be tailored by suitably controlling the suspension used to feed the spray dryer. In the present work it was 2.9% (w/w). The magnetic system produced may prove to be very promising for eradication of Helicobacter pylori infections / A Helicobacter pylori ? a principal causa de gastrites, ?lceras gastroduodenais e c?ncer g?strico. O esquema terap?utico de primeira escolha para a erradica??o desse pat?geno leva muitas vezes a elevado n?mero de rea??es adversas, baixa ades?o do paciente e consequentemente falha na terap?utica. A vetoriza??o magn?tica ? uma t?cnica bastante difundida na literatura que visa minimizar esses problemas, atrav?s da associa??o de f?rmacos a n?cleos magn?ticos direcionando para o local de a??o por interm?dio de campo magn?tico externo. O presente trabalho relata o estudo da s?ntese e caracteriza??o de part?culas polim?ricas magn?ticas contendo os mais frequentes antimicrobianos (amoxicilina e claritromicina) usados no tratamento de infec??es por Helicobacter pylori, objetivando a produ??o de um sistema para vetoriza??o magn?tica por via oral. Granulometria baseada no di?metro de Feret, microscopia eletr?nica de varredura e transmiss?o, difratometria de raio-x, isotermas de adsor??o/dessor??o de nitrog?nio e magnetometria de amostra vibrante revelaram que as part?culas de magnetita, produzidas pelo m?todo da coprecipita??o, consistem em grande n?mero de agregados de cristalitos de tamanhos nanom?tricos (da ordem de 6 nm) os quais formam part?culas microm?tricas superparamagn?ticas de alta susceptibilidade magn?tica, tendo formato irregular com di?metro m?dio de 6,8 ? 0,2 μm. Os n?cleos magn?ticos foram revestidos por pol?mero (Eudragit? S100) em conjunto com amoxicilina e claritromicina (forma polim?rfica II) sendo obtido micropart?culas n?cleo-camada de formato irregular, pela t?cnica de secagem por aspers?o (spray dryer), com um di?metro m?dio de 14,2 ? 0,2 μm. A quantidade de magnetita presente no sistema pode ser adaptada pelo controle da suspens?o inicial usada na alimenta??o do spray dryer. No presente trabalho o conte?do magn?tico final foi estimado em 2,9 % (p/p). Com base nos resultados obtidos, o sistema magn?tico produzido pode se tornar bastante promissor na erradica??o de infec??es por Helicobacter pylori

Atualmente, muitas são as diretrizes na literatura quanto à influência do Helicobacter pylori na Doença do Refluxo Gastroesofágico. Alguns autores acreditam que o H. pylori poderia ter um efeito protetor para o desenvolvimento na DRGE e outros até mesmo concluem que o agente possa ser um fator agravante na doença. Muitas publicações nos alertam para o desenvolvimento de sintomas da DRGE, ou mesmo da esofagite, em uma porcentagem razoável de pacientes erradicados pelo esquema tríplice para tratar o H. pylori, sendo que aproximadamente 10% teriam DRGE. Na verdade, por essas dúvidas, ainda não foi estabelecido um consenso quanto à importância do H. pylori na etiopatogenia da DRGE e suas complicações. Fato também discutido, seria a importância das cepas para a formação da esofagite em pacientes submetidos à erradicação. Talvez as mais virulentas, assim como a presença da “ilha de patogenicidade”(cagA) ou algumas cepas vacuolizantes (vacA), teriam uma maior relação com a prevenção da esofagite. Outro mecanismo importante, apontado por muitos, para a formação da esofagite em pacientes erradicados seria a elevação do índice de Massa Corpórea nesse grupo de pacientes erradicados associados ou não à presença da hérnia hiatal e justificados pela melhor qualidade de vida após melhora dos sintomas depois da erradicação. Em nosso estudo, 148 pacientes com úlcera péptica ativa ou cicatrizada receberam esquema tríplice de erradicação para o Helicobacter pylori e foram submetidos a exame endoscópico e ao teste histopatológico das amostras colhidas por biópsias de corpo e antro, teste respiratório com Carbono 14 e urease, antes e após o tratamento. Realizamos a genotipagem do agente, através do PCR, separando amostras de corpo e de antro, para determinar as cepas do agente. Os pacientes foram seguidos ambulatorialmente por um ano e avaliados quanto à melhora ou piora dos sintomas relacionados a DRGE (pirose) e sintomas considerados inespecíficos como a dor epigástrica; também procuramos quantificar o ganho ou perda do IMC. Encontramos 28 pacientes (18,9%) com esofagite erosiva (24 grau A e 4 grau B de Los Angeles) endoscópica após o tratamento do agente. Deste grupo, somente 3 pacientes que não tinham sintomas desenvolveram pirose (2%). A grande maioria dos pacientes se beneficiou com o tratamento, mostrando que 69 46,6%) melhoraram da pirose e outra grande maioria melhorou dos sintomas inespecíficos. Em 18 pacientes ulcerosos com esofagite, a análise de fragmentos de corpo foi cagA positiva (64,3%) e em amostras de antro 21 eram cagA positivos (75%). Assim como no grupo geral, as cepas vacuolizantes s1b/m1 e s1b foram, respectivamente, as mais encontradas no grupo da esofagite endoscópica. Houve ligeiro aumento nos Índices de Massa Corpórea em pacientes com e sem esofagite, sendo estatisticamente mais significativo nos 120 pacientes sem esofagite. Apesar do aparecimento da esofagite erosiva endoscópica em número razoável de pacientes, a sintomatologia não foi fator determinante, pois muitos melhoraram dos sintomas após o tratamento, e a erradicação não foi importante para determinar o grau de esofagite erosiva. Não foi encontrada nenhuma relação entre a genotipagem do agente e o desenvolvimento de esofagite endoscópica. O aumento de IMC, também não justifica, em nosso estudo a esofagite em pacientes ulcerosos tratados contra o H. pylori. / Nowadays, there are many directrixes in literature as to the influence of Helicobacter pylori, in the Disease of Gastroesophagic reflux. Some authors believe that H. pylori could have a protective effect to the development of GERD, and others even conclude that the agent may be an aggravating factor in the disease. Many publications allert us to the development of symptoms of GERD, or even the esophagitis,in a reasonable percentage of erradicated patients by the triplicit scheme to treat H. pylori, and 10%, approximately, would have GERD. In fact, due to these doubts, a consensus has not been established yet to the importance of H. pylori in the GERD’s etiopathogenic and its complications. The strains importance to the formation of esophagitis in patients submitted to erradication is another fact that has also been discussed. Maybe the most virulent ones, as the presence of “pathogenical island”(cagA) or some other vacuolating cytotoxin (vacA), would have a larger relation in the esophagitis prevention. Another important mechanism, pointed by many, to the formation of esophagitis in erradicated patients would be the elevation of Body Mass Index in this group of eradicated patients associated or not to the presence of hiatal hernia and justified by a better quality of life due to symptoms’ improvement after erradication. In our studies, 148 patients with active or healed peptic ulcer received triplicit scheme of erradication to the Helicobacter pylori and were submitted to endoscopic exams and histopathologic test of gathered samples by body and antro biopsies, respiratory test with carbon 14 and ureasis, before and after treatment. We have done the agent genotyping, through the PCR, separating samples of body and antro, to determine the agent Cepas. The patients have been followed ambulatorially for a year and evaluated as to the improvement or worsening of the symptoms related to GERD (pyrosis) and symptoms considered non-specific as epigastric pain; we have also tried to quantify the gain or loss of Body Mass Index. We found 28 patients(18.9%) with endoscopic erosive esophagitis (24 degree A and 4 degree B of Los Angeles) after agent’s treatment. In this group, only three patients who had no symptoms developed pyrosis (2%). Most of the patients benefitted from treatment showing that 69 (46.6%) presented improvement in pyrosis and another great majority improved non-specific symptoms. In 18 ulcered patients with esophagitis, the body analysis fragments was positive cagA (64.3%)and in antro samples of 21 were positive cagA (75%). As in the general group, the vacuolizing cepas slb/ml and slb were, respectivelly, the most found in the endoscopic esophagitis group. There was a slight raise in the BMI in patients with and without esophagitis, and it is, statistically more meaningful in the 120 patients without esophagitis. Even though there was the appearance of endoscopic erosive esophagitis in a reasonable number of patients, the symptmology was not a determining factor, because many have got better after the treatment, and erradication was not important to determine the erosive esophagitis. It was not found any relation between the agent genotyping and the development of endoscopic esophagitis. The raise of BMI does not justify in our study the esophagitis in ulcered patients treated against H. pylori.

In der humanen Magenschleimhaut regulieren eine Vielzahl von Interaktionen zwischen verschiedenen Zellpopulationen die Verdauung und die Überwachung von Infektionen. Epithelzellen in der Schleimhaut differenzieren in spezialisierte Zelltypen, die schützenden Mukus, Magensäure, Verdauungsenzyme oder Hormone produzieren. Eine Infektion mit Helicobacter pylori kann die Gewebehomöostase fehlregulieren, was die Wahrscheinlichkeit erhöht, dass an der Infektionsstelle ein Magengeschwür, ein Adenokarzinom oder letztendlich Magenkrebs auftritt. In dieser Arbeit wird die Entwicklung eines neuartigen in vitro Kulturmodells für humane primäre Magenepithelzellen, die sogenannte Mukosoidkultur, gezeigt. Die Mukosoidkulturen sind repräsentativ für Epithelbarrieren und rekapitulieren die meisten Funktionen der menschlichen Magenschleimhaut in vivo, einschließlich der Schleimproduktion, und ermöglichen eine langfristige und stabile Kultivierung von Epithelzellen sowie Infektionsstudien mit H.pylori. Mukosoidkulturen aus Corpus wurden verwendet, um die Nischenfaktoren zu untersuchen, die die Differenzierung von Oberflächenepithelzellen, Hauptzellen und Parietalzellen fördern. EGF erwies sich zusammen mit BMP/Noggin als ein wichtiger Regulator bei der Differenzierung. Stromazellen sind Teil der Lamina propria der Magenschleimhaut. Über die Wechselwirkung mit dem Epithel unter homöostatischen Bedingungen und bei bakteriellen Infektionen mit H.pylori ist nur sehr wenig bekannt. Die Co-Kultur von humanen primären Stromazellen des Magens mit Epithelzellen unter Verwendung des Mukosoidkultur-Modells zeigte die aktive Signalübertragung zwischen beiden Zelltypen auf. Darüber hinaus wurden Mukosoidkulturen erfolgreich mit H.pylori infiziert. Die Ergebnisse zeigen, dass Stromazellen aktiv mit Cytokin- und Chemokinexpression auf eine epitheliale Infektion reagieren. Gleichzeitig erhöhten Stromazellen die NFκB-gesteuerte Entzündungsreaktion in Epithelzellen. / In the human gastric mucosa, multiple interactions between different cell populations regulate digestion and surveillance of infections. Epithelial cells in the mucosa differentiate into specialized cell types to produce protective mucins, gastric acid, digestive enzymes or hormones. Infection with Helicobacter pylori dysregulates the tissue homeostasis increasing the chance to develop a gastric ulcer, adenocarcinoma or ultimately gastric cancer at the site of infection. In this thesis, the development of a novel in vitro culture model for human primary gastric epithelial cells, called the mucosoid culture, is shown. The mucosoid cultures are representative of epithelial barriers and recapitulate most of the functions of the human gastric mucosa in vivo, including mucus production, and allow long-term and stable cultivation of epithelial cells as well as infection studies with H.pylori. Corpus derived mucosoids were used to investigate the niche factors that promote the differentiation of foveolar cells, chief cells, and parietal cells. EGF was found to be a major regulator in differentiation together with BMP/Noggin. Stromal cells are part of the lamina propria of the gastric mucosa. Very little is known about the interaction with the epithelium under homeostatic conditions and during bacterial infections with Helicobacter pylori. The co-culture of human primary gastric stromal cells with epithelial cells using the mucosoid culture model demonstrated the active signaling between both cell types. Furthermore, mucosoid cultures were successfully infected with H. pylori. The results revealed that stromal cells actively respond to epithelial infection with cytokine and chemokine expression. Concurrently stromal cells increased the NFκB-driven inflammatory response in epithelial cells.

Eines der prävalentesten humanen Pathogene ist das Magenbakterium Helicobacter pylori, welches ca. die Hälfte der Weltbevölkerung infiziert. Die Persistenz geht mit einer chronischen Gastritis einher, welche bis zu Magenkrebs fortschreiten kann. H.pylori bedient sich diverser Mechanismen um sich der Erkennung des Immunsystems zu entziehen und somit eine chronische Infektion zu ermöglichen. Erhöhte Expression des Immunzellinhibitors PD-L1 wurde in Magenepithelzellen gefunden, welche mit diesem Gram-negativen Erreger infiziert wurden. In dieser Arbeit wurde die Regulation auf in vitro Ebene untersucht, wobei zwei unterschiedliche Mechanismen identifiziert wurden. Ursächlich für die frühe PD-L1-Induktion ist die ADP-heptose/ALPK1 Signalkaskade. Der bakterielle Metabolit ADP-heptose, welcher für die Bildung von LPS benötigt wird, wurde als PAMP identifiziert, welcher durch das Sekretionssystems cagT4SS in die infizierte transportiert und anschließend von der Host Kinase ALPK1 erkannt wird. Gegensätzlich hierzu, wurde festgestellt, dass die zweite PD-L1-Hochregulation auf der metabolischen Reprogrammierung des Wirts beruht. Ein Merkmal von H. pylori ist dessen Bedarf an Cholesterin, welches es aus dem Medium oder aus membranösen Lipidregionen des Wirts extrahiert wird. Es konnte bewiesen werden, dass dieser Sterol-Abbauprozess zu einer erhöhten Stoffwechselaktivität führt, die spezifisch mit einer Zunahme der Glykolyse verbunden ist und mit einer Expressionsverschiebung des ersten Glykolyseenzyms Hexokinase von der Isoform 1 zu 2 einhergeht. Knockdown und Knockout- Experimente wiesen auf einen Zusammenhang mit der Regulation des Immunzellinhibitoren PD-L1 hin. / One of the most prevalent bacteria is the gastric bacterium Helicobacter pylori, which infects half of the world’s population. Persistence is accompanied with chronic gastritis which can progress towards gastric cancer. Several strategies are used by H.pylori to evade the immune system, enabling chronic infection. Heightened expression of the immune cell inhibitor PD-L1 was found in gastric epithelial cells, infected with this Gram-negative pathogen. Within this thesis, upregulation was studied in in vitro models, revealing two distinct mechanism. Causative for early PD-L1 induction is the ADP heptose/ALPK1 signaling axis. The bacterial metabolite ADP heptose, which is needed for LPS synthesis, was identified as PAMP, which is transported through the secretion system cagT4SS into the infected cell and is recognized by the host kinase ALPK1. In contrast, late upregulation of PD-L1 was found to be linked to metabolic reprogramming upon infection. Characteristic to H.pylori is its need of cholesterol, which it has to extract from the surrounding medium or lipid-rich regions within the host membrane. It could be shown that this sterol extraction process is accompanied with an increased metabolic activity which is linked with enhanced glycolysis and an expression shift of the glycolytic enzyme hexokinase isoform 1 to 2. Knockdown and knockout experiments showed a link between HK2 and regulation of the immune checkpoint PD-L1.

Cancer immunotherapy has recently made remarkable clinical progress. Adoptive transfer of T-cells engineered with a chimeric antigen receptor (CAR) against CD19 has been successful in treatment of B-cell leukemia. Patient’s T-cells are isolated, activated, transduced with a vector encoding the CAR molecule and then expanded before being transferred back to the patient. However some obstacles restrict its success in solid tumors. This thesis explores different aspects to improve CAR T-cells therapy of cancer. Ex vivo expanded T-cells are usually sensitive to the harsh tumor microenvironment after reinfusion. We developed a novel expansion method for T-cells, named AEP, by using irradiated and preactivated allo-sensitized allogeneic lymphocytes (ASALs) and allogeneic mature dendritic cells (DCs). AEP-expanded T-cells exhibited better survival and cytotoxic efficacy under oxidative and immunosuppressive stress, compared to T-cells expanded with established procedures. Integrating retro/lentivirus (RV/LV) used for CAR expressions randomly integrate in the T-cell genome and has the potential risk of causing insertional mutagenesis. We developed a non-integrating lentiviral (NILV) vector containing a scaffold matrix attachment region (S/MAR) element (NILV-S/MAR) for T-cells transduction. NILV-S/MAR-engineered CAR T-cells display similar cytotoxicity to LV-engineered CAR T-cells with undetectable level of insertional event, which makes them safer than CAR T-cells used in the clinic today. CD19-CAR T-cells have so far been successful for B-cell leukemia but less successful for B-cell lymphomas, which present semi-solid structure with an immunosuppressive microenvironment. We have developed CAR T-cells armed with H. pylorineutrophil-activating protein (HP-NAP). HP-NAP is a major virulence factor and plays important role in T-helper type 1 (Th1) polarizing. NAP-CAR T-cells showed the ability to mature DCs, attract innate immune cells and increase secretion of Th1 cytokines and chemokines, which presumably leads to better CAR T-cell therapy for B-cell lymphoma. Allogeneic-DCs (alloDCs) were used to further alter tumor microenvironment. The premise relies on initiation of an allo-reactive immune response for cytokine and chemokines secretion, as well as stimulation of T-cell response by bringing in tumor-associated antigen. We demonstrated that alloDCs promote migration and activation of immune cells and prolong the survival of tumor-bearing mice by attracting T-cells to tumors and reverse the immune suppressive tumor microenvironment.