Introdução e objetivos: Eosinofilia duodenal está associada com parasitoses intestinais e com alergias alimentares, e tem sido sugerida como possível fator etiológico da dispepsia funcional, pela capacidade de causar alterações na motilidade e na sensibilidade do aparelho digestivo. Sua relação com o Helicobacter pylori é pouco conhecida, tendo sido avaliada apenas como achado secundário em alguns estudos, com resultados controversos. Esse estudo tem como objetivos avaliar o papel da infecção gástrica pelo H. pylori no número de eosinófilos duodenais e avaliar a relação dos eosinófilos duodenais com os sintomas da dispepsia funcional. Métodos: foram avaliados 100 pacientes dispépticos funcionais, de acordo com os critérios de Roma III, dos quais 50 foram H. pylori positivos e 50 negativos. Os pacientes foram submetidos à endoscopia digestiva alta com biópsias gástricas e duodenais. A positividade do H. pylori foi avaliada pelo teste de urease e pelo exame histológico (Hematoxilina-eosina e Giemsa). As biópsias duodenais foram avaliadas com hematoxilina-eosina e a número de eosinófilos duodenais foi quantificada pela média de eosinófilos por 5 campos de grande aumento (CGA) aleatórios e não sobrepostos. Eosinofilia duodenal foi definida pela presença de >22 eosinófilos/CGA. As medianas das médias aritméticas dos eosinófilos duodenais por cinco CGA foram comparadas entre os pacientes H. pylori positivos e negativos. Também foi avaliada a relação do número de eosinófilos duodenais com a intensidade e tipo de sintomas dispépticos, determinados por questionário validado (PADYQ). Os eosinófilos duodenais foram avaliados para variáveis demográficas e endoscópicas. Resultados: Pacientes do sexo feminino representaram 88% da amostra e a idade média foi de 41,7 anos As características basais dos pacientes H. pylori positivos e H. pylori negativos foram semelhantes. Apenas um paciente, no grupo H. pylori positivo, apresentou eosinofilia duodenal. As medianas dos eosinófilos duodenais/CGA foram 4,6 [P25-75: 2,8-7,2] nos pacientes H. pylori negativos e 4,7 [P25-75: 3,4-8,4] nos H. pylori positivos (p= 0,403). O número de eosinófilos 8 duodenais foi significativamente maior em pacientes com sintomas mais intensos: pacientes com escore do PADYQ >22 (>50% da pontuação máxima) apresentaram mediana de eosinófilos duodenais/CGA de 5,4 [P25-75: 3,4–7,6] e pacientes com escore ≤22 de 3,4 [P25-75: 2,2–6,0] (p= 0,018). Os pacientes foram divididos em tercis, de acordo com a intensidade dos sintomas: grupo 1 com 31 pacientes (sintomas leves); grupo 2 com 30 pacientes (sintomas moderados); e grupo 3 com 31 pacientes (sintomas acentuados). A mediana dos eosinófilos duodenais/CGA no grupo 1 foi de 3,4 [P25-75: 2,2 -6,0]; no grupo 2 de 4,7 [P25-75: 3,2-6,4]; e o grupo 3 de 5,8 [P25-75: 3,6-8,2] (P=0,033). Houve diferença estatisticamente significativa no número de eosinófilos duodenais entre fumantes e não fumantes (p= 0,030) e entre pacientes com índice de massa corporal (IMC) <25 kg/m2 e IMC ≥ 25 kg/m2 (p= 0,035). Na análise multivariada por regressão linear, os fatores que tiveram influência sobre o número de eosinófilos duodenais foram o tabagismo (p= 0,026) e a intensidade dos sintomas dispépticos (p= 0,039). Conclusões: Esse estudo não mostrou associação entre a infecção pelo H. pylori e a contagem de eosinófilos duodenais, nessa população de pacientes dispépticos funcionais. Entretanto, foi demonstrada uma relação diretamente proporcional e estatisticamente significativa entre o número de eosinófilos duodenais e a intensidade dos sintomas dispépticos. / Background and Aims: Duodenal eosinophilia is associated with intestinal parasitosis and food allergies. It has also been implicated as a potential factor on the etiology of functional dyspepsia, probably by causing changes in digestive tract motility and sensitivity. The association with Helicobacter pylori is poorly understood, and has been only evaluated as a secondary finding in 9 previous studies, with conflicting results. This study aims to evaluate the potential role of gastric H. pylori infection in the duodenal eosinophil count, and the influence of duodenal eosinophils on symptoms in functional dyspeptic subjects. Methods: One hundred functional dyspeptic subjects, according to Rome III criteria, were evaluated, and 50 were H. pylori positive and 50 H. pylori negative. Patients were submitted to upper gastrointestinal endoscopy with gastric and duodenal biopsies. H. pylori positivity was evaluated by urease test and gastric histology (Hematoxylin-eosin and Giemsa). Duodenal biopsies were evaluated with Hematoxylin-Eosin staining, and the duodenal eosinophil count was determined by the mean of eosinophil by 5 random nonoverlapping high power fields (HPF). Duodenal eosinophilia was defined as >22 eosinophils/HPF. The median of the arithmetic means of the duodenal eosinophils counts per high power field were compared between H. pylori positive and H. pylori negative subjects. The relationship between the number of duodenal eosinophils and the intensity and type of dyspeptic symptoms was determined by validated questionnaire (PADYQ). Duodenal eosinophils counts were also evaluated by demographic variables and endoscopic findings. Results: 88% of the subjects were female and the mean age was 41.7 years. Baseline characteristics were similar between H. pylori positive and H. pylori negative subjects. Only one patient, in the H. pylori positive group, had duodenal eosinophilia. The median duodenal eosinophils/HPF were 4.6 [Percentiles 25-75(P25-75): 2.8-7.2] in H. pylori negative and 4.7 [P25-75: 3.4-8.4] in H. pylori positive subjects (p= 0.403). The duodenal eosinophil count was greater in subjects with higher symptoms severity: patients with PADYQ score more than 22 (>50% of the maximum score) had median duodenal eosinophil/HPF of 5.4 [P25-75: 3,4–7,6] and subjects with PADYQ score ≤22 of 3.4 [P25-75: 2.2–6.0] (p= 0.018). The patients were divided into terciles, according to symptoms severity: group 1 with 31 subjects (mild symptoms); group 2 with 30 subjects (moderate symptoms); and group 3 with 31 subjects (severe symptoms). 10 The median duodenal eosinophils/HPF was 3.4 [P25-75: 2.2-6.0] in group 1; 4.7 [P25-75: 3.2-6.4] in group 2; and 5.8 [P25-75: 3.6-8.2] in group 3 (p=0.033). There was a higher duodenal eosinophils count in smokers (current or former) (p=0.030), and subjects with BMI ≥ 25 kg/m2 (p=0.035). In the multivariate analysis by linear regression, the duodenal eosinophil count were influenced by smoking (p = 0.026) and dyspeptic symptoms severity (p= 0.039). Conclusion: This study did not show an association between H. pylori infection and the number of duodenal eosinophils, in this population of functional dyspeptic patients. However, a directly proportional and statistically significant relationship between the number of duodenal eosinophils and the intensity of dyspeptic symptoms has been demonstrated.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / O H. pylori infecta atualmente metade da populaÃÃo mundial e à relacionado com o desenvolvimento das afecÃÃes gÃstricas. O Enteroteste à um mÃtodo minimamente invasivo que pode ser usado para detecÃÃo do H. pylori por meio nÃo endoscÃpico. O objetivo deste estudo foi avaliar a sensibilidade e especificidade do Enteroteste frente ao Teste RespiratÃrio e estudar o perfil genÃtico das cepas de H. pylori em indivÃduos residentes na comunidade Parque UniversitÃrio. O suco gÃstrico foi colhido a partir do Enteroteste, e realizada a cultura e a extraÃÃo do DNA do H. pylori. A genotipagem das cepas foi realizada atravÃs da tÃcnica de PCR e os sÃtios de fosforilaÃÃo EPIYA de sequenciamento Participaram do estudo 50 indivÃduos, 43 positivos e 7 negativos para a infecÃÃo pelo H. pylori atravÃs do Teste RespiratÃrio. A cultura e o PCR a partir do Enteroteste apresentaram sensibilidade de 86% e 77%, respectivamente, com especificidade de 100% em ambos os mÃtodos 33 cepas foram genotipadas como vacA positivas, sendo 39,4% vacA s1m1; 15,2% vacA s1m2; 18,2% vacA s2m2 27,2% com perfil vacA s com ausÃncia do alelo m. Foram cagA positivas 66,6% das cepas sendo 54,5% com perfil EPIYA-ABC, 41,0% EPIYA-ABCC e 4,5% EPIYA-AB. O Enteroteste mostrou-se um mÃtodo confiÃvel com boa sensibilidade e especificidade para identificaÃÃo do H. pylori atravÃs do cultivo e da tÃcnica de PCR. A maioria das cepas expressou o alelo vacA s1, com predomÃnio do subtipo s1b e da combinaÃÃo alÃlica s1m1. Mais da metade das cepas estudadas expressaram o gene cagA e a maioria dessas cepas tinham 3 ou 4 sÃtios de fosforilaÃÃo, com perfil EPIYA-ABC ou EPIYA-ABCC. O perfil genÃtico apresentado por essas cepas à o descrito para a AmÃrica do Sul e diferente do padrÃo AsiÃtico, a maioria das cepas circulantes na comunidade tÃm importante potencial patogÃnico. O Enteroteste à um mÃtodo seguro, sensÃvel e especÃfico para detecÃÃo do H. pylori. / The H. pylori infect currently half of the worldâs population and is related to the development of gastric disorders. The Enterotest is a minimally invasive method that can be used for detection of H. pylori through endoscopic not. The objective of this study was to evaluate the sensitivity and specificity of Enterotest opposite the Respiratory Testing and studying the genetic profile of strains of H. pylori individuals resident in the Community College Park. The gastric juice was collected from Enteroteste, and held the culture and the extraction of DNA from H. pylori. The genotyping of strains was carried out by the PCR technique and phosphorylation sites EPIYA sequencing participated in the study 50 individuals, positive and negative 7 43 for infection H. pylori through Respiratory Test. Culture and PCR from Enteroteste showed sensitivity of 86% and 77%, respectively, with 100% specificity in both methods. 33 strains were positive, genotipadas as Cow being 39.4% Cow s1m1; 15.2% Cow s1m2; 18.2% Cow s2m2 27.2% with Cow s profile with absence of allele m. Were positive 66.6% Bran of strains being profiled 54.5% EPIYA-ABC, 41.0% EPIYA-ABCC and 4.5% EPIYA-AB. The Enterotest proved to be a reliable method with great sensitivity and specificity for identification of H. pylori through cultivation and PCR technique. Most strains expressed alelo Cow s1, with a predominance of subtype s1b and allele combination s1m1. More than half of the studied strains expressed gene Shit and most of these strains were 3 or 4, phosphorylation sites profiled EPIYA-ABC or EPIYA-ABCC. The genetic profile presented by these strains is described for South America and nonstandard Asia, most strains circulating in the community have important potential pathogenic. The Enterotest is a safe method, sensitive and specific detection of H. pylori.

Helicobacter pylori is one of the most potential and successful human pathogen which colonizes atleast 50% of world population. One of the important characteristics of this pathogen is the degree of allelic diversity and genetic variability which helps it to adapt and colonize. Phase variation is one of the mechanisms used by Helicobacter pylori to generate variation, where presence of homopolymeric nucleotide or dinucleotide repeats in an ORF make it prone to frequent length changes as a consequence of slipped strand mispairing mediated mutagenesis. An important feature of H. pylori biology is the presence of a large number of Restriction-Modification (R-M) systems in its genome. Till date, seven strains have been completely sequenced and each have more than 20 R-M systems. The presence of homopolymeric nucleotide or dinucleotide repeats in many of R-M systems make them an interesting subject for investigation. Here, we show that hp0051 which codes for a C5 cytosine methyltransferase from H. pylori is a hypermutable gene, which undergoes random mutations. In addition it exhibits phase variation due to presence of a dinucleotide (AG) repeat which results in a truncated protein. hp0051 homologs were amplified and sequenced from different clinical isolates of H. pylori. Sequence analysis showed that hp0051 homologs from 23 clinical isolates are different from each other suggesting a hypervariable nature of the sequence. It was observed that when over expressed in E. coli hp0051 undergoes random mutations. These mutations give rise to different variants of HP0051 with different biochemical properties. Different variants of HP0051 were biochemically characterized. All variants recognize 5´-CCTC-3´ and methylate the first cytosine. A few of the isoforms exhibit degeneracy in the recognition site as they recognize 5´- CNCC-3´ (N being any nucleotide) and methylates third cytosine. Molecular modelling studies suggest that HP0051 has two domains, one large domain having catalytic and AdoMet binding motifs and small domain having target recognition domain. DNA sequencing, peptide finger mapping, MALDI MS-MS and CD have been used to establish the differences between the different isoforms of HP0051. Interestingly when a mutant protein which lacks methylation activity was expressed in E.coli random mutations were not observed. To understand the role of methylation in the occurrence of random mutations, microarray analysis was done. Microarray analysis have shown that the overexpression of HP0051 results in the down regulation of deoxyadenine methyltransferase (dam) in E.coli. Microarray data were further authenticated by RT PCR analysis. dam plays a vital role in mismatch repair pathway and down regulation of dam results in enhanced mutation rates. A large number of clinical isolates were analysed for the presence of hp0051 and hp0051 was found to be present in 83% of strains obtained from patients compared to 25 % of strains from healthy volunteers. Single colonies obtained from the same patient were analysed and it was found that variation in hp0051 exists within a patient also. Deletion of an orphan C5 cytosine methyltransferase, hp0051 in H. pylori strains 26695, SS1 and 98.4 has a significant effect on the expression of number of genes belonging to motility, adhesion and virulence. 98.4∆hp0051 mutant strain has a different LPS profile and is able to induce high IL-8 production compared to wild-type. H. pylori strain 26695∆hp0051 is more motile than the wild- type. hp0051 from strain 26695 is able to complement mutant SS1 and 98.4 strains. This study highlights the possible significance of cytosine methylation in the physiology of H. pylori. hp0050 is a N6 DNA adenine methyltransferase which overlaps with the hp0051 ORF .hp0050 was cloned, over expressed and purified to near homogeneity. It recognizes the sequence 5´GRRG 3´ (where R is A or G) and most intriguingly methylates both adenines when R is A (5´GAAG 3´). Kinetic analysis suggest a non processive (repeated hit) mechanism of methylation in which HP0050 methyltransferase methylates one adenine at a time in sequence 5´GAAG 3´. Interestingly, HP0050 homologs from two clinical strains PG227 and 128 methylate only 5´GAGG 3´ compared to 5´GRRG 3´ in strain 26695. HP0050 MTase is highly conserved as it is present in more than 90% of strains. Inactivation of hp0050 in strain PG227 resulted in poor growth suggesting its important role in the physiology of Helicobacter pylori. Collectively, these findings provide impetus for exploring the role(s) of this conserved DNA methyltransferase in the cellular processes of Helicobacter pylori. In one of the clinical isolate it was found that hp0051 and hp0050 can code for a single polypeptide due to an insertion mutation. This mutant ( hp0050 and hp0051 fusion ) was cloned, overexpressed and purified. It was found that fusion protein is able to methylate both adenine and cytosine in the cognate sequence. Similarly, hp1369 - hp1370 is a phase variable type III MTase and it belongs to ɛ group of MTases based on the arrangement of motifs. It has a poly G repeat in its ORF and any change in the number of repeats can result in a functional (full length) or non functional (truncated) protein. Within strain 26695, it has 10 G repeat which results in a truncated protein. Addition of a single nucleotide by site directed mutagenesis in the repeat results in a full length functional protein. HP1369_HP1370 fusion protein recognizes and methylates 5´ TCAGC 3´. DNA methyltransferases are known to play a critical role in gene regulation, cell cycle regulation and pathogenesity in a number of pathogens. H. pylori genome is rich in DNA methyltransferases and this study shows that these methyltransferases exhibit unique features like phase - variation and polymorphism .We propose that high degree of variation that exists in these methyltransferases could play a vital role in enhancing the ability of H. pylori to adapt its host.

No description available.

<p><em>Helicobacter pylori </em>is a bacterial infection of the stomach lining known to cause ulcers and stomach cancer This infection has become a major concern of Indigenous peoples living in the Northwest Territories, where <em>H. pylori </em>infection and stomach cancer are more prevalent relative to much of southern Canada and the United States. I joined the Canadian North <em>Helicobacter pylori</em> (CAN<em>Help</em>) Working Group in 2010 to conduct participant observation in the Aklavik <em>H. pylori </em>Project (AHPP) and identify ways that ethnography can be integrated into the ongoing multi-pronged research that incorporates epidemiology, microbiology, gastroenterology, knowledge translation, and the development of public health policy.</p> <p>Between September, 2011 and June, 2012, I lived as a participant observer in Aklavik. I led an epidemiological study of the incidence and re-infection of <em>H. pylori </em>infection. I examined how different risk perceptions emerge from processes of “making sense” of <em>H. pylori </em>as a “pathogen” or as a “contaminant” and described how these different constructions influence people’s behaviours. Ethnography, in this way, can make visible the lenses through which different groups of actors perceive, experience, and react to <em>H. pylori </em>infection. The recognition that the social inequities most strongly associated with <em>H. pylori </em>infection and re-infection that exist today are the result of Aklavik’s colonial history is one example of a space in which different lenses can be brought into a shared focus. From such shared understandings, consensus knowledge can be built collaboratively between outside researchers and Indigenous Arctic communities in an ongoing, and community-driven, research project. Furthermore, I critically examined the definition and use of the “household” as a level-unit of risk assessment and have outlined steps for assessing possible risk factors as these are distributed across multi-household extended kin groups that can be identified and followed in long-term research.</p> / Doctor of Social Science

Diversos estudios señalan que varias especies pertenecientes a las Bacterias Acido Lácticas (BAL) poseen propiedades probióticas y se encuentran comúnmente en los derivados lácteos. Actualmente, en la Comunidad Valenciana se comercializan quesos frescos y madurados elaborados a partir de la leche de oveja guirra, autóctona de esta comunidad e incluida dentro del catálogo de razas protegidas en España. Sin embargo, hasta el momento no se han realizado ensayos para determinar el potencial probiótico de cepas aisladas de esta leche. En esta tesis, se han aislado 131 BAL de leche de oveja Guirra. Siguiendo los criterios establecidos por la FAO, estas cepas se han identificado inicialmente con métodos fenotípicos a nivel de género y especie. Posteriormente, se ha evaluado, en condiciones in vitro, la actividad antimicrobiana de las cepas lácticas frente a patógenos implicados en enfermedades del hombre como H. pylori y Salmonella spp. En detalle, se ha estudiado el efecto de las sustancias producidas por dos cepas BAL frente a la viabilidad de H. pylori. Las cepas BAL destacadas en la actividad antimicrobiana han sido identificadas y caracterizadas por medio de técnicas moleculares, perfiles de resistencia a antibióticos, habilidad de adhesión a la mucina de cerdo y finalmente, se ha evaluado la resistencia frente a las condiciones gastrointestinales. Los resultados muestran que las propiedades probióticas se pueden atribuir a una cepa y no es posible generalizarlo a una especie o género. Algunas de las cepas lácticas de oveja y de la CECT resultaron de especial interés porque en condiciones in vitro demostraron características probióticas que deberían ser confirmadas en posteriores estudios in vivo. Cabe resaltar que algunas de estas cepas se han aislado de productos que son actualmente comercializados y por tanto las propiedades probióticas de estas cepas representarían un valor añadido para los mismos. / Amorocho Cruz, CM. (2011). Caracterización y potencial probiótico de bacterias lácticas aisladas de leche de oveja guirra [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/13830

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.

No description available.

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.