Abstract Calcific aortic valve disease (CAVD) represents a disease spectrum, ranging from mild aortic valve sclerosis to severe obstructive aortic stenosis (AS), associated with a high risk of myocardial infarction and cardiovascular death. It is a common disease in the Western countries, and with their aging populations, its prevalence is likely to increase. Today, CAVD is recognized as an actively regulated disease. Mechanical stress and endothelial injury are the initiating factors, followed by lipid accumulation and oxidation, leading to inflammation, fibrosis and calcification. Ultimately, the progressive calcification hinders the normal valvular function and obstructs the flow of blood through the valve. The only effective treatment for symptomatic AS is aortic valve replacement. The trials with pharmacological treatments, mainly with anti-atherosclerotic drugs, have not been successful in slowing the progression of the disease. This study was aimed to identify differentially expressed transcripts, and molecular markers taking part in the pathophysiology behind CAVD. In particular, factors related to the renin-angiotensin system, and the apelin – APJ pathway, were investigated during the development of CAVD. In addition, the expressions of granzymes and perforin, as well as podoplanin, were studied in different stages of CAVD. It was demonstrated that these molecules are expressed in aortic valves and dysregulated in AS. These results can help to clarify the mechanisms driving CAVD, thus being potential targets for pharmacological therapy. Furthermore, the studied molecules may reflect the stage and possible subgroups of CAVD. / Tiivistelmä Aorttaläpän ahtauma edustaa tautijatkumoa, joka alkaa lievästä aorttaläpän paksuuntumisesta eli aorttaskleroosista ja jatkuu vaikeaan aorttaläpän kalkkeutuneeseen ahtaumaan eli aorttastenoosiin, johon liittyy korkea sydäninfarktin ja sydän- ja verisuonitatutiperäisen kuoleman riski. Aorttaläpän ahtauma on yleinen tauti länsimaissa, ja väestön ikääntyessä sen esiintyvyys on luultavimmin lisääntymässä. Nykyään aorttaläpän ahtauman tiedetään olevan aktiivisesti säädelty tauti. Mekaaninen rasitus ja endoteelivaurio käynnistävät tautiprosessin, läppäkudokseen kertyy lipidejä ja ne hapettuvat, mikä johtaa tulehdukseen, sidekudoksen lisääntymiseen ja kalkkeutumiseen. Lopulta etenevä kalkkeutuminen heikentää läpän normaalia toimintaa ja estää veren normaalia virtausta sydämestä aorttaan. Ainoa tehokas hoito oireiseen aorttastenoosiin on aorttaläpän korvausleikkaus. Lääkehoitoina on kokeiltu erityisesti ateroskleroosin hoitoon käytettäviä lääkkeitä, mutta niillä ei ole onnistuttu estämään taudin etenemistä. Tässä väitöskirjatyössä tutkittiin molekyylejä ja biokemiallisia reittejä, jotka liittyvät reniini-angiotensiinijärjestelmään ja apeliini-APJ-reittiin. Lisäksi tutkittiin grantsyymien ja perforiinin sekä podoplaniinin ilmentymistä aorttaläpän ahtauman eri kehitysvaiheissa. Tulosten perusteella näitä tekijöitä ilmennetään aorttaläpässä ja niiden määrä on muuttunut kalkkeutuneessa läpässä. Tulokset auttavat osaltaan ymmärtämään aorttaläpän ahtaumaan ja kalkkeutumiseen johtavia mekanismeja, joita voidaan hyödyntää uusia lääkehoidon kohteita suunniteltaessa. Tutkitut molekulaariset tekijät voivat kuvastaa aortan ahtaumataudin vaiheita ja mahdollisia alaryhmiä.

B virus (Macacine herpesvirus 1, Cercopithecine herpesvirus 1, herpes B virus) is an Old World monkey simplex virus endemic in macaques. B virus infection in its natural host, macaque, is very similar to HSV-­‐1 infection in humans causing mild or asymptomatic infection. On the other hand, zoonotic infection in humans results in death in the absence of early initiation of antiviral drugs. Viruses evade host immune responses in order to survive and propagate. Most herpes viruses including HSV-­‐1 down-­‐regulate major histocompatibility complex class I (MHC class I) surface expression on infected cells in order to prevent CD8+ T-­‐cell recognition and subsequent cell lysis. MHC class I molecules bind to the inhibitory receptors of NK cells and prevent NK cell activity. Thus, this mechanism protects HSV-­‐1 infected cells from CD8+ T-­‐cell lysis, making them sensitive to natural killer (NK) cell cytotoxicity. To investigate if B virus pathogenicity is a result of novel immune evasion mechanisms employed by B virus, we determined NK cell regulation during B virus infection. To this end, our experiments demonstrate that B virus does not down-­‐ regulate MHC I expression as effectively as HSV-­‐1, leading us to hypothesize that B virus in-­‐ fected cells are resistant to NK cell activity. We examined the expression of MHC I chain related genes (MICA/ MICB), which are activation ligands to NKG2D receptors on NK cells. Our results show that there is no significant difference in MICA and MICB expression between HSV-­‐1 and B virus infected cells. Furthermore, we tested for the up-­‐regulation of cytokines and chemokines responsible for NK cell activation and migration. Our results indicate a significant up-­‐regulation of IFN-­‐α from PBMCs co-­‐cultured with HSV-­‐1 infected cells, which plays an important role in activating NK cells. NK cells within these PBMCs up-­‐regulate perforin release indicative of NK cell activity. PBMCs co-­‐cultured with B virus infected cells do not up-­‐regulate any cytokines or chemokines responsible for NK cell activity. As a result the NK cells within these PBMCs do not significantly up-­‐regulate perforin release. These results demonstrate that B virus employs a novel immune evasion mechanism to subvert NK cell activity.

L'immunothérapie en agissant au niveau de la tumeur primitive et en empêchant le développement des métastases constitue une des stratégies du traitement des patients atteints de cancer. Afin d'améliorer l'efficacité de celle-ci, il est nécessaire de comprendre comment est induit la mort des cellules tumorales. Dans le laboratoire, il a été observé la guérison de rats BDIX porteurs de tumeurs PROb par un triacyl lipide A. Il a été montré que cet effet impliquait le système immunitaire en mettant en jeu des interactions avec les TLR présents sur de nombreuses cellules tumorales et de l'immunité innée comme les neutrophiles.Dans ce travail, nous avons étudié l'implication éventuelle des neutrophiles dans l'activité anti tumorale du triacyl lipide A chez l'homme.Dans une étude de phase 1 chez des patients porteurs de tumeurs solides réfractaires, nous avons montré que le triacyl lipide A était bien toléré et qu'il induisait la sécrétion de cytokines impliquées dans la réponse immunitaire et notamment dans le recrutement des neutrophiles. Nous avons ensuite, dans un second temps démontré l'implication éventuelle des neutrophiles dans cette réponse immunitaire en vérifiant leur présence dans des tumeurs coliques humaines et en analysant leur proximité avec les cellules tumorales, ces deux facteurs déterminant leur cytotoxicité vis-à-vis des cellules tumorales. Nous avons ensuite fait une analyse comparative par rapport au tissu sain pour rechercher si ces neutrophiles étaient activés et comparer l'expression de chimio attractants.

Made available in DSpace on 2014-07-29T15:21:56Z (GMT). No. of bitstreams: 1 DISSERTACAO NADIA DO L COSTA.pdf: 215211 bytes, checksum: 98b2cf88b4766dae4e25cfa06b0970d4 (MD5) Previous issue date: 2010-02-26 / The cytotoxic T lymphocytes (CTL) and natural killer (NK) cells are more effective in fighting cancer because these cells recognize tumor cells and release cytotoxic granules rich in perforin and granzyme B (GB). The perforin form pores in tumor cells allowing the influx of GB. When inside the cell, the GB promotes tumor cell death through apoptosis. In this context, high expression of GB into the microenvironment of different types of cancers has been considered a key event for effective antitumor immunity. Therefore, the objective of this study was to identify and quantify GB+ cells, peri- and intratumoral, and its relationship with clinical prognostic parameters (size of the primary lesion, location, metastasis and survival) and microscopic (microscopic grading and cell proliferation index and apoptosis of neoplastic cells) of squamous cell carcinoma (SCC) of the oral cavity. GB+ cells were identified by the technique of immunohistochemistry, a method of polymer, in 20 samples from patients with SCC of the oral cavity that had metastasized to cervical lymph nodes and in 35 samples from patients with SCC of the oral cavity without metastasis to cervical lymph nodes. Our results showed that the density of peritumoral GB+ cells was significantly higher in the non-metastatic SCC when compared with metastatic group (p=0.03). In addition, patients with high expression of peritumoral GB had a longer survival than those with low expression of this protease (Kaplan Meier, Log Rank p=0.02). We showed also that patients with high density of peritumoral GB+ cells showed a low percentage of neoplastic cells bcl2+ (antiapoptotic protein) (P=0.004) and high density of neoplastic cells Bax+ (apoptotic protein) (p=0.031) when compared to the group of low density of peritumoral GB+ cells. In agreement with these data, patients who had a high density of peritumoral GB+ cells showed high expression of Annexin V by neoplastic cells. Additionally, the density of GB+ cells intratumoral and peritumoral was significantly higher in the T1 and T2 (39.44±7.21 and 14.61±3.60, respectively) when compared to T3 and T4 (31.03±3.76 and 11.90±1.88, respectively), however these results were not statistically significant (p>0.05). The association between the density of cells GB+ and other characteristics of SCC of the oral cavity, such as location, tumor proliferation and tumor grading was not observed. Our findings suggest that the increased of expression of GB in tumor microenvironment of SCC of the oral cavity may have beneficial effect against neoplastics cells, contributing to apoptosis of these cells, lower lymph node involvement and increased survival time of patients. / Os Linfócitos T Citotóxicos (LTC) e as células Natural Killer (NK) são as células mais efetivas no combate ao câncer, pois essas células reconhecem células tumorais e liberam grânulos citotóxicos ricos em perforina e granzima B (GB). A perforina forma poros nas células tumorais permitindo o influxo da GB. Quando no interior da célula, a GB promove a morte da célula tumoral através da apoptose. Neste contexto, a alta expressão de GB no microambiente de diferentes tipos de cânceres tem sido considerado um evento fundamental para uma efetiva imunidade antitumoral. Portanto, o objetivo do presente estudo foi identificar e quantificar células GB+, peri- e intratumoral, e sua relação com parâmetros de prognóstico clínicos (tamanho da lesão primária, localização, metástase e sobrevida) e microscópicos (gradação microscópica e índices de proliferação celular e de apoptose das células neoplásicas) do carcimoma espinocelular (CEC) de cavidade oral. As células GB+ foram identificadas pela técnica da imunoistoquímica, método do polímero, em 20 amostras de pacientes com CEC de cavidade oral que apresentaram metástase para linfonodos cervicais e em 35 amostras de pacientes com CEC de cavidade oral sem metástase para linfonodos cervicais. Nossos resultados demonstraram que a densidade de células GB+ peritumoral foi significativamente maior no grupo de CEC não metastático quando comparado com o metastático (p=0,03). Além disso, os pacientes com alta expressão de GB peritumoral apresentaram um maior tempo de sobrevida do que aqueles com baixa expressão dessa protease (Kaplan Meier, Log Rank p=0,02). Evidenciamos, também, que os pacientes com alta densidade de células GB+ peritumoral apresentaram baixa porcentagem de células neoplásicas bcl2+ (proteína anti-apoptótica) (P=0.004) e alta densidade de células neoplásicas Bax+ (proteína pró-apoptótica) (p=0,031) quando comparado ao grupo de baixa densidade de células GB+ peritumoral. Em concordância com esses dados, os pacientes que apresentaram alta densidade de células GB+ peritumoral apresentaram alta expressão de Anexina V por células neoplásicas. Adicionalmente, a densidade de células GB+ peritumoral e intratumoral foi significativamente maior no grupo T1 e T2 (39,44±7,21 e 14,61±3,60, respectivamente) quando comparado a T3 e T4 (31,03±3,76 e 11,90±1,88, respectivamente), no entanto esses resultados não foram estatisticamente significativo (p>0,05). A associação entre a densidade de células GB+ e outras características do CEC de cavidade oral, como localização, proliferação tumoral e gradação tumoral não foi observada. Nossos achados sugerem que a alta expressão da GB no microambiente do CEC de cavidade oral pode ter um efeito benéfico contra células neoplásicas, contribuindo para apoptose dessas células, baixa metástase linfonodal e maior tempo sobrevida desses pacientes

Abstract Calcific aortic valve disease (CAVD) is the most common valvular heart disease in the Western world. Although it shares mainly the same risk factors as coronary heart disease (CHD), i.e. similar initial events in both diseases but with time, they lead to different clinical outcomes. Thus, when it affects the coronary arteries, the disease leads to an obstructive or rupture-prone plaque whereas in the aortic valve, it causes massive calcification and ossification. This obstructs the blood flow from the left cardiac ventricle, causing myocardial hypertrophy, and if left untreated, heart failure and death. Many of the pathobiological differences between CAVD and CHD remain unknown. Currently, there are no effective lifestyle- or pharmacologic treatments for CAVD and the only therapy is a valve replacement operation. In this thesis, several studies utilizing large-scale methods were undertaken to profile the molecular events leading to CAVD. Surgically removed valves from patients in different stages of the disease were obtained and gene transcripts, microRNA-molecules and several proteins were identified as being differentially expressed. Several of these were investigated further, including two pro-inflammatory CC-type chemokine ligands 3 and 4 (CCL3 and CCL4), microRNA-125b, several granzyme-proteins and heat-shock protein 90. The results of this thesis provide a large dataset of hundreds of molecular changes associated with CAVD. It is proposed that they can be used as a basis for the generation of new hypotheses and assist in the design of experiments to clarify the mechanisms driving CAVD. / Tiivistelmä Aorttaläpän kalkkeutuva ahtauma on länsimaiden yleisin sydänläppäsairaus. Riskitekijät ovat pääosin samat kuin sepelvaltimotaudissa, ja molemmat saavat alkunsa samalla tavalla. Ajan myötä ne kuitenkin johtavat varsin erilaisiin kliinisiin ilmenemismuotoihin: sepelvaltimoihin kasvaa ahtauttavia ja repeytymisherkkiä plakkeja, kun taas aorttaläppään muodostuu runsaasti kalkkia ja luuta. Se haittaa verenvirtausta sydämen vasemmasta kammiosta aorttaan, mikä aiheuttaa sydänlihaksen paksuuntumista. Hoitamattomana tauti johtaa lopulta sydämen vajaatoimintaan ja kuolemaan. Monet syyt eroihin sepelvaltimotaudin ja aorttaläpän ahtauman välillä ovat edelleen tuntemattomia. Tällä hetkellä aorttaläpän ahtaumaan ei ole olemassa tehokasta elintapa- tai lääkehoitoa, ja ainoa hoitomuoto onkin vioittuneen aorttaläpän korvaaminen proteesilla. Tässä väitöskirjatyössä tehtiin useita laaja-alaisia molekyylitason profilointitutkimuksia, joilla selvitettiin aorttaläpän ahtaumaan mahdollisesti johtavia mekanismeja. Aineistona oli leikkauksessa potilailta poistettuja, erilaisissa taudin vaiheissa olevia aorttaläppiä. Niistä kerättiin tietoja kaikkien geenien ilmentymisestä, mikroRNA-molekyyleistä sekä koko proteomitason muutoksista. Useat tunnistetuista molekyyleistä valittiin jatkotutkimuksiin niiden tarkempien ominaisuuksien selvittämiseksi. Näitä olivat tulehdusta välittävät kemokiinit CCL3 ja CCL4, mikroRNA-125b, useat grantsyymiproteiinit sekä lämpöshokkiproteiini 90. Väitöskirjatyön tuloksista voidaan muodostaa ainutlaatuinen aineisto sadoista erilaisista aorttaläpän ahtaumaan johtavista molekyylitason muutoksista. Sitä voidaan hyödyntää uusien tutkimushypoteesien muodostamisessa sekä aorttaläpän ahtauman tarkempien mekanismien selvittämiseen tähtäävien kokeellisten tutkimusten suunnittelussa.

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