Made available in DSpace on 2014-08-20T14:31:33Z (GMT). No. of bitstreams: 1 dissertacao_jacqueline_radin.pdf: 589146 bytes, checksum: 57a338810c6c34920d4047b74e163eaf (MD5) Previous issue date: 2011-03-11 / The Toxoplasma gondii is a protozoan which causes opportunistic infections in individuals with a compromised immune system. There exist a lot of studies correlating toxoplasmosis with immunosuppressed patients, however, in neoplasia carriers, who may suffer a process of immunosuppression during the chemotherapy, few studies were conducted. The aim of the present study was to evaluate, through serological profile, the risk of acute infection (or reactivation) of T.gondii in cancer patients who had chemotherapy treatment in the School Hospital of Pelotas Federal University and in the Radiotherapy and Cancer Center of Pelotas Santa Casa de Misericórdia , as well as to correlate such cancer with toxoplasmosis, through clinical and epidemiological data. A longitudinal cohort prospective study was carried out with a total of 95 patients, who were followed during the antineoplastic treatment by approximately two cycles, from March to November of 2010. The serological search was performed through Indirect Immunofluorescence Techniques (IFI) and Enzyme Linked Immunosorbent Assays (ELISA), and positive results to antibodies IgM anti-T. gondii were confirmed through Electrochemiluminescence Immunoassay (ECLIA). The epidemiological data were obtained through a questionnaire and the clinical, from the analysis of previously authorized patient dossiers. It was verified that the seropositive rate for IgG anti-T.gondii antibodies was of 84.21% at the pre-treatment chemotherapy sample, and of 83.33% at the post-treatment sample through the IFI technique, observing the low titration of antibodies, while through ELISA, 100% of the samples in both analysis were reagents. Class M antibodies were detected in six of the patients (6.3%) through IFI or ELISA and confirmed by ECLIA in one of them. In the risk factor analysis, it was noted a significant association (p<0.05) among seropositive patients for IgM in relation to the variables death (OR= 4.78) and race (OR= 10.88), respectfully. The results obtained point towards the necessity to perform the monitoring toxoplasmosis in cancer patients who are undergoing chemotherapy treatment, in order to avoid grave or even fatal consequences. / Toxoplasma gondii é um protozoário oportunista causador de infecções em indivíduos com o sistema imunológico comprometido. Existem vários estudos correlacionando a toxoplasmose com pacientes imunocomprometidos, porém, em portadores de neoplasias, que podem vir a sofrer um processo de imunodepressão durante o tratamento quimioterápico, poucos estudos foram realizados. O objetivo deste trabalho foi avaliar, através do perfil sorológico, o risco de infecção aguda ou reativação de T. gondii em pacientes oncológicos, que realizaram tratamento quimioterápico no Hospital Escola da Universidade Federal de Pelotas e no Centro de Radioterapia e Oncologia da Santa Casa de Misericórdia de Pelotas, além de correlacionar o câncer com a toxoplasmose, através de dados clínicos e epidemiológicos. Foi realizado um estudo de coorte longitudinal prospectivo, com um total de 95 pacientes, os quais foram acompanhados por pelo menos duas sessões de quimioterapia, no período de março a novembro de 2010. A pesquisa sorológica foi realizada através das técnicas de Imunofluorescência Indireta (IFI) e ensaio imunoenzimático (ELISA), e os resultados positivos para IgM anti-T.gondii foram confirmados pela eletroquimioluminescência (ECLIA). Os dados epidemiológicos foram obtidos pela aplicação de um questionário e os clínicos através da análise dos prontuários dos pacientes, previamente autorizados. Constatou-se que a taxa de soropositivos para IgG anti-T.gondii foi de 84,21% na amostra pré-tratamento quimioterápico e 83,33% na amostra pós-tratamento pela técnica de IFI, observando-se baixas titulações de anticorpos, enquanto que por ELISA, 100% das amostras, nas duas análises, foram reagentes. Anticorpos da classe M foram detectados em seis pacientes (6,3%) através da técnica de IFI ou ELISA e confirmado por ECLIA em um dos pacientes. Na análise dos fatores de risco, foi verificada associação significativa entre os pacientes soropositivos para IgM em relação às variáveis óbito (OR=4,78) e raça (OR=10,88), respectivamente. Os resultados obtidos indicam a necessidade de se realizar o monitoramento da toxoplasmose em pacientes oncológicos, que estão realizando tratamento quimioterápico, para evitar consequências graves e até mesmo fatais.

Hepatitis C Virus (HCV) is a small RNA virus that progresses to chronicity in 50-80% of infected individuals. Direct-acting antivirals (DAAs) are revolutionary treatments for HCV with 90-98% cure rates. However, over time, chronic HCV infections can result in advanced liver disease, including cirrhosis. Patients with advanced fibrosis experience a poor response to vaccination, recurrent infections and increased risk for hepatocellular carcinoma (HCC). These outcomes are, in part, a consequence of immune dysfunction. Increased inhibitory receptor and Galectin-9 (GAL-9) expression is a possible mechanism promoting lymphocyte dysfunction. In this study, blood samples were collected from chronic HCV patients with different degrees of liver fibrosis. I conducted a 13-parameter flow stain on the peripheral blood mononuclear cells (PBMC) of these patients. Next, I measured the expression of inhibitory receptors (PD-1, CTLA-4, LAG-3, TIGIT and TIM-3) and GAL-9 on bulk T cell and NK cells of 15 chronic HCV patients with no to moderate fibrosis (F0-F2) and 15 with advanced fibrosis (F3-F4). To analyze receptor co-expression, I employed t-distributed stochastic neighbor embedding (t-SNE) analysis to dimensionally reduce the multi-parametric data. Notably, I found that F3-F4 patients had higher frequencies of >3 inhibitory receptor co-expression on NK cells. Moreover, t-SNE analysis of bulk T cells revealed that F3-F4 patients manifest a higher frequency of cells in the clusters with CD25+TIGITmed-hi CD4+ T cells and PD-1medLAG-3med-hiGAL-9med-hi CD4+ T cells. t-SNE analysis of NK cells also showed that F3-F4 patients manifest a higher frequency of cells in the cluster with CD25+TIGITmed-hiTIM-3med-hi CD56Dim NK cells and CCR7+ PD-1medLAG-3med-hiGAL-9med-hi CD56Dim NK cells. Lastly, the frequency of cells in these clusters was found to positively correlate with patient’s extent of liver damage. In conclusion, I identified phenotypes of immune dysregulation that could explain the increased susceptibility to infection and HCC in chronic HCV patients with advanced fibrosis. These phenotypes could identify targets for combinatorial checkpoint blockade therapy to potentially improve immune function in these patients.

Myelodysplastic syndromes (MDS) represent a group of clonal stem cell disorders characterized by ineffective hematopoiesis, peripheral cytopenia, morphological dysplasia and the risk of transformation to acute myeloid leukemia (AML). MDS belongs to one of the most common hematological diseases in patients over 60 years old. MDS incidence is still increasing. Appropriate therapy of MDS remains challenging. There is no curative approach besides peripheral stem cells transplantation, which is regretfully appropriate only for a small group of patients due to a higher median age of the MDS population. This is why the search for therapeutic alternatives remains paramount. MDS treatment was rather frustrating until the recent introduction of two new therapeutic approaches: immunomodulation therapy with lenalidomide and epigenetic or demethylating therapy with 5-azacytidine. Both new drugs have significantly higher effect than standard therapy. However, the precise mechanism of this effect remains unknown. As a result, we decided to initiate several research projects while introducing this promising treatment to our patients. Our aim is to investigate the mechanism of both agents in relation to disease pathogenesis by examining changes of certain occurrences and factors prior to and during the course of...

Hintergrund: Die ambulant erworbene Pneumonie (CAP) ist bei Patienten mit schwerer Immunsuppression häufig und mit einer schlechten Prognose assoziiert. Scores zur Risikoprädiktion bei Sepsis oder CAP sind bei diesen Patienten kaum untersucht. Fragestellung: Ziel der Studie war die Evaluation der prognostischen Prädiktion der qSOFA- und CRB-65-Scores bei Patienten mit Pneumonie und schwerer Immunsuppression. Methoden: Es handelt sich um eine retrospektive Kohortenstudie am Uniklinikum Dresden zwischen 2014 und 2017 mit Einschluss konsekutiver Patienten mit CAP und schwerer Immunsuppression (u.a. Neutropenie, aktive hämatologische Neoplasie, Z.n. allogener Stammzell- oder Organtransplantation, HIV–Infektion mit CD4-Zellen < 200/µl, zytostatische oder rheumatologische immunsuppressive Therapie innerhalb der letzten 3 Monate, Prednisolon-Äquivalent >10mg/d > 3 Monate). Patienten mit dokumentierter Therapielimitation oder direkter Aufnahme auf die Intensivstation wurden ausgeschlossen. Die CRB-65- und qSOFA-Kriterien wurden bei Erstvorstellung dokumentiert. Der primäre Endpunkt war definiert als Notwendigkeit mechanischer Beatmung oder von Vasopressoren (MVVS) und/oder Krankenhausletalität. Um die prognostischen Eigenschaften der Scores, der einzelnen Score- Parameter, sowie der darüber hinaus erhobenen Parameter zu untersuchen, wurden univariate und multivariate Regressionsanalysen sowie ROC-Kurvenanalysen durchgeführt. Ergebnisse: Von 198 eingeschlossenen Patienten erfüllten 41 (21%) den primären Endpunkt, 19 (10%) verstarben. Das Alter war kein unabhängiger Prädiktor, dagegen waren sowohl der CRB- als auch der qSOFA-Score in der Kaplan-Meier-Analyse sowie in der multivariaten Analyse unabhängig von anderen Prädiktoren mit dem primären Endpunkt assoziiert (jeweils p < 0.001). In der ROC-Analyse erreichten beide Scores eine moderate Prädiktion (AUC 0,70 bzw. 0,69), bei 0 vorliegenden Kriterien zeigte sich ein NPV von jeweils 89% (13/120 bzw. 12/105 Patienten „übersehen“). Bei ≥ 2 Kriterien resultierten PPVs von 44 bzw. 58%. Diskussion: Sowohl die CRB- als auch die qSOFA-Kriterien zeigten eine moderate, aber signifikante prognostische Aussagekraft. Das Alter ist dagegen in dieser Population kein geeigneter prädiktiver Parameter. Auch bei den Scores ohne Alterskriterium ist der NPV jedoch nicht ausreichend zum Ausschluss von Komplikationen. Daher sollten alle schwer immunsupprimierten Patienten mit Pneumonie zumindest initial stationär, bei > 1 positivem Score-Kriterium auch intensiv hinsichtlich einer akuten Organdysfunktion, überwacht werden.:ABBILDUNGSVERZEICHNIS V TABELLENVERZEICHNIS VI ABKÜRZUNGS- UND SYMBOLVERZEICHNIS VIII 1 EINLEITUNG 1 1.1 DIE AMBULANT ERWORBENE PNEUMONIE 1 1.1.1 Definition und Einteilung 1 1.1.2 Epidemiologie 2 1.1.3 Diagnosestellung 3 1.1.4 Erregerspektrum bei CAP ohne Immunsuppression 4 1.1.5 Therapie der CAP ohne Immunsuppression 5 1.1.6 Verlauf, klinische Stabilitätskriterien und Therapiedauer 6 1.2 RISIKOSTRATIFIZIERUNG DER CAP OHNE IMMUNSUPPRESSION 7 1.2.1 Bedeutung der korrekten und schnellen Risikostratifizierung 7 1.2.2 Risikostratifizierung der CAP ohne Immunsuppression 8 1.2.3 Aktuelle Studien zur Risikostratifizierung mittels CRB-65/qSOFA 13 1.3 CAP BEI IMMUNSUPPRESSION 15 1.3.1 Aufbau des Immunsystems 15 1.3.2 Immunsuppression 16 1.3.3 Ursachen der Immunsuppression 17 1.3.4 Bedeutung der CAP bei Immunsuppression 19 1.3.5 Verändertes Erregerspektrum und Therapie bei CAP-Patienten mit Immunsuppression 20 1.3.6 Risikostratifizierung bei CAP und Immunsuppression 23 1.4 RATIONALE UND STUDIENZIEL 26 2 METHODEN 28 2.1 ÜBERBLICK 28 2.2 STUDIENDESIGN 28 2.3 SELEKTION DER STUDIENPOPULATION 28 2.3.1 Datenbasis 28 2.3.2 Einschlusskriterien 29 2.3.3 Ausschlusskriterien 30 2.3.4 Studienpopulation 31 2.4 ENDPUNKTE 33 2.5 DATENERFASSUNG 33 2.5.1 Erhobene Parameter 33 2.5.2 Berechnete Scores und Parameter 34 2.6 FALLZAHLSCHÄTZUNG 34 2.7 STATISTISCHE ANALYSE 34 3 ERGEBNISSE 36 3.1 PATIENTENCHARAKTERISTIKA 36 3.2 MIKROBIOLOGIE 39 3.3 UNIVARIATE ANALYSEN 41 3.3.1 Primärer Endpunkt 41 3.3.2 Sekundärer Endpunkt 45 3.4 MULTIVARIATE ANALYSEN 48 3.5 KAPLAN-MEIER-ANALYSE 54 3.6 ROC-KURVENANALYSE FÜR QSOFA-, CRB-65-, QSOFA-65- UND CRB- SCORE 56 4 DISKUSSION 61 4.1 WICHTIGSTE ERGEBNISSE DER ARBEIT 61 4.2 REPRÄSENTATIVITÄT DER PATIENTENKOHORTE 61 4.2.1 Patientencharakteristika 61 4.2.2 Mikrobiologie 65 4.2.3 Endpunkte 66 4.3 PRÄDIKTIVE PARAMETER 67 4.3.1 CRB-65-Einzelkriterien und -Score 67 4.3.2 qSOFA-Einzelkriterien und -Score 69 4.3.3 Neuer Score 70 4.3.4 qSOFA-Score und CRB-65-Score im direkten Vergleich 70 4.3.5 Komorbiditäten 71 4.3.6 Laborchemische Prognoseparameter 72 4.3.7 Weitere Prognoseparameter 73 4.4 LIMITATIONEN 75 4.5 SCHLUSSFOLGERUNG UND KLINISCHE BEDEUTUNG 75 4.6 AUSBLICK 77 5 ZUSAMMENFASSUNG 78 6 SUMMARY 79 7 LITERATURVERZEICHNIS 80 8 ANHANG 93 9 DANKSAGUNG 101 10 SELBSTSTÄNDIGKEITSERKLÄRUNG 102 / Background: Community-acquired pneumonia (CAP) in immunocompromised patients is a common issue and often associated with poor prognosis. Scores for risk prediction used in immunocompetent patients with sepsis or CAP are poorly evaluated for these patients. Aim: The purpose of the study was to evaluate the prognostic value of the qSOFA- and CRB-65-criteria for risk stratification of immunocompromised patients with CAP. Methods: The retrospective cohort study including 198 consecutive patients hospitalized in the university hospital of Dresden with CAP and severe immunosuppression (neutropenia, active haematological neoplasia, stem cell transplantation, solid organ transplantation, HIV-infection with CD4-cells < 200/µl, immunosuppressive treatment within the last 3 months, prednisolone equivalent > 10 mg/d > 3 months) was conducted between 2014 and 2017. Patients that were admitted directly to the intensive care unit and those with treatment restrictions were excluded. The CRB- and qSOFA-criteria were documented when patients entered the emergency department. Primary outcome was defined as need of mechanical ventilation (MV) or vasopressor support (VS) and/or hospital-mortality. Univariate and multivariate regression analysis as well as ROC curve analysis were performed to investigate the prognostic properties of all scores, the single score parameters and other predictive parameters. Results: 41 (21 %) of 198 included patients reached the primary endpoint and 19 (10 %) of the patients died. Age was not an independent predictive parameter. Using Kaplan-Meier and multivariate logistic regression analysis, both the CRB- and qSOFA-scores were independently associated with the primary endpoint (each p < 0,001). However, after ROC curve analysis both scores only showed moderate prediction (AUC 0,70 and 0,69). With a score of 0, the negative predictive value (NVP) was about 89% in both scores (13/120 and 12/105 missed patients, respectively). When 2 or more parameters were positive the positive predictive values (PPV) were 44 and 58%, respectively. Conclusion: Both, the qSOFA as well as the CRB score, showed moderate but significant prognostic properties. In this population, age was an inappropriate predictive parameter. Even without the age criterion the NPV was inadequate to exclude the possibility of organ failure and complications. Therefore, all immunocompromised patients, especially those with a score > 1, should be monitored intensively concerning organ failure when having a CAP.:ABBILDUNGSVERZEICHNIS V TABELLENVERZEICHNIS VI ABKÜRZUNGS- UND SYMBOLVERZEICHNIS VIII 1 EINLEITUNG 1 1.1 DIE AMBULANT ERWORBENE PNEUMONIE 1 1.1.1 Definition und Einteilung 1 1.1.2 Epidemiologie 2 1.1.3 Diagnosestellung 3 1.1.4 Erregerspektrum bei CAP ohne Immunsuppression 4 1.1.5 Therapie der CAP ohne Immunsuppression 5 1.1.6 Verlauf, klinische Stabilitätskriterien und Therapiedauer 6 1.2 RISIKOSTRATIFIZIERUNG DER CAP OHNE IMMUNSUPPRESSION 7 1.2.1 Bedeutung der korrekten und schnellen Risikostratifizierung 7 1.2.2 Risikostratifizierung der CAP ohne Immunsuppression 8 1.2.3 Aktuelle Studien zur Risikostratifizierung mittels CRB-65/qSOFA 13 1.3 CAP BEI IMMUNSUPPRESSION 15 1.3.1 Aufbau des Immunsystems 15 1.3.2 Immunsuppression 16 1.3.3 Ursachen der Immunsuppression 17 1.3.4 Bedeutung der CAP bei Immunsuppression 19 1.3.5 Verändertes Erregerspektrum und Therapie bei CAP-Patienten mit Immunsuppression 20 1.3.6 Risikostratifizierung bei CAP und Immunsuppression 23 1.4 RATIONALE UND STUDIENZIEL 26 2 METHODEN 28 2.1 ÜBERBLICK 28 2.2 STUDIENDESIGN 28 2.3 SELEKTION DER STUDIENPOPULATION 28 2.3.1 Datenbasis 28 2.3.2 Einschlusskriterien 29 2.3.3 Ausschlusskriterien 30 2.3.4 Studienpopulation 31 2.4 ENDPUNKTE 33 2.5 DATENERFASSUNG 33 2.5.1 Erhobene Parameter 33 2.5.2 Berechnete Scores und Parameter 34 2.6 FALLZAHLSCHÄTZUNG 34 2.7 STATISTISCHE ANALYSE 34 3 ERGEBNISSE 36 3.1 PATIENTENCHARAKTERISTIKA 36 3.2 MIKROBIOLOGIE 39 3.3 UNIVARIATE ANALYSEN 41 3.3.1 Primärer Endpunkt 41 3.3.2 Sekundärer Endpunkt 45 3.4 MULTIVARIATE ANALYSEN 48 3.5 KAPLAN-MEIER-ANALYSE 54 3.6 ROC-KURVENANALYSE FÜR QSOFA-, CRB-65-, QSOFA-65- UND CRB- SCORE 56 4 DISKUSSION 61 4.1 WICHTIGSTE ERGEBNISSE DER ARBEIT 61 4.2 REPRÄSENTATIVITÄT DER PATIENTENKOHORTE 61 4.2.1 Patientencharakteristika 61 4.2.2 Mikrobiologie 65 4.2.3 Endpunkte 66 4.3 PRÄDIKTIVE PARAMETER 67 4.3.1 CRB-65-Einzelkriterien und -Score 67 4.3.2 qSOFA-Einzelkriterien und -Score 69 4.3.3 Neuer Score 70 4.3.4 qSOFA-Score und CRB-65-Score im direkten Vergleich 70 4.3.5 Komorbiditäten 71 4.3.6 Laborchemische Prognoseparameter 72 4.3.7 Weitere Prognoseparameter 73 4.4 LIMITATIONEN 75 4.5 SCHLUSSFOLGERUNG UND KLINISCHE BEDEUTUNG 75 4.6 AUSBLICK 77 5 ZUSAMMENFASSUNG 78 6 SUMMARY 79 7 LITERATURVERZEICHNIS 80 8 ANHANG 93 9 DANKSAGUNG 101 10 SELBSTSTÄNDIGKEITSERKLÄRUNG 102

Hintergrund: Patienten mit chronischen entzündlichen Erkrankungen sind aufgrund ihrer Grundkrankheit, aber auch durch die häufig notwendige immunsuppressive Therapie gefährdet, an einer impfpräventablen Infektionskrankheit zu erkranken. In einer Stichprobe sollte der Impfstand bei Patienten mit chronisch-entzündlichen Darmerkrankungen (CED) erhoben werden. Besondere Beachtung galt Vorbehalten der Patienten gegen die empfohlenen Schutzimpfungen. Methoden: Wir baten 203 Patienten mit CED (davon 57% Mb. Crohn, 63% weiblich; medianes Alter 36 Jahre), die im letzten Jahr keine Impfberatung erhalten hatten, einen Fragebogen mit 38 Fragen zu beantworten. Zudem wurden alle Impfnachweise erfasst und mit den aktuellen Empfehlungen der Ständigen Impfkommission abgeglichen. Die Befragung erfolgte vom 1.4. bis 30.9.2009. Ergebnisse: Nur 83% der Patienten hatten einen Impfausweis. Es fanden sich erhebliche Impfdefizite; so wurden in den letzten zehn Jahren nur 67% der Patienten gegen Tetanus und 21% gegen Pertussis geimpft, 28% nahmen die Impfung gegen die saisonale Grippe 2008 wahr und nur 9% wurden jemals gegen Pneumokokken geimpft. Im Subgruppenvergleich von Patienten mit TNF-Blockern (n=39) mit denjenigen Patienten, die noch nie eine immunsuppressive Dauertherapie erhielten (n=67), zeigten sich keine Unterschiede. 80% der Patienten wären bereit, alle offiziell empfohlenen Schutzimpfungen durchführen zu lassen. 22% aller Patienten gaben an, Schutzimpfungen zu vermeiden, weil sie Nebenwirkungen befürchteten, 15% weil das Immunsystem „nicht intakt“ ist und 9% befürchten eine Verschlimmerung der CED durch eine Impfung. Schlussfolgerungen: Der Impfstand in der untersuchten Stichprobe war unzureichend. Es fand sich insbesondere eine deutliche Diskrepanz zwischen der hohen Bereitschaft der Patienten, Schutzimpfungen durchführen zu lassen, und dem tatsächlichen Impfstand. Unsere Daten legen die Notwendigkeit einer erhöhten ärztlicher Wachsamkeit für Impflücken bei immunsuppressiv behandelten Patienten nahe. / Background: Patients with chronic inflammatory diseases are at increased risk for vaccine preventable infectious diseases. This is caused by the inflammatory state itself as well as often necessary immunosuppressive therapy. In a random sample, we investigated whether patients with inflammatory bowel disease (IBD) are sufficiently vaccinated. Special attention was spent to arguments for vaccine refusal. Methods: Between 1.4.2009 and 30.9.2009, we asked 203 consecutive IBD patients (thereof 57% Crohn’s disease, 63% female; median age 36 years), who got no vaccination advise within the last year to answer a questionnaire with 38 questions. As well, the vaccination cards were adjusted with the official recommendations. Results: Only 83% of patients had a vaccination card. We recognized substantial vaccination deficiencies. Within the past 10 years, only 67% of patients had tetanus and 21% had pertussis vaccination. Only 28% had an influenza vaccination in 2008 and only 9% were ever immunized against pneumococcus. A subgroup analysis of patients with TNF-blockers (n=39) with patients, who never had immunosuppressive therapy (n=67) revealed no difference. 80% of all patients are willing to adhere to all officially recommended vaccinations. 22% and 15% of patients stated that they avoid vaccinations as they afraid side effects or as they assess their immune system as not intact. Nine per cent feared a worsening of IBD after vaccination. Conclusions: In this random sample, the adherence to vaccination recommendations was low. We observed a marked difference between the willingness of IBD patients for immunizations and the realized vaccinations. Our data suggest that an increased medical awareness for vaccination deficiencies in immunosuppressed patients is mandatory.

Le mélanome est le cancer de la peau le plus mortel. Il est caractérisé par une grande hétérogénéité et une reprogrammation métabolique importante qui lui confère l’habileté de promouvoir des programmes immunosuppressifs et de développer une résistance aux traitements. Cette capacité permet au mélanome d’agir sur le microenvironnement tumoral et d’échapper à l’immunosurveillance du système immunitaire. La famille des peroxisome-proliferator activated receptor gamma coactivator 1 (PGC-1s) est un joueur clé du métabolisme cellulaire en régulant la biogenèse mitochondriale, la phosphorylation oxydative et la détoxification du stress oxydatif. Des études ont montré que l’expression de PGC-1α module la fonction mitochondriale. Les fonctions de PGC-1β et PRC, les 2 autres membres de cette famille, dans le mélanome restent largement inexplorées. Ce mémoire montre pour la première fois que l’expression des PGC-1s est non seulement associée à l’expression de plusieurs molécules pro-inflammatoires (IL-8, TNF, IL-1), mais aussi à l’expression de molécules immunosuppressives (CD73, PD-L2, Galectin-9) pouvant contrôler la réponse immunitaire. Par l’utilisation d’inhibiteurs ciblant des voies de signalisation de l’immunité innée, nous avons montré que la régulation de ces molécules s’effectue via MEK et IKK dans les cellules déplétées en PGC-1β. La déplétion en PGC-1 altère la fonction mitochondriale, induisant l’expression de p21 et l’arrêt du cycle cellulaire d’une manière soutenue et via un mécanisme indépendant des dérivés réactifs de l’oxygène (ROS). Nos travaux montrent que les PGC-1s possèdent d’importantes fonctions immunitaires dans le mélanome qui peuvent potentiellement dicter la croissance tumorale, l’évasion cellulaire et la réponse aux thérapies anticancéreuses. / Melanoma is the deadliest form of skin cancer. It is defined by great heterogeneity and extensive metabolic reprogramming which gives it the ability to promote immunosuppressive programs and develop therapy resistance. This ability allows melanoma to define the tumor microenvironment and escape the immunosurveillance of the immune system. The peroxisome-proliferator activated receptor gamma coactivator 1 (PGC-1s) family is a key player in cell metabolism by regulating mitochondrial biogenesis, oxidative phosphorylation and oxidative stress detoxification. Studies have shown that the expression of PGC-1α is linked to increased mitochondrial function and the metastatic potential of melanoma. The functions of PGC-1β and PRC, the other 2 members of this family, in melanoma remain largely unexplored. This thesis shows for the first time that the expression of PGC-1s is not only associated with the expression of several pro-inflammatory molecules (IL-8, TNF, IL-1) but also with the expression of immunosuppressive molecules (CD73, PD-L2, Galectin-9) which can control the immune response. Using inhibitors targeting innate immunity signaling pathways, we have shown that the regulation of these molecules occurs via MEK and IKK in PGC-1β depleted melanoma cells. Depletion of PGC-1 impairs mitochondrial function and leads to p21 induction and cell cycle arrest in a sustained manner by a reactive oxygen species (ROS)-independent mechanism. Our work shows that PGC-1s have important immune functions in melanoma that can potentially dictate tumor growth, cell evasion and response to cancer therapies.

Le virus de l'herpès simplex de sérotype 1 (HSV-1) est la plus grande cause de l’aveuglement infectieuse dans les pays développés. Les infections cornéennes à HSV-1 ont plusieurs conséquences, comme la difficulté à éliminer l'infection virale et l'inflammation provoquant une plus grande opacité de la cornée. Une infection cornéenne a montré qu'il y a colocalisation des cellules souches et les cellules amplificatrices transitoires avec le virus, mais le HSV-1 était toujours abondant dans le limbe de l'œil. Pour combattre le virus, anciennes publications ont montré que LL37, une cathélicidine humaine, peut réduire la charge virale. Le GF19, un fragment de LL37 modifié pour favoriser la perméabilité, a été capable de réduire la charge virale in vitro et ex vivo, avec la possibilité d'avoir des effets thérapeutique et préventif. Pour combattre les conséquences inflammatoires, un agoniste cannabinoïde CB2r impliqué dans la modulation de la neuroinflammation, TA-A001, a été testé. Des souris ayant reçu des brûlures alcalines pour induire l’inflammation et ils ont montré de meilleurs résultats cliniques avec le TA-A001 qu'avec le véhicule du médicament seul ou un corticostéroïde, la prednisolone. En conclusion, il apparaît que l’HSV-1 infecte rapidement le limbe, que le GF19 a pu réduire la charge virale, et que le TA-A001 a pu réduire l'inflammation en ayant peu d'effets secondaires. Une combinaison des traitements antiviraux et immunosuppresseurs administrés à la cornée pourrait être examinée plus pour combattre contre les infections à HSV-1 dans les yeux. / Herpes Simplex Virus serotype 1 (HSV-1) is the most common cause of infectious blindness in developed countries. Little is known about the early events in HSV-1 ocular infections since clinical symptoms often appear a week after infection. There are two significant consequences of HSV-1 corneal infection: the viral impacts of the disease and the inflammatory impacts. In mouse corneas, after HSV-1 infection, viruses localized in the limbal area of the cornea. However, there was no/little immunohistochemical co-localization with the stem cells or transient amplifying cells. Previous work has shown that LL37, a human cathelicidin, can reduce the viral burden. GF19, a fragment of LL37 with a modification to promote permeability, reduced viral loads in vitro and in ex vivo corneas. To combat the inflammatory consequences of HSV-1 infection, a cannabinoid CB2r agonist implicated in neuroinflammation modulation, TA-A001, was tested. Mice given alkali burns to induce inflammation showed better clinical results with TA-A001 than with the drug’s vehicle alone or a corticosteroid, prednisolone. In conclusion, it appears that HSV-1 quickly infects the limbus, GF19 was able to reduce viral burden, and CB2 agonists such as TA-A001 could reduce inflammation with few side effects. A combination of the anti-viral and immunosuppressant treatments could be a potential HSV-1 treatment.

Background/Objectives: The sequence of graft implantation in simultaneous pancreas-kidney transplantation (SPKT) warrants additional study and more targeted focus, since little is known about the short- and long-term effects on the outcome and graft survival after transplantation. Material and methods: 103 patients receiving SPKT in our department between 1999 and 2015 were included in the study. Patients were divided according to the sequence of graft implantation into pancreas-first (PF, n = 61) and kidney-first (KF, n = 42) groups. Clinicopathological characteristics, outcome and survival were reviewed retrospectively. Results: Donor and recipient characteristics were similar. Rates of post-operative complications and graft dysfunction were significantly higher in the PF group compared with the KF group (episodes of acute rejection within the first year after SPKT: 11 (18%) versus 2 (4.8%); graft pancreatitis: 18 (18%) versus 2 (4.8%), p = 0.04; vascular thrombosis of the pancreas: 9 (14.8%) versus 1 (2.4%), p = 0.03; and delayed graft function of the kidney: 12 (19.6%) versus 2 (4.8%), p = 0.019). The three-month pancreas graft survival was significantly higher in the KF group (PF: 77% versus KF: 92.1%; p = 0.037). No significant difference was observed in pancreas graft survival five years after transplantation (PF: 71.6% versus KF: 84.8%; p = 0.104). Kidney graft survival was similar between the two groups. Multivariate analysis revealed order of graft implantation as an independent prognostic factor for graft survival three months after SPKT (HR 2.6, 1.3–17.1, p = 0.026) and five years (HR 3.7, 2.1–23.4, p = 0.040). Conclusion: Our data indicates that implantation of the pancreas prior to the kidney during SPKT has an influence especially on the early-post-operative outcome and survival rate of pancreas grafts.

Background: Periodontitis is a chronic immuno-inflammatory disease characterized by inflammatory destruction of tooth-supporting tissues. Its pathogenesis involves a dysregulated local host immune response that is ineffective in combating microbial challenges. An integrated investigation of genes involved in mediating immune response suppression in periodontitis, based on multiple studies, can reveal genes pivotal to periodontitis pathogenesis. Here, we aimed to apply a deep learning (DL)-based autoencoder (AE) for predicting immunosuppression genes involved in periodontitis by integrating multiples omics datasets. Methods: Two periodontitis-related GEO transcriptomic datasets (GSE16134 and GSE10334) and immunosuppression genes identified from DisGeNET and HisgAtlas were included. Immunosuppression genes related to periodontitis in GSE16134 were used as input to build an AE, to identify the top disease-representative immunosuppression gene features. Using K-means clustering and ANOVA, immune subtype labels were assigned to disease samples and a support vector machine (SVM) classifier was constructed. This classifier was applied to a validation set (Immunosuppression genes related to periodontitis in GSE10334) for predicting sample labels, evaluating the accuracy of the AE. In addition, differentially expressed genes (DEGs), signaling pathways, and transcription factors (TFs) involved in immunosuppression and periodontitis were determined with an array of bioinformatics analysis. Shared DEGs common to DEGs differentiating periodontitis from controls and those differentiating the immune subtypes were considered as the key immunosuppression genes in periodontitis. Results: We produced representative molecular features and identified two immune subtypes in periodontitis using an AE. Two subtypes were also predicted in the validation set with the SVM classifier. Three “master” immunosuppression genes, PECAM1, FCGR3A, and FOS were identified as candidates pivotal to immunosuppressive mechanisms in periodontitis. Six transcription factors, NFKB1, FOS, JUN, HIF1A, STAT5B, and STAT4, were identified as central to the TFs-DEGs interaction network. The two immune subtypes were distinct in terms of their regulating pathways. Conclusion: This study applied a DL-based AE for the first time to identify immune subtypes of periodontitis and pivotal immunosuppression genes that discriminated periodontitis from the healthy. Key signaling pathways and TF-target DEGs that putatively mediate immune suppression in periodontitis were identified. PECAM1, FCGR3A, and FOS emerged as high-value biomarkers and candidate therapeutic targets for periodontitis.

Cancer immunotherapy has gained attention in recent years for its successes in potentiating immune responses that can elicit tumor control. In particular, adoptive cell therapy (ACT), which involves the autologous/allogeneic transplant of ex vivo-cultivated tumor-specific T lymphocytes, can mediate potent tumor recognition and killing; however, durable clinical responses are often difficult to obtain in solid tumors. Solid tumors and their unique microenvironments have the capacity to evade and suppress antitumor immune responses and represent significant hurdles for effective ACT. Recently, we have discovered that chemical inhibition of histone deacetylases via MS-275 (Entinostat) during ACT can subvert tumor resistance to foster potent, broad-spectrum antitumor immunity. Overall, the work described supports the efficacy of ACT in the treatment of immunosuppressive, solid tumors; however, consistency in durable clinical outcomes can only be achieved through the concurrent therapeutic targeting of tumor resistance mechanisms. This thesis uses pre-clinical models to describe how tumor resistance to ACT can manifest, and demonstrates that concurrent MS-275 delivery drives extensive immunomodulation to promote sustained tumor clearance. This includes: 1) The polarization of tumor-infiltrating myeloid cells into cytotoxic effectors with the ability to reject immune escape variants 2) The inflammatory remodeling of the tumor microenvironment to potentiate epitope spreading against secondary tumor antigens 3) The transcriptional reprogramming of adoptively transferred T cells to overcome tumor-burden-dependent exhaustion We expect that the results will help facilitate the development of next-generation ACT platforms that will feature strategies for multi-mechanistic perturbation of tumor resistance. / Thesis / Doctor of Philosophy (PhD) / The host immune system has the ability to recognize and destroy tumor cells. Therapeutic platforms that leverage antitumor immune cells, specifically T cells, have shown potency in the elimination of cancer. In the clinic, cancer immunotherapies have demonstrated early success against hematological malignancies; however, are unreliable in the treatment of solid tumors. Solid tumors utilize intrinsic and adapted mechanisms of resistance to mitigate the effectiveness of cancer immunotherapy. This thesis pursues research questions aimed at understanding how tumors resist immunotherapy, what mechanisms are utilized, and how to overcome these obstacles. We anticipate that these results will contribute to the development and incorporation of strategies to subvert tumor resistance and potentiate T cells against solid tumors.