The study of the immune system has provided insight in the mechanism of protection induced by vaccination; primarily that most clinically protective vaccines are potent in generating neutralizing antibody responses. However, vaccination fails to protect against a wide range of acquired chronic infections caused by viruses, such as HIV, HBV and HCV. One of the major reasons for weak responses to therapeutic vaccine is the impaired function of effector T cells resulting from viral persistence. Although IL-2 can potently increase effect function of viral specific T cells, systemic administration of IL-2 induces organ pathology and expansion of Treg cells. In this study, we have now developed a novel vaccine delivery system IL-2-nanoAPC delivering antigen-MHC complexes (pMHC), co-stimulatory molecules and IL-2 to antigen specific T cells. NanoAPC are derived from the endoplasmic reticulum (ER) membranes of human B cell line 721.221 engineered with selected HLA allele and IL-2 as the ER retention proteins. The IL-2-nanoAPC interacted with antigen specific T cells, induced immune synapses and expression of high affinity IL-2 receptor and enhanced effector function of antigen specific T cells, but did not affect bystander T cells and Foxp3+ Treg cells. Together with pMHC, co-stimulatory molecules, the selective delivery of IL-2 not only increased the CD4 and CD8 T cell responses to viral antigens but also enhanced TCR proximal signalling and suppressed expression of PD1 molecules on IFNγ producing effector CD8 T cells. We also found that the co-induction of T helper responses by IL-2-nanoAPC in a mixed culture could increase CD8 T cell responses to viral antigen. The IL-2-nanoAPC effectively induced responses of CD4 and CD8 T cells from chronic HBV patients. The results demonstrate that selective delivery of IL-2, together with pMHC and co-stimulatory molecules, by nanoAPC to antigen specific T cells has potential to recover anti-viral immune responses in chronic HBV patients.

O câncer cervical representa a terceira causa de morte por câncer em mulheres e está associado a infecções persistentes pelo Vírus do Papiloma Humano (HPV) em mais de 99% dos casos. Evidências sólidas mostram que a expansão de Células Mielóides Supressoras (MDSC) e fatores solúveis como a interleucina IL-10 são importantes mediadores da evasão tumoral à resposta imunológica contra tumores, que limita a eficácia de imunoterapias. Dada a importância epidemiológica dos tumores induzidos por HPV e a necessidade eminente do desenvolvimento de imunoterapias ativas contra essas lesões, desenvolvemos durante os últimos 12 anos, uma estratégia vacinal terapêutica baseada em DNA. Esta vacina codifica a proteína E7 do HPV-16 fusionada à glicoproteína D (gD) do Vírus Herpes Simplex do tipo 1 (HSV-1), denominada pgDE7h. O presente trabalho propôs a investigação de estratégias que restringem a imunossupressão, baseadas em um plasmídeo que codifica o receptor solúvel da citocina IL-10 (pIL10R) e da quimioterapia com gencitabina, na potencialização da vacina pgDE7h para controlar o crescimento de tumores que expressam as proteínas E6 e E7 do HPV-16 em modelo murino (células TC-1). Foi possível observar um atraso no crescimento do tumoral a partir da combinação da vacina com o pIL-10R. Adicionalmente, a utilização da eletroporação como método de entrega dos plasmídeos aumentou a proteção terapêutica para 90% e 60% quando os animais foram imunizados 5 ou 14 dias após o desafio, respectivamente. A combinação dos plasmídeos foi ainda capaz de elevar o número de linfócitos T CD8+ E7-específicos ativados, encontrados sistemicamente e no sítio tumoral. No consócio da imunização com a pgDE7h à gencitabina, foi possível observar um efeito sinérgico dessa associação, que aumentou a proteção antitumoral de 20% para 100% de animais livres de tumor, concomitante ao controle da expansão de populações imunossupressoras no baço. Além disso, a quimioimunoterapia administrada até 14 dias após o desafio com as células tumorais mostrou-se protetora em modelo de recidivas, simuladas por meio de transplantes subsequentes de células tumorais. Na busca de um protocolo vacinal com maior viabilidade clínica, combinamos a coadministração dos plasmídeos pgDE7h e pIL- 10R com o tratamento com gencitabina. Esta combinação terapêutica mostrou-se mais eficiente, onde se observou um aumento robusto da ativação de linfócitos T CD8+ E7-espefíficos, com regressão completa de tumores pré-estabelecidos. Em suma, esses resultados evidenciam que a associação de abordagens terapêuticas pode superar barreiras imunológicas presentes no ambiente tumoral e aumentar as chances de sucesso clínico do tratamento proposto. / Cervical cancer represents the third cause of cancer death among women, which is associated with persistent Human Papilloma Virus (HPV) infection in more than 99% of cases. Solid evidences show that the expansion of Myeloid-derived Suppressor Cells (MDSC) and soluble factors, such as IL-10, are important mediators of immune evasion mechanisms expressed by tumor cells, that limits the efficacy of immunotherapeutic approaches. Given the epidemiological importance of HPVinduced tumors and the crucial importance of developing active immunotherapies against neoplasias, during the past 12 years, we have been developing a DNA-based therapeutic vaccine strategy encoding the HPV-16 E7 protein fused to the Herpes Simplex Virus type 1 (HSV-1) glycoprotein D (gD), named pgDE7h. This work aimed to investigate the potential role of immunossupression restriction using a plasmid encoding the soluble IL-10 receptor (pIL10R) and the chemotherapeutic drug gemcitabine to enhance in enhancing the pgDE7h vaccine potency in the control of tumors expressing HPV-16 E6 and E7 proteins in a murine model (TC-1 cells). It was possible to observe a tumor growth delay after combining the vaccine with pIL-10R. Additionally, the use of electroporation as a plasmid delivery method provided a therapeutic protection of 90% and 60% when the animals were immunized 5 or 14 days after challenge, respectively. The combination of plasmids was also capable to increase substantially the numbers of activatedE7-specific CD8+ T lymphocytes both systemically and at the tumor site. When pgDE7h immunization was combined to chemotherapy, we observed a synergistic effect, which increased the antitumor protection from 20% to 100% and promoted the control of immunosuppressive cell populations in the spleen. It was possible to maintain the high antitumour protective effects of the chemo-immunotherapy when the animals were immunized 14 days after tumor cell challenge and tumor relapses after subsequent challenges with tumor cells. To search a vaccine protocol with greater applicability in a clinical setting, we combined co-administration of pgDE7h and pIL-10R and gemcitabine treatment. Our data showed that the combined treatment induced a robust increase in the activation of CD8+ T lymphocytes and a complete regression of pre-established tumors. All together, these results show that the combination of therapeutic approaches can overcome immunological barriers present in the tumor environment and increase the chances of clinical success of the propose therapeutic treatment.

A imunoterapia baseada em MoDC constitui uma estratégia para tratamento de indivíduos HIV+. Protocolos para obtenção de MoDC em geral utilizam IL-4 e GM-CSF (IL4-DC). Alguns estudos utilizam as IFN-DC (IFN-α + GM-CSF), que exibem um fenótipo combinado de DC mielóide, DC plasmocitóide (pDC) e célula NK. Esse perfil misto pode aperfeiçoar a imunoterapia para pacientes HIV+. Para tanto, monócitos de pacientes HIV+ foram cultivados com GM-CSF e IL-4 ou IFN-α por 5 dias e estimuladas por 48 horas com pulso de HIV inativado por AT-2 e/ou coquetel de citocinas pró-inflamatórias. Avaliamos a expressão de moléculas de superfície de IFN-DC e ativação de linfócitos T por citometria de fluxo; produção de citocinas IL-12 e IL-10 por ELISA. IFN-DC apresentaram morfologia e fenótipo basais ativados e características de pDC e célula NK, diferente das IL4-DC. As IFN-DC foram capazes de produzir IL-12, estimular a proliferação e produção de IFN-γ de linfócitos TCD4 e CD8, porém similares às IL4-DCs. IFN-DC são capazes de estimular resposta de linfócitos T tanto quanto IL4-DC. / Immunotherapy based on MDDCs is a strategy for treating HIV-infected patients. Alternatively to the conventional protocol for DC differentiation based on IL-4 and GM-CSF (IL4-DC) some studies suggest the use of IFN-DC (IFN-α + GM-CSF). These cells exhibit a combined phenotype of myeloid DC, plasmacytoid DC (pDC) and NK. Considering the mixed profile of IFN-DCs alternative protocols can bring novel elements for immunotherapy. Monocytes isolated from HIV-infected patients were cultured in the presence of GM-CSF and IL-4 or IFN-α. On day 5 DCs were pulsed with AT-2-inactivated HIV and stimulated for 48 hours with a cocktail of proinflammatory cytokines. We assessed IFN-DC surface markers expression and T cell activation by flow cytometry; IL-10 and IL-12 production by ELISA. IFN-DC showed activated morphological and phenotypic features during basal state of maturity and exhibited features of pDC and NK different from IL4-DC. The IFN-DC like IL4-DC were able to produce IL-12 and stimulated T cells. So, the IFN-DC were able to stimulate the T cells as well as IL4-DCs.

A imunoterapia baseada em MoDC constitui uma estratégia para tratamento de indivíduos HIV+. Protocolos para obtenção de MoDC em geral utilizam IL-4 e GM-CSF (IL4-DC). Alguns estudos utilizam as IFN-DC (IFN-α + GM-CSF), que exibem um fenótipo combinado de DC mielóide, DC plasmocitóide (pDC) e célula NK. Esse perfil misto pode aperfeiçoar a imunoterapia para pacientes HIV+. Para tanto, monócitos de pacientes HIV+ foram cultivados com GM-CSF e IL-4 ou IFN-α por 5 dias e estimuladas por 48 horas com pulso de HIV inativado por AT-2 e/ou coquetel de citocinas pró-inflamatórias. Avaliamos a expressão de moléculas de superfície de IFN-DC e ativação de linfócitos T por citometria de fluxo; produção de citocinas IL-12 e IL-10 por ELISA. IFN-DC apresentaram morfologia e fenótipo basais ativados e características de pDC e célula NK, diferente das IL4-DC. As IFN-DC foram capazes de produzir IL-12, estimular a proliferação e produção de IFN-γ de linfócitos TCD4 e CD8, porém similares às IL4-DCs. IFN-DC são capazes de estimular resposta de linfócitos T tanto quanto IL4-DC. / Immunotherapy based on MDDCs is a strategy for treating HIV-infected patients. Alternatively to the conventional protocol for DC differentiation based on IL-4 and GM-CSF (IL4-DC) some studies suggest the use of IFN-DC (IFN-α + GM-CSF). These cells exhibit a combined phenotype of myeloid DC, plasmacytoid DC (pDC) and NK. Considering the mixed profile of IFN-DCs alternative protocols can bring novel elements for immunotherapy. Monocytes isolated from HIV-infected patients were cultured in the presence of GM-CSF and IL-4 or IFN-α. On day 5 DCs were pulsed with AT-2-inactivated HIV and stimulated for 48 hours with a cocktail of proinflammatory cytokines. We assessed IFN-DC surface markers expression and T cell activation by flow cytometry; IL-10 and IL-12 production by ELISA. IFN-DC showed activated morphological and phenotypic features during basal state of maturity and exhibited features of pDC and NK different from IL4-DC. The IFN-DC like IL4-DC were able to produce IL-12 and stimulated T cells. So, the IFN-DC were able to stimulate the T cells as well as IL4-DCs.

O câncer de colo do útero é a segunda principal causa de morte em mulheres por câncer, sendo causado principalmente pela infecção persistente por HPV. A principal forma atual de prevenção desse câncer é a realização de exames citológicos periódicos e a vacinação profilática disponibilizada recentemente pelo Ministério da Saúde. Entretanto, tais ações visam a prevenção da infecção por HPV ou a detecção de lesões, pois não há um tratamento específico contra infecções e lesões já estabelecidas. Dentre as proteínas expressas por HPV, L2 está presente no capsídeo viral e é bem conservada entre diversos tipos de HPV, enquanto E6 é uma proteína oncogênica capaz de induzir a transformação maligna das células. Este estudo visa o desenvolvimento de uma vacina profilática e terapêutica capaz de proteger contra a infecção por diversos tipos virais, assim como combater as células já modificadas por qualquer tipo de HPV. Assim, foi construído um vetor vacinal contendo peptídeos selecionados das proteínas L2 e E6 de HPV16 testadas em modelo murino, para avaliar sua eficiência como vacina de DNA ministrada antes ou após desafio com células tumorais. Os ensaios em modelo animal demonstraram que a vacina foi capaz de induzir a produção de anticorpos específicos anti-L2 e anti-E6, assim como induzir a produção de citocinas TNF e impedir o desenvolvimento tumoral de células HPV-positivas. Portanto, foi possível concluir que o vetor construído foi capaz de induzir uma resposta imune humoral e celular em camundongos, capaz de prevenir contra o HPV, assim como tratar os cânceres a ele associados. / Cervical cancer is the second most frequent cause of death in women due to cancer, mainly caused by persistent HPV infection. The primary prevention method of this cancer is through periodic cytological exams and prophylactic vaccination which has been recently made available by the Ministry of Health. However, such actions aim towards prevention of HPV infection or the detection of lesions, since there is no specific treatment against pre-existing infections and injuries. Among the proteins expressed by HPV, L2 is present in the viral capsid and is well conserved among several types of HPV, whereas E6 is an oncogenic protein, capable of inducing malignant mutations in cells. This study aims towards the development of a prophylactic and therapeutic vaccine, capable of protecting against infections caused by several viral types, as well as combating cells which have already been modified by any type of HPV. Thus, a vaccine vector, containing peptides selected from HPV16s L2 and E6 proteins, tested in the murine model, was constructed in order to evaluate its efficiency as a DNA vaccine, to be administered either before or after challenging with tumour cells. The animal model assays demonstrated that the vaccine was able to induce the production of anti-L2 and anti-E6 specific antibodies, as well as TNF cytokines, and to prevent tumour development in HPV-positive cells. Therefore, it was possible to conclude that the designed vector was indeed able to induce humoral and cellular immune responses in mice, capable of preventing against HPV, as well as of treating cancers associated with it.

Neuartige Vakzinierungsstrategien zur Aktivierung einer Tumor-spezifischen zellulären Immunantwort sind vielversprechende Ansätze zur Therapie von Tumoren, insbesondere Human Papillomvirus (HPV)-assoziierte Tumore. Bisherige HPV-Impfstudien zeigen zwar die Aktivierung einer spezifischen zellulären Immunantwort, eine Tumorreduktion bleibt jedoch aus. Um diesen Effekt auf Immunzellebene zu definieren, wurde die Wirkung der HPV-Vakzine Ad p14 im Mausmodell und an Untersuchungsmaterial humaner Tumore analysiert. In Mäusen bildeten sich HPV+ TC1-Tumore einer frühen Entwicklungsphase nach Vakzinierung zurück. Tumore einer späten Entwicklungsphase wuchsen dagegen in zwei Intervallen aus. Immunologische Eigenschaften der Tumorzellen blieben dabei unverändert. Unterschiede zeigten sich in den Frequenzen Tumor-infiltrierender Lymphozyten; in progressiven Phasen wurden nur CD4+ T Zellen nachgewiesen, in Regressionsphasen zusätzlich zytotoxische CD8+ T Zellen. Immunmodulatoren, wie Interferon alpha oder DTA-1, einem Antikörper für den Glucocorticoid-induzierten Tumornekrosefaktor-Rezeptor, unterstützten die Wirkung der Vakzine; letzterer erhöhte die Anzahl zytotoxischer CD8+ T Zellen und führte zur Abstoßung der TC1-Tumore. HPV+ Tumorgewebe des Menschen, wie auch ihre Vorstufen, zeigten im Vergleich zu anderen Tumoren, wie Bronchial oder Kolonkarzinomen einen signifikant höheren Anteil an CD4+ und CD8+ T Zellen und an Forkhead Box P3+ regulatorischen T Zellen. Die Ergebnisse deuten darauf hin, dass die immunologischen Abläufe bei der Entwicklung HPV-assoziierter Tumore mit denen vorangeschrittener chronischer Erkrankungen vergleichbar sind, in denen sich CD4+ und CD8+ T Zellantworten erschöpfen während sich gleichzeitig immunsuppressive Mechanismen verstärken. Um die Entwicklung von Impfstoffen zur Therapie HPV-assoziierter Tumore zu verbessern sollten diese Mechanismen ausführlicher betrachtet werden. / Novel vaccination strategies, activating cellular tumour specific immune responses represent a promising approach for the treatment of cancer. Especially featured for these treatments are tumours evolving from chronic human papillomavirus (HPV) infections. But current strategies have not yet proved efficacious for complete tumour regression. Addressing cellular immunological aspects of tumour vaccination, this work focused on effects of HPV vaccine Ad p14 in mice and in samples of human tumours. In mice vaccination resulted in complete regression of early stage murine HPV+ TC1 tumours. Late stage TC1 tumours increased discontinuously. During that process, TC1 cells preserved their immunological characteristics. But frequencies of tumour-infiltrating lymphocytes varied; in progressing tumours only CD4+ T cells occurred, in temporary regressing tumours also CD8+ T cells were detected. Immune modulators, like interferon alpha or glucocorticoid-induced tumour necrosis factor receptor targeting antibody DTA-1 aggravated the effects of vaccination; latter raised cytotoxic CD8+ T cell numbers and resulted in complete tumour regression. Human HPV+ tumours as well as HPV+ precancerous stages revealed numbers of CD4+ and CD8+ T cells and especially of forkhead box P3+ regulatory T cells that were significantly increased compared to melanoma, bronchial or colon carcinoma. To assist further analysis of human HPV-associated cervical cancer and facilitate studies on therapeutic approaches, a humanized mouse model was established. The present work points to immunological exhaustion in the development of HPV-related tumours comparable to chronic diseases where CD4+ and CD8+ T cells exhaust and immunosuppression by regulatory T cells increases at the same time. For the development of appropriate strategies to enhance efficacy in HPV-associated tumour therapy, further knowledge of mechanisms involved in specific T cell activation, T cell exhaustion and immunosuppression is necessary.

Les cancers des voies aéro-digestives supérieures, liés à la consommation d'alcool et de tabac mais également à l'HPV-16, ont un pronostic médiocre malgré les traitements actuels. Le développement de nouvelles stratégies innovantes dans des modèles précliniques adaptés est ainsi nécessaire. Nous avons préalablement développé une stratégie vaccinale ADN permettant l'auto-assemblage in vivo de pseudo-particules virales non infectieuses exprimant l'oncoprotéine E7 de l'HPV-16 (pVLP-E7). Nous avons notamment montré que l'injection de pVLP-E7 en intradermique (ID) était capable d'induire de bonnes réponses anti-tumorales dans un modèle murin de cancer obtenu en injectant dans le flanc des cellules d'une lignée exprimant les antigènes E6 et E7 de l'HPV-16, mais qu'il était nécessaire d'ajouter des adjuvants de types agoniste de TLR 7 et 9 dans des tumeurs avancées. Afin de tester de nouvelles voies vaccinales dans un modèle pertinent, nous avons développé un modèle orthotopique intrabuccal présentant des caractéristiques anatomiques et inflammatoires plus proches des cancers observés chez l'homme que le modèle ectopique. Dans ce modèle, nous avons testé une voie vaccinale muqueuse intrajugale qui a montré de meilleures réponses T CD8+ spécifiques en comparaison à la voie ID. Nous avons montré que ce type de vaccination en association à des adjuvants, était efficace dans des tumeurs établies, en lien avec une infiltration intratumorale et ganglionnaire de lymphocytes T CD8+ spécifique, permettant également une protection lors de rechallenge tumoral. Cette stratégie apparaît donc prometteuse dans le traitement de ces cancers fréquemment récidivants. / Head and neck squamous cell cancer (HNSCC) associated with alcohol and tobacco consumption, and recently with human papillomavirus-16 (HPV-16), have bad prognosis despite current therapies. Development of innovative vaccine strategies and adequate pre-clinical tumor models are required to better evaluate HNSCCs. We developed a DNA vaccination that creates non-infectious virus-like particles, which express HPV-16 E7 oncoprotein (pVLP-E7). Results showed that pVLP-E7 induced an E7-specific immune response in vivo and in vitro. Moreover, using an ectopic model of HNSCC that expresses E6/E7 (TC-1), we found that pVLP-E7 intradermic (ID) immunizations induced anti-tumoral responses at early stages. For larger established tumors, pVLP-E7 vaccines were only efficient when administered with TLR-7 and TLR-9 agonists. In an orthotopic model that shares anatomical and inflammatory features with human HNSCC we observed that intra-cheek (IC) infusion of either TC-1 or NR-S1 cells into mice elicited higher numbers of inflammatory infiltrates in the tumor compared to ectopic models. Using this orthotopic IC model, we found that mucosal IC pVLP-E7 vaccination elicited better vaccine-specific CD8+ T-cell responses than ID administration in naive and tumor-bearing mice. Furthermore, pVLP-E7 IC immunizations in combination with TLR agonists led to rejection of established tumors and long-term protection, both of which were associated with E7-specific CD8+ T cell infiltration in tumors and lymph nodes. Our findings demonstrate that pVLP-E7 IC vaccination with adjuvants is efficient against these tumor models and together provides a valuable therapeutic strategy for HNSCCs.

Les lymphocytes T CD8+ jouent un rôle prépondérant dans le contrôle de l’infection par le VIH suggérant ainsi qu’un vaccin efficace doit induire une réponse cellulaire T CD8+ robuste et durable.En fournissant une source antigénique importante qui fait défaut chez les patients répondeurs aux poly-chimiothérapies antirétrovirales, la vaccination thérapeutique pourrait favoriser ce type de réponse cellulaire, non restaurée par les seuls traitements antirétroviraux. Les cellules dendritiques (DC) autologues, qu’elles soient chargées en virus inactivé, en peptides viraux ou en ARN messagers (ARNm) sont capables d’induire des réponses robustes des cellules T CD8+ contre les antigènes du VIH, faisant de bons candidats vaccins thérapeutiques.Dans ce projet, nous avons étudié l’efficacité d’une vaccination thérapeutique basée sur l’injection de DC autologues transfectées ex vivo avec des ARNm codant les protéines du VIH (projet initié en collaboration avec Guido Vanham, Institute of Tropical Medicine, Anvers). La composante antigénique du vaccin est fournie par les séquences virales endogènes du patient; ainsi nous espérons adapter la spécificité de la réponse immunitaire aux virus autologues. Nous travaillons avec le Macaque cynomolgus comme modèle animal d’infection par les virus d’immunodéficience (SIV), modèle pertinent dans l’approfondissement des connaissances en pathogénèse et en développement vaccinal, notamment pour tester l’innocuité et l’efficacité des vaccins basés sur l’utilisation des DC. La mise au point un système de culture de DC basé sur la prolifération puis la différenciation des progéniteurs hématopoïétiques CD34+, qui nous a permis de générer in vitro des DC matures en nombre suffisant pour la vaccination (au moins 10.106).Nous avons caractérisé ces DC phénotypiquement, avec une attention particulière vis-à-vis de l’expression de lectines de type C et d’autres récepteurs DC-spécifiques. Nous avons mis en évidence que l’état d’activation des DC définit le niveau d’expression de ces molécules. Ces récepteurs membranaires sont impliqués dans la capture et la présentation des antigènes aux effecteurs, ainsi que dans l’orientation de la réponse immune. Le phénotype des DC générées in vitro a été comparé au phénotype de plusieurs population de cellules présentatrices d’antigène présentes in vivo chez le macaque.La transfection avec des ARNm par électroporation est un moyen sûr et efficace de charger les DC en antigènes. Nous avons étudié dans un premier temps l’immunogénicité du vaccin chez des macaques sains. Les résultats montrent qu’une réponse cellulaire de type Th1 (IFN-gamma et interleukine-2) spécifique à Gag est induite dès la première injection et peut être renforcée après les injections suivantes. Nous avons également mis en évidence l’induction de lymphocytes T CD8+ capables de sécréter en réponse à Gag plusieurs de ces cytokines, IFNg, IL2, TNFa, la chimiokine MIP1b, ou encore le marqueur de dégranulation cytotoxique CD107a. En revanche, aucune sécrétion de cytokine de type 2 ni de réponse anticorps spécifique de Gag n'a pu être mise en évidence.La seconde partie de notre projet a consisté en l’étude d’une stratégie de vaccination par ciblage des DC in vivo avec des protéines de fusion DC-spécifiques associées à des antigènes. Ce travail a été mené en collaboration avec le Baylor Insitute for Immunology Research (BIIR) à Dallas. Nous avons tout d’abord sélectionné les meilleurs clones d’Ac spécifiques de molécules humaines pour leur réactivité croisée avec les molécules du macaque cynomolgus. L’immunogénicité de protéines de fusion (dirigées contre LOX-1 et DC-ASGPR couplées à Gag du VIH ou HA1 de Influenza), a ensuite été évaluée in vivo chez le macaque. Ces travaux ont confirmé in vivo que l’induction de différents profils de réponses immunitaires Ag-spécifiques (Th1 et IL10) est possible par ciblage in vivo des DC avec des protéines de fusion dirigées contre différentes molécules (LOX-1 et DC-ASGPR). / Current treatments against HIV infection would benefit from the development of complementary immunotherapeutic strategies. Dendritic cells (DC) play a major role in the induction of immune responses. In this thesis, we examine the use of the DC in therapeutic vaccination. Ex vivo loading of DC with messenger RNA encoding viral proteins and in vivo loading of DC by targeting antigen to DC-specific endocytic receptors are two strategies evaluated in healthy macaque.

La tuberculose (TB), maladie pulmonaire causée par le Mycobacterium tuberculosis (Mtb), reste la première cause de mortalité par un agent infectieux. La TB est responsable de près de 1,7 million de morts et de 10,4 millions de nouveaux cas par an dans le monde. L’émergence et la propagation de souches bactériennes multi-résistantes aux antibiotiques (MDR) représentent une menace majeure grandissante et reflètent l’efficacité partielle des thérapies actuelles. Le traitement des patients atteints de TB-MDR est constitué actuellement de combinaisons d’antibiotiques, souvent toxiques, administrés pendant une longue durée, avec une efficacité limitée. Il existe donc un besoin urgent de développer de nouveaux traitements antituberculeux. L’immunothérapie, dont l’objectif est d’améliorer la réponse immunitaire de l’hôte contre le Mtb, représente une approche complémentaire intéressante dans le but de diminuer la durée et d’augmenter l’efficacité des traitements actuels de la TB-MDR. Le premier objectif de cette thèse a été de caractériser un nouveau vaccin thérapeutique, basé sur le virus de la vaccine modifié d’Ankara (Modified Vaccinia virus Ankara, MVA), le MVATG18598, qui exprime dix antigènes représentatifs des trois phases de l’infection par Mtb. En utilisant différentes lignées de souris, nous avons montré que la vaccination par MVATG18598 entraîne l'induction de réponses spécifiques cellulaires et humorales. Les cellules T produisent plusieurs cytokines de type Th1 et présentent une activité cytolytique. Dans des modèles murins d’efficacité, le MVATG18598, associé à un traitement antibiotique, réduit significativement la charge bactérienne dans les animaux infectés ainsi que le taux de rechute de la maladie après l’arrêt du traitement. Le deuxième objectif de cette thèse a été d'analyser l'impact des antituberculeux sur l'immunogénicité du vaccin MVATG18598. Nous avons montré que les antibiotiques de première ligne, et principalement l’isoniazide, diminuent la réponse immunitaire Th1 induite par le MVATG18598. De plus, nous avons démontré que la réponse humorale induite par le candidat vaccin est modifiée et s’oriente vers une augmentation du rapport IgG1/IgG2a en présence d’antibiotiques. En conclusion, nous montrons qu'un vaccin immunothérapeutique, tel que le MVATG18598, a la capacité de contribuer au contrôle de la tuberculose en augmentant l'efficacité des traitements antituberculeux. De plus, nos résultats indiquent que les antibiotiques modulent la réponse immunitaire induite par le vaccin, données devant être prises en compte lors du développement des futures stratégies immunothérapeutiques / Tuberculosis (TB), a lung disease caused by Mycobacterium tuberculosis (Mtb), remains the leading cause of death worldwide from an infectious disease. TB is responsible for an estimated 1,7 million of deaths and 10,4 million new cases annually. The emergence and spreading of multidrug resistance (MDR) Mtb strains represent a major global threat and reflect limitation of current treatments. Patients with MDR-TB are currently treated with multiple drug regimens, often toxic, given for long durations, with a limited efficacy. Therefore, developing novel TB therapies is urgently needed. Immunotherapy aiming at triggering specific immune response against Mtb represents an attractive approach to shorten the duration and increase the efficacy of current MDR-TB treatment. The first aim of this PhD project was to characterize a novel therapeutic vaccine, based on the Modified Vaccinia virus Ankara (MVA), MVATG18598, expressing ten antigens representative of the three phases of Mtb infection. Using different strains of mouse, we showed that MVATG18598 vaccination is able to trigger Mtb antigens-specific humoral and cellular responses. Both CD4 and CD8 T cells display the capacity to produce multiple Th1-cytokines together with cytolytic activity. In post-exposure mouse models, MVATG18598 combined with an antibiotic regimen decreases significantly the bacterial burden in lungs of infected mice as well as the disease relapse rate after treatment completion. The second aim of this project was to analyze the impact of TB antibiotics on the immunogenicity of the MVATG18598 vaccine. We showed that first-line antibiotic regimen, mostly isoniazid, decreases antigen-specific Th1 immune response triggered by MVATG18598 vaccination in mice. Moreover, we demonstrated that Mtb-specific antibody response induced by the vaccine candidate is modified and shifted towards an increase of IgG1/IgG2a ratio in presence of drugs. Altogether, these results illustrate that immunotherapeutic vaccine such as MVATG18598 has the capacity to contribute to the control of TB by improving efficiency of anti-TB drugs treatment. In addition, our results indicate that antibiotics are able to modulate vaccine-induced immune response, a feature to consider for the future development of immunotherapies

生物科技為目前世界各國極力投入之新興產業，此產業無需大量天然資源及低污染的特性，同時又能解決人類的醫療問題並提昇生活水準的未來發展空間，更使得此一新興產業吸引了眾人的眼光。 　　本論文提出一個評估的模式，讓此產業之技術、產品或專利之價值能夠經系統化的分析後完整呈現，並可基於此分析結果作出策略上之判斷，並以GnRH vaccine技術為例。因為GnRH分子之序列早已發表，經本研究分析得兩種常用的專利保護策略，第一種是將GnRH與不同的載體進行結合，而新生成一個嵌合化合物，並申請此新化合物之專利；第二種是進行GnRH分子結構上之改變以取得新序列的專利保護，取得效果優於自然設計之分子，或藉以增加與免疫載體之結合率。經分析後發現，GnRH疫苗應用理論已經相當成熟，未來幾年應該會有成熟產品通過上市之審核過程；再隨著新科技的進步，可預期將會有更多的新產品會上市，而進一步地有效提昇產品功效並降低製造成本。 　　本研究最後針對GnRH未來在人用藥品及動物用藥之未來市場加以分析，並對於以重複免疫原在重組型疫苗製備法之開發提出行銷、財務、通路、價格、推廣、臨床實驗之建議，以期能經由策略規劃的角度將生物技術的價值作最大化的管理。 / Biotechnology attracts high attentions among many countries recently. New biotechnology will provide a key solution to cure diseases and potentially will be able to increase human life quality without damaging the environment and consuming massy natural resources. 　　In this thesis, we presented a possible process, which involved in academic, marketing and patent information analysis, to effectively evaluate the feasibility and potential of any novel biological technologies, so as to provide the managerial and strategic suggestions based on the analysis. GnRH repeat immunogens vaccine development was taken as an example to demonstrate if the proposed process can be executed adequately. After discretly cross examining the collected information, we concluded that many independent GnRH vaccine patents are available but will not be effective enough to stop to new competitors to get in this sector because GnRH sequence was disclosed in very early research and nobody held the patent for it and most of GnRH patents were granted to either different GnRH-Carrier chimeras or the GnRH analog sequences. Analysis results show that there is only one company closely approaching the final product approval at this moment. However, any improved technology can easily employed to provide a better product with higher effectiveness and lower cost following the first product's upcoming marketing clearance and then make the future market very complicated. 　　Based on those findings, we further analyze the Taiwanese current environment and provide a few managerial suggestions to maximize the value of a novel GnRH vaccine preparation technology.