Orientador: Mary Luci de Souza Queiroz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T08:29:05Z (GMT). No. of bitstreams: 1 Torello_CristianeOkuda.pdf: 8596128 bytes, checksum: e07457446c814c5f191e0c629491876d (MD5) Previous issue date: 2009 / Resumo: Neste trabalho, investigamos os efeitos do extrato padronizado de Rhodiola rosea L. (ERR) sobre a resposta imunohematopoética de camundongos infectados com Listeria monocytogenes. Os resultados demonstram que o ERR aumenta a resistência dos animais frente uma dose letal de Listeria quando administrado profilaticamente nas doses de 100 e 250 mg/kg por sete dias consecutivos anteriores à inoculação. Paralelamente, reversão da mielossupressão induzida pela infecção, concomitante ao aumento na atividade de células natural killers (NK) e na produção das citocinas TNF-a, IFN-? e fatores estimuladores de colônias foram observados. Os resultados obtidos demonstram que o ERR compartilha da habilidade de regular positivamente os desequilíbrios hematopoiéticos e imunológicos envolvidos nos estágios iniciais da infecção com L. monocytogenes. Estes efeitos podem ser atribuídos à recuperação no equilíbrio da resposta hematopoiética através da produção de IL-1a e IL-6 pelas células estromais no microambiente medular e também da produção de fatores estimuladores de colônias a partir das 24 horas de infecção, promovendo aumento no número de progenitores de macrófagos e granulócitos na medula óssea. Além disso, a eficácia do ERR também depende do aumento na produção das citocinas TNF-a e IFN-?, do aumento na atividade funcional das células NK e polarização da resposta celular para Th1. Juntos, estes efeitos contribuem para o aumento na resistência a L. monocytogenes. / Abstract: In this work, we have investigated the effects of Rhodiola rosea L. extract (ERR) in Listeria monocytogenes infected mice. Our results demonstrated that ERR protects mice from a lethal dose of L. monocytogenes, when administered prophylactically at 100 and 250 mg/kg, for seven consecutive days prior to the infection. In addition, prevention of myelosuppression induced by infection, concomitant to increasing natural killers (NK) cells activity and production of TNF-a, IFN-? and colony-stimulating factors were observed. The results showed that ERR share the ability of regulating positively the hematopoietic and immunological unbalance involved in the initial stages of infection with this pathogen. These effects could be attributed to recovering of the hematopoietic response through the production of IL-1a and IL-6 by stromal cells in the bone marrow microenvironment and the production of colony-stimulating factors at 24 hours of infection, promoting an increase in the number of granulocytes and macrophages progenitors in the bone marrow microenvironment. Moreover, the efficacy of ERR depends on high levels of TNF-a and IFN- ?, increased NK cells activity and polarization to Th1 response. Together, these effects contribute to increasing resistance to L. monocytogenes. / Universidade Estadual de Campi / Farmacologia / Doutor em Farmacologia

Cancer immunotherapy is an encompassing term referring to therapeutic strategies that aim to boost the immune system to fight cancer. These strategies include administering immune cells that have been altered to have greater anti-tumor activity or using biologics and small molecules that target immune components to also promote tumor clearance. Natural Killer (NK) cells are cells of the innate immune system that recognize and kill abnormal cells such as cancer cells and play an important role in the anti-tumor response. Because of their crucial role in tumor immunity, NK cells are prime targets for immunotherapies. Repurposing small molecule drugs is an attractive strategy to identify new immunotherapies from already approved drugs. Here, we screened 1,200 approved drugs from the Prestwick Chemical Library to identify drugs that increase NK cell cytotoxicity. We used a high-throughput luciferase-release cytotoxicity assay to measure the killing of the myeloid leukemia cell line, K562 cells expressing nano luciferase (NL) by NK92 cells, a human NK cell line. From the drug candidates identified from the screening assay, the antibiotic colistin sulfate increased cytotoxicity of the NK92 cell line and unstimulated human NK cells towards K562-NL cells. This increase in NK cytotoxicity was short-lived as pre-treating NK92 cells with colistin for 1 hour or 24 hours did not increase cytotoxicity. Also, we show pre-treating K562-NL target cells with colistin does not sensitize them to NK-mediated killing. Further studies are needed to uncover the mechanism of action of colistin, thus contributing to knowledge of fundamental NK cell biology regarding NK cell cytotoxicity which will aid in identifying additional small molecule drugs that enhance NK cell activity.

Depuis peu, l’immunothérapie a émergé comme une nouvelle stratégie chez les patients atteint de Cancer Bronchique Non à Petites Cellules (CBNPC), confirmant ainsi le rôle du système immunitaire dans cette maladie. Malgré ces nouveaux traitements (thérapies ciblées, immunothérapie), les taux de réponses restent faibles avec un impact modeste sur la survie globale. Des biomarqueurs sont donc nécessaire pour définir les populations cibles de ces traitements. Une des pistes explorées est le statut immunitaire des patients, en effet celui-ci a un impact pronostic et pourrait influencer la réponse aux traitements standards tels que la chimiothérapie, les thérapies ciblées et même l’immunothérapie. Parmi les cellules du système immunitaire, les cellules Natural Killer (NK) auraient un rôle effecteur dans le CBNPC. Il est maintenant clairement établit que les cellules NK favorisent la mise en place d’une immunité adaptative fonctionnelle et efficace. Ainsi une altération des fonctions NK pourrait être un mécanisme associé à l’échappement à l’immunité adaptative de la tumeur. Dans notre première étude, nous avons mis en évidence que les exosomes de cellules dendritiques stimulaient les cellules NK via NKp30, cette activité étant associée à un gain de survie sans progression chez des malades inopérables porteurs d’un CBNPC avancé. Notre second projet a révélé, pour la première fois, un rôle pronostic des transcrits de NCR3 (gène de NKp30) chez des patients naïfs de tout traitement. L’activation des cellules NK via NKp30 pourrait être une stratégie efficace d’immunomodulation chez les patients atteints de CBNPC avancé. Ces travaux confirment le rôle important des cellules NK dans le CBNPC avancé. / Recently, immunotherapy has emerged as a new strategy in Non-Small Cell Lung Cancer (NSCLC) patients, confirming the key role of the immune system in this disease. Despite these new treatments (targeted therapies, immunotherapy), response rates remain low with a modest impact on overall survival. Biomarkers are needed to define the target population of these treatments. One of the options explored is the immune status; indeed the immune status of cancer patients has a prognosis impact and may influence the response to standard treatments such as chemotherapy, targeted therapies and even immunotherapy. Among the immune cells, Natural Killer cells (NK) have an effector role in NSCLC. It is now established that NK cells can promote a functional and efficient adaptive immunity. Therefore, an impaired NK functions could be a mechanism associated with the escape from adaptive immunity of the tumor. In our first study, we demonstrated that exosomes from dendritic cells stimulated NK cells through NKp30, this activity is being associated with improved survival in advanced NSCLC. Our second project has revealed, for the first time, a independent prognostic role of NCR3 transcript (NKp30 gene) for naïve advanced NSCLC. Activation of NK cells via NKp30 could be an effective strategy for immunomodulation in advanced NSCLC patients. These studies confirm a major role of NK cells in advanced NSCLC.

Study of receptor-ligand pair NKR-P1F and Clrg Mouse NKR-P1F:Clr-g receptor:ligand pair is important component of the receptor "zipper" that occurs at the contact between natural killer cell and its target cell, and represents a recently discovered example of lectin-lectin interactions important for recognition among immune cell subsets. In order to study structure of these proteins and interactions between them, we have prepared pET-30a(+) bacterial expression vectors coding parts of extracellular domains of the two receptors. After induction of protein production with IPTG, the proteins precipitated into inclusion bodies, from which they could be refolded in vitro. Refolded proteins were purified using combination of ion exchange and size exclusion chromatography. NKR-P1F construct yielded only small amounts of soluble protein using standard refolding protocols. Furthermore we have experienced difficulties with reproducibility of the refolding results. In the case of Clrg the standard protocols for protein refolding were not sufficient. In order for the Clrg to fold properly, the odd cysteine which does not fit into the pattern usual for this family of receptors was substituted for serine and resulting C148S construct was shown to be more useful. Further, using (benzyldimethylammonio)propanesulfonate in...

(english) Natural Killers - NK cells play an important role in immune surveilance and regulation either by direct cytotoxicity towards infected, transformed or otherwise damaged cells, or by production of cytokines and chemokines. The resulting response of NK cells is given by the sum of stimulating and inhibiting signals, tranduced by a wide array of receptors. Killer Ig-like receptors KIR2DL4 and LILRB1, which recognize self HLA-G molecules in pregnancy, as well as NKR-P1 receptors, which differ in the number of isotypes, are species-dependent and reduced during phylogenesis. NKG2D, reacting to stress-inducible proteins, and adenosine receptors (AR), which supress the inflamatory reaction, remain evolutionary conserved. The aim of this work was to study the involvement of NK cells and their receptors in several immune disorders and in various species, to provide new insights into their function and posisible immune modulation. We have shown here, that the choice of species in the study of NK cell effector functions may be crucial in some cases. The reaction to glycans, using synthetic GlcNAc-terminated glycomimetics GN8P, exerted opposing effects on NK cell function in humans and C57Bl/6 mice. In humans, the glycomimetic decreased cytotoxic activity of high NKR-P1A expressing NK cells, while in...

The kinetics of tumor growth and progression are governed by the interaction between tumor cells, the non-malignant stroma and both innate and adaptive immune cell lineages. Innate immunity has a critical role in the control of tumor cell growth and metastasis. The microenvironment of many tumors is populated with innate immune cells, including regulatory natural killer (NK) cells and dendritic cells (DCs), tumor associated macrophages, and myeloid derived suppressor cells, that suppress normal immune function. Much of our understanding of interactions between tumors and the innate immune system is based on experimental studies performed in mouse “syngenic” models. However, there is clear need for a mechanistic understanding of the human innate immune system within the tumor microenvironment. The goal of my thesis is to characterize the interactions between human innate immune cells and tumors and to define specific pathways and cell lineages that are targets for immune modulation. A central focus of my thesis is the use of cutting-edge humanized mouse models based on the immunodeficient NOD-scid IL2Rgnull (NSG) mouse strain to study human immuno-oncology. In the first section of my thesis I describe studies that evaluate the influence of inflammatory stimuli on innate immune control of tumors. Agents that induce inflammation have been used since the 18th century for the treatment of cancer. The inflammation induced by agents such as toll-like receptor (TLR) agonists is thought to stimulate tumor-specific immunity in patients and augment control of tumor burden. While NSG mice lack murine adaptive immunity (T and B cells), these mice maintain a residual murine innate immune system that responds to TLR agonists. Here I describe a novel NSG mouse strain lacking TLR4 that fails to respond to lipopolysaccharide (LPS). NSG-Tlr4null mice support human immune system engraftment and enables the study of human specific responses to TLR4 agonists. My data demonstrate that specific stimulation of TLR4 activates human innate immune system and promotes regression of human patient derived xenograft (PDX) tumors. In the second section of my thesis I describe the development of an NSG mouse strain that constitutively expresses human Interleukin 15 (IL15) and supports the development of functional human NK cells. Using humanized NSG-IL15 transgenic mice (NSG-Tg(Hu-IL15), my data clearly demonstrate a critical role for human NK cells in limiting growth of a PDX melanoma. In the third section of my thesis I describe, the use of the bone marrow/liver/thymus (BLT) humanized mouse model to study the interactions between the human immune system and PDX melanoma and to evaluate the response of the melanoma to immunotherapy modalities. My results collectively suggest that mice engrafted with human immune systems and bearing human tumors can be harnessed as translational models, which are critically needed as tools to study tumor immunotherapy. These humanized mouse models are an ideal translational tool to advance our understanding of human immuno-oncology and for development and testing of novel immune therapies for the treatment of malignancies.

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Diverses études ont souligné le rôle prépondérant du dialogue entre les cellules NK et les cellules dendritiques au cours des réponses immunes. Cependant, les récepteurs impliqués dans ce processus restent incertains. Au cours de ce travail, nous nous sommes attachés à identifier les récepteurs mis en jeu lors de la reconnaissance virale à l’aide de modèles humains et murins. Pour cela, nous avons mimé l’infection virale en utilisant deux ARN bicaténaires synthétiques – poly(AU) et poly(IC) – et montré qu’ils sont tous deux capables d’activer TLR3 mais que seul poly(IC) engage les hélicases RIG-I et MDA5. Les deux ARN induisent l’activation des cellules NK au sein des PBMC humaines, mais seul poly(IC) induit la production d’IFN-gamma. Les DC myéloïdes (mDC) sont requises pour cette activation sans nécessité d’un contact cellulaire entre les cellules NK et les mDC. En outre, les IFN de type I et l’IL-12 secrétés par les DC sont respectivement nécessaires à l’initiation du potentiel lytique et à la production d’IFN-gamma. Poly(IC), au contraire de poly(AU), a une action synergique avec l’IL-12 produite par les mDC pour induire la production d’IFN-gamma en agissant directement sur les cellules NK. Enfin, l’activation conjointe de TLR3 et des hélicases RLR sur les mDC et RIG-I sur les cellules NK, nécessaire à la production d’IFN-gama en réponse à l’ARN bicaténaire, a été confirmée à l’aide de souris déficientes pour TLR3 et Cardif et d’un ligand spécifique de RIG-I. En conclusion, nous rapportons pour la première fois la nécessité pour un composé microbien d’engager deux familles de récepteurs sur deux populations cellulaires distinctes pour induire une réponse innée éfficace. / Crosstalk between NK cells and DC is critical for the response to the microbial mimic poly(IC) but the dsRNA receptors involved in each cell types remained to be defined. We show herein that two dsRNA, poly(AU) and poly(IC), similarly engaged TLR3 while only poly(IC) triggered the RIG-I and MDA-5 helicases. Both dsRNA triggered NK cell activation within PBMC but only poly(IC) induced IFN-gamma. mDC were required for NK cell activation by the two dsRNA, suggesting that they triggered at least TLR3 on mDC. DsRNA induction of cytolytic potential and IFN-gamma production in NK cells did not require contact with mDC but was dependent on the secretion of type I IFN and IL-12, respectively. Poly(IC) but not poly(AU) synergized with mDC-derived IL-12 for high IFN-gamma production by acting directly on NK cells. Finally, the requirement of TLR3 and the RLR on mDC and the involvement of the RIG-I but not TLR3 on NK cells for the production of IFN-gamma induced by dsRNA was confirmed using TLR3 and Cardif deficient mice and RIG-I specific activator. This cooperation was further confirmed using inactivated FLU virus infected-target cells both in human and mouse system demonstrating that NK cells were able to sense viral material by a direct transfer from infected cells likely through lytic immunological synapse without prior infection of NK cells. Thus, we report for the first time the requirement of cotriggering

La maladie du greffon contre l’hôte (GvHD) est une complication majeure des greffes de cellules souches hématopoïétiques (HSCT) qui survient dans 30 à 70% des cas et peut causer la mort, malgré un traitement prophylactique bien conduit. Il existe donc une réelle demande clinique pour améliorer ces traitements prophylactiques. Parce que ces traitements prophylactiques reposent en général sur des agents immunosuppresseurs, ceux-ci contribuent à diminuer la reconstitution immunitaire du patient, ce qui a un impact défavorable sur les infections et les taux de rechute d’hémopathie maligne, et donc limite leur utilisation. Les immunoglobulines (IVIG) pourraient représenter une alternative intéressante puisqu’elles ont des propriétés immunomodulatrices et qu’elles sont de plus couramment utilisées en clinique pour traiter des patients ayant un déficit immunitaire. Leur capacité à réduire l’apparition et la sévérité de la GvHD, sans toutefois inhiber ou nuire à la reconstitution immunitaire chez le patient n’a néanmoins jamais été clairement démontrée. Les objectifs de ce projet sont donc d’évaluer l’efficacité des IVIG à réduire l’incidence et la sévérité de la GvHD dans un modèle murin humanisé de GvHD, ainsi que de déterminer le mécanisme d’action des IVIG. Ce modèle consiste à injecter des huPBMCs à des souris immunodéprimées ne pouvant les rejeter. Les résultats obtenus suggèrent que les IVIG possèdent un effet immunomodulateur permettant de réduire les signes cliniques et de retarder l’apparition de la GvHD, tout en permettant l’apparition de cellules NK. Les IVIG agiraient de façon indirecte sur les huPBMCs afin d’induire l’apparition des cellules NK. / Graft-versus-host disease (GvHD) is a major complication following hematopoietic stem cell transplantation (HSCT), occuring in 30 to 70% of HSCT despite proper prophylactic treatment, and can result in death. It is therefore primordial to improve the prophylactic treatments in order to reduce the frequency and severity of GvHD. Since these prophylactic treatments are based on the use of immunosuppressive agents, they inhibit the immune reconstitution and thus increase the risk of infections and relapse. Because of their immunomodulating properties, immunoglobulins (IVIG) represent a promissing alternative. Furthermore, IVIG are already widely used in patients with immune deficits. Since no study has yet clearly shown that IVIG can reduce GvHD without inhibiting the immune reconstitution in the patient, the scientific community is still debating their usefullness in GvHD prevention. Should their efficacy to reduce the incidence and severity of GvHD without impairment to the immune reconstitution be demonstrated, the use of IVIG could change the clinical outcome for HSCT patients, improving their remission and quality of life. The objectives of this project are to evaluate IVIG efficacy in GvHD prevention and to define the mechanism of action of IVIG. To fulfill these objectives, we will use a GvHD humanized mouse model, which consists of injecting huPBMCs in immunodeficient mice who can not reject them. Our results demonstrate an immunomodulatory effect of IVIG, allowing for reduced clinical signs and a slighlty increased survival in GvHD. A population of NK cells also appeared upon IVIG treatment and is believed to be indirectly induced by IVIG.