Introdução: A resistência a infecção pelo HIV-1 depende de fatores virais, genéticos e imunológicos do hospedeiro, incluindo os componentes da resposta imune inata e adaptativa. As células Natural Killer (NK) e as células T CD8+ são as principais células efetoras que medeiam atividade citotóxica contra células transformadas ou infectadas, que exercem importante papel protetor nos indivíduos expostos e não infectados por HIV-1 (ENI). Objetivo: Avaliar a expressão de receptores de ativação e inibição/exaustão nas células NK e T CD8+, e a capacidade das células NK em secretar citocinas e componentes citotóxicos após estimulação via receptores Toll-like (TLRs), e a resposta de células T CD8+ a peptídeos da Gag do HIV-1 em indivíduos ENI e seus parceiros infectados por HIV-1. Resultados: No grupo ENI foi observado aumento da frequência de células NK CD56bright que expressam moléculas de ativação NKG2D e CD95 na população CD56dim, enquanto no grupo HIV-1 foi mais prevalente a expressão de MIC A/B em ambas populações de células NK, com redução da expressão de NKG2D na população CD56dim. Além disto, foi observado expansão da população de células NK CD56dim que expressam CD94, NKG2C e principalmente de CD57 foi mais prevalente nos indivíduos ENI, com correlação positiva com títulos de anticorpos IgG anti-citomegalovírus humano. Nos indivíduos ENI foi observado que a ativação via TLR-3, TLR-7 ou TLR-7/8 foi capaz de potencializar a expressão de marcadores de desgranulação e de citotoxicidade, CD107a e granzima B, principalmente na população CD56dim, e de IFN-y e TNF nas populações CD56bright e CD56dim. Além disto, somente o grupo ENI, foi detectado aumento da freqüência de células NK secretoras de CD107a, granzima B, IFN-y e TNF, após estimulação com acetato de miristato de forbol e ionomicina. A frequência de expressão de alelos de KIR (killer cell immunoglobulin-like receptors) foi similar entre os grupos analisados. Elevada frequência de células T CD8+ CD38+ e CD8+PD-1+ (programmed cell death protein 1) foi detectado nos grupos ENI e HIV-1, cuja alteração foi observada em todas as fases de maturação celular. Os indivíduos ENI mostraram presença de resposta antígeno-específica de células T CD8+ secretoras de CD107a, granzima B, IFN-y e TNF, semelhante ao grupo HIV-1. Conclusão: Os resultados mostraram que no grupo ENI, as células NK expressam um perfil de ativação, com potente resposta aos estímulos de resposta inata e células NK com perfil de memória. Presença de células TCD8+ antígeno-específica foi evidenciada no grupo ENI, com perfil semelhante, mas de menor magnitude ao detectado no grupo infectado por HIV. Em conjunto, os achados mostraram que no grupo ENI a resposta inata está potencialmente ativa, e que em associação a resposta T CD8+ antígeno-específica podem contribuir para a resistência a infecção pelo HIV-1 / Introduction: Resistance to human immunodeficency virus 1 (HIV-1) is dependent on viral, genetic and immunological host factors, including components of innate and adaptive immune response. Natural Killers cells (NK) and CD8+ T cells are main effectors cells mediating cytotoxic role against transformed or infected cells, playing a crucial role in HIV-1 exposed uninfected individuals (EU). Aim: To evaluate the expression of activation and inhibitory/exhaustion receptors on NK cells and CD8+ T-cells, and to determine the NK cells ability to cytokines and cytotoxic molecules secretion upon Toll-like receptors (TLRs) pathway activation as well as CD8+ T-cells response to HIV Gag peptides in EU individuals and HIV-1 infected partner. Results: Increased frequency of NK CD56bright cells expressing NKG2D and CD95 on CD56dim cells have been observed in EU group, while HIV-1 group was more prevalent MIC A/B expression in both NK cells subsets, with reduced expression of NKG2D in CD56dim cells. Moreover, expansion of NK CD56dim cells expressing CD94, NKG2C, and CD57 was prevalent on ENI group, which positive correlation with anti-human cytomegalovirus IgG serum titers. EU individuals showed that TLR-3, TLR-7 or TLR-7/8 pathway activation was able to enhance CD107a and granzyme B expression in CD56dim cells, and IFN-y and TNF expressions levels in both CD56bright and CD56dim NK cells. Moreover, only in EU group, high frequency of NK cells expressing CD107a, granzyme B, IFN-y and TNF were detected upon phorbol myristate acetate and ionomicyn stimulation. Frequency of KIR alleles (killer cell immunoglobulin-like receptors) was similar between groups. High frequency of CD8+CD38+ and CD8+PD-1+ (programmed cell death protein 1) T-cells were observed in EU and HIV-1 groups, in all stages of cellular differentiation. EU subjects showed presence of antigen-specific response by CD8+ T-cells secreting CD107a, granzyme B, IFN-y and TNF similar to HIV-1 group. Conclusion: The results showed that NK cells in EU subjects express activating profile, with potent ability to innate immune stimuli, as well as NK cells with memory profile. Presence of antigen-specific CD8+ T-cells was detected in EU group, with similar profile, but in less magnitude than HIV-1 group. Taken together, the findings showed an enhanced innate immune response in EU subjects, in association with antigen-specific CD8+ T-cell response can contribute to resistance to HIV-1 infection

INTRODUÇÃO: O objetivo do estudo foi avaliar o perfil de marcadores imuno-histoquímicos relacionados às células NK em biópsias de aloenxertos renais com diagnóstico anatomopatológico de rejeição aguda (mediadas por células T ou anticorpos) e estabelecer relações desses marcadores com parâmetros morfológicos de lesão à microcirculação e sobrevida do enxerto. MÉTODOS: Estudo retrospectivo histórico que revisou 74 biópsias realizadas entre janeiro de 2009 e dezembro de 2012, de pacientes com rejeição aguda mediada por células T (n=36), rejeição aguda mediada por anticorpos com expressão positiva (n=19) ou negativa (n=19) para o marcador C4d, juntamente com levantamento de dados clínicos e laboratoriais pertinentes ao estudo. Foram realizadas reações imuno-histoquímicas, para os marcadores CD56, CD57, CD16, CD68, CD3, CD8 e CD4 com ênfase para os marcadores CD56 e CD16. Foi feita análise das células positivas em toda a cortical da biópsia nos compartimento intersticial, glomerular e vascular. Testes estatísticos foram aplicados conforme os pressupostos definidos no objetivo da pesquisa. RESULTADOS: No compartimento intersticial, células CD56+ (P = 0,004) e CD57+ (P < 0,001) foram expressas em maior quantidade em biópsias negativas para dosagem sérica de anticorpos específicos anti-doador (DSA) com diagnóstico de rejeição aguda mediada por células T. CD56 intersticial foi associado estatisticamente com presença de glomerulite (g >= 1) (P = 0,02) e ausência / leve capilarite peritubular (ptc <= 1) (P = 0,003). Células intersticiais positivas para o marcador CD56 com média superior a 0,56 céls/mm2 tiveram uma pior sobrevida do enxerto renal (P = 0,028). Biópsias com contagem inferior ou igual a 0,56 cél/mm2 tiveram associação estatisticamente significante para ausência ou leve capilarite peritubular (P = 0,012) e com contagem superior a 0,56 céls/mm2, foram associadas à presença de glomerulite (P = 0,002). Foi observado maior número de células positivas para o marcador CD16 no compartimento glomerular em biópsias positivas para dosagem sérica de DSA com diagnóstico de rejeição aguda mediada por anticorpos (P = 0,03) e em biópsias com presença de glomerulite (P = 0,009). Presença de maior número de células CD16+ no compartimento intersticial associou-se com capilarite peritubular (P = 0,0001). CONCLUSÕES: Maior expressão de células CD56 positivas no compartimento intersticial das biópsias foi significantemente associada com escores relacionados à lesão na microcirculação, especialmente glomerulite, com rejeição aguda mediada por células T e pior sobrevida do enxerto renal. Células CD16 positivas, no compartimento glomerular foram associadas com rejeição aguda mediada por anticorpos e glomerulite. As variações na expressão dos marcadores de células NK nos diferentes compartimentos da biópsia renal podem sugerir presença de envolvimento das células NK em diferentes vias do sistema imune nas rejeições agudas de aloenxertos renais / INTRODUCTION: The aim of this study was to investigate the immunohistochemical profile of markers related to NK cells from renal allograft biopsies with morphological diagnosis of acute rejection (T-cells or antibodies mediated rejection) and to study associations of those markers with types of rejection, microcirculation injury morphological parameters and graft survival. METHODOLOGY: Historical retrospective study that reviewed 74 biopsies performed between January 2009 and December 2012 in patients with acute T-cell-mediated rejection (n=36) and acute antibody-mediated rejection with (n=19) or without evident C4d deposition (n=19). The study was performed with relevant clinical and laboratory data. Immunohistochemical reactions were performed for CD56, CD57, CD16, CD68, CD3, CD8 and CD4 markers with highlights for CD56 and CD16. Counting of positive cells throughout cortical biopsy was performed in glomerular, interstitial and vascular compartments. Statistical tests were applied according to assumptions set out the goal of the study.RESULTS: DSA-negative biopsies-from patients with acute T-cell mediated rejection (aTCMR) had an increased expression of CD56+ and CD57+ cells (P = 0.004 and P < 0.001) in the interstitial compartment in comparison with donor-specific antibodies ( DSA)-positive biopsies from patients acute antibody-mediated rejection with and without C4d deposition. Interstitial CD56+ cells had an increased expression for presence of glomerulitis (g >= 1) (P = 0.02) and peritubular capillaritis (ptc >= 2) (P = 0.003). Interstitial CD56 + cells with mean superior to 0.56cells/mm2 had worse allograft survival (P = 0.028). CD56+ cells in the interstitial compartment with mean inferior or equal to 0.56cells/mm2 associated with absence or mild peritubular capillaritis (P = 0.012) and mean superior to 0.56cells/mm2 was associated with presence of glomerulitis (P = 0.002). CD16+ cells was increased in the glomerular compartment in DSA-positive biopsies (P = 0.03) and in the presence of glomerulitis (P = 0.009). Interstitial CD16+ cells associated with peritubular capillaritis (P = 0.0001).CONCLUSION: CD56+ cell infiltrates in the interstitial compartment were significantly associated with microcirculation injury scores, especially glomerulitis, acute T-cell mediated rejection and clinical outcomes. CD16+ cell infiltrates in glomerular compartment was associated with acute antibody-mediated rejection and glomerulitis. Our findings showed variations in expression of NK cells markers in renal biopsy different compartments which might suggest the involvement of NK cells in different immune system pathways in acute renal allograft rejection

Orientador: Mary Luci de Souza Queiroz / Tese ( doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T11:14:50Z (GMT). No. of bitstreams: 1 Ramos_AlineLisie_D.pdf: 13996403 bytes, checksum: 20b3e94e609f9ce6fd4214680378bb52 (MD5) Previous issue date: 2008 / Resumo: A Chlorella vulgaris (CV) é uma alga microscópica bastante rica em nutrientes. Além de alto valor nutritivo, a Chlorella tem demonstrado possuir importantes atividades terapêuticas. Vários trabalhos do nosso laboratório e outros demonstram os efeitos protetores desta alga contra infecções virais e bacterianas, tumores, entre outros. No presente trabalho avaliamos os efeitos do tratamento profilático/terapêutico com a dose de 50mg/Kg/dia de CV sobre a resposta imunohematopoética de animais normais e portadores de tumor ascítico de Ehrlich (TAE). O estudo dos mecanismos envolvidos na proteção produzida pela alga frente às alterações induzidas pelo TAE no sistema imuno-hematopoético, demonstrou aumentos significativos na atividade de células NK, na produção de citocinas com padrão Th1 (IL-2 e INF-g) e na liberação de TNF-a por células esplênicas, paralelamente a uma diminuição na produção de IL-10 (padrão Th2). Além disso, o tratamento com CV protegeu o hospedeiro da mielossupressão provocada pelo desenvolvimento tumoral, seja agindo diretamente na formação e manutenção do estroma medular, estimulando a atividade das células estromais, ou ainda estimulando a produção de citocinas reguladoras da hematopoese como a IL-6 e a IL-1a. Constatamos ainda que o tratamento com CV aumenta a atividade estimuladora de colônias (CSA) no soro de animais portadores de tumor e a capacidade proliferativa de células esplênicas. Outros resultados que merecem destaque são aqueles relacionados à ativação macrofágica. Nossos resultados demonstram que, em animais normais, o tratamento com CV promove aumento significativo nos níveis de TNF-a nos sobrenadantes das culturas de macrófagos peritoneais e esplênicos sem alterar a produção de IFN-g e IL-10. Além disso, o restabelecimento da produção normal de TNF-a, IFN-g e IL-10 por macrófagos peritoneais de animais portadores de TAE e reversão parcial dos efeitos produzidos pela presença do tumor na atividade dos macrófagos esplênicos, também foram observados. Outro efeito do CV sobre macrófagos peritoneais de animais portadores de TAE foi o estímulo da produção de H2O2 e NO2 -. Analisando nossos resultados podemos dizer que a CV além de possuir alto valor nutritivo, capacidade antioxidante e atividade anti-viral e antibacteriana, apresenta importante atividade imunomoduladora frente ao desenvolvimento tumoral, já que na presença do tumor o hospedeiro que vem recebendo Chlorella é capaz de reagir mais prontamente e com maior vigor na indução de mecanismos essenciais de defesa imunológica. Neste sentido, sugerimos que a alga Chlorella vulgaris pode ser um candidato a agente preventivo e complementar no tratamento do câncer. / Abstract: Chlorella vulgaris (CV) is a microscopic alga rich in nutrients. Besides the high nutritive value, this alga has shown important therapeutic properties. Many studies from our laboratory and others have shown the protective effects of CV against viral and bacterial infections, tumors, among others. In this work we evaluated the effects of the prophylactic/therapeutic treatment with a dose of 50 mg/Kg/day in normal and Ehrlich ascites tumor (EAT)-bearing mice. The study of the mechanisms involved in the protection produced by the CV against the EAT, induced alterations in the immune-hematopoietic system; demonstrating significant improvements in the NK cells activity, Th1 (IL-2 and INF-g) and TNF-a cytokines production by mononuclear spleen cells, concomitantly with the decrease of IL-10 (Th2) production. Moreover, treatment with CV protected the host of myelosuppression caused by tumor development, it is acting directly in the formation and maintenance of bone marrow stroma, by stimulating the activity of stromal cells, or stimulating the production of important hematopoiese regulatory cytokines like IL-6 and IL-1a. We are also certain that the treatment with CV increases the colony-stimulating activity (CSA) in the serum of tumor bearing mice and the proliferative capacity of spleen cells. Other results that deserve attention are those related to macrophage activation. Our results show that in normal mice, treatment with CV, promotes significant increase in the TNF-a levels in upernatants of the cultures of peritoneal and spleen macrophages without altering the production of IFN-g and IL-10. Moreover, restoration of the normal production of TNF-a, IFN-g and IL-10 by peritoneal macrophages from animal carriers of EAT and partial reversal of the effects produced by the presence of tumor in the splenic macrophages activity were also observed. Another effect of CV on peritoneal macrophages of tumor bearing mice was the stimulation in the production of NO2 - and H2O2. Looking at our results we can say that the alga Chorella vulgaris in addition to its high nutritional value, antioxidant capacity and antiviral and antibacterial activities, it also presents important immunomodulatory activity against tumor development, since that in the presence of the tumor, the host that has received Chlorella is able to react more promptly and with greater force in the induction of essential mechanisms of immune defense. Accordingly, we suggest that the alga Chlorella vulgaris can be a candidate for the preventive and complementary treatment of cancer by strengthening the immune system. / Doutorado / Farmacologia

Orientadores: Carmino Antonio de Souza, Jeane Eliete Laguila Visentainer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T20:55:46Z (GMT). No. of bitstreams: 1 Marangon_AmandaVansan_D.pdf: 2274304 bytes, checksum: 433df5157fab3588b51689f24c4b86cf (MD5) Previous issue date: 2014 / Resumo: O Linfoma difuso de grandes células B (LDGCB) representa o subtipo mais prevalente de linfoma maligno não-Hodgkin, sendo responsável por 30-40% de todos os casos de LNH. O LDGCB não tem etiologia e patogênese bem definidas, porém o seu desenvolvimento parece estar relacionado a respostas imunes ineficazes, devido a frequente associação desse linfoma com estados de imunossupressão. Os fatores genéticos envolvidos no desenvolvimento e evolução da doença não são bem entendidos. Nesse contexto, o objetivo desse trabalho foi avaliar a influência dos genes KIR, dos ligantes HLA e do polimorfismo em genes de citocinas na susceptibilidade ou resistência ao desenvolvimento de LDGCB, bem como na evolução clínica e resposta ao tratamento. Para tanto, foram selecionados 112 pacientes com diagnóstico de LDGCB e 292 doadores de sangue e medula óssea como grupo controle. As tipificações dos genes KIR e dos ligantes HLA foram realizadas com a técnica de PCR-SSOP e a tipificação de citocinas foi realizada com a técnica PCR-SSP. As análises estatísticas foram realizadas pelo pacote estatístico "R" versão 3.0.2 para o programa Windows e os valores de P<0,05 foram considerados significativos. A distribuição dos genes KIR nos grupos estudados mostrou uma menor frequência do gene KIR2DL2 nos pacientes quando comparados aos controles (45,5% vs 58,1%; P=0,036), essa associação mostrou-se significativa também na combinação de KIR2DL2 com C1 (33,0%vs 45,9%; P=0,026) sugerindo um papel de proteção desse gene ao desenvolvimento de LDGCB. Em relação à evolução clínica da doença, os ligantes HLA-Bw4 e HLA-Bw4 80I foram mais frequentes nos pacientes com estádios mais avançados da doença (64,7% vs 40,9%; P=0,020 e 44,1% vs 25,0%; P=0,046, respectivamente) sugerindo que a presença desses ligantes pode ser fator de prognóstico ruim ao LDGCB. Em relação à resposta terapêutica, o gene KIR2DL3 foi associado positivamente ao tratamento do LDGCB, pois esse gene foi mais frequente nos indivíduos com resposta completa que nos indivíduos não respondedores (88,3% vs 71,0%; P=0,044). A respeito dos genes reguladores de citocinas, o genótipo IFN-gama-874/A:A foi associado positivamente ao LDGCB, sendo encontrado mais frequente nos pacientes que nos controles (50,9% vs 27,9%; P=0,001). Contrariamente os genótipos: IFN-gama-874/T:A, IL10-819/C:C e IL10-592/C:C foram menos frequentes nos pacientes que nos controles (P=0,001; P=0,025; P=0,025). Ademais, o genótipo IL10-1082/G:G foi relacionado a maior sobrevida livre de progressão. Os resultados encontrados sugerem que os genes KIR, os ligantes HLA e os genes de citocinas parecem ter envolvimento na proteção, susceptibilidade, evolução clínica e resposta ao tratamento do LDGCB / Abstract: Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of malignant non-Hodgkin lymphoma and affects approximately 30-40 % of all cases. The DLBCL has no clearly defined etiology and pathogenesis, but its development seems to be related to ineffective immune responses due to frequent association of lymphoma with immunosuppression. Genetic factors involved in the development and progression of the disease are not well understood. The aim of this study was to evaluate the influence of KIR genes, HLA ligands and cytokine polymorphisms in the susceptibility or resistance to the development of DLBCL, as well as influence in the clinical course and response to treatment. To this end, we selected 112 patients with DLBCL and 292 bone marrow donors as control group. The typing of KIR genes and HLA ligands were performed by PCR-SSOP and typing of cytokine genes was performed by PCR-SSP technique. Statistical analyzes were performed by the statistical package " R " version 3.0.2 for Windows program. P values < 0.05 were considered significant. The distribution of KIR genes in both groups showed a lower frequency of the KIR2DL2 gene in patients compared to controls (45.5% vs 58.1% P=0.036), this association was significant also in combination KIR2DL2 with C1 (33.0% vs 45.9%, P=0.026) suggesting a protective role of this gene to the development of DLBCL. Regarding the clinical course of the disease, HLA-Bw4 and HLA-Bw4 80I ligands were more frequent in patients with more advanced stages of the disease (64.7% vs 40.9%, P=0.020 and 44.1% vs 25 0%, P=0.046, respectively) suggesting that the presence of these ligands may be poor prognostic factor to DLBCL. In regard to treatment response, the KIR2DL3 gene was positively associated with the treatment of DLBCL, because this gene was more frequent in individuals with complete response than in nonresponders individuals (88.3% vs 71.0%, P=0.044 ). Regarding the cytokine genes , IFN -gamma-874/A genotype:A/A was positively associated with DLBCL, it was more frequently in patients than in controls (50.9% vs 27.9%, P=0.001). On other hand genotypes: IFNG -874 /T:A, IL10-819/C:C and IL10 -592 /C:C were less frequent in patients than in controls (P=0.001, P=0.025, P=0.025 respectively). Moreover, the genotype IL-1082/G:G was related to increased progression-free survival. The results suggest that the KIR genes, HLA ligands and cytokine genes seem to be involved in the protection, susceptibility, clinical course and response to treatment of DLBCL / Doutorado / Clinica Medica / Doutora em Clínica Médica

La formation et le développement d'une tumeur sont provoqués par une série de défauts qui se produisent à l'intérieur de la cellule cancéreuse et dans son microenvironnement. Ces anomalies permettent à la cellule de développer ses propres stratégies de croissance, de prolifération, de différenciation et de métabolisme. Toutes ces adaptations, ainsi que la création d'un micro-environnement unique favorisent la croissance de la tumeur et inhibent la réponse immunitaire anti-tumorale. Le métabolisme des cellules cancéreuses et l'évasion immunitaire sont des points très sensibles dans le développement des cancers et peuvent être utilisés en clinique. Les études récentes suggèrent que ces deux phénomènes sont liés, et que le métabolisme des cellules cancéreuses peut amener à l'échappement immunitaire par la tumeur. Le métabolisme des cellules tumorales a tendance à éviter l'activité mitochondriale et la phosphorylation oxydative, et est principalement basée sur la glycolyse pour la production d'énergie (effet Warburg). Mon travail de thèse est divisé en deux parties. Dans la première partie nous avons proposé un concept thérapeutique novateur avec une nouvelle thérapie combinatoire pour le traitement de cancers hématologiques. Cette thérapie est basée sur l'induction de changements métaboliques par le dichloroacétate (DCA), et elle est associée avec la chimiothérapie conventionnelle (doxorubicine, vincristine) pour réactiver les fonctions de p53. Les tumeurs avec p53 mutantes sont résistantes à cette combinaison. Dans ce cas, nous avons constaté que le DCA peut coopère avec 17-AAG (l'inhibiteur de Hsp90) pour éliminer spécifiquement les cellules cancéreuses. En conséquence, une meilleure compréhension des signaux et des mécanismes par lesquels le DCA sensibilise les cellules tumorales à la chimiothérapie est nécessaire pour en comprendre le mode d'action. En outre, l'identification de ce mécanisme permettra d'élucider les voies métaboliques impliquées dans la survie des cellules cancéreuses. La deuxième partie de ma thèse se concentre sur la biologie des cellules NK. Les cellules NK sont des lymphocytes du système immunitaire inné et possèdent une cytotoxicité naturelle contre les cibles, c'est à dire les cellules tumorales. L'utilisation optimale des cellules NK en clinique nécessite leur expansion et leur activation in vitro. Les cellules NK s'activent en présence de cytokines ou par le contact avec les cellules cibles. L'activation des cellules NK induit la prolifération, mais celle-ci dépend aussi de la présence d'autres cellules immunitaires. L'activation, par les cytokines et par les cellules cibles, induit un différent ARNm/microARN profil d'expression. L'analyse détaillée des isoformes de la protéine tyrosine phosphatase CD45 a permis de caractériser de nouvelles populations de cellules NK anti-tumorales humaines. L'identification de différentes populations de cellules NK est très importante pour la compréhension de leur physiologie et pour l'amélioration de leur utilisation en immunothérapie clinique. Cela peut également donner des informations précieuses sur l'état physiologique de l'hôte. En effet, l'augmentation des cellules CD45RAdim et CD45RO + dans le compartiment des cellules NK matures identifie clairement les patients avec des hémopathies malignes. Nous pensons que leur détection peut être utilisée comme un outil de diagnostic et également pour évaluer l'efficacité des traitements anti-tumoraux, car ces populations de cellules NK spécifiques devraient diminuer lors de l'élimination de cellules tumorales cibles. Dans l'avenir, nous voulons combiner le traitement du métabolisme de la tumeur avec la thérapie anti-tumorale basée sur les cellules NK. Sur la base de nos données préliminaires, nous pouvons proposer le traitement des cellules cancéreuses par des médicaments métaboliques pour augmenter la sensibilité et la reconnaissance par les cellules NK activées. / Tumor formation and development are caused by a range of defects that occur inside the cancer cell and in the external cellular microenvironment. These abnormalities allow developing tumors to establish their own strategies of growth, proliferation, differentiation and metabolism. All these adaptations, as well as the creation of a unique microenvironment, promote tumor growth and suppress the anti-cancer immune response. Tumor cell metabolism and immune evasion are sensitive points of cancer development that can be targeted in clinic. Recent studies suggest that these two phenomena are related and that cancer cell metabolism may propel tumor immune escape. Tumor cell metabolism tends to avoid mitochondrial activity and oxidative phosphorylation (OXPHOS), and largely relies on glycolysis to produce energy (Warburg effect). My thesis work is divided into two parts. The first one proposes an innovative therapeutic strategy, which is the use of different combinatorial therapy depending on the p53 status for the treatment of hematological cancers. This is based on the induction of metabolic changes by dichloroacetate (DCA), combined with conventional chemotherapy (doxorubicin, vincristine) to reactivate wild type p53 functions. Mutant p53 tumors are resistant to this combination approach. However, we found that DCA synergized with the Hsp90 inhibitor 17-AAG to specifically eliminate these cells. Therefore, a clearer understanding of the signals and mechanisms by which DCA sensitize cancer cells to chemotherapy was needed to understand its mode of action. We uncovered it in our work. In addition, identification of this mechanism will help to elucidate metabolic pathways involved in cancer cell survival.The second part of my thesis is focused on the study of NK cell biology. NK cell is an innate immune system lymphocyte lineage with natural cytotoxicity against targets, i.e. tumor cells. Its optimal use in the clinic requires in vitro expansion and activation. Cytokines and the encounter with target cells activate NK cells, induce their proliferation, and cause clearly different mRNA/miRNA expression profile. Detailed analysis of the leucocyte-specific phosphatase CD45 isoforms allowed us to characterize new human anti-tumor NK cell populations. The identification of the different NK cell populations is important for understanding their physiology and for improving their therapeutic use in the clinic. It can also give valuable information about the host physiological status. Indeed, the increase of CD45RAdim and CD45RO+ cells in the mature NK cell compartment clearly identifies patients with hematological malignancies. We thus hypothesize that their detection could be used as a diagnostic tool, and also to assess the efficacy of antitumor treatments, because these specific NK cell populations should decrease upon removal of the targeted tumor cells. Our future goal is to use a novel combinatorial therapy in hematological cancers that will combine metabolic drugs and NK cell-based therapy. Based on our preliminary data, we propose that the treatment of cancer cells with metabolic drugs could increase their sensitivity and recognition by activated NK cells.

Les cellules Natural Killer (NK) représentent une population de cellules innées lymphoïdes aux fonctions anti-infectieuses et antitumorales. Les leucémies aiguës lymphoblastiques pré-B (LAL pré-B) constituent le cancer de l’enfant le plus fréquent et ont été décrites comme résistantes à la cytotoxicité médiée par les NK bien que les bases moléculaires demeurent inconnues.L’objectif de ces travaux a été de caractériser cette résistance. En développant un essai de cytotoxicité par cytométrie en flux et en utilisant des cellules effectrices activées in vitro, nous avons établi la sensibilité retardée des LAL pré-B à la cytotoxicité NK : initialement résistantes après 4h d’incubation, elles sont fortement tuées après 25h.Cette cytotoxicité est contact-dépendante mais ni la voie de l’exocytose des granules cytotoxiques ni celle des récepteurs de mort n’y contribuent. La mort cellulaire des cibles est de profil apoptotique mais indépendante des caspases ; la signalisation mitochondriale l’amplifie partiellement. Interférer avec les dérivés de l’oxygène par un antioxydant diminue la cytotoxicité. Nous montrons que les cellules NK de patients atteints de granulomatose septique chronique liée à l’X présentent un défaut de cette nouvelle cytotoxicité. Nous démontrons l’expression par les NK des composants clefs d’une NADPH oxydase distincte du complexe utilisé par les phagocytes. Nos travaux établissent l’existence d’une voie de cytotoxicité non conventionnelle et en définissent les principaux prérequis moléculaires. / Natural Killer (NK) cells are innate lymphoid cells with anti-infectious and anti-tumoral activities. Among neoplasia, pre-B acute lymphoblastic leukemias (pre-B ALL) represent the most common form of cancer in childhood and were shown to be resistant to NK cell mediated cytotoxicity although the mechanisms explaining this phenomenon are incompletely understood.In the present work, we investigated the relative immune resistance of pediatric pre-B ALL targets to activated NK cells. We developed a flow cytometry based cytotoxicity assay to assess the NK activity and the involvement of long term cytotoxic pathways. Although pre-B ALL blasts were strongly resistant at 4h, we found a considerable delayed NK killing at 25h.Further investigations revealed that cell contact was mandatory for efficient killing but also that neither the granule exocytosis nor the death receptor pathway were involved. Target cell death was caspase independent but mitochondria signaling amplified it. We then showed that NK cells from patients with X-linked chronic granulomatous disease could not kill efficiently ALL blasts and that NK cells expressed key components of a NADPH oxidase complex that was distinct from the phagocyte type. Our work reveals an uncharacterized effector pathway among cytotoxic lymphocytes and establishes key molecular requirements for this unconventional pathway.

Natural killer (NK) cells are an intensively studied part of immune system, possessing unique ability to recognize and induce death of tumor and virus-infected cells without prior antigen sensitization. Their function is regulated by a fine balance of signals induced by multiple activating and inhibitory cell surface receptors and their interaction with the ligands present on the target cell. Recent research in their C-type lectin-like receptors repertoire has shown that ligands of some of these previously orphan receptors lie within their own family, describing a lectin-lectin interaction. This is the case of human inhibitory receptor NKRP1 (gene KLRB1) and its ligand LLT1 (gene CLEC2D). Previous studies have shown that overproduction of LLT1 in cancer cells or lower production of NKRP1 in NK cells is connected to cancerous manifestations. This master's thesis shows a successful production of the extracellular part of LLT1 utilizing a mammalian expression system based on transient transfection of modified human embryonic kidney (HEK) cell lines. It was found that the five cystein residues contained within the lectin domain of LLT1 tend to cause misfolding and formation of aggregates. Stabilization of the domain was achieved by restoration of the sixth cystein residue at the evolutionary conserved...

Dendritic cells (DCs) are professional antigen-presenting cells, which display an extraordinary capacity to induce T-cell responses. Recent findings revealed that DCs also play a crucial role in the activation of natural killer (NK) cells representing important effectors in the innate immune defense against viruses and tumors. Here, we summarize various studies investigating the bidirectional crosstalk between human DCs and NK cells. In this context, it has been reported that DCs efficiently enhance CD69 expression, proliferation, interferon (IFN)-γ secretion and cytotoxic activity of NK cells. Cell membrane-associated molecules as well as soluble factors such as interleukin-12, tumor necrosis factor-α and type I IFNs contributed to DC-mediated NK cell activation. Reciprocally, the ability of human NK cells to enhance the immunostimulatory capacity of DCs was shown. Thus, NK cells promoted the maturation of DCs and markedly augmented their capacity to produce proinflammatory cytokines and to stimulate T-cell responses. The NK cell-mediated effects on DCs were dependent on cell membrane-associated molecules such as NKp30 and soluble factors such as tumor necrosis factor-α and IFN-γ. In conclusion, the reciprocal activating interaction between human DCs and NK cells may play a pivotal role in the immune defense against viruses and tumors. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Host immune responses must be tightly regulated by an intricate balance between positive and negative signals while fighting pathogens; persistent pathogens may usurp these regulatory mechanisms to dampen host immunity to facilitate survival in vivo. Here we report that Tim-3, a negative signalling molecule expressed on monocytes and T cells, is up-regulated on natural killer (NK) cells in individuals chronically infected with hepatitis C virus (HCV). Additionally, the transcription factor T-bet was also found to be up-regulated and associated with Tim-3 expression in NK cells during chronic HCV infection. MicroRNA-155 (miR-155), an miRNA that inhibits signalling proteins involved in immune responses, was down-regulated in NK cells by HCV infection. This Tim-3/T-bet over-expression and miR-155 inhibition were recapitulated in vitro by incubating primary NK cells or NK92 cell line with Huh-7 hepatocytes expressing HCV. Reconstitution of miR-155 in NK cells from HCV-infected patients led to a decrease in T-bet/Tim-3 expression and an increase in interferon-γ production. Blocking Tim-3 signalling also enhanced interferon-γ production in NK cells by improving signal transducer and activator of transcription-5 phosphorylation. These data indicate that HCV-induced, miR-155-regulated Tim-3 expression regulates NK cell function, suggesting a novel mechanism for balancing immune clearance and immune injury during chronic viral infection.

Immunotherapy has emerged as a current and future paradigm of cancer treatment, which utilizes the body’s immune system to eradicate cancer. Natural Killer (NK) cells as part of the innate immune system have immense potential in their anti-tumor cytotoxic activities and host cell surveillance properties. NK cells comprise approximately five to fifteen percent of peripheral blood lymphocytes and can be proliferated in vitro using recently developed methods with co-cultures with feeder cells (derived from engineered tumor cells) or plasma membrane (PM) particles, produced from the fore mentioned feeder cells, in combination with soluble cytokines. For efficient growth and maintenance of these NK cells, Interleukin-2 (IL-2) is utilized. IL-2 in solution, through receptor mediated signaling, stimulates proliferation of T-cells and NK cells. NK cells have lower responsiveness to IL-2 and consequently require a larger systemic dose to stimulate them as opposed to competing cell populations that have higher expression of receptors for IL-2, such as T-cells, which can have the effect of lower effective stimulation of NK cell growth. Such difference in the stimulatory capability of IL-2 toward NK cells and the short circulation lifetime of soluble IL-2 require higher dosages of soluble IL-2 for effective in vivo NK cell proliferation for therapeutic application against cancer, but is toxic. Therefore establishing another form of IL-2 delivery that improves its specific targeting to NK cells would be beneficial and may be crucial for novel therapeutic improvement. The Copik Laboratory has made an IL-2 fusion protein construct having a membrane anchor for expression of membrane-bound IL-2 on K562-41bbl-21 cells (K562-IL21). K562-IL21 cells are selectively recognized by NK cells and stimulate their proliferation and cytotoxicity. Hence, a K562-IL21 membrane–bound IL-2 form should be targeted to NK cells with IL-2 delivery. K562-IL21-2 cells were then used to prepare PM21-2 particles which have the potential to provide NK cell targeted, long-lived form of IL-2 for use as an injectable drug for in vivo adjuvant stimulation of NK cells. The presence of IL-2 on the in the PM21-2 particle product was verified by Western blot, and ELISA. Particle preparations from the modified K562 cells should possess characteristics that allow them to possibly replace soluble IL-2 and more specifically increase the numbers or anti-tumor activity of NK cell populations. The effect of PM21-2 particles was studied in in vitro culture based experiments, which tested the effectiveness the PM21-2 particles to induce selective NK cells expansion as compared to PM21 particles in the presence or absence of soluble IL-2.