Les cellules Natural Killer (NK) sont de grands lymphocytes granuleux capables de rapidement éliminer des cellules tumorales et des cellules infectées par des virus sans immunisation au préalable. Au cours de ma thèse, j’ai analysé plusieurs paramètres impliqués dans la reconnaissance et la lyse des cellules de mélanome par les NK. J’ai montré à partir d’analyses ex vivo que les NK sanguines de patients atteints de mélanome métastatique (stade III-IV) présentent un faible potentiel lytique. Cependant, de telles NK provenant de patients mélanomes de tout stade clinique activées in vitro par de l’IL-2 lysent efficacement des lignées de mélanome métastatique. L’analyse du phénotype de NK circulantes de patients stade IV a montré une diminution de l’expression du récepteur activateur NKp46/NCR1 comparé aux NK de donneurs sains. J’ai également montré une corrélation positive entre l’expression du NKp46 à la surface des NK et la durée du stade IV. Pour caractériser les NK infiltrant le mélanome, J’ai analysé ex vivo les NK infiltrant des ganglions métastatiques (GG) provenant de 25 patients en stade III. Les GG de patients mélanomes contiennent une population unique de NK CD56brightCD16+ représentant 50% des NK dans ces GG qui expriment fortement les récepteurs NK NCR, NKG2D, KIRs et produisent une plus forte proportion de perforin comparée aux NK CD56brightCD16- ganglionnaires. Les NK immunsélectionnées à partir de GG et activées avec de l’IL-2 ou de l’IL-15 lysent rapidement et efficacement des lignées cellulaires de mélanome. Elles sont caractérisées par des capacités lytiques supérieures aux NK sanguines. De plus, afin d’évaluer l’impact des NK au cours du mélanome, j’ai analysé in situ les NK infiltrant des ganglions sentinelles positive et négatif ainsi que des tumeurs cutanées primaires. Les NK sont faibles dans les GS ; cependant nous avons montré que le nombre de NK infiltrant ces ganglions sentinelles est associé à une plus forte rechute à cinq ans des patients. Les cellules NK infiltrant les tumeurs cutanées sont présentes préférentiellement dans la zone peritumorale et sont très rares dans la tumeur.Chez les patients atteints de mélanome, les NK sanguines et infiltrant les tumeurs ont des caractéristiques phénotypiques et fonctionnelles différentes. Une meilleure compréhension de telles différences doit être prise en compte, ainsi la biologie des NK et de leur modulation au cours du cancer est nécessaire pour développer une stratégie thérapeutique à base de cellules NK efficace. / Cytotoxic immune effectors can control the development and growth of certain solid tumours. Among these cytotoxic effectors, NK cells are capable of rapidly eliminating tumour cells and virus-infected cells without prior immunization.The objectives of my thesis were to evaluate the potential role of NK cells in the immune response against melanoma. First, I have characterized the functional status of blood NK cells from melanoma patients at different stages of the disease. I showed that ex vivo NK cells from most advanced stage III-IV patients display low lytic potential. However, IL-2-activated NK cells from patients efficiently lyse melanoma cells and that independently to the clinical stage. Moreover, the expression of the activating receptor NKp46/NCR1 by blood NK cells was decreased in stage IV patients compared to healthy donors, and a positive correlation between NKp46 expression by NK cells and the duration of stage IV was found. I have also characterized ex vivo NK cells infiltrating metastatic lymph nodes (M-LN) from stage III melanoma patients. I have identified in M-LN a unique subpopulation of mature CD56brightCD16+ NK cells that expressed higher NCR, NKG2D, KIRs, and perforin levels than CD56brightCD16- NK cells counterpart. NK cells from M-LN activated with IL-2 or IL-15, rapidly lysed metastatic melanoma cell lines with higher efficiency than autologous blood NK cells. Finally, to determine if NK cells display a prognostic value, I analysed by immunohistochemistry NK cells and other immune cells infiltrating positive and negative sentinel lymph nodes (SLN). SLN are characterized by high densities of macrophages and endothelial cells, even higher in SLN+. Few NK cells and Granzyme B+ cells infiltrate SLNs while CD8+ T cells are numerous. Moreover, numbers of NK cells in SLN correlated with higher rate of 5 year-relapse of patients. Compared to SLN, primary cutaneous melanomas contain high numbers of NK cells that are preferentially localized in the periphery of the tumour and are not related to the Breslow. My findings showed that in melanoma patients, circulating and tumour infiltrating NK cells display unique phenotypic and functional characteristics, indicating that tumour may alter their function. However, they respond to cytokine activation and acquire antitumor lytic potential. In the new landscape of melanoma treatment, NK cells are worthy to be considered for combined treatment with BRAF inhibitors.

Peanut allergy typically results from sensitisation to one or more integral seed storage proteins; Ara h 1, 3 or 2/6. Reactions can be triggered by as little as 3 mg protein in 10% of allergic individuals and are often severe, inducing anaphylaxis which can be fatal. Accidental exposure through unintended presence can therefore be hazardous and foods must be labelled appropriately. Thermal processing is one of the main factors affecting protein properties in food systems, including the formation of Maillard reaction products. Research has suggested a link between the allergenicity of foods and cooking methods employed. A systematic study was undertaken to assess the thermal dependence of these hazard proteins, focusing on changes to solubility and chemical modifications which may alter IgE binding. Proteomic profiling was used to assess the allergenic content of peanut products and develop alternative methods for allergen analysis to support evidence-based application of precautionary allergen labelling. Runner variety peanuts were processed (boiled, fried, roasted) and their protein content determined. Proteins extracts were characterised by 1D- and 2D-polyacrylamide gel electrophoresis, including differential in-gel electrophoresis. Proteomic profiling was undertaken using label-free analysis to assess allergen composition and investigate the formation of Maillard reaction products on the most clinically relevant proteins. Peanut allergen peptide targets were then identified and used to develop label-based quantitation methods and applied to (i) investigate effects of processing on peptide targets and (ii) determine peanut in chocolate products in comparison with a commercial ELISA kit. Orthogonal studies were performed using serum samples from peanut allergic patients obtained from the Manchester Respiratory, Allergy and Thoracic Surgery (ManARTS) Biobank. Patient IgE reactivity to peanut and processed peanut products was assessed by immunoblotting, inhibition ELISA and mediator release assays. Protein solubility was reduced by thermal processing and processed protein required harsh denaturing conditions for extraction. Qualitative analysis highlighted decreased solubility of key allergens, modifications and aggregation after heating. Proteomic profiling identified and quantified different isoforms of the major peanut allergens. The protein content of processed peanuts was reduced by boiling, specifically the 2S albumins, which transferred into the cooking water. The performance of peptides selected for targeted MRM experiments was influenced by thermal processing and the presence of cocoa phenolics. Ara h 2 peptides flanked by arginine were thermostable and may prove more reliable for quantification. Application of microfluidic separation enhanced the efficiency of target ionisation in complex matrices acquiring important sensitivity gains. Maillard modifications to clinically relevant proteins Ara h 2/6 were found within IgE binding domains in raw and processed peanuts. IgE reactivity studies confirmed reduced IgE binding capacity of extensively boiled peanut and hydrolysed protein, but this did not correlate to a reduction in mediator release in poly-sensitised patients. While effective extraction limits the efficacy of analyses, buffers used in MS analyses are more robust in analysing processed protein. Proteomic profiling provides a means of characterising and profiling of allergenic proteins including food ingredients used in clinical applications. Peptides selected for targeted analyses should be validated to assess their suitability in model foods. Cooking waters collected from extensively boiled peanuts may provide an alternative and safer immunotherapy agent for patients predominantly sensitised to Ara h 2/6.

by Ho Cheong Yip. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 152-164). / ACKNOWLEDGMENTS --- p.I / ABBREVIATIONS --- p.II / ABSTRACT --- p.VI / CHAPTER / Chapter 1 --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1 --- Immunomodulators of biological origin --- p.1 / Chapter 1.2 --- Effector cells involved in anti-tumor immunity --- p.3 / Chapter 1.2.1 --- Cytotoxic T lymphocytes --- p.3 / Chapter 1.2.2 --- Macrophages --- p.4 / Chapter 1.2.3 --- Natural killer cells --- p.5 / Chapter 1.2.4 --- Lymphokine-activated killer cells --- p.7 / Chapter 1.2.5 --- Tumor-infiltrating lymphocytes --- p.9 / Chapter 1.3 --- Cytokines involved in immunomodulation and anti-tumor immunity --- p.11 / Chapter 1.3.1 --- Interleukin-1 --- p.11 / Chapter 1.3.2 --- Interleukin-2 --- p.13 / Chapter 1.3.3 --- Interleukin-3 --- p.14 / Chapter 1.3.4 --- Tumor necrosis factor-alpha --- p.15 / Chapter 1.3.5 --- Interferons --- p.18 / Chapter 1.4 --- Carbohydrates used as potential immunopotentiating agents --- p.19 / Chapter 1.5 --- General properties of K1 capsular antigen --- p.20 / Chapter 2 --- AIM AND SCOPE OF THIS DISSERTATION --- p.22 / Chapter 3 --- MATERIALS AND METHODS --- p.24 / Chapter 3.1 --- Materials --- p.24 / Chapter 3.2 --- Methods --- p.33 / Chapter (I) --- "Extraction, purification and characterization of K1 capsular antigen from Klebsiella pneumoniae" / Chapter 3.2.1 --- Extraction and purification of Kl capsular antigen --- p.33 / Chapter 3.2.2 --- Gel filtration of K1 capsular antigen --- p.35 / Chapter 3.2.3 --- Characterization of K1 capsular antigen --- p.35 / Chapter 3.2.3.1 --- Determination of carbohydrate and protein contents --- p.35 / Chapter 3.2.3.2 --- Determination of uronic acid content --- p.35 / Chapter 3.2.4 --- Determination of bio-toxicity of K1 capsular antigen --- p.35 / Chapter 3.2.5 --- Treatment of K1 capsular antigen with sodium periodate --- p.36 / Chapter 3.2.6 --- Treatment of K1 capsular antigen with sodium hydroxide followed by acetic acid neutralization --- p.36 / Chapter (II) --- Isolation and preparation of cells / Chapter 3.2.7 --- Murine splenocytes --- p.37 / Chapter 3.2.8 --- Removal of red blood cells and dead cells using Ficoll-paque gradient method --- p.37 / Chapter 3.2.9 --- Murine thymocytes --- p.37 / Chapter 3.2.10 --- Murine peritoneal exudate cells (PEC) --- p.38 / Chapter 3.2.11 --- Bone marrow cells --- p.38 / Chapter (III) --- Assays of immunomodulatory activities of K1 capsular antigen on lymphocytes / Chapter 3.2.12 --- In vitro mitogenic assay --- p.39 / Chapter 3.2.13 --- In vivo mitogenic assay --- p.39 / Chapter 3.2.14 --- "In vitro co-mitogenic assay of K1 capsular antigen with Polymyxin B sulfate, LPS or Con A" --- p.40 / Chapter 3.2.15 --- In vitro mitogenic effect of K1 capsular antigen on lymphocyte sub-populations --- p.40 / Chapter 3.2.16 --- Assay of murine interleukin-2 --- p.41 / Chapter 3.2.17 --- Assay of murine interleukin-1 --- p.41 / Chapter (IV) --- Assays of immunomodulatory activities of K1 capsular antigen on macrophages and bone marrow cells / Chapter 3.2.18 --- In vivo migration of macrophages --- p.42 / Chapter 3.2.19 --- Assay of interleukin-1 produced from murine macrophages --- p.42 / Chapter 3.2.20 --- Assay of nitric oxide produced from murine macrophages --- p.43 / Chapter 3.2.21 --- Assay of proliferation of murine bone marrow cells --- p.44 / Chapter 3.2.22 --- Assay of differentiation of murine bone marrow cells --- p.44 / Chapter (V) --- Assays of anti-tumor activities of K1 capsular antigen / Chapter 3.2.23 --- In vitro cytostatic effect of K1 capsular antigen on murine tumor cell lines --- p.45 / Chapter 3.2.24 --- In vivo anti-tumor activities of K1 capsular antigen --- p.45 / Chapter 3.2.25 --- In vitro stimulation of TNF-α-like factor release from thioglycollate-elicited murine peritoneal macrophages by K1 capsular antigen --- p.46 / Chapter 3.2.26 --- Effects of K1 capsular antigen on TNF-α production in normal mice in vivo --- p.47 / Chapter 3.2.27 --- Effects of K1 capsular antigen on TNF-α production as well as EAT growth in vivo --- p.48 / Chapter 3.2.28 --- In vitro induction of macrophage-mediated cytostasis on tumor cells --- p.48 / Chapter 3.2.29 --- In vitro induction of macrophage-mediated cytolysis on tumor cells --- p.49 / Chapter 3.2.30 --- In vivo induction of alloreactive cytotoxic T cells --- p.49 / Chapter 3.2.31 --- In vitro induction of lymphokine-activated killer cell activity --- p.50 / Chapter 3.2.32 --- In vivo induction of lymphokine-activated killer cell activity --- p.51 / Chapter 3.2.33 --- In vivo induction of lymphokine-activated killer cell activity in tumor-bearing mice --- p.52 / Chapter 3.2.34 --- In vivo induction of lymphokine-activated killer cell activity in tumor-bearing mice with in vitro culture --- p.52 / Chapter 3.2.35 --- Phenotypic characterization of LAK cells by flow cytometry --- p.53 / Chapter 3.2.36 --- Winn-type tumor-inhibition of LAK cells --- p.54 / Chapter 3.2.37 --- Adoptive transfer of LAK cells to tumor-bearing mice --- p.54 / Chapter 3.2.38 --- In vivo stimulation of tumor-infiltrating lymphocytes --- p.55 / Chapter 3.2.39 --- Statistical analysis --- p.57 / Chapter 4 --- "EXTRACTION, PURIFICATION AND CHARACTERIZATION OF K1 CAPSULAR ANTIGEN FROM KLEBSIELLA PNEUMONIAE" / Introduction --- p.58 / Results --- p.59 / Chapter 4.1 --- Extraction and purification of Kl capsular antigen from Klebsiella pneumoniae --- p.59 / Chapter 4.2 --- Gel filtration of Kl capsular antigen --- p.59 / Chapter 4.3 --- Characterization of Kl capsular antigen --- p.62 / Chapter 4.4 --- Determination of toxicity (LC50) of Kl capsular antigen by brine shrimp assay --- p.62 / Discussion --- p.62 / Chapter 5 --- IMMUNOMODULATORY ACTIVITIES OF K1 CAPSULAR POLYSACCHARIDE ANTIGEN FROM KLEBSIELLA PNEUMONIAE / Introduction --- p.67 / Results --- p.69 / Chapter 5.1 --- Mitogenic activity of Kl capsular antigen on murine lymphocytes in vitro --- p.69 / Chapter 5.2 --- Mitogenic activity of K1 capsular antigen on murine lymphocytes in vivo --- p.69 / Chapter 5.3 --- Evidences to support the mitogenic activity of K1 capsular antigen is due to its polysaccharide structure rather than due to the contamination by LPS --- p.74 / Chapter 5.4 --- Effect of Kl capsular antigen on IL-2 production from murine lymphocytes in vitro --- p.79 / Chapter 5.5 --- Effect of K1 capsular antigen on IL-1 -like factor production from murine thymocytes in vitro --- p.79 / Chapter 5.6 --- Immunopotentiating activities of Kl capsular antigen on macrophages --- p.85 / Chapter 5.6.1 --- In vivo migration of macrophages in K1-treated mice --- p.85 / Chapter 5.6.2 --- Effect ofKl capsular antigen on the macrophage EL-1-like factor production in vitro --- p.85 / Chapter 5.6.3 --- Effect ofKl capsular antigen on the macrophage nitric oxide (NO) production in vitro --- p.85 / Chapter 5.7 --- Effects of Kl capsular antigen on the proliferation and differentiation of murine bone marrow cells --- p.89 / Discussion ´ب --- p.94 / Chapter 6 --- ANTI-TUMOR ACTIVITIES OF K1 CAPSULAR POLYSACCHARIDE ANTIGEN FROM KLEBSIELLA PNEUMONIAE / Introduction --- p.100 / Results --- p.102 / Chapter 6.1 --- In vitro cytostatic effects of Kl capsular antigen on murine tumor cell lines --- p.102 / Chapter 6.2 --- In vivo anti-tumor activities of Kl capsular antigen --- p.102 / Chapter 6.3 --- Effects of Kl capsular antigen on TNF-α production and on EAT growth in vivo --- p.110 / Chapter 6.4 --- In vitro induction of macrophage-mediated cytostatic effect on tumor cells by K1 capsular antigen --- p.110 / Chapter 6.5 --- In vitro induction of macrophage-mediated cytolytic effect on tumor cells by K1 capsular antigen --- p.115 / Chapter 6.6 --- Effect of Kl capsular antigen on the activation of alloreactive cytotoxic T cells --- p.115 / Chapter 6.7 --- Effect of Kl capsular antigen on the activation of lymphokine- activated killer (LAK) cells in vitro and in vivo --- p.115 / Chapter 6.8 --- Phenotypic characterization of LAK cells by flow cytometry --- p.123 / Chapter 6.9 --- Winn-type tumor inhibition assay of LAK cells --- p.126 / Chapter 6.10 --- Adoptive transfer of LAK cells to tumor-bearing mice --- p.132 / Chapter 6.11 --- Effect ofKl capsular antigen on the activation of tumor- infiltrating lymphocytes (TILs) in tumor-bearing mice --- p.132 / Discussion --- p.136 / Chapter 7 --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.146 / BIBLIOGRAPHY --- p.152

by Chen Paul. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 141-150). / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Immunomodulation --- p.1 / Chapter 1.2 --- Effector cells mediating anti-tumour immunity --- p.1 / Chapter 1.2.1 --- Cytotoxic T Lymphocytes --- p.3 / Chapter 1.2.2 --- Macrophages --- p.4 / Chapter 1.2.3 --- Natural Killer Cells --- p.5 / Chapter 1.2.4 --- Lymphokine-activated Killer (LAK) --- p.6 / Chapter 1.3 --- Cytokines as immunomodulators in cancer therapy --- p.7 / Chapter 1.3.1 --- Tumour Necrosis Factor-α (TNF-α) --- p.7 / Chapter 1.3.2 --- Interleukin-1 (IL-1) --- p.9 / Chapter 1.3.3 --- Interleukin-2 (IL-2) --- p.9 / Chapter 1.3.4 --- Granulocytes/Macrophages Colony-Stimulating Factors --- p.10 / Chapter 1.4 --- Polysaccharides as potential immunostimulating agents --- p.11 / Chapter 1.5 --- General properties of Klebsiella pneumoniae --- p.12 / Chapter 2. --- AIM AND SCOPE OF THIS DISSERTATION --- p.16 / Chapter 3. --- MATERIALS AND METHODS --- p.18 / Chapter 3.1 --- Materials --- p.18 / Chapter 3.1.1 --- Animals --- p.18 / Chapter 3.1.2 --- Klebsiella pneumoniae K24 --- p.18 / Chapter 3.1.3 --- Cell lines --- p.18 / Chapter 3.1.4 --- "Buffer, Culture media and Chemicals" --- p.19 / Chapter 3.2 --- Methods --- p.27 / Chapter 3.2.1 --- Extraction and Characterization of Klebsiella pneumoniae K24 Capsular Polysaccharide (K24 CPS) --- p.27 / Chapter 3.2.2 --- Assays of Immunomodulatory Activities of K24 CPS on Lymphocytes --- p.30 / Chapter 3.2.3 --- Assays of Immunomodulatory Effect of K24 CPS on Macrophages --- p.34 / Chapter 3.2.4 --- Assays of Anti-Tumour Activities of K24 CPS --- p.39 / Chapter 3.2.5 --- Assays of the Effects of K24 CPS on the Proliferation and Differentiation of Murine Bone Marrow Cells --- p.54 / Chapter 3.2.6 --- Assays of the Immunorestorative Activities of K24 CPS --- p.56 / Chapter 4. --- EXTRACTION AND CHARACTERIZATION OF KLEBSIELLA PNEUMONIAE K24 CAPSULAR POLYSACCHARIDE (K24 CPS) --- p.59 / Chapter 4.1 --- Preparation of Klebsiella pneumoniae K24 CPS Capsular Polysaccharide (K24 CPS) --- p.59 / Chapter 4.2 --- Acetic Acid Treatment of K24 CPS --- p.59 / Chapter 4.3 --- Gel Filtration --- p.59 / Chapter 4.4 --- Carbohydrate and Protein contents of K24 CPS --- p.61 / Chapter 4.5 --- Cytotoxicity Assay using Artemia franciscana (Brine Shrimp) --- p.61 / Chapter 5. --- IMMUNOMODULATORY EFFECTS OF K24 CPS --- p.68 / Chapter 5.1 --- The Effect of K24 CPS in vitro Mitogenic Assay of K24 CPS using Murine Splenocytes --- p.68 / Chapter 5.2 --- The in vivo Mitogenic Effect of K24 CPS on Murine Splenic Lymphocytes --- p.73 / Chapter 5.3 --- The Effect of K24 CPS on the Production of Interleukin-2 (IL-2)-like substance by Murine Splenocytes --- p.73 / Chapter 5.4 --- The effect of K24 CPS on the in vitro Stimulation of Murine Macrophage Nitric Oxide (NO) Production --- p.73 / Chapter 5.5 --- The effect of K24 CPS on the in vitro Stimulation of Macrophage Interleukin-1-like Production --- p.77 / Chapter 5.6 --- The effect of K24 CPS on in vivo Migration of Macrophage --- p.82 / Chapter 5.7 --- The effect of K24 CPS in vitro Stimulation of Macrophage Tumour Necrosis Factor- a (TNF-a) Production --- p.82 / Chapter 6. --- IN VITRO ANTI-TUMOUR EFFECT OF K24 CPS --- p.89 / Chapter 6.1 --- The in vitro Cytostatic effect of K24 CPS on the Suppression of EAT growth --- p.89 / Chapter 6.2 --- The effect of K24 CPS on cell cycle of EAT cells --- p.89 / Chapter 6.3 --- Study of the cytostatic effect of K24 CPS on EAT cells using Western Analysis --- p.93 / Chapter 6.3.1 --- Pattern of Phosphotyrosine Proteins --- p.93 / Chapter 6.3.2 --- Pattern of Phosphoserine Proteins --- p.96 / Chapter 6.3.3 --- Pattern of Phosphothreonine Proteins --- p.96 / Chapter 6.3.4 --- Level of c-fos --- p.99 / Chapter 6.3.5 --- Level of c-jun --- p.99 / Chapter 6.3.6 --- Level of c-myc --- p.102 / Chapter 7. --- THE IN VIVO ANTI-TUMOUR ACTIVITIES OF K24 CPS --- p.103 / Chapter 7.1 --- The effect of K24 CPS on the In vivo Suppression of EAT growth --- p.103 / Chapter 7.2 --- The effect of K24 CPS on the survival of EAT-bearing mice --- p.103 / Chapter 7.3 --- The effect of K24 CPS on the in vivo induction of Natural Killer (NK) Cell Cytotoxicity --- p.111 / Chapter 7.4 --- The effect of K24 CPS in vitro induction of Lymphokine-activated Killer (LAK) Cell Cytotoxicity --- p.111 / Chapter 7.5 --- The effect of K24 CPS on the in vivo Induction of Lymphokine-activated Killer (LAK) Cell Cytotoxicity --- p.114 / Chapter 7.6 --- The effect of K24 CPS on the endogenous production of TNF-α --- p.114 / Chapter 7.7 --- The effect of K24 CPS on the endogenous TNF-α production and EAT growthin vivo --- p.117 / Chapter 8. --- THE IMMUNORESTORATIVE ACTIVITIES OF K24 CPS --- p.122 / Chapter 8.1 --- The in vivo Immunorestorative Activities of K24 CPS in EAT-bearing Mice --- p.122 / Chapter 8.2 --- The in vitro Immunorestorative Activities of K24 CPS in Mice bearing 10-day-old- EAT --- p.122 / Chapter 9. --- THE EFFECT OF K24 CPS IN VITRO INDUCTION OF MURINE BONE MARROW CELLS PROLIFERATION AND DIFFERENTIATION --- p.126 / Chapter 9.1 --- The effect of K24 CPS in vitro induction of Murine Bone Marrow Cells Proliferation --- p.126 / Chapter 9.2 --- The effect of K24 CPS in vitro induction of Murine Bone Marrow Cells Differentiation --- p.126 / Chapter 10. --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.135 / Chapter 11. --- BIBLIOGRAPHY --- p.141

A asma alérgica é uma doença pulmonar de inflamação crônica caracterizada por uma resposta imune do tipo Th2 e uma das principais abordagens terapêuticas para o seu tratamento no futuro, poderia ser a imunoterapia baseada na modulação da resposta imune Th2 para um perfil Th1 e anti-inflamatório. Nosso grupo já demonstrou a eficácia de uma imunoterapia, baseada em um plasmídeo de DNA contendo o gene hsp65 de M. Leprae (DNAHsp65) em modelo murino de asma alérgica. No entanto, apesar dos excelentes resultados, o grupo está procurando outras alternativas imunoterapêuticas, usando a Hsp65 micobacteriana, para futura utilização clinica na área de saúde humana e veterinária. Efeitos benéficos na prevenção e tratamento de doenças alérgicas vêm sendo obtidos com o uso de probióticos. Nossa hipótese é de que uma nova formulação terapêutica, como o probiótico Lactococcus lactis expressando Hsp65 micobacteriana (LLHsp65), apresentaria vantagens significativas no desenvolvimento de pesquisas translacionais. Diante disso, este estudo teve como objetivo avaliar se o probiótico LLHsp65 apresenta atividades imunoterapêuticas no modelo de asma experimental induzida por ovalbumina (OVA). Em diferentes grupos experimentais, 5x109 CFU de LLHsp65 ou de L. lactis selvagem (LLSELV), foram administrados por via oral durante 10 dias consecutivos aos camundongos BALB/c previamente sensibilizados e desafiados com OVA. Em seguida, investigamos os efeitos do tratamento na inflamação alérgica, modulação do padrão de citocinas, produção de anticorpos específicos, hiper-responsividade das vias aéreas e inflamação pulmonar. Nossos resultados demonstraram que o tratamento oral com LLhsp65 modula a resposta imune alérgica de padrão Th2 para o perfil Th1 com aumento dos níveis de IFN-?, IL-12, TNF-?, IL-10, IL-6 e IL- 17, e com a redução das citocinas IL-4, IL-5 e IL-13. Os níveis de IgE e IgG1 anti-OVA no soro também foram significativamente diminuídos. Como consequência desses resultados, também observamos diminuição significativa do infiltrado de eosinófilos no lavado broncoalveolar, na hiper-responsividade nas vias aéreas e a atenuação da inflamação e produção de muco no tecido pulmonar, quando comparados com o grupo controle (OVA/SAL). Por conseguinte, nossos resultados demonstraram que a administração oral de LLHsp65 proporciona uma melhora significativa do processo inflamatório alérgico induzido por OVA, sendo portanto, uma estratégia terapêutica promissora para o desenvolvimento de pesquisa translacional no tratamento de asma alérgica. / Allergic asthma is a chronic inflammatory lung disease characterized by a Th2-type immune response and one of the main therapeutic approaches to its treatment in the future could be immunotherapy based on the modulation of the Th2 immune response to a Th1 and anti-inflammatory profile. Our group has already demonstrated the efficacy of an immunotherapy based on a DNA plasmid carrying the mycobacterial hsp65 gene (DNAHsp65) in murine model of allergic asthma. However, despite the excellent results, our group is looking for other immunotherapeutic alternatives, using mycobacterial Hsp65, for future clinical use in the area of human and veterinary health. Beneficial effects in the prevention and treatment of allergic diseases have been obtained with the use of probiotics. Our hypothesis is that a new therapeutic formulation, such as the probiotic Lactococcus lactis expressing mycobacterial Hsp65 (LLHsp65), would present significant advantages in the development of translational research. The objective of this study was to evaluate whether the probiotic LLHsp65 has immunotherapeutic activities in the ovalbumin-induced asthma model. In different experimental groups, 5x109 CFU of LLHsp65 or control L. lactis (ctLL) were administered orally for 10 consecutive days to BALB/c mice previously sensitized and challenged with OVA. We then investigated the effects of treatment on allergic inflammation, modulation of the cytokine pattern, production allergen-specific antibodies, airway hyperresponsiveness and pulmonary inflammation. Our results demonstrated that oral treatment with LLhsp65 modulates the allergic Th2 immune response to Th1 profile with increased levels of IFN-?, IL-12, TNF-?, IL-10, IL-6 and IL-17 and with the reduction of IL-4, IL-5 and IL-13 cytokines. Serum anti-OVA IgE and IgG1 levels were also significantly decreased. Correspondingly with these results, we also observed a significant decrease in eosinophil infiltrate in bronchoalveolar lavage, airway hyper responsiveness and attenuation of inflammation and mucus production in lung tissue when compared to the control group (OVA/SAL). Therefore, our results demonstrated that oral administration of LLHsp65 provides a significant improvement of the OVA-induced allergic inflammatory process and is therefore a promising therapeutic strategy for the development of translational research in the treatment of allergic asthma.

Allergies are considered atopic diseases, or diseases that cause the immune system to create an abnormal amount of IgE antibodies when the body is exposed to an allergen. Allergies affect many people around the world, however many studies have shown a higher rate of allergy in developed countries when compared to developing countries. This discrepancy is hypothesized to be in part because of a decrease in parasitic infections, which have shown to have a protective effect for autoimmune-type diseases, like allergies. There are not many long-term, effective allergy treatments, however a promising allergen-specific immunotherapy technique uses a vaccine that targets B cell epitopes with the hope of increasing the amount of IgG antibodies as opposed to IgE specific antibodies to decrease the likelihood of an allergic reaction. This paper proposes a study that combines the protective effects of a parasite infection with a helminth infection and a B cell epitope vaccination, an already studied BM32 vaccine, to improve allergy symptoms of those with grass pollen allergy. This combination treatment will aim to decrease the number of symptomatic days, eosinophil count found at a scratch test site, and IgE antibodies found within the blood in grass pollen allergic people during peak grass pollen season.

Colorectal cancer will kill approximately 50,000 people in the United States this year. Current treatment options, including surgery, chemotherapy, and radiation, are often able to force the cancer into remission, but better treatments are needed to help those who don't respond to current treatments. A new and promising treatment option, monoclonal-antibody therapy, has the potential to help reduce the deaths caused by colorectal cancer, but most monoclonal-antibody drugs are currently still in trial phases, and the variations in the dosing schedule of those currently approved for use have not been heavily explored. We have modified a nonlinear ODE tumor/treatment model by de Pillis and colleagues to include monoclonal antibody treatments. Parameter values have been modified for colorectal cancer, with irinotecan as the chemotherapy agent and the two monoclonal antibodies cetuximab, which is FDA approved, and panitumumab, which is still undergoing clinical trials. We have run Matlab simulations of current treatment options, and have found new dosing schedules which, in our simulations, reduce tumor size more effectively that the current schedules. Equilibria of the system and its sensitivity to parameters have also been examined.

Alzheimer's disease (AD) is defined as a progressive neurodegenerative disorder and is characterized by a devastating mental decline. There are three pathological hallmarks of the disease necessary for its diagnosis, these are extracellular amyloid plaques comprised of the beta-amyloid (Aβ) protein, intracellular neurofibrillary tangles comprised of hyperphosphorylated tau protein, and marked neuronal loss. Active immunization against Aβ1-42 or passive immunization with monoclonal anti-Aβ antibodies has been shown to reduce amyloid deposition and improve cognition in transgenic mouse models of AD, aged beagles, and nonhuman primates. Unfortunately, due to cerebrovascular adverse events, both active and passive immunization strategies targeting Aβ have failed in clinical trials. It is, therefore, necessary to identify novel amyloid-clearing therapeutics that do not induce cerebrovascular adverse events. We hypothesized that neuroinflammatory modulation could be a potential novel target. Triggering receptor expressed on myeloid cells-2 (TREM2) is a lipid and lipoprotein binding receptor expressed exclusively in the brain by microglia. Homozygous TREM2 loss of function mutations cause early-onset progressive presenile dementia while heterozygous, function-reducing point mutations triple the risk of sporadic, late-onset AD. Heterozygous TREM2 point mutations, which reduce either ligand binding or cell surface expression, are associated with a reduction in the number of microglia surrounding amyloid plaques, microglial inability to phagocytose compact Aβ deposits and form a barrier between plaques and neurons, an increase in the number of phospho- tau-positive dystrophic neurites and increased tau in the cerebrospinal fluid. Heterozygous mutations also double the rate of brain atrophy and decrease the age of AD onset by 3-6 years. Although human genetics supports the notion that loss of TREM2 function exacerbates neurodegeneration, it is unclear whether activation of TREM2 in a disease state is beneficial. The work we present here characterizes a TREM2 agonizing antibody as a potential therapeutic for amyloid reduction. We found that its administration results in immune modulation, recruitment of microglia to the site of amyloid plaques, reduced amyloid deposition and improvement in spatial learning and novel object recognition memory in the 5xFAD model of AD. More specifically, we show that intracranial injection of TREM2 agonizing antibodies into the frontal cortex and hippocampus of 5xFAD mice leads to clearance of diffuse and compact amyloid. We also show that systemic injection of TREM2 agonizing antibodies weekly over a period of 14 weeks results in clearance of diffuse and compact amyloid as well as elevated plasma concentrations of Aβ1-40 and Aβ1-42. Furthermore, systemic administration of these antibodies led to immune modulation and enhanced cognitive performance on radial arm water maze and novel object recognition tests. Importantly, we show the TREM2 agonizing antibody does not induce the adverse cerebrovascular events known to accompany amyloid modifying therapies. Though systemic administration of both TREM2 agonizing and anti-Abantibodies does not further enhance amyloid clearance or cognitive performance, co-administration mitigates the adverse cerebrovascular events associated with anti-Aβ antibodies. Collectively, these data indicate TREM2 activators may be an effective therapeutic target for the treatment of AD.

Des molécules sont présentées aux T Vγ9Vδ2 par une protéine de co-stimulation immune BTN3A.Le membre BTN3A2 est surexprimé dans 4 cancers, et pourrait agir comme récepteur leurre.Récemment, l’isoforme BTN3A2 a été décrite comme régulant la localisation membranaire du BTN3A1 grâce à une hétérodimérisation.L’objectif de mon projet était d’identifier le ligand de BTN3A2 pour une immunothérapie.Ainsi, nous avons tout d’abord sélectionné, par des études de liaison utilisant la cytométrie en flux, quelques lignées cellulaires T exprimant le ligand de BTN3A2. Puis basé sur notre sélection, la comparaison du profil d’expression génique a été effectuée, nous permettant d’établir une liste de protéines membranaires candidats du ligand de BTN3A2,les molécules HLA de classe II. Après génération de lignées cellulaires surexprimant les candidats potentiels de la méthode transcriptomique, ces cellules ont été utilisées pour des tests de liaison avec le BTN3A2-Fc qui se sont révélés négatifs dans les différentes conditions.De plus, la technologie de transfections transitoires puis tests de liaison, a été utilisée pour identifier les récepteurs partenaires potentiels de BTN3A2.Les quatre produits géniques restants ont été sélectionnés, PLPP3, SEMA6A, SEMA6C et MSR1 mais non validés.Finalement, nous avons utilisé un agent de capture avec trois bras, permettant une liaison covalente, qui a montré que BTN3A1 était le candidat potentiel. Dans notre projet, nous avons confirmé l’hétérodimérisation de BTN3A1/A2 et nous avons démontré la forme existante d’hétérodimérisation pour former une voie de signalisation activant les cellules T Vγ9Vδ2. / Molecules are presented to Vγ9Vδ2 T cells by immune costimulatory protein BTN3A.BTN3A2 which is devoid of a functional intracellular domain, is overexpressed in 4 cancers. Recently, BTN3A2 was described as regulator of subcellular localization of BTN3A1 thanks to heterodimerization. The aim of our project, was to identify the ligand of BTN3A2 for immunotherapy. Therefore, we have first selected by binding studies using flow cytometry, few T cell lines expressing BTN3A2 ligand.Based on the selection, a gene expression profile comparison was performed and allowed us to establish a list of membrane proteins expressed only in positive cell lines, BTN3A2 ligand candidates. The highest FC were found for HLA class II molecules. Cell lines overexpressing potential candidates of transcriptomic method were used for binding assays using BTN3A2-Fc, but were negative in all conditions. Then cell microarray technology was used to identify potential receptor partners of BTN3A2. 4 remaining gene products were selected, PLPP3, SEMA6A, SEMA6C and MSR1. The validation of these candidates was not done after transient transfection and binding test with BTN3A2-Fc (using flow cytrometry). Moreover, chemoproteomic experiments were performed to isolate and identify by mass spectrometry (MS) BTN3A2 ligand. Therefore, we used an original capture reagent (TFR) with three moieties, allowing covalent binding, which showed clearly BTN3A1 as a potential candidate. In our project, we have confirmed the heterodimerization of BTN3A1/A2 and we have demonstrated an existing form of heterodimerization that could interact with other proteins, to form a signaling pathway activating Vγ9Vδ2 T cells.

Cancer is a collection of diseases that is characterized by an uncontrolled proliferation of aberrant cells. The conventional treatment strategies including chemotherapy and radiotherapy prove detrimental to healthy cells and are unable to combat primary and secondary metastases. Hence immunotherapy is gaining momentum in cancer clinics and translational research labs as an alternative safer and more efficacious approach to tumor therapy. Vaccines based on antigen alone lack the ability to optimally activate the antigen presenting cells (APCs) including dendritic cells (DCs) to generate significantly greater antigen-specific T cell responses. A typical strategy to overcome this limitation has been the use of adjuvants in order to improve the immunogenicity of the vaccines. A newer class of adjuvants called toll like receptor (TLR) ligands recognize pathogen associated molecular patterns (PAMP) and thus elicit a Th-1 polarized response. The hypothesis of the current research is that co-delivery of antigen and adjuvant in a microparticulate carrier will elicit a strong cell-mediated immune response conferring anti-tumor immunity. Furthermore, we proposed that a combination of TLR ligands when co-delivered with an antigen will be able to mount a synergistic anti-tumor response in comparison to the delivery of antigen alone. There were three primary objectives of the study; 1) Fabrication, process design optimization and characterization of antigen and adjuvant co-loaded microparticles (MP), 2) Study the ability of the MP fabricated in step 1 in eliciting a potent immune response in a murine model by various routes of administration and 3) Study the effect of the various treatment as prophylactic and therapeutic cancer vaccines in a murine tumor model. Objective 1 was achieved by optimizing various process parameters including PLGA type and concentration, surfactant concentration and modification of a previously reported double emulsification solvent evaporation technique. Process optimization lead to the development of the following 5 treatment groups, a) Empty PLGA MP, b) OVA PLGA MP, c) OVA + CpG PLGA MP, d) OVA + poly I: C PLGA MP and e) OVA + CpG + poly I:C tri-component PLGA MP. The optimized microparticles exhibited a mean particle size of 1.5 πm with a smooth spherical surface and a desirable biphasic release pattern of the entrapped components. Results from step 2 indicated the ability of the co-delivery and the tri-component systems to generate several fold higher immunostimulatory response in comparison to the group treated with antigen alone. Of the two routes of administration tested, the intraperitonial (i.p) route gave the strongest response followed by intramuscular (i.m) route. A synergistic antibody response response was observed upon vaccination with the tri-component model. Prophylactic vaccination studies showed that the co-delivery and tri-component system affording the strongest protection against aggressive tumor growth. The therapeutic studies also indicated enhanced tumor protection and 2-fold improvement in survival times when the mice vaccinated with the co-delivery and tri-component MP carriers in comparison to vaccination with microparticles loaded with antigen alone. The carriers also showed strong evidence for the generation of anti-tumor immunogenic memory. In summary, the current study has laid an interesting premise for the use of immunotherapy using a combination of antigen and TLR adjuvants alone or in conjunction with chemotherapy as a treatment strategy for tumor therapy. This research is expected to lead to the utilization of PLGA delivery systems as novel carriers for cancer immunotherapy.