Дисертації з теми "Activation de cellules immunitaires"
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Ouedraogo, Richard. "La spectrométrie de masse : application à l'étude des cellules immunitaires." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM5062/document.
In view of the many advantages in terms of speed, cost , sensitivity and reliability of the MALDI -TOF mass, we thought we could apply it to the study of intact eukaryotic cells, in particular the study of cells immune . We have shown that this approach is applicable to the global analysis of eukaryotic cells including circulating immune cells. In addition, it allowed us to characterize the many faceted of human macrophage activation by analyzing the data with the R software library " MALDIquant " and specific algorithms. The protein/peptide fingerprint induced by the M1 agonists : IFN - γ , TNF , LPS and LPS + IFN - γ or M2 agonists : IL- 4 , TGF - β1 and IL- 10 are distinct to unstimulated macrophages and specific for each agonist. MALDI -TOF Mass spectrometry can then be used to characterize the subtypes M1 and M2 macrophages . In addition, fingerprints induced by extracellular bacteria ( group B streptococcus , Staphylococcus aureus ) are specific and closed to those induced by IL -4 . The responses of macrophages to intracellular bacteria (BCG, Orientia tsutsugamushi , Coxiella burnetii ) are also unique. Mass spectrometry MALDI -TOF of whole cell revealed therefore the multifaceted activation in human macrophages . Finally, preliminary results show that our approach could be used clinically for the analysis of circulating cells in the case of host-pathogen interaction
Al, Hajj Sally. "Effets des concentrations élevées en chlorure de sodium sur les fonctions immunitaires des cellules dendritiques." Electronic Thesis or Diss., Tours, 2019. http://www.theses.fr/2019TOUR3309.
Recent evidence showed that in response to elevated sodium dietary intakes, many body tissues retain Na+ ions for long periods to reach concentrations up to 200 mM. Recent studies suggested that the immune system might be the bridge linking high sodium intake to several cardiovascular diseases and cancer progression as well. However, the studies about the effects of sodium on immunity brought about contrasted results. So far the effects of sodium on human dendritic cells (DCs) remain unknown. Considering their central role in the immune response, we tested how sodium chloride-enriched medium influences the immune properties of human DCs. DCs were derived from CD14+ monocytes from healthy donors and then stimulated by LPS, in sodium-enriched medium (from 140 up to 200 mM) and finally analyzed. We found that DCs cultivated in high Na+ concentrations remain viable and maintain the expression of DC markers up to 200 mM. In response to LPS, their maturation, their chemotaxis toward CCL19, their production of pro-inflammatory cytokines and ROS were inhibited by high [Na+]. In line with these results, we report that the T-cell allostimulatory capacity of DCs was also inhibited. Finally our data indicate that these effects were mediated through the phosphorylation of SGK-1 (serum and glucocorticoid induced kinase-1) and ERK1/2 kinases.Our results raised the possibility that the effects of sodium on T-cells might be counterbalanced by its ability to downregulate DC activation. Therefore the effects of high sodium diet on the immune response might be more complex than previously thought
Boitelle, Agnès. "Mécanismes de recrutement et de régulation de l'activité des macrophages alvéolaires, dans un contexte de pathologie interstitielle pulmonaire." Lille 1, 1997. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1997/50376-1997-85.pdf.
LOOR, PATRICE. "Signalisation via tyrosine-kinases dans l'activation des cellules t : etude par technique biosensor des interactions entre grb2 et dynamine." Strasbourg 1, 1995. http://www.theses.fr/1995STR15018.
Bercovici, Nadège. "Activation et induction de tolérance des lymphocytes T dans des modèles de souris transgéniques." Paris 11, 1999. http://www.theses.fr/1999PA11T030.
Antigen recognition by T cell can lead to immunity but also to antigen-specific T-cell tolerance. Immunological tolerance can be induced experimentally and may be useful for the treatment of organ-specific autoimmune diseases such as autoimmune diabetes. In this work, I have investigated the mechanisms of activation and tolerance induction in mature CD4+ and CDS+ T cells from TCR-transgenic mice. Systemic administration of soluble peptide is remarkably efficient to induce peripheral T-cell tolerance in vivo. Although one single injection induced transient T-cell tolerance, chronic intravenous (i. V. ) injections of soluble peptide is able to maintain CD4+ T-cell tolerance for more than 12 weeks. I have also shown that i. V. Injection of soluble peptide can tolerize naive CDS+ T cells but can also target effector CDS+ T cells thereby blocking the progression of an ongoing CDS-mediated autoimmune diabetes. Importantly, CDS+ T cell infiltrates are eliminated without bystander tissue damage. Furthermore, I have demonstrated that i. V. Injection of soluble MHC class I : peptide complexes represent an alternative strategy to induce CDS+ T cell tolerance in vivo. Tolerance was achieved by deletion and anergy of antigen-specific CDS+ T cells and allow to down-regulate an ongoing CDS mediated autoimmune diabetes. In experiments conducted in vitro with naïve T cells from TCR-transgenic mice, we have shown that antigen recognition by CD4+ T cells rapidly induced cytoskeletal alterations that are crucial for calcium responses and proliferation. Under conditions in which equal numbers of specific MHC class Il :peptide complexes are presented by dendritic cells (DC) and B cells, we could demonstrate that DC are always more efficient antigen presenting cells underlying the importance of adhesion/costimulatory molecules abundantly expressed by DC. Moreover, we provide evidence for the induction of small calcium signals in CD4+ T cells interacting with DC in the absence of specific antigen that involve MHC/TCR interactions. Finally, we have shown that naive CDS+ T cells can be fully activated and differentiated after antigenic stimulation in the absence of co-stimulatory signals. Altogether, these data contribute to our understanding of the mechanisms of activation and tolerance induction of CD4+ and CDS+ T cells
Miloro, Giorgia. "Déterminer le rôle du récepteur de mort Fas/CD95 dans la co-stimulation des cellules T." Electronic Thesis or Diss., Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ6036.
Fas (CD95/TNFRSF6), a type-I transmembrane receptor of the tumor necrosis factor receptor (TNFR) superfamily, is a well-known cell death activator. However, it has been also implicated in non-cell death processes including cell survival, differentiation, migration. Whereas the molecular cascade that initiates apoptosis upon Fas engagement with its ligand FasL is particularly well described, the informations concerning the molecular mechanisms underlying the Fas mediated non-apoptotic pathways are sparse.As indicated by the induction of autoimmunity and lymphoproliferation in ALPS patients harboringmutations in either the receptor or its ligand, the Fas/FasL system plays a major role in T cell immune homeostasis and thus, in the control of autoimmunity and cancer. On one side, the Fas mediated death has been described critical for (i) the deletion of autoreactive lymphocytes, and thus in the maintenance of peripheral tolerance; (ii) the control of the number of lymphocytes activated by weak antigens during pathogen infections.On the other side, and beyond cell death induction, some Fas non-death pathways have been described in T cells, among which the role of Fas as co-regulatory receptor for the TCR during its activation. Despite the potential importance of this role in immunotherapeutic strategies, only few and controversial studies related to this involvement were done. Indeed, whereas several studies have described Fas as a TCR co-stimulatory receptor, others defined an inhibition of T cell activation by Fas-TCR concomitant stimulation. In this context, the aim of my PhD project consisted into molecularly dissect the Fas-TCR co-signaling.By using both primary T cells and cell lines bearing a specific transgenic TCR, we could define Fas as a costimulatory receptor. By exploiting biochemical approaches as well as flow cytometry and microscopy we could decipher the Fas-TCR crosstalk both at functional and molecular level. First, we show that Fas-TCR costimulation occurs in both naïve and in memory T cells as well as in both CD4+ and CD8+ T cell subpopulations.Molecularly, we could describe that Fas enhances the TCR signaling at membrane proximal level, since the phosphorylation of the first proteins involved in TCR activation is increased. Furthermore, both membrane-bound and soluble FasL are capable to initiate Fas co-stimulatory signal. Lastly, we could exclude the involvement of FADD and Caspase-8, first actors of Fas signaling, in the co-activation, and even more importantly, the involvement of the death domain of Fas cytoplasmic tail, unveiling the implication of another Fas receptor domain. To describe the molecular mechanisms and the context where Fas-TCR co-stimulation occurs might be of an outstanding importance in the comprehension of Fas physiopathology in T cells and for future studies that might involve its potential for immunotherapeutic strategies
Chevalier, Mathieu. "Sous-populations lymphocytaires T régulatrices et réponses Th17 en primo-infection VIH : rôle dans le contrôle de l'activation immunitaire." Paris 7, 2013. http://www.theses.fr/2013PA077017.
Generalized and persistent immune activation plays a central role in the pathogenesis of HIV infection. The immune activation set point, as defined by CD8 T-cell activation at the end of primary HIV infection (PHI), is predictive of disease progression (CD4 T-cell loss). The aim of this study was to identify early mechanisms that could be involved in the control of systemic immune activation. Twenty-seven patients with PHI were enrolled in a prospective longitudinal study with a 6 month follow-up. We showed that there was no evidence for a role of natural regulatory T cells in the control of immune activation during PHI. However, our data suggest that double-negative T cells could be able to dampen immune activation, probably via the production of anti-inflammatory cytokines. Microbial translocation is thought to be one of the major causes of immune activation in the chronic phase of HIV infection. In our study, the Th17/Treg ratio was negatively correlated to the level of T-cell activation and to monocyte activation (measured by the plasma levels of soluble CD14 and IL-1RA). However, we demonstrated that systemic microbial translocation did not occur during the phase of PHI in the great majority of patients. Thus, data indicate that T-cell and monocyte activation observed in PHI mostly result from viral replication and not from microbial translocation. Interestingly, plasma levels of soluble CD14 and IL-1RA at baseline were predictive of the T-cell activation set point. These plasma soluble proteins may be considered for use in clinical practice as early surrogate markers for disease progression
Achard, Carole. "Le virus oncolytique de la rougeole : sensibilité du mésothéliome pleural malin et activation du système immunitaire." Nantes, 2016. https://archive.bu.univ-nantes.fr/pollux/show/show?id=f2d251a0-7c4c-48bf-bcfb-f3839dd6159c.
I worked on an antitumor virotherapy strategy based on the use of an attenuated strain of measles virus (MV) to treat malignant pleural mesothelioma (MPM). It is described that MV preferentially infects tumor cells which overexpress its major receptor CD46 on their surface. By studying in vitro 22 human MPM cell lines, I demonstrated that 70% of the MPM cell lines are sensitive to the infection and that the sensitivity to MV depends on defects of their antiviral type I interferon (IFN) response rather than on the overexpression of CD46. Healthy cells are not sensitive to MV since they develop a full type I IFN response. Thus, 70% of patients may be sensitive to this therapeutic approach. It is admitted that MV induces immunogenic death of tumor cells, which is able to activate dendritic cells (DCs) and their capacity to cross-present tumor antigens. I continued to characterize the effects of MV on DCs and I showed that blood myeloid CD1c+ DCs and plasmacytoid DCs (pDCs) express TRAIL on their surface in response to MV. This TRAIL expression depends on their IFN-α secretion which is induced by the detection of viral RNA by the cytosolic sensors RLRs (RIG-I like receptors) in both types of DCs, and by TLR7 (Toll-like receptor 7) activation in pDCs only. These DCs are then able to induce the lysis of TRAILsensitive cells. Altogether, my results lead to a better understanding of the oncolytic activity of MV, which relies not only on the infection and lysis of tumor cells but also on the activation of the immune system against tumors
Yatim, Nader. "Coordinated activation of cell death and inflammatory pathways in dying cells regulate adaptive immunity." Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC233.
Dying cells initiate adaptive immunity by providing both antigens and inflammatory stimuli for dendritic cells (DCs), which in turn activate CD8' T cells through a process called antigen cross-priming. To define how different forms of programmed cell death influence immunity, we established models of necroptosis and apoptosis, where dying cells are generated by RIPK3 and CASP8 dimerization, respectively. We found that release of inflammatory mediators such as damage-associated molecular patterns (DAMPs) by dying cells was not sufficient for CD8+ T cell cross-priming. Instead, robust cross-priming required RIPK1 signaling and NF-KB-induced transcription within dying cells. Decoupling NF-1(13 signaling from necroptosis or inflammatory apoptosis reduced priming efficiency and tumor immunity. Our results reveal that coordinated inflammatory and cell death signaling pathways within dying cells orchestrate adaptive immunity
Herblot, Sabine. "Etude des mécanismes moléculaires impliqués dans la différenciation et l'activation des cellules du système immunitaire : différenciation des macrophages, activation des lymphocytes T par l'IL-2." Bordeaux 2, 1997. http://www.theses.fr/1997BOR28518.
Merle, Nicolas. "Mechanisms of complement activation under hemolytic conditions." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB076/document.
Complement system is a complex and tightly regulated innate immune defensive cascade, which can promote tissue damage, when overactivated. Hemolysis-derived danger associated molecular pattern heme is able to activate complement in serum and on endothelial cells (EC) in vitro, providing a rational for scrutinizing the impact of complement activation in hemolytic diseases. The objectives of this work were to study whether and how intravascular hemolysis induces complement activation in vivo, and to understand the underlying mechanism that leads to the acquisition of a complement activating phenotype of the endothelium in order to identify novel therapeutic strategies. We found complement deposits, including C3 activation fragments and C5b-9, within kidneys of patients with sickle cell disease (SCD) nephropathy (a prototypical hemolytic disease) as well as in a mouse model of SCD. We set up and characterized the renal injury of a mouse model of massive intravascular hemolysis, triggered by injection of phenylhydrazine (PHZ). We revealed C3 deposition within kidneys of the PHZ-treated animals. It was prevented by heme scavenging with hemopexin (Hx) and reproduced by injections of free heme, thus demonstrating the importance of heme for the complement activation in vivo. SCD erythrocytes microvesicles (MVs), are a pathologically relevant source of labile heme, since they carry three times more heme on their surface compare to MVs from healthy donors. We demonstrated that MVs, generated from SCD erythrocytes, activate complement in human serum and on EC surface, in part on a heme-dependent manner. These data highlight the importance of heme as a complement activator in hemolytic diseases. Further, we found that the C3 activation fragments deposits on endothelium in vivo and on EC in vitro can be in part explained by interaction of heme with TLR4. Indeed, the use of a specific inhibitor of TLR4, TAK-242, reduced about 50% the complement deposits on EC surface and such deposits on vascular endothelium in PHZ- or heme-injected mice were attenuated TLR4-/- mice. Moreover, we found that heme/TLR4-dependent complement deposition was mediated by the rapid expression of P-selectin, which in turn, recruited C3b and C3(H2O) on the EC surface, as evidenced by real time protein interaction analyses and using of blocking antibodies. Together our results demonstrated that heme and erythrocytes MVs are the hemolysis-derived products which promoted complement activation. At cellular level, heme induced complement-activating phenotype of EC by triggering TLR4/P-selectin axis and resulting in C3 activation fragments on cell surface. Together, these studies underline the potential benefits of Hx and TAK-242 against complement activation in pathologies related to hemolysis
Nayrac, Manon. "Persistance du VIH-1 et reconstitution des lymphocytes T CD4+ dans la muqueuse intestinale sous traitement antirétroviral." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30110.
Current antiretroviral therapies control HIV-1 replication allowing subsequent reconstitution of the immune system. However, the persistence of integrated proviruses in long-lived reservoir cells precludes virus eradication. Residual virus replication could also replenish the reservoir and contributes to its stability. The gut is a key compartment during HIV-1 infection as it contains numerous effector memory CD4+ T cells that are highly permissive to HIV-1 replication. Here we characterized the blood and intestine compartments of HIV-1-infected individuals on prolonged antiretroviral therapy and showed: (i) a compartmentation of viral quasispecies between the blood and gut compartments, with an enrichment of CCR5-using virus in the gut; (ii) the persistence of a residual production in gut which replenishes the viral reservoir; (iii)a chronic antigenic stimulation exerted by residual virus production; (iv) a dynamic equilibrium between the residual production and immune control of the reservoir. HIV-1 persistence in the intestine mucosa under antiretroviral therapy also contributes to the default of immune reconstitution in this compartment. The HIV-1-specific immune response is associated with the reduction of CCL25 expression by enterocytes, a chemokine required for CD4+CCR9+ T cell migration in the intestine. Among gut CD4+ T cell subsets, th17 cells remain depleted contrasting with a normal frequency of Th22 cells. Th17 cells migration to the gut remains impaired because of the reduced production of CCL20 by enterocytes. Th22 cells could alternatively use the CCR10-CCL28 and CCR6-CCL20 chemotactic axes, depending on the CCL28/CCL20 ratio in the intestinal microenvironment. Th22 cells produce IL-22 that reduces CCL20 production by an IL-18-dependant mechanism, thus blunting Th17 cells recruitment to the gut mucosa. By contrast, CCL28 production is maintained and allows Th22 cells to be recruited along this axis
Germaud, Nathalie. "Polymorphisme du gène NCR3/NKp30 et variabilité de la fonction des cellules Natural Killer humaines." Phd thesis, Université René Descartes - Paris V, 2012. http://tel.archives-ouvertes.fr/tel-00789417.
Espagnolle, Nicolas. "Etude des interactions moléculaires à l'aire de contact formée entre les lymphocytes T et les cellules présentatrices d'antigène." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/16/.
T cell/APC interaction is the central event in adaptive immune response. This encounter allows the reorganization of several surface molecules and intracellular signaling components at the cell-cell contact area. This molecular reorganization is named the immunological synapse (IS). Actually, IS functions are not completely understood. To understand the « raison d'être » of this structure, in a first study, we searched the impact of CD2 molecule engagement with its ligand CD58 at IS, on calcium signaling in antigen stimulated human T cells. Therefore, we have shown that CD2 engagement permits optimal recruitment and activation of PLC1 and plays a key role in sustaining [Ca2+]i increase in antigen-stimulated T cells. Without being intrinsically able to trigger the calcium pathway, CD2/CD58 interaction modulates this TCR induced signaling pathway allowing to full T lymphocyte activation. In a second study, still going on, we aim to study IS formed between T cells and unconventional APCs : mast cells. For that, in a first time, we developped methods allowing to derive mast cells from bone marrow cells and, in a second time, we are now studying their capacity to present antigen to T cells
Chabaudie, Nadine. "Action des hypodermines sur le système immunitaire bovin." Tours, 1990. http://www.theses.fr/1990TOUR3802.
Bovine hypodermosis associated to an insect producing myasis is widely spread all over the herds of the northern hemisphere. Its economic incidence (on meat and leather production) had led to national programs of control. They are all based on chemotherapy. But, if very efficient molecules are not applicable to dairy cow due to their long lasting residue in milk. Howerver, a development of resistance to these antiparasitic molecules could be suspected. So a control by vaccination could be a alternative issue. The relationships between the parasite and the defense system of the host need to bu understood. In previous studies we have already demonstrated the antiinflammatory activity of the parasite secretions : hypodermins A, B and C. This study aimed to analyse the activity of these hypodermins on the bovine cellular and humoral responses. In vitro studiees : the lymphocytes co-cultivated with different mitogens and hypodermins modulate the proliferative response of lymphocytes to mitogens : hypodermin B increases this response, whereas hypodermins A and B decrease it. In vivo studies : lymphocytes from previously uninfested and infested cattle, receiving hypodermins A or C by injection and co-cultivated with mitogens confirm the in vitro inhibiting activity of hypodermin A, whereas hypodermin C does not modify the lymphoproliferation. Moreover, hypodermin A injections induce, on previously unfested and non unfested animals, a similar humoral and cellular response. Immunization of naive cattle with hypodermin A associated with different adjuvants leads to a low protection against natural infestation which do not reach 30%
Klezovich, Maria. "Dialogue entre les cellules Natural Killer et Bacillus anthracis in vitro et in vivo : rôle dans la réponse immunitaire innée et le contrôle initial de l'infection." Paris 7, 2012. http://www.theses.fr/2012PA077114.
NK cells are important immune effectors for preventing microbial invasion and dissemination, through natural cytotoxicity and cytokine secretion. Bacillus anthracis spores present the original property of driving efficient IFN-y production by NK cells. However, there was no data available on the role of NK cells during anthrax infection. Infection with B. Anthracis —the etiological agent of anthrax— results in death through a combination of acute bacterial infection and toxemia. The present study provides insights into the mechanisms of cytokine and cellular signaling that underlie the process of NK-cell activation by B. Anthracis and the bacterial strategies to subvert and evade this response. We have demonstrated that IFN-y production by NK cells in response to B. Anthracis spores was: i) contact-dependent through RAE-1-NKG2D interaction with macrophages (the expression of RAE molecules on macrophages is induced through stimulation with spores); ii) IL-12, IL-18, and IL-15-dépendent, where IL-12 played a key role and regulated both NK cell and macrophage activation; and iii) required IL-18 for only an initial short time window. Infection with non-toxigenic encapsulated B. Anthracis induced recruitment of NK cells and macrophages into the draining lymph node. Production of edema (ET) or lethal (LT) toxin during infection impaired this cellular recruitment. NK cell depletion led to accelerated systemic bacterial dissemination, indicating that NK cells probably play an important role in controlling B. Anthracis infection at the initial step. We also show that B. Anthracis toxins subverted both NK cell essential fonctions. ET and LT disrupted IFN-y production through different mechanisms. LT acted both on macrophages and NK-cells, whereas ET mainly affected macrophages and did not alter NK-cell capacity of IFN-y secretion. In contrast, ET and LT inhibited the natural cytotoxicity fonction of NK cells, both in vitro and in vivo. The subverting action of ET thus led to dissociation in NK cell fonction and blocked natural cytotoxicity without affecting IFN-y secretion. The high efficiency of this process stresses the impact that ET may exert in anthrax pathogenesis, and highlights a potential usefolness for controlling excessive cytotoxic responses in immunopathological diseases. Our findings therefore exemplify the delicate balance between bacterial stimulation and evasion strategies. This highlights the potential implication of the crosstalk between host innate defences and B. Anthacis in initial anthrax control mechanisms. D reached the draining lymph nodes, the disease evolved in a very fast and regular way to septicemia within two days
Krzysiek, Roman. "Rôle des interactions cellulaires et des chimiokines dans la réponse lymphocytaire B." Paris 11, 2000. http://www.theses.fr/2000PA11T001.
Maturation of the B cell response to peptide antigens mostly depends on the limiting amount of T cell help. Lt depends on both, the availability of Ag-specifie T cells and on the ability of Ag-binding B cells to efficiently recruit them. We showed that B-cell Ag receptor (BCR) engagement on ali functional subsets of mature B ce lis selectively induces the production of MIP-lα/ β and fractalkine, chemokines which elicit migratory response in CD4+ T cells of memory/etfector phenotype. The blocking experiments strongly suggest that BCR-activated B cells produce other chemokines with activity towards T cells by. In vitro, fractalkine expression in B cells was also induced by CD40 triggering. In situ, it was found in germinal centers of secondary follicles and dendritic cells (DC) within T cell area. Furthermore, we have demonstrated that within the B cell lineage, CCR6 chemokine receptor (MIP-3α/LARC β and -defensins receptor) is a marker of peripheral mature B cell pool but is absent within in central pro-, pre-B compartement and germinal center B cells and plasma cells in the periphery. In Boyden-type microchamber chemotaxis and F-actin polimerization assays, MIP-3α is a potent B-cell hemoattractant but seems to be only functional on CCR6(high) memory B cells. MIP-3α responsiveness in B cell is strongly enhanced by INFα, the cytokine of the innate immune response. Altogether, these data provide new insides in the role of chemokines gradients and direct cell-cell interactions during maturation of the B cell reponse
Rivière, Élodie. "Rôle des cellules épithéliales salivaires au cours du Syndrome de Sjögren primitif Salivary gland epithelial cells from patients with Sjögren’s syndrome induce B-lymphocyte survival and activation Interleukin-7/Interferon axis drives T-cell and salivary gland epithelial cell interactions in Sjögren’s syndrome." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS124.
Primary Sjogren's syndrome (pSS) is an auto-immune disease characterized by a lymphocytic infiltration of lacrimal and salivary glands leading to an ocular and oral dryness. The objective of this work was to understand the role of salivary gland epithelial cells (SGECs) in the pathophysiology of pSS and especially via their interactions with B and T lymphocytes. We observed a differential effect of SGECs from pSS and controls subjects since, in coculture, SGECs from pSS were able to induce a better survival of B lymphocytes compared to SGECs from controls. The interaction between SGECs and B lymphocytes involved mainly soluble factors. Our hypothesis is that several factors are involved and act in synergy. Indeed, inhibition of one of each soluble factor individually did not block the support of SGECs to B lymphocytes. In contrast, the addition of leflunomide, or a BTK inhibitor or a PI3K inhibitor inhibited the induction of B lymphocytes viability by SGECs.Regarding the interactions between SGECs and T lymphocytes, we showed that SGECs secrete interleukin 7 (IL7) after type I or II interferon (IFN)stimulation. In turn, IL7 is able to induce the production of type II IFN by T lymphocytes, suggesting the existence of an amplification loop between IL7 and IFN. The addition of a monoclonal antibody inhibiting the IL7 receptor (anti-IL7R) downregulated the expression of IFN induced genes in cultured salivary glands explants.These mechanisms could induce and/or maintain locally, the chronic B lymphocytes hyperactivation during pSS, as well as, the IFN signature described in the salivary glands. Thus, these results confirmed the hypothesis that SGECs play an active role in the pathogenesis of pSS. A better understanding of their mechanisms of action could help to define new therapeutic strategies in pSS
Kakwata-Nkor, Deluce Nora. "Induction de sous-populations de cellules dendritiques humaines pro-tolérogènes par des fragments d’anticorps bispécifiques." Thesis, Tours, 2019. http://www.theses.fr/2019TOUR3805.
Dendritic cells (DCs) have a central role in immunity and induce both specific immunity and immune tolerance thanks to their surface pathogen receptors (PPRs). The immune tolerance induced by tolerant DCs (Tol-DCs) appears as an interesting way to explore in order to improve the long-term transplantation outcome. Four DC subsets, at least, have been identified including conventional DCs (BDCA-1; BDCA-3), plasmacytoid DCs (pDC), Inflammatory DCs(MoDC) and Langerhans cells (LC). For each DC subset, an array of pathogen recognition receptors (PRRs) have been identified on their surface. The PRRs profile differs between DC subsets providing an individual responsiveness to target specific pathogens as well as to trigger and modulate immunological responses. The aim is to target DC subset PRRs by bispecific antibodies (BsAb) in order to induce physiological tolerance. Monocyte derived DC (moDC) and monocyte derived Langerhans DC (moLC) were obtained from CD14+ cells. The plasmacytoïd DC (pDC) were purified from an enriched DC cells fraction obtained by Percoll® gradient of PBMCs. The moDC, pDC and moLC subsets were analyzed by phenotype labelling and FACS. A Bispecific Ab (tandem scFv) were built to target PRR on DC subsets. The tandem is made of 2 scFv of 55KDa. The BsAb were produced using insect S2 (BIC05) or CHO cell (BIC15 or BIC25) and purified by protein L column. Each scFV recognize a PRR on DC. Each BsAb have been evaluated on its DC target and on PBMC at the phenotypic and functional levels by evaluating the maturation markers (CD83, CD86, CD25 and HLA-DR), cytokine secretions (IL-10, IL-12p70 and IFN- ) and the capacity to activate naïve T-cell as well as to induce regulatory T-cell (Treg)
Barbin, Thomas. "Rôle immunorégulateur de la protéine GILZ dans les cellules dendritiques pendant l’infection virale chronique par le VIH-1 et perspectives dans des stratégies vaccinales." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC0022.
When the GILZ (glucocorticoid-induced leucine zipper) protein is overexpressed in dendritic cells (DC), they acquire a tolerogenic phenotype that support an immunoregulatory function, notably inducing regulatory CD4+ T cells of a Tr1 type. At the molecular level, GILZ can be induced by anti-inflammatory extracellular signals like IL-10 and TGF-b, as well as by some pro-inflammatory signals (PGE2, IL-6, IL-1b, TNF).A deregulation of GILZ expression in DC has been reported in immune pathologies relying on a disequilibrium between effectors and regulatory CD4+ T cells like allergic diseases and cancers.Considering the central role played by DC in the implementation of immune responses and their deregulation in chronic viral infections, we explored GILZ expression and function in DC in the context of HIV-1 infection, in chronically HIV-1-infected patients under efficacious antiretroviral therapies and in elite controllers that naturally control the infection and preserve immunogenic DC while controlling the level of inflammation. Our data bring new knowledge on the mechanisms of modulation of DC in the chronic infection by HIV-1, between beneficial immunogenicity of DC from elite controllers that barely express GILZ and deleterious tolerance of DC from patients under efficacious antiretroviral therapies that strongly express GILZ. These discoveries may potentially found applications in vaccination, DC also playing a crucial role in vaccine strategies
Mourtada, Jana. "Mécanismes d’activation de la réponse immunitaire par DNp63 dans les cancers des voies aérodigestives supérieures HPV-positifs." Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAJ127.
HPV+ oropharyngeal tumors display both prognostic and molecular heterogeneity. Patients prognosis can be distinguished by the presence or absence of a molecular signature that depends on the ΔNp63 transcription factor. We demonstrated that ΔNp63 inhibits the migratory and invasive capabilities of HPV+ HNSCC cell lines and increases their sensitivity to platinum-based chemotherapy, implying its role in tumor progression. A functional analysis of ΔNp63 revealed its ability to stimulate the phagocytosis of cancer cells by macrophages in vitro. Consistently, a transcriptomic analysis of the same cellular model highlighted that ΔNp63 regulates the expression of secreted factors, including chemokines and interleukins, among which is the DKK3protein. Our findings indicate that DKK3 secretion by cancer cells activates the NF-κB pathway in macrophages, mimicking ΔNp63's effects on phagocytosis regulation. Induction of the NF-κB pathway by DKK3 in macrophages is mediated by its receptor CKAP4. Finally, our analyses suggest that ∆Np63 regulates the expression of factors involved in the inflammasome, as well as those of other cytokines such as TNFRSF11B, CCL26, CCL11, TIMP1 and TIMP2. Altogether, our results show that ΔNp63 plays a unique role in the prognosis of HPV+ patients by regulating secreted molecules involved in the recruitment and immune cell activation
Messal, Nassima. "Expression, régulation et caractérisation fonctionnelle des molécules de co-signalisation immunitaire, PD-L2 et CD277 dans l'activation lymphocytaire T." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX20654.
PD-1 (programmed death-1) is a new CD28 families member, that deliver inhibitory signals that regulate the balance between T cell activation, tolerance, and immunopathology. (1) (ref octa).PD-1, is inducibly expressed on T cells. The PD-1 ligands PD-L1 (B7-H1) and PD-L2 (B7-DC) exhibit distinct patterns of expression: PD-L1 is expressed more broadly than is PD-L2. PD-L1 is expressed on resting and up regulated on hematopoietic, nonhematopoietic cells and cancer cell. However, PD-L2 is expressed only on professional antigen-presenting cells. In addition, it has been demonstrated that PD-L1 and PD-L2 are differentially regulated by Th1 and Th2 cytokines.Suggesting that PD-L2 is regulated differently in the former versus the latter, and this proved to be the case, both in transcription and promotion (2) (ref octa) However, little is known about the regulation of PD-L2 expression and nine is known about the expression of PD-L2 on T cells. In the present study, we observed in the first time, by flow cytometer and real time PCR (RT PCR) that PD-L2 expression is induced on ex vivo on activated CD4+ and CD8+ T cells, on in vitro on activated JURKAT T cell line and this expression is inhibited by the immunosuppressive drogue Cyclosporin A (CsA). In the second time we showed that PD-L2 is up regulated in vivo on Non hodchkin lymphoma, other up regulation of PD-L2 expression is observed on Vb8+ T cells after PBMC treatment with the Staphylococcal enterotoxin E (SEE) super antigen. Finally, we attributed a function to PD-L2 to be a co-inhibitory molecule for CD4+ T cells activation
Gentili, Matteo. "Identification of viral and host mechanisms that determine innate immune activation by the DNA sensor cGAS." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB023.
Nucleic acids are potent activators of innate immune responses. To control infections, multicellular organisms have developed multiple ways to detect pathogens. One of these is the recognition of DNA in the cytoplasm. Presence of DNA in the cytoplasm is usually linked to infections by bacteria or viruses, such as HIV. Cyclic GMP-AMP synthase (cGAS) is an essential cytosolic sensor for DNA in mammals. Upon DNA recognition, cGAS synthetizes the small second messenger cyclic GMP-AMP (cGAMP), which activates innate immune signaling pathways. cGAS plays a pivotal role in response to microbes and in the development of autoimmune diseases such as interferonopathies. This thesis investigate the role of cGAS in response to viruses and to self DNA. By exploring the cGAS-mediated response to HIV, we found that in cells producing virus, cGAS-synthesized cGAMP is packaged in viral particles and extracellular vesicles. Viral particles efficiently deliver cGAMP to target cells and activate a potent antiviral response. The transfer of cGAMP requires cGAS catalytic activity and fusion of the viral particles with the target cells. We also showed that in the context of an infection, DNA viruses such as MVA and mCMV can package cGAMP. Therefore viral mediated cGAMP transfer is a generalized defense mechanism of the innate immune system. We further investigated cGAS activation by DNA focusing our attention on nuclear chromatin DNA. In eukaryotic cells, DNA is compartmentalized in two organelles: the nucleus and the mitochondrion. Nuclear compartmentalization of DNA can be transiently lost upon nuclear envelope breakdown during cell division and upon nuclear envelope ruptures in migrating dendritic cells (DCs). We found that nuclear envelope breakdown or loss of nuclear envelope integrity leads to cGAS recruitment on the nuclear DNA. We also showed that DCs present with a nuclear pool of cGAS at steady state. Nuclear envelope breakdown during cell cycle leads to cGAS recruitment to the nuclear DNA. By manipulating cGAS localization, we showed that cGAS is poorly active when in the nucleus, and that providing exogenous DNA unmasked its full enzymatic activity. Expression of nuclear localized-cGAS in DCs leads to DCs maturation and Type I interferon (IFN) production. The N-terminal region of cGAS regulates cGAS nuclear/cytoplasmic distribution in interphase cells and we established Lamin A/C as required for cGAS accessibility to nuclear DNA in migrating DCs. Unexpectedly, we show that cGAS is not activated upon nuclear envelope rupture. Finally, we identify the pericentromeric heterochromatin as the preferential binding DNA for expressed nuclear cGAS in DCs. Altogether, our study shows the nucleus to act as an intracellular immune-privileged site for the activation of cGAS. Collectively, we have shown relevance of cGAS activation upon viral infection and uncovered a Trojan horse mechanism of cGAMP incorporation in the viral progeny. We have also described yet to be defined regulatory mechanisms that limit responses towards chromatin DNA in the nucleus. As evidence grows for cGAS involvement in response to pathogens, in autoimmune diseases, in response to DNA damage and in the development of cell senescence, fully understanding the mechanisms of distinction between self and pathogen related DNA by the sensor will be important to develop effective means to regulate the pathway
Letscher, Hélène. "Étude des propriétés régulatrices d’une population de précurseurs de cellules dendritiques plasmacytoïdes conditionnée par le CpG dans le cadre de réponses auto-immune et allogénique Innate activation primes bone marrow plasmacytoid dendritic cell precursors for tolerance Rôle protecteur des CpG-pre-pDC dans le cadre d’une réponse allogénique : la maladie du greffon contre l’hôte." Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2171&f=13417.
Hematopoietic progenitors can sense innate signals. Their early education by such signals within the bone marrow, prior to their egress, may have considerable impact on the outcome of immune responses. While mature plasmacytoid dendritic cells (pDC) are known to either aggravate or ameliorate disease both auto-immune and allogeneic, it remains unknown whether immune regulatory function can be stably imprinted at the precursor stage in the pDC lineage onwards. We herein investigated whether activation with the oligonucleotide CpG, a Toll-like receptor-9 agonist, confers to bone marrow pDC precursors (CpG-prepDCs) characterized by the c-kit+Sca-1+B220intPDCA-1+ phenotype the capacity to protect against two kinds of murine immune pathologies: Experimental Autoimmune Encephalomyelitis (EAE), a model of multiple sclerosis which is an autoimmune disease and graft versus host disease (GVHD), an allogeneic response. We demonstrate that the adoptive transfer of relatively low number of CpG-pre-pDCs (80.000 in EAE and 200.000 in GVHD) was able to clinically reduce both diseases. Interestingly, CpG-pre-pDCs migrated to the spinal cord in EAE and to the spleen in GVHD where their progeny retained a relatively immature pDC phenotype. In EAE, the progeny of CpG-pre-pDCs massively produces IL-27 and TGFß and moderately GM-CSF. In the inflamed central nervous system, the progeny switches the immune response of infiltrating CD4+ T cells from pro-inflammatory (IFNy+ GM-CSF+ IL-17+) to anti-inflammatory (TGFß+, IL-27+, IL-17-, GM-CSFlo). The key role of TGFß and IL-27 was assessed using precursors incapacitated for the production of each of those cytokines. These experiments demonstrated that the two soluble factors acted sequentially: TGFß ensures early phases of the immunomodulation mediated by the CpG-pre-pDC while IL-27 is required for later protection. In GVHD, the mechanisms of protection are different yet similar in some ways. As for EAE, the progeny of CpG-pre-pDCs is still able to produce TGFß but this time in combination with IL-12, another cytokine from the IL-27 family. Additionally, those cells were able to reduce the IL-17 production by both pathogenic CD4+ and CD8+ T cells. The human equivalent of CpG-pre-pDC could be a new therapeutic tool in patients with multiple sclerosis or graft versus host disease either per se or enriched in the hematopoietic stem cell transfer already implemented to treat those two immune conditions
Segura, Elodie. "Fonctions immunitaires des exosomes de cellules dendritiques." Paris 7, 2006. http://www.theses.fr/2006PA077163.
Dendritic cells (DC) secrete vesicles from endocytic origin called exosomes which bear Major Histocompatibility Complex (MHC) molecules and can induce immune responses in tumoral Systems. The aim of this work was to identify the nature of exosome-induced immune responses and to determine how exosomes interact with recepient cells. We have shown that exosomes transfer antigen that is contained inside their lumen, but also transfer preformed functionnal MHC-peptide complexes. Exosomes from mature DC are the most efficient in vitro and in vivo for stimulating T lymphocytes. Immature and mature DC-derived exosomes display different quantities of some molecules, among which ICAM-1 is essential for exosomes functionnal activity. Exosomes are captured by DC through an interaction between LFA-1 on DC and ICAM-1 on exosomes
Ben, Larbi Nadia. "Plasticité du phénotype neuroendocrinien dans les cellules immunitaires." Lille 1, 2006. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2006/50376_2006_77.pdf.
Delobel, Pierre. "Evolution du tropisme du HIV-1 sous traitement antirétroviral et impact sur l'homéostasie lymphocytaire T." Toulouse 3, 2007. http://www.theses.fr/2007TOU30059.
Boitel, Brigitte. "La reconnaissance T d'un peptide de la toxine tétanique présenté par la molécule de classe II HLA-DR : illustration des bases moléculaires des intéractions TCRαβ / peptide / CMH". Paris 6, 1993. http://www.theses.fr/1993PA066726.
Vitiello, Sergio. "Modifications fonctionnelles des cellules immunitaires liées à l'asymétrie cérébrale." Bordeaux 2, 1993. http://www.theses.fr/1993BOR28224.
Vaillant, Solenne. "Suivi in vivo de cellules immunitaires par imagerie multimodale." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS021/document.
Recent clinical trial results have demonstrated the efficacy of immunotherapy in cancer patients. This type of therapy involves treating cancer cells by stimulating the patient's immune defenses. The aim of this thesis project is to develop a biomarker of efficacy for this therapy, in order to better understand the biological mechanisms involved, and to have an early and non-invasive indicator of the patient’s response to immunotherapy. To do this, two imaging techniques (MRI and PET) were used as in vivo monitoring tools for the biodistribution of different populations of immune cells. The first step of this work was to establish different protocols for labeling immune cells. For the PET approach, the immune cells were labeled with Zirconium 89; and for MRI, two labeling techniques were studied: the first uses iron nanoparticles, and the other uses micelles loaded with Fluorine 19. After validation of their non-toxicity, the sensitivity of each labeling was evaluated in vitro, then in vivo in a second step, thus making it possible to study the biodistribution of the immune cells after different types of injections. The labeling with Zirconium 89 was then tested on different animal models of immunotherapies (PD1/PDL1 for example). Finally, since direct markings do not allow optimal cellular monitoring in the long term, a cell labeling approach using reporter genes has been considered. It involved modifying the genome of the immune cells so that they could express an enzyme (for example the viral thymidine kinase HSV1-TK) or a transporter (such as the NIS iodine transporter) allowing the internalization of a radioactive tracer in vivo, and thus be able to carry out indirect labeling of the cells
Mosser, Coralie-Anne. "Implication des cellules microgliales dans le développement des réseaux synaptiques du néocortex somatosensoriel Microglial BDNF promotes the functional maturation of thalamocortical synaptic networks Microglia and prenatal inflammation regulate local and horizontal wiring of inhibitory circuits." Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2167&f=13404.
Microglial cells are a population of specialized macrophages residing in the CNS only. They have long been studied solely under pathological contexts and were thought to be active only upon homeostatic disturbance following a brain lesion. However, over the last decade, they have been increasingly recognized to be essential players in the physiological functioning of the CNS. Specifically, during the CNS formation, microglia has been shown to regulate apoptosis and neuronal survival. They are also able to directly interact with synapses, by eliminating supernumerary and inappropriate connections, by promoting synapse formation or by regulating their activity. However, mechanisms by which microglia influence wiring and functional maturation of cortical are not fully understood. To better assess the role of microglia in cortical development, we used the barrel field as a model of neuronal development and we combined in vivo manipulations together with electrophysiology, optogenetics, pharmacologic and histologic approaches on brain slices of genetically-engineered mice. We first explored the consequences of microglia entry near the terminals of thalamic afferents (center of the barrels) in the primary somatosensory cortex during the first postnatal week on functional properties of thalamocortical synapses and associated disynaptic feedforward inhibition. By selectively depleting microglia at early postnatal days by intracerebral injections of clodronate-encapsulated liposomes, we show that microglia absence during the first postnatal week delays the functional maturation of both monosynaptic thalamocortical synapse and feedforward inhibition of layer 4 principal cells of the barrel cortex (PC) up to the 10th and 12th postnatal days (P10-12). To identify the mechanism underlying this process, we used the CX3CR1+/CreERT2; BDNFlox/lox mouse line allowing the conditional deletion of microglial BDNF during the first postnatal week. Our recordings indicate that the absence of microglial BDNF, as well as early microglia depletion, leads to a deficit in the functional maturation of both monosynaptic excitatory and disynaptic inhibitory thalamocortical connexions between P10-12. We therefore identified a microglial key factor in the maturation of cortical synapses. Our recordings in the young adult suggest that early microglial BDNF deletion has a long-term effect on thalamocortical excitatory synapses. In a second study, we investigated the consequences of microglia dysfunction during embryonic development on cortical networks wiring. Maternal immune activation (MIA) triggered by bacterial lipopolysaccharide (LPS) injection modifies the laminar repartition of parvalbumin-expressing inhibitory interneurons (PV+), key actors in neuropsychiatric disease, in the cortex until P20. Our functional data revealed that these MIA and depletion protocols lead to an increase of layer 4 PC perisomatic inhibition at P20, as well as a horizontal exuberance of cortical inhibition supported by PV+ interneurons. This increased inhibition does not last within development as suggested by our recordings in the adult. On the opposite, it seems that MIA and early microglia depletion result in weaker inhibitory synapses at P60. To conclude, we postulate that microglial cells are the missing link between maternal immune challenge and à higher risk of having neurodevelopmental pathologies like autism or schizophrenia. Our results highlight the crucial role of microglial cells in neuronal network development during perinatal period
Touch, Sothea. "Cellules immunitaires dans les maladies cardiométaboliques : altérations phénotypiques et fonctionnelles." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066084/document.
A common feature between cardiometabolic diseases (CMDs) is a state of chronic low-grade inflammation. In obesity and type-2-diabetes (T2D) notably, insulin resistance has been linked to inflammation in several tissues. The objective of this project is to evaluate the interactions between immune cell alterations and metabolic perturbations in CMDs. In a first study, we investigated intestinal immunity and cytokine production of intestinal T cells in a cohort of lean and obese subjects and evaluated the functional relationship between T cells and enterocytes. We demonstrated that T cell density and cytokine production was increased in the jejunal mucosa of obese subjects and promoted insulin resistance in enterocytes in vitro. In a second study, we characterized mucosal-associated invariant T (MAIT) cells, a subset of T cells recognizing bacterial vitamin B derivatives, in 5 groups of patients with different forms CMDs (metabolic syndrome, obesity, T2D, coronary artery disease with or without heart failure) compared to healthy subjects. We demonstrated that MAIT cell decrease is correlated with HbA1c and is a common feature in all CMD groups. In an ex vivo study, we show that their depletion in the blood could be explained by a higher propensity to apoptosis under high glucose concentrations. Altogether, our findings suggest that the jejunal immune microenvironment could participate in local and systemic metabolic perturbations in human obesity. We also demonstrate that the abundance immune cells, such as circulating MAIT cells could serve as an early marker of cardiometabolic dysfunction
Mège, Jean-Louis. "Activation des cellules phagocytaires." Aix-Marseille 2, 1990. http://www.theses.fr/1990AIX22015.
Picard, Émilie. "Etude phénotypique et fonctionnelle des cellules NK dans un contexte de cancer et d'inflammation." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCE022.
NK cells are innate lymphocytes involved in the recognition and elimination of infected or tumor cells. Their cytotoxic activity is finely regulated by a set of activating and inhibitory receptors. However, receptors expression and NK cell functions may be modified according to environment. Here, we were interested in NK cell-phenotype and function modulations and their relationship with CD4 T cells, in NSCLC patients and under IL-21 influence in inflammatory context. The first study highlighted an increase circulating rate of CD56dim CD16- NK cell subset concomitantly with a decrease rate of CD56dim CD16+ NK cell subset in NSCLC patients. Ex vivo analysis of NK cell phenotype highlighted a specific group of patients with an overall altered expression of NCRs and NKG2D on NK cell subsets. The main defect was the decrease of NK cells expressing NKp46 and we showed a negative correlation between the patients’ survival and NKp46+ NK cell percentage. Interestingly, NKp46 neutralization on NK cells was associated with a better antitumor CD4 T cell response. The second study showed that IL-21 promotes the differentiation of a specific NK cell subset coexpressing CD86/HLA-DR and CD86/CD30. While NK cell activation via CD30 promotes a high degranulation and IFN-γ secretion, IL-21-activated NK cells also produce MIF. This soluble factor provide costimulatory signaling during naïve CD4 T cell priming inducing the differentiation of uncommitted central memory T cells. Such HLA-DR+ MIF+ NK cells were identified in inflammatory human appendix suggesting that they could activate CD4 T cells in vivo. Altogether, these studies highlighted a different modulation of NK cell phenotype accordingg to envoronment which could impact the crossstalk NK-T celles. thus, these findings support a regulatory role of NK celles in adaptive immune responses
De, Becker Geneviève. "Induction et régulation des réponses immunitaires par les cellules présentatrices d'antigènes." Doctoral thesis, Universite Libre de Bruxelles, 1996. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212431.
Lise, Marie-Claude. "Neuropeptides et cellules immunitaires : implication dans la physiopathologie des lymphocytes B." Limoges, 2010. https://aurore.unilim.fr/theses/nxfile/default/ee6a0759-ed6f-4a1a-9af6-3da7b50aed5e/blobholder:0/2010LIMO310O.pdf.
Trescos, Yannick. "Effets des toxines de Bacillus anthracis sur le cytosquelette des cellules immunitaires : implication sur la phagocytose et les fonctions immunitaires." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAV026/document.
Bacillus anthracis, the agent of anthrax, is also a major agent of biological warfare threat. Its virulence is caused by two main factors : the capsule and two toxins, edema toxin (ET = PA + EF) and lethal toxin (LT = LF + PA). EF is a calcium and calmodulin-dependent adenylate cyclase, producing a rise in intracellular cAMP concentration, while LF is a zinc metalloprotease cleaving the majority of Mitogen Activated Protein Kinase Kinases. The toxins play a central role in the pathogenesis of the disease and the deregulation of the functions of immune cells. The actin cytoskeleton is actively participating in the phagocytosis and the migration of macrophages and dendritic cells.However, few studies analyze the involvement of the actin cytoskeleton of immune cells in the pathogenesis of toxins. ET induces a time-dependent retraction of dendritic cells and macrophages on fibronectin micropatterns, accompanied by actin depolymerization and a loss of the anchor points of dendritic cells. ET early activates cofilin by activating the cAMP - PKA - Protein phosphatases signaling pathway. Despite these alterations of the actin cytoskeleton, ET does not induce any change in the phagocytic capacity of dendritic cells, except for a deregulation of the phagosomes maturation. ET also leads to an increase in the migration of dendritic cells in vitro by activation and expression of CCR7 and CXCR4 on the surface of dendritic cells.In contrast, LT results in a time-dependent spreading of micropatterned dendritic cells, accompanied by a dysregulation of actin dynamics causing abnormal combinations of actin filament. LT activates myosin phosphatase via the RhoA-ROCK pathway to dephosphorylate myosin II. Unlike ET, LT inhibits the dendritic cells phagocytosis but does not lead to a change in dendritic cells migration in vitro
Vincent, Julie. "Rôles des cellules myéloïdes suppressives et des infiltrats immunitaires dans le cancer." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00967901.
Poli, Caroline. "Il-26 : une cytokine pro-inflammatoire stimulant les cellules immunitaires innées myéloïdes." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0068.
In physiological conditions, self-DNA released by dying cells is not detected by intracellular DNA sensors. Inchronic inflammatory disorders, unabated inflammation has been associated with a break in innate immune tolerance to self-DNA. However, to gain access to intracellular DNA sensors, extracellular DNA has to complex with DNA-binding molecules. IL-26 is a member of the IL-10 cytokine family, overexpressed in numerous chronic inflammatory diseases, which biological activity remains unclear. We demonstrate here that IL-26 binds to DNA and shuttles it in the cytosol of human myeloid cells. As a consequence, IL-26 allows extracellular DNA to trigger proinflammatory cytokine secretion by monocytes, in a STING- and inflammasome-dependent manner. Supporting these biological properties, IL-10-based modelling predicts two DNA-binding domains, two amphipathic helices, and an in-plane membrane anchor in IL-26, structural features of cationic amphipathic cell penetrating peptides. In line with these properties, patients with active autoantibody-associated vasculitis, a chronic relapsing autoimmune inflammatory disease associated with extensive cell death, exhibit high levels of both circulating IL-26 and IL-26-DNA complexes. Moreover, in patients with crescentic glomerulonephritis, IL-26 is expressed by renal arterial smooth muscle cells and deposits in necrotizing lesions. Accordingly, human primary smooth cells secrete IL-26 in response to proinflammatory cytokines. In conclusion, IL-26 expressed in lesions confers proinflammatory properties to DNA released by dying cells, setting up a positive amplification loop between extensive cell death and unabated inflammation
Delale, Thomas. "Implication des récepteurs de type Toll dans la production d'interférons et l'initiation des réponses immunitaires antivirales." Lyon 1, 2005. http://www.theses.fr/2005LYO10054.
Bussière, Françoise. "Magnésium et activation des cellules inflammatoires." Clermont-Ferrand 1, 2001. http://www.theses.fr/2001CLF1PP10.
Meffre, Eric. "Les cellules proB humaines : sous-populations médullaires physiologiques et nouveaux déficits immunitaires primitifs." Aix-Marseille 2, 1996. http://www.theses.fr/1996AIX22093.
Fontes, Pascaline. "Etude fonctionnelle de la protéine prion cellulaire dans deux populations de cellules immunitaires." Montpellier 2, 2007. http://www.theses.fr/2007MON20011.
Prion diseases are neurodegeneratives pathologies of multiples determinisms. Inherited, sporadic or infectious forms are all associated with the expression of one protein, called prion protein or PrP. Infectious diseases are suspected to be caused by an abnormal conformational isoform of the cellular prion protein (PrPC) named “scrapie” or PrPSc. Physiopathologic events associated with prion diseases are not completely understood, in part because physiological function of PrPC is not precisely known. PrPC is a glycoprotein located in the extracellular side of the membrane with GPI anchorage. Due to its location, PrPC has been implicated in many cellular functions as signalling, apoptosis modulation, cellular adhesion or receptor for the bacteria Brucella. However, many of these functions are not clear or are controversial. We try to determine the physiological role of cellular prion protein by studying different cellular mechanisms of two populations of immune cells : Tγ9δ2 lymphocytes in which important expression of PrP has been found and murine macrophages where PrP has been implicated in the entry and intracellular proliferation of Brucella. But, in both cases, we were unable to demonstrate a functional implication of the cellular prion protein
Guillerey, Camille. "Etude de l'initiation des réponses immunitaires innées et adaptatives par les cellules dendritiques plasmacytoïdes." Paris 7, 2013. http://www.theses.fr/2013PA077250.
Plasmacytoid dendritic cells (pDCs) are well known for their ability to secrete huge amounts of type I interferons. We generated a new mouse model lacking pDCs : the IK L/L Rag -/- mice. This model is based on an hypomorphic mutation of the Ikaros gene on a Rag 2 deficient background, leading to the absence of pDCs, B and T cells. Using the IK L/L Rag -/- mice, we established that pDCs are essential for NK cell responses to a TLR-9 stimulation by CpG. We also demonstrated that pDCs are crucial for the systemic production of chemokines required for innate cell recruitment following TLR-9 triggering. Moreover, by injecting pDC-depleted splenocytes to IK L/L Rag -/- mice, we were able to reconstitute both B and T cell compartments. Thus, these mice can be used to study adaptive immune responses in the absence of pDCs. Finally, we studied the activation- induced mechanisms that allow antigen cross-presentation by pDCs. Finally, we studied the activation-induced mechanisms that allow antigen cross-presentation by pDCs. We showed that a TLR-7 stimulation allows the protection of internalized antigens by regulating pDC phagosomal pH. In addition, we found that reactive oxygen species participate to the up-regulation of co--stimulatory molecule and to T cell activation by pDCs. Altogether, these results contribute to a better understanding of how pDCs initiate innate and adaptive immune responses
Hamada, Attoumani. "Les propriétés immunitaires des cellules souches de la pulpe dentaire dans un contexte infectieux." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0660/document.
Dental pulp Stem cells (DPSCs) are mesenchymal stem cells (MSCs) isolated from the dental pulp. DPSCs are able to self-renew and differentiate into several cell types such as odontoblasts, osteoblasts, chondrocytes, neuroblasts and adipocytes.The immune properties of DPSCs are being studied more and more, they harbor Toll-like receptor on the surface and have an immunomodulatory activity.However, immune properties such as those described in professional immune cells such as phagocytosis, production of antimicrobial compounds and the new concept "Trained immunity" could be studied.A brief review has been developed to highlight the set of immune properties of DPSCs described in the literature. Then, experimentally, we showed that DPSCs could internalize the bacterial pathogen Bartonella quintana.In addition, we have described the ability of DPSCs to develop trained immunity. It is an inflammatory memory concerning two cytokines IL-6 and MCP-1. Priming DPSCs with the bacterial ligand LPS or PGN induces an increase in the expression and production of IL-6 and PGN after a second stimulus.Overall, the study of the immune properties of DPSCs shows that DPSCs can act as immune cells
Hervé, Caroline Dantal Jacques. "Etude des désordres immunitaires dans le syndrome néphrotique idiopathique et sa récidive après transplantation rénale." [S.l.] : [s.n.], 2006. http://castore.univ-nantes.fr/castore/GetOAIRef?idDoc=27396.
Maheux, Catherine. "Influence de l'expression du CD103 et du CD34 sur la fonction de cellules immunitaires au poumon en contexte inflammatoire." Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/30788.
Cordier-Dirikoc, Sevda. "Rôle des cellules immunitaires et effet des cannabinoïdes dans la physiopathologie des maladies à prions." Phd thesis, Université de Nice Sophia-Antipolis, 2008. http://tel.archives-ouvertes.fr/tel-00317568.
La fonction physiologique de la PrPc est encore mal connue, en particulier dans le système immunitaire. La recherche de partenaires protéiques pourrait permettre de mieux comprendre le rôle de la PrPc. Des traceurs fluorescents composés de PrP recombinante ont été produits et utilisés pour caractériser les sites de liaison de la PrPc dans les différentes populations de splénoctytes murins. La liaison des traceurs sur des lymphocytes B entraîne l'activation de la voie des MAP kinase et l'élévation transitoire de la concentration calcique intracellulaire démontrant que la liaison de la PrPc à ses récepteurs est fonctionnelle. Le rôle physiologique de ces interactions et la nature moléculaire des récepteurs reste à être déterminés.
Mauffre, Vincent. "Identification de marqueurs précoces de la gestation dans les cellules immunitaires circulantes chez les ruminants." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1193.
In cattle farming, reproductive performance is closely linked to farm profitability. The early identification of non-pregnant females, using pregnancy diagnosis tests, would allow rapid re-insemination of the animals, thus shortening the interbreeding interval. Ideally, pregnancy detection would be performed prior to the return to oestrous, namely at the time of implantation, which is not possible using current state-of-the-art pregnancy diagnosis techniques. At this early stage of pregnancy, the conceptus produces a ruminant-specific antiluteolytic signal, the interferon tau, which is responsible for the maternal pregnancy recognition. This interferon is critical in the communication between conceptus and maternal organism. The expression of numerous genes has been reported to be regulated by the interferons, in the endometrium and in blood leucocytes of ruminants, at the time of implantation.Recent technical advances for functional analysis of the genome have provided new opportunities for the use of these biological markers in pregnancy diagnosis. The main purpose of this work was to identify non-invasive, reliable and early pregnancy diagnostic markers in immune circulating cells, along with the characterisation of the local and systemic responses of the maternal organism to pregnancy.In order to identify new candidate genes, we performed a transcriptome analysis of pregnant and non-pregnant peripheral blood mononuclear cells, which we combined to a transcriptome analysis of the caroncular endometrium and the lymph nodes that specifically drain the uterus. For practical and cost-effectiveness reasons, these samples were collected in sheep. Based on the results of the transcriptome analysis, we selected, among the differentially expressed genes (DEG), a set of candidate genes in order to develop an early pregnancy diagnosis test initially in ewes and in cows in a second step. Expression of these genes was assessed using real time qPCR. Based on the expression levels of these candidate genes, pregnancy diagnosis tests were performed on different sets of animals: an experimental set of ewes, an experimental set of cows and finally, on a set of ewes from commercial herds. Five candidate genes were identified and evaluated: CXCL10, STAT1, MX1, MX2 and ISG15. Diagnosis tests displayed reliable results in the experimental sets of animals but failed to discriminate pregnancy in the set of farm animals. In this group, we observed high variations in interferon stimulated genes (ISG) expression levels highlighting the low specificity of ISG based pregnancy diagnosis tests performed in farm on heterogeneous batch of animals.To understand this lack of specificity, a simultaneous transcriptome analysis of blood leucocytes, lymph nodes and caroncular endometrium revealed respectively 118, 17 and 2823 DEG. Very few DEG were noticed in the lymph nodes. But if 78% of the DEG in blood leucocytes were found in the endometrium as well, only 3% of the DEG in the endometrium were shared with blood cells. Data mining analysis of the lists of DEG showed a strong pregnancy associated response in both blood leucocytes and the endometrium, an interferon response type, related to the implication of the interferon tau. However, this transcriptomic signature, identified in both biological tissues, is not pregnancy specific as it is frequently associated with pathogen agents.Finally, this work has enabled to highlight the slight correlation between the local (endometrium) and the peripheral (blood leucocytes) response during early pregnancy. But this work has also pointed out that the transcriptomic signature related to pregnancy, an interferon response type, is not pregnancy-specific. This lack of specificity is due to the unreliability of ISG based pregnancy diagnosis tests. Further investigations are needed to identify alternative pregnancy markers, independent of the interferon tau
Cordier-Dirikoc, Sevda. "Rôle des cellules immunitaires et effets des cannabinoïdes dans la physiopathologie des maladies à prions." Nice, 2008. https://theses.hal.science/tel-00317568.
The key event in prion diseases is the conversion of the cellular prion protein (PrPc) into a pathological and proteolysis-resistant isoform, named PrPres. PrPres is responsible for both neuropathogenesis and transmissibility of the disease. The search for molecules able to inhibit its formation in the brain is potentially a therapeutic strategy. Cannabidiol, a non psycho-active component of Cannabis Sativa, inhibits PrPres formation in vitro and in vivo and significantly prolongs the survival time of prion-infected mice. Numerous studies suggest the involvement of immune cells in the uptake and transport of PrPres. Using a transgenic mouse model of transient depletion of dendritic cells, we demonstrated the involvement of these cells in the lymphoinvasion process after intra-peritoneal but not oral infection. The physiological functions of the PrPc are poorly understood, particularly in the immune system. Finding its partners could shed light on the role of PrPc. Fluorescent probes made of recombinant PrP were produced and used to characterize the PrPc binding sites in murine splenoctytes. The binding of tracers onto B lymphocytes resulted in the activation of the MAP kinase pathway and the transient elevation of intracellular calcium concentration demonstrating the functionality of the binding. The physiological role of these interactions and the molecular nature of PrPc receptors remain to be determined