To see the other types of publications on this topic, follow the link: Macrophage activation.
Dissertations / Theses on the topic 'Macrophage activation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Macrophage activation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Svensson, Ulf. "Macrophage activation by bacteria signalling to prostaglandin and cytokine responses /." Lund : Dept. of Medical & Physiological Chemistry, Lund University, 1994. http://books.google.com/books?id=sAhrAAAAMAAJ.
Full text
2
Tabata, Yasuhiko. "Macrophage phagocytosis of polymer microspheres and antitumor activation of macrophages." Kyoto University, 1987. http://hdl.handle.net/2433/74704.
Full text
3
Pound, J. D. "Parameters of human macrophage activation." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381442.
Full text
4
Cano, Antonella. "Characterization of Acanthamoeba macrophage activation." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25992.
Full text
5
Hunter, Catriona Mhairi. "MicroRNA regulation of macrophage activation." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/31027.
Full textAbstract:
Macrophages are mononuclear phagocytic cells that have diverse roles within the body. Tissue specific macrophages, e.g. Kupffer cells, microglia and osteoclasts, have roles in tissue homeostasis, while circulating macrophages play an important role in the innate immune system. Macrophages detect the presence of pathogen associated molecular patterns (PAMPs) via a range of receptors known collectively as pathogen recognition receptors (PRRs). Detection of pathogens causes the macrophages to become ‘activated,’ during which the macrophages undergo extreme morphological and translational changes that enable the pathogen to be neutralised and other immune system components to be recruited. Macrophage activation must be carefully regulated and promptly resolved, as chronic inflammation is damaging to the host. MicroRNAs have emerged as one mechanism by which activation is regulated. MicroRNAs are small, non-coding pieces of RNA that function as a post-transcriptional regulatory mechanism. Their action is exerted through binding with a complementary region in the 3’ untranslated region (3’UTR) of the target mRNA. This binding, facilitated by the ribonuclear protein complex RISC, prevents successful translation of the mRNA into its protein product. MicroRNAs have been shown to function across species, throughout development and during the adult life-span. In the immune system, microRNAs are known to be required for correct formation of germinal centres and normal development of B- and T-cells. MicroRNAs have also been shown to be differentially regulated during macrophage activation with different stimuli. In particular, miR-155, miR-146a and miR-21 are associated with macrophage activation by lipopolysaccharide (LPS). The objective of this work was to further understand the role of microRNAs during macrophage activation with LPS. Two approaches were adopted. Firstly, the regulation of individual microRNAs in LPS-activated bone marrow derived macrophages (BMDMs) was characterised by the use of illumina small RNA sequencing. Secondly, the requirement of the global microRNA population during macrophage biology was investigated through the use of DGCR8 and Dicer knockout systems. In keeping with the large number of changes reported in mRNA translation upon activation, expression of >400 microRNAs were found to be differentially regulated by exposure to LPS. Twelve of these microRNAs were chosen for further study (miR- 142-3p, -146a, -15b, -155, -16, -191, -21, -27b, -30b, -322-5p, -378 and -7a). Individual knock-down of these microRNAs in the RAW264.7 macrophage-like cell line mostly demonstrated subtle, rather than dramatic changes to the activation marker genes studied by RT-QPCR analysis. However, knock-down of miR-146a, -15b, - 155 and -191 were able to significantly alter the expression of the activation marker genes (Tnf-a, Cox2, Cxcl2, Il-6 and Saa3). Interestingly, knock-down of miR-142-3p, miR-146a and miR-155 appeared to show cross-regulation of these microRNAs. The cell index (CI) data suggested that miR-191 and miR-21 influence adhesion in activated macrophages. Studies with the DGCR8 and Dicer knockout systems showed that the global microRNA population was required for successful differentiation of macrophages from embryonic stem cells, and for normal expression of differentiation and activation markers in bone marrow derived macrophages. Overall, these results show that dynamic expression of microRNAs is an integral part of the macrophage response to LPS.
6
Ghanipour, Ali. "IL-10 regulates macrophage activation through activation of SHIP." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/30873.
Full textAbstract:
IL-10 is a potent anti-inflammatory and immunosuppressive cytokine, which
regulates macrophages by activation of the STAT3 pathway. However, several lines of
evidence suggest that IL-10 can inhibit macrophage activation independent of STAT3
through currently unknown mechanisms and pathways. Here for the first time, we show
that in murine macrophages, IL-10 activates Src Homology 2 Domain-containing Inositol
5'-Phosphatase (SHIP), a molecule with reported anti-inflammatory effects. Activation
of SHIP by IL-10 is required for inhibition of Tumor necrosis factor alpha (TNFα) in
macrophages. Additional experiments revealed that IL-10 activation of SHIP acted at the
post-transcriptional level and inhibited translation of TNFα . Using a novel small
molecule activator of SHIP, AQX-016A, we further confirmed that activation of SHIP
alone could inhibit TNFα translation.
IL-10 activation of SHIP results in the inhibition of the LPS induced increase in
the PI3K product, PIP3, at the membrane. However, conflicting data as to the role of
PI3K in regulation of TNFα have been presented. Our studies show that PI3K inhibition
downregulates TNFα production in peritoneal and several other macrophage lines, and
upregulates it bone marrow derived macrophages (BMDM). Interestingly, this difference
is due to the increased amount of autocrine negative regulators produced in BMDM,
removal of which exposes the positive role PI3K plays in regulation of TNFα. Therefore,
our studies confirm that PI3K activity positively regulates TNFα production in
macrophages and that inhibition of TNFα by IL-10 or AQX-016A through activation of
SHIP is likely due to SHIP'S ability to antagonize this pathway. The importance of this pathway is further highlighted as IL-10 inhibition of LPS-induced septic shock in mice
lacking one allele of SHIP is significantly attenuated. Furthermore, activation of SHIP
by AQX-016A inhibits TNFα production in septic mice.
We also found that IL-10 inhibited LPS induced p38 activity in a cell-dependent
manner. However in all cells tested, IL-10 activated p38 rapidly. We identified several
IL-10 induced genes including CRIM1, a transmembrane protein with no previous report
of involvement in the immune system. We found that IL-10 induction of CRIM1 was
partly dependent on the activity of p38. However, expression of CRIM1 does not seem
to be involved in the anti-inflammatory effects of IL-10.<br>Medicine, Faculty of<br>Biochemistry and Molecular Biology, Department of<br>Graduate
7
Wu, Wei-Kang. "Modulating angiogenesis via altering macrophage activation." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539772.
Full text
8
DUARTE, Madalena Bento. "Macrophage direct activation by Leishmania Spp." Master's thesis, Instituto de Higiene e Medicina Tropical, 2019. http://hdl.handle.net/10362/97877.
Full textAbstract:
Leishmanioses é um grupo de doenças causadas por parasitas do género Leishmania que apresenta elevada morbidade e de mortalidade. As manifestações clínicas dependem de interações complexas que se estabelecem entre Leishmania spp. e a resposta imunitária do hospedeiro. A doença pode manifestrar-se de maneiras diferentes, desde uma simples úlcera cutânea até ao envolvimento dos órgãos profundos que pode originar doença visceral fatal ou kala-azar. A resistência a drogas terapêuticas é um problema muito evidente em países endémicos, existindo uma crescente procura por alternativas eficazes. A pesquisa de vacina(s) capaz de deter a propagação da doença tem sido exaustiva. Um dos aspectos mais importante de Leishmania spp. é a capacidade destes parasitas conseguirem, por um lado, evitar e, por outro, alterar a resposta imunitária do hospedeito, que permita a sobrevivência do parasita e do hospedeiro, originando infeção crónica. O objectivo desta dissertação é investigar a capacidade de Leishmania spp. (L.shawi, L.amazonensis, L.guyanensis e L.infantum) modular a activação de MØ humanos, avaliando o fenótipo de MØ infetados através da expressão de dois biomarcadores de superfície, o CD68 e o CD163, associados à fagocitose e á actividade oxidativa. Os resultados mostraram que promastigotas de Leishmania induziram a mudança no fenótipo dos MØ que aponta para a existência de fagocitose intensa e inibação da actividade oxidativa. O incremento da fagocitose associado á diminuição da actividade oxidativa dos MØ infetados facilita o estabelecimento da infeção no hospedeito humano, garante a sobrevivência do parasita e assegura a conclusão do seu ciclo de vida, sobretudo nos parasitas causadores de leishmaniose cutânea<br>Leishmanias is a group of diseases with different clinical manifestations and is the leading cause of high morbidity and mortality worldwide. The clinical manifestations of Leishmanias in humans depend on complex interactions between the virulence characteristics of infecting Leishmania spp. and the immune responses of its hosts. The disease can manifest in a number of forms, ranging from simple cutaneous ulcers to the involvement of visceral organs, causing highly fatal visceral disease or kala-azar. Drug resistance is a very evident problem in some of endemic countries within the increasing demand for effective alternatives. The urgent demand for a vaccine capable of halting the spread of the disease has been exhausting. One of the most important aspects of Leishmania spp. infection is the ability of these parasites to evade and sabotage the host immune responses, which allow the parasite to persist and established chronic infection. The aim of the present dissertation is to investigate Leishmania spp. (L. shawi, L. amazonensis, L. guyanensis, and L. infantum) ability in modulating MØ activation, by accessing cell phenotype through the expression of two surface biomarkers, CD68 and CD163that are associated with phagocytosis and oxidative burst. Results showed that Leishmania promastigotes induced a change in MØ phenotype that point towards active phagocytosis and inhibition of the oxidative burst. Modulating the MØ activity to increase phagocytosis and decrease oxidative burst allows the parasite to establish host infection and ensures their own survival and the accomplishment of the life cycle, at least by the parasites that cause cutaneous leishmaniasis.
9
Sobhani, Kimia. "Proteomic analysis of macrophage proinflammatory programmed cell death and macrophage activation /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/8688.
Full text
10
Graham, Susan. "Studies on the activation of rainbow trout (Salmo gairdneri) macrophages and the characterization of a macrophage activating factor." Thesis, University of Aberdeen, 1989. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU498113.
Full textAbstract:
Rainbow trout macrophages were stimulated with PMA to produce 02- and H2O2 as detected by the reduction of nitroblue tetrazolium (NBT) and the oxidation of phenol red respectively. Addition of DDC or nitroprusside, inhibitors of superoxide dismutase (SOD) increased O2-levels and decreased H2O2 levels, whereas addition of exogenous SOD had the reverse effect. Such data are indicative of a respiratory burst pathway in teleost macrophages comparable with that of mammals. Respiratory burst activity, acid phosphatase activity and RNA synthesis in rainbow trout macrophages which have been stimulated in vitro with the mitogen Concanavalin A (Con A) or in vivo by injection of formalin-fixed Aeromonas salmonicida in Freund's incomplete adjuvant (FIA) was analysed. With Con A, in vitro stimulated head kidney (HK) or elicited macrophages had increased O2-production and RNA synthesis but no significant increases in H2O2 or acid phosphatase activity after 72h post-stimulation with Con A. In contrast, all functions were increased in in vivo stimulated macrophages compared with FIA-elicited peritoneal macrophages. In a bactericidal assay, Con A stimulated macrophages did not show an increase in killing of an avirulent strain of A. salmonicida (004) above control levels whereas in vivo stimulated macrophages not only displayed increased killing of the avirulent strain of bacteria but also acquired the ability to kill a virulent strain (048). Thus, Con A stimulated macrophages only possessed some of the features of activation whereas in vivo stimulated macrophages were activated as defined by the increased bactericidal activity. Peritoneal washes obtained in the collection of activated macrophages were able to increase NBT reduction in normal HK macrophages suggesting the presence of a soluble activating factor. Lymphokine (LK)-containing supernatants produced using either HK or blood derived leucocytes, by pulsing with 10ug/ml Con and 5ng/ml PMA, were able to increase O2- and H2O2 production, to enhance the killing of an avirulent strain of A. Salmonicida and conferred the ability to kill a virulent strain of A. salmonicida. The LK present in these supernatants was therefore designated a macrophage activating factor (MAF). The use of potential second signals to enhance the killing of bacteria by LK-treated macrophages, met with limited success. Only A. salmonicida (strain 004) LPS was able to produce a small increase in killing above LK-treatment. The MAF produced in this study was tested for antiviral/interferon (IFN) activity. The results showed that the supernatants did contain IFN activity. Attempts to semi-purify the MAF from antiviral activity showed the two activities to co-purify, indicating that both activities may be due to the same molecular species. The retention time of the MAF/IFN, coupled with the results of SDS-PAGE analysis showed the molecular weight of the moiety to be approximately 19K daltons. Both activities were sensitive to low pH (pH 2), high temperature (60oC) and trypsin, providing further evidence that the MAF and IFN activity produced in these studies may be due to the same molecular species, possibly akin to IFN- of higher vertebrates.
11
Burrowes, Hannah Mahony. "Macrophage Activation and Differentiation with Cholesterol Crystals." Thesis, University of Canterbury. Biological Sciences, 2012. http://hdl.handle.net/10092/7532.
Full textAbstract:
Cholesterol crystals have been linked to activation of the NLRP3
inflammasome and the formation of foreign body giant cells (FBGCs). It
has been hypothesized that FBGCs have a role in advanced atherosclerotic
plaque formation. This thesis examined the feasibility of producing
stable cultures of FBGCs starting with human monocytes with the
goal to examine pterin production by these cells in comparison to
human monocyte derived macrophages (HMDMs). The study also
investigated the effect of cholesterol crystals on 7,8-dihydroneopterin
(7,8-NP) production and modulation of IL-1β levels in macrophages.
7,8-Dihydroneopterin is a potent antioxidant generated by macrophages
which also down regulates the expression of macrophage scavenger
receptor CD36. The use of alpha-tocopherol and IL-4 as FBGC fusion
mediators was explored. Using these mediators, large numbers of
FBGC were successfully cultured. The rates of fusion achieved in the
cultures were low, and the cells had poor adhesion, which prevented
pterin measurement. FBGC, which are thought to remove crystallized
cholesterol from the plaque, cleared 21% of cholesterol crystal compared
to 50% cleared by HMDM cells. Due to this result, the effect of
cholesterol crystals on pterin production in monocytes and macrophages
was explored. Cholesterol crystals cause inflammation through the
activation of the NLRP3 inflammasome, however, it was unknown
whether they could modulate 7,8-NP production. Cholesterol crystals
caused an intracellular dose-dependent loss of 7,8-NP to its oxidized form,
neopterin, in HMDM cells. Cholesterol crystals induced intracellular
synthesis of 7,8-NP in HMDMs. 7,8-NP was released into the supernatant
and oxidized to neopterin in media. Monocytes treated with cholesterol
crystals released up to 100 nM of neopterin and 120 nM of 7,8-NP in
the media after 48 hours. The combination of IFN- and cholesterol
crystals appeared to inhibit the release of 7,8-NP into the media for the
first 48 hours, after this time 7,8-NP release rapidly increased. The
addition of exogenous 200 μM 7,8-NP showed that in the presence of
monocytes, cholesterol crystals did not cause the oxidation of 7,8-NP to
neopterin, as seen in HMDMs but possibly to 7,8-dihydroxanthopterin
or xanthopterin. The presence of 7,8-NP increased IL-1β expression in
the presence of cholesterol crystals after 24 hours incubation. FBGCs
and the removal of cholesterol crystals may be a key process in the
resolution of atherosclerotic plaques. It appears that cholesterol crystals
are able to modulate inflammatory processes including activation of
the inflammasome and balance of 7,8-dihydroneopterin to the oxidized
neopterin. The infiltrating monocytes may provide antioxidant protection
against the inflammation induced by cholesterol crystals and the activity
of the infammasome.
12
Raza, Sobia. "Modelling and analysis of macrophage activation pathways." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5898.
Full textAbstract:
Macrophages are present in virtually all tissues and account for approximately 10% of all body mass. Although classically credited as the scavenger cells of innate immune system, ridding a host of pathogenic material and cellular debris though their phagocytic function, macrophages also play a crucial role in embryogenesis, homeostasis, and inflammation. De-regulation of macrophage function is therefore implicated in the progression of many disease states including cancer, arthritis, and atherosclerosis to name just a few. The diverse range of activities of this cell can be attributed to its exceptional phenotypic plasticity i.e. it is capable of adapting its physiology depending on its environment; for instance in response to different types of pathogens, or specific cocktail of cytokines detected. This plasticity is exemplified by the macrophages capacity to adjust rapidly its transcriptional profile in response to a given stimulus. This includes interferons which are a group of cytokines capable of activating the macrophage by interacting with their cognate receptors on the cell. The different classes of interferons activate downstream signalling cascades, eventually leading to the expression (as well as repression) of hundreds of genes. To begin to fully understand the properties of a dynamic cell such as the macrophage arguably requires a holistic appreciation of its constituents and their interactions. Systems biology investigations aim to escape from a gene-centric view of biological systems. As such this necessitates the development of better ways to order, display, mine and analyse biological information, from our knowledge of protein interactions and the systems they form, to the output of high throughput technologies. The primary objectives of this research were to further characterise the signalling mechanisms driving macrophages activation, especially in response to type-I and type- II interferons, as well as lipopolysaccharide (LPS), using a ‘systems-level’ approach to data analysis and modelling. In order to achieve this end I have explored and developed methods for the executing a ‘systems-level’ analysis. Specifically the questions addressed included: (a) How does one begin to formalise and model the existing knowledge of signalling pathways in the macrophage? (b) What are the similarities and differences between the macrophage response to different types of interferon (namely interferon-β (IFN-β) and interferon-γ (IFN-γ))? (c) How is the macrophage transcriptome affected by siRNA targeting of key regulators of the interferon pathway? (d) To what extent does a model of macrophage signalling aid interpretation of the data generated from functional genomics screens? There is general agreement amongst biologists about the need for high-quality pathway diagrams and a method to formalize the way biological pathways are depicted. In an effort to better understand the molecular networks that underpin macrophage activation an in-silico model or ‘map’ of relevant pathways was constructed by extracting information from published literature describing the interactions of individual constituents of this cell and the processes they modulate (Chapter-2). During its construction process many challenges of converting pathway knowledge into computationally-tractable yet ‘understandable’ diagrams, were to be addressed. The final model comprised 2,170 components connected by 2,553 edges, and is to date the most comprehensive formalised model of macrophage signalling. Nevertheless this still represents just a modest body of knowledge on the cell. Related to the pathway modelling efforts was the need for standardising the graphical depiction of biology in order to achieve these ends. The methods for implementing this and agreeing a ‘standard’ has been the subject of some debate. Described herein (in Chapter-3) is the development of one graphical notation system for biology the modified Edinburgh Pathway Notation (mEPN). By constructing the model of macrophage signalling it has been possible to test and extensively refine the original notation into an intuitive, yet flexible scheme capable of describing a range of biological concepts. The hope is that the mEPN development work will contribute to the on-going community effort to develop and agree a standard for depicting pathways and the published version will provide a coherent guide to those planning to construct pathway diagrams of their biological systems of interest. With a desire to better understand the transcriptional response of primary mouse macrophages to interferon stimulation, genome wide expression profiling was performed and an explorative-network based method applied for analysing the data generated (Chapter-4). Although transcriptomics data pertaining to interferon stimulation of macrophages is not entirely novel, the network based analysis of it provided an alternative approach to visualise, mine and interpret the output. The analysis revealed overlap in the transcriptional targets of the two classes of interferon, as well as processes preferentially induced by either cytokine; for example MHC-Class II antigen processing and presentation by IFN-γ, and an anti-proliferative signature by IFN-β. To further investigate the contribution of individual proteins towards generating the type-I (IFN-β) response, short interfering RNA (siRNA) were employed to repress the expression of selected target genes. However in macrophages and other cells equipped with pathogen detection systems the act of siRNA trasfection can itself induce a type-I interferon response. It was therefore necessary to contend with this autocrine production of IFN-β and optimise an in vitro assay for studying the contribution of siRNA induced gene-knock downs to the interferon response (described in Chapter-5). The final assay design incorporated LPS stimulation of the macrophages, as a means of inducing IFN-β autonomously of the transfection induced type-I response. However genome-wide expression analysis indicated the targeted gene knock-downs did not perturb the LPS response in macrophages on this occasion. The optimisation process underscored the complexities of performing siRNA gene knockdown studies in primary macrophages. Furthermore a more thorough understanding of the transcriptional response of macrophages to stimulation by interferon or by LPS was required. Therefore the final investigations of this thesis (Chapter-6) explore the transcriptional changes over a 24 hour time-course of macrophage activation by IFN-β, IFN-γ, or LPS and the contribution of the macrophage pathway model in interpreting the response to the three stimuli. Taken together the work described in this thesis highlight the advances to be made from a systems-based approach to visualisation, modelling and analysis of macrophage signalling.
13
Fransson, Jennifer. "Macrophage activation profiles of multiple sclerosis patients." Thesis, Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=http://theses-intra.upmc.fr/modules/resources/download/theses/2019SORUS106.pdf.
Full textAbstract:
La sclérose en plaques (SEP) est une maladie inflammatoire neurodégénérative où l’invasion des cellules immunitaires dans le système nerveux central (SNC) entraîne la destruction de la myéline. Les macrophages, comprenant les cellules microgliales du SNC, sont majoritaires dans les lésions de la SEP. Nous avons modélisé l'activation des macrophages de patients SEP afin de définir quelles propriétés intrinsèques vont diriger leur contribution au développement ou à la réparation de la lésion. Les profils fonctionnels et transcriptomiques des macrophages de donneurs sains et de patients SEP ont été examinés suite à des stimuli activateurs. Les macrophages de patients SEP reproduisent plusieurs aspects observés dans les lésions inflammatoires et présentent une amplitude de réponse plus restreinte que les macrophages de donneurs sains. Grâce à une méthode d'identification des gènes régulateurs construit à partir d’un réseau prédéfini d'interactions géniques, nous avons identifié des gènes clés, pertinents d’un point de vue biologique et pathologique, dont la modulation permettrait de modifier une grande partie du réseau dérégulés. En utilisant un modèle murin humanisé, nous avons également noté que les effets modulateurs des lymphocytes de patient SEP sur la remyélinisation se fait par l’intermédiaire du contrôle de l'activation des macrophages. Les résultats de cette thèse démontrent que la contribution des macrophages à l’environnement inflammatoire reflète l'hétérogénéité clinique des patients. Des recherches futures utilisant ces modèles pourraient être utiles à la fois pour développer de nouveaux traitements et pour prévoir les effets potentiels pour chaque patient<br>Multiple sclerosis (MS) is an inflammatory, neurodegenerative disease in which infiltration of immune cells in the central nervous system (CNS) leads to myelin destruction. Macrophages, including the CNS-resident microglia, are prevalent in MS lesions. We propose that models of macrophage activation based on MS patient leukocytes can provide information on the intrinsic capacities of macrophages to participate to lesion formation and repair. The functional and transcriptomic profiles of MS patient and healthy control monocyte-derived macrophages were examined after exposure to activating stimuli. MS macrophages reproduced several aspects of the inflammatory lesion, and displayed a limited amplitude of response to activating stimuli. We also developed a method to identify key regulators in networks of several altered genes. This was done according to a pre-defined network of gene interactions. Testing a pro- inflammatory network for the possibility to control genes that are dysregulated in MS, we identified biologically and pathologically relevant genes as key drivers, supporting the framework of the method. Using a humanized mouse model of remyelination, we also noted that the remyelination- modulating effects of patient lymphocytes are mediated through the activation of macrophages. In conclusion, the results of this thesis provide evidence that macrophages contribute to an inflammatory environment, and that patient heterogeneity in both lymphocytes and macrophages impact this contribution. Further research using these and similar models could be useful for both developing new treatments and predicting effects for each patient
14
Hamerman, Jessica Ann. "Macrophage activation during Mycobacterium bovis BCG infection /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8359.
Full text
15
Steck, Ryan Perry. "Pharmacologic Immunomodulation of Macrophage Activation by Caffeine." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4251.
Full textAbstract:
Caffeine is one of the most widely used neurostimulants in the world and there is considerable debate on its effect in immune cells. One of its main targets is proposed to be adenosine receptors which mediate an anti-inflammatory switch in activated immune cells while another target is phosphodiesterase where it acts as an inhibitor. In macrophages, caffeine has been shown to cause both pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes. If the primary effect of caffeine on macrophages were to antagonize adenosine receptors we would expect cells exposed to caffeine to have a prolonged M1 response. However, we show that caffeine suppresses phagocytosis at physiological concentrations (an indicator of M2 phenotype). This suppression was reversed when macrophages were pretreated with protein kinase A inhibitor, suggesting that at physiological concentrations caffeine's phagocytic suppression may be due to its function as a phosphodiesterase inhibitor, pushing cells towards an M2 fate. However, mRNA expression profiling suggests that caffeine can modulate A2A receptor expression and suppress MKP-1 expression, a hallmark of M1 macrophages. Caffeine is, therefore an immunomodulator that can suppress or prolong inflammatory responses in macrophages, which may account for the abundance of contradicting evidence in the literature. Additionally, these effects are complicated by regular caffeine intake and fitness level, emphasizing that tolerance and immune robustness are important factors in macrophage activation.
16
DRUFUCA, LORENZO. "ROLE OF MICRORNA IN MACROPHAGE POLARIZED ACTIVATION." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/565701.
Full textAbstract:
Macrophages are cells from the innate branch of immune system with central roles both under physiologic and pathologic conditions. Such complex behaviour relies on extreme functional plasticity of these cells. Cellular activation and plasticity in macrophages are complex phenomena that require tight regulation. In recent years, microRNAs and lncRNAs emerged as important regulators of many cellular processes and have been proposed as key mediators of the plasticity observed in macrophages.
In this study we investigate the possible roles of different microRNAs on macrophage activation and functionality, taking advantage of animal models selectively depleted of candidate miRNA in macrophages.
We found that selective depletion of miR-125a in macrophages did not affect clinical outcome in different in vivo models of inflammation. Nonetheless it altered macrophage activation and functions, as evidenced by reduced secretion of TNFα after endotoxin challenges. Consistently, macrophages deficient in miR-125a displayed reduced killing of extracellular bacteria although they showed increased phagocytic rate as compared to miR-125a competent cells.
With a similar approach, we confirmed that miR-9 is induced in macrophages upon inflammatory stimuli. Increased expression of miR-9 mature form in mice was sustained by the synchronous activation of transcription in both pri-miR-9.1 and pri-miR-9.3 loci, in contrast to human.
Finally we identified a lncRNA interfering with the processing of a pro-inflammatory miRNA in differentially activated human macrophages, highlighting a new layer of regulation of macrophage activation.
The finding of the present project give new insights into the complex mechanism regulating macrophage activation and underscores the need for future studies to thoroughly identify the molecular mechanisms and the involvement of different miRNA in macrophage activation. Moreover, such studies could set the basis for the transition from basic research to new therapeutic options enabling precise regulation of macrophages activation in different immune pathologies.
17
Lisowski, Zofia Maria. "Targeting the macrophage in equine post-operative ileus." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33191.
Full textAbstract:
Post-operative ileus (POI) is the functional inhibition of propulsive intestinal motility which is a frequent occurrence following abdominal surgery in the horse and in humans. Rodent and human-derived data have shown that manipulation-induced activation of the resident muscularis externa (ME) macrophages in the intestine contributes to the pathophysiology of the disease. Most studies of the disease, specifically in the horse, have focussed on identification of risk factors, descriptive studies of the disease or the assessment of the efficacy of various therapeutic and prophylactic interventions. As a result, the proposed pathogenesis of equine POI is largely reliant on the translation of data from rodent models. The aims of this thesis were to identify macrophage populations in the normal equine gastrointestinal tract (GIT) and to study equine macrophage activation by stimulating equine bone marrow-derived macrophages (eqBMDMs) with lipopolysaccharide (LPS) as a model for intestinal macrophage activation. Firstly, the normal population of macrophages in the equine GIT was determined. Using CD163 as an immunohistochemical marker for macrophages. CD163+ve cells were present in all tissue layers of the equine intestine: mucosa, submucosa, ME and serosa. CD163+ve cells were regularly distributed within the ME, with accumulations adjacent to the myenteric plexus, and therefore to intestinal motility effector cells such as neurons and the Interstitial Cells of Cajal. The differentiation and survival of intestinal macrophages depends upon signals from the macrophage colony-stimulating factor (CSF-1) receptor. LPS translocation from the gut lumen is thought to be a key activator of ME macrophages. To provide a model for gut macrophages, a protocol was optimised to produce pure populations of equine bone marrow-derived macrophages (eqBMDMs) by cultivation of equine bone marrow in CSF-1. Macrophage functionality was assessed using microscopy, flow cytometry and phagocytosis assays. EqBMDMs responded to LPS stimulation with increases in expression of positive control genes, tumour necrosis factor alpha (TNF-α) and Indoleamine 2,3-dioxygenase (IDO1). The same mRNA was subjected to transcriptomic (RNA-Seq) analysis. Differential gene expression and network cluster analysis demonstrated an inflammatory response characterised by the production of pro-inflammatory cytokines such as interleukin 1 beta (IL-1β) and interleukin 6 (IL-6). However, in contrast to rodent macrophages, eqBMDMs failed to produce nitric oxide in response to LPS, showing species-specific variation in innate immune biology. Using these data, we compared gene expression in normal equine intestine and in intestine from horses undergoing abdominal surgery for colic (abdominal pain). Horses undergoing abdominal surgery showed evidence of increased expression of IL-1β, IL-6 and TNF-α in the mucosa and ME when compared to control tissue. Horses with post-operative reflux (POR), a clinical sign of POI, had increased gene expression of IL-1β, IL-6 and TNF-α compared to horses that did not develop POR following abdominal surgery. These preliminary data suggest that there is macrophage activation within the ME of the intestine during abdominal surgery in the horse, and that a greater activation state is present in horses that subsequently develop POR. The final part of this study was to investigate the effect of a long-acting form of CSF- 1, an Fc fusion protein (CSF1-Fc), as a potential treatment for POI using a mouse model. This work, performed in collaboration with another research group, found that mice lacking the C-C chemokine receptor type 2 (CCR2) gene, which is required for monocyte recruitment into tissues, had a longer recovery period following intestinal manipulation (IM) than wild type (WT) mice. With the administration of CSF1-Fc, infiltration of neutrophils to the ME was reduced and the number of macrophages in the ME was increased in both WT and CCR2-/- mice following IM. Administration of CSF1-Fc in CCR2-/- mice improved recovery of gastrointestinal transit three days following IM, to the same extent as WT mice. Network cluster analysis and RT-qPCR of the ME revealed clusters of genes induced and downregulated by CSF1-Fc, with increased expression of anti-inflammatory and pro-resolving genes after IM in WT and CCR2-/- mice following treatment with CSF1-Fc.
18
Sester, David Peter. "Mechanisms of macrophage activation by bacterial/CpG DNA /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17063.pdf.
Full text
19
Wojciechowski, Wojciech. "Molecular mechanism of IFN-[gamma]-induced macrophage activation." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37667.
Full textAbstract:
Macrophages are considered as one of the early effector cells involved in the immunological response against infection. Following macrophages interaction with pathogens, macrophages become activated and attempt to eliminate the invader. Interferon gamma (IFN-gamma) is one of the most important activators of macrophage function. In macrophages IFN-gamma is promoting the expression of major histocompatibility complex class II (MHC-II) molecules and other proteins directly involved in the process of containing infection.<br>The effect of the Nramp1, on macrophage function is investigated in this thesis. Nramp1 has been shown to determine the resistance or susceptibility of mice to infections with several intracellular microorganisms, including Mycobacterium bovis BCG. Although the precise mechanism of Nramp1 action is unknown, there are several well-established effects associated with the Nramp1. In general, it has been shown that macrophages derived from mice susceptible to infections with M. bovis BCG are less efficient in the production of nitric oxide (NO), reactive oxygen intermediates (ROI), TNF-alpha, and MHC-II antigens in response to IFN-gamma.<br>Using macrophage cell lines derived from mice that are either resistant (B10R) or susceptible (B10S) to M. bovis BCG infection, we have demonstrated that lower levels of IFN-gamma-induced expression of MHC-II antigens is correlated with less efficient phosphorylation of the STAT1 protein in B10S macrophages compared to B10R macrophages. We have shown that low levels of MHC-II expression in B10S macrophages correlate with less efficient expression of CIITA (Class II Transactivator). We have observed that infection of macrophages with M. bovis BCG has an inhibitory effect on both CIITA and MHC-II expression in macrophages stimulated with IFN-gamma.<br>We have also studied the effect of lipopolysaccharide (LPS) on MHC-II expression in macrophages. We have found that the inhibitory effect of LPS on CIITA gene transcription does not involve changes in the binding of STAT1 to CIITA promoter IV. We have also demonstrated that unlike M. bovis BCG, the inhibitory effect of LPS on MHC-II expression is mediated by Toll-like receptor 4 (TLR4). In addition, we have shown that inhibitory effects of both LPS and M. bovis BCG depend on the adaptor protein MyD88.<br>We have also analyzed the regulation of IFN-gamma- or/and LPS-stimulated expression of TLR2 in macrophages. We have shown that regulation of TLR2 expression by IFN-gamma depends on TLR4 expression. We have also determined that the phenol extractable fraction present in the commercial preparations of endotoxins from Gram-negative bacteria is able to synergize with IFN-gamma and activate TLR4-deficient macrophages.<br>Overall, we believe that these studies significantly contribute to the understanding of the molecular mechanism of the process of macrophage activation.
20
Rivier, Agnès. "Activation des phagocytes mononucléés chez les sujets normaux et les sujets asthmatiques/ Agnès Rivier." Montpellier 1, 1994. http://www.theses.fr/1994MON1T020.
Full text
21
Longbrake, Erin Elisabeth. "Consequences of differential macrophage activation after spinal cord trauma." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1177686458.
Full text
22
Chow, Nancy Ann-Marie. "TNF gene expression in macrophage activation and endotoxin tolerance." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11231.
Full textAbstract:
TNF is an inflammatory cytokine that plays a critical role in the acute phase response to infection, and its dysregulation has been implicated in the pathology of several inflammatory and autoimmune disorders. TNF gene expression is regulated in a cell type- and inducer-specific manner that involves chromatin alterations at both the TNF promoter and distal DNase I hypersensitive (DH) sites within the TNF/LT locus. While the mechanisms underlying TNF gene activation in monocytes/macrophages and T cells have been studied intensively, the mechanisms of enhanced, repressed, and restored TNF gene expression in the context of classical macrophage activation and endotoxin tolerance remain largely unknown. We set out to understand how TNF gene expression is modulated during these biological processes by characterizing the chromatin environment of the TNF/LT locus.
23
Longbrake, Erin E. "Consequences of differential macrophage activation after spinal cord trauma." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1177686458.
Full text
24
Oda, Tomoyuki. "Activation of hypoxia-inducible factor 1 during macrophage differentiation." Kyoto University, 2007. http://hdl.handle.net/2433/135669.
Full text
25
Willems, Jorine Joanna Lamberta Paulina. "Apoptosis-driven activation of macrophages by starry-sky B-cell lymphoma." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/18738.
Full textAbstract:
In high-grade ‘starry-sky’ non-Hodgkin’s lymphoma (NHL), particularly Burkitt’s lymphoma (BL), large numbers of apoptotic tumour cells are engulfed by infiltrating tumour-associated macrophages (TAM). In situ studies suggest that in starry-sky TAM in a xenograft model of BL various tumour-promoting, trophic, angiogenic, tissue remodelling, and anti-inflammatory pathways are activated. Furthermore, apoptotic cells have been shown to activate expression of tumour-promoting matrix metalloproteinases in macrophages. This work investigates the hypothesis that apoptotic cells or factors released from apoptotic cells induce additional aspects of the starry-sky TAM signature, which serve to promote tumour growth. Macrophages at different stages of maturation, cultured in vitro in the presence of large numbers of apoptotic cells, were shown to differ in phenotype, giving credibility to the hypothesis. Less mature mouse bone marrow-derived macrophages (BMDM) were better at migrating towards apoptotic cells, whereas mature BMDM were better at phagocytosing them. Lactoferrin, which is released from cells undergoing apoptosis and inhibits the migration of neutrophils, was selected as a candidate mediator in the activation of macrophages by apoptotic cells. Lactoferrin was shown to bind viable human and murine monocytes and macrophages, however only high concentrations, which are unlikely to be physiologically or clinically relevant, were found to affect expression of starry-sky TAM genes or reduce classically-activated macrophage cytotoxicity. The direct effect of apoptotic cells on macrophage activation was assessed. Mature BMDM were not used for these studies as their development in vitro in a highly apoptotic environment was judged likely to bias their activation state toward that of TAM, therefore macrophages were first classically-activated with IFN-γ and LPS. This reduced the expression of many starry-sky TAM genes, including several genes associated with responses to apoptotic cells. However, classical activation did not inhibit apoptotic cell engulfment, but rather enhanced it. Co-culture with apoptotic cells, but not viable cells, increased the gene expression of Gas6, Mrc1, Cd36, Timp2, and Pparg, and the latter was dependent on direct interaction with macrophages rather than factors released from apoptotic cells. Furthermore, classically-activated macrophages were found to induce apoptosis in lymphoma cells, and although pre-co-culture of the macrophages with apoptotic cells did not reduce their ability to induce apoptosis, it enhanced tumour cell growth. Macrophage deficiency of IL-4Rα or galectin-3 did not affect classically-activated macrophage responses to apoptotic cells. However, classical activation of galectin-3 deficient macrophages appeared to restore the decreased ability of galectin-3 deficient, untreated macrophages to phagocytose apoptotic cells. Because of the unique new method of laser-capture microdissection by which starry-sky TAM signatures were established, direct comparisons with expression databases of tissue and in vitro cultured macrophages were not possible, but indirect comparisons suggest starry-sky TAM activation reflects the activation phenotype of a mixture of tissue macrophages. Furthermore, it highlighted phagocytosis as one of the most important pathways activated by starry-sky TAM. Together the results presented here suggest apoptotic lymphoma cells can shape TAM activation signatures in starry-sky NHL, even when macrophages are pre-activated to induce apoptosis in lymphoma cells. This is important when considering the consequences of anti-cancer therapies that induce apoptosis or aim to redirect phagocyte activation.
26
Cozon, Grégoire. "Activation macrophagique et infection lentivirale dans le modèle du virus Visna-Maedi." Lyon 1, 1992. http://www.theses.fr/1992LYO1H007.
Full text
27
Haddad, Elias K. "Study of the role of macrophage activation and macrophage derived cytotoxic factors in early embryo loss." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ29928.pdf.
Full text
28
Haddad, Elias K. "Study of the role of macrophage activation and macrophage derived cytoxic factors in early embryo loss." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=42023.
Full textAbstract:
Using murine models of spontaneous and induced embryo resorption, we have investigated the role of macrophages in the mechanism of early embryo loss. The results showed that macrophage derived nitric oxide was associated with embryo resorption, and that decidual macrophages could be triggered by lipopolysaccharide (LPS) to produce nitric oxide, indicating that the decidual mononuclear cells were primed in situ. Using double immunostaining, we have shown that macrophages were the cellular source of the inducible nitric oxide production. We further showed that embryo abortion can be significantly decreased by inhibiting the production of nitric oxide in vivo. The results presented strongly suggested a role for nitric oxide as an effector molecule in mediating early embryo loss and showed that the in situ activation of decidual macrophages was an early event preceding spontaneous abortion.<br>It is known that interferon-$ gamma$ (IFN-$ gamma$) is the major cytokine responsible for the priming of macrophages and that LPS can trigger primed macrophages to produce nitric oxide. Therefore, the observation that exogenous LPS induced embryo abortion in most strains of pregnant mice suggested that the decidual macrophages have been previously primed in situ. To investigate the role of IFN-$ gamma$ as a potential priming signal for decidual macrophage activation, we studied the effect of the depletion of IFN-$ gamma$ on LPS induced pregnancy loss. The results showed that IFN-$ gamma$ deficient mice were more resistant to LPS induced abortion than control mice. This suggested that IFN-$ gamma$ was essential for the priming of decidual macrophages and that decidual macrophages from IFN-$ gamma$ deficient mice could not be activated when exposed to LPS both in vivo and in vitro. Our results also showed increased IFN-$ gamma$ mRNA expression simultaneously in the same embryos that also expressed elevated iNOS mRNA, a macrophage activation marker. This suggested that macrophage activation, subsequent nitric oxide production, and spontaneous embryo loss could be a consequence of local IFN-$ gamma$ over production.<br>While LPS serves as an exogenous triggering factor, endogenous TNF-$ alpha$ is known to trigger NO production by primed macrophages. Therefore, we investigated the role of TNF-$ alpha$, as a second signal, in mediating embryo loss. Our studies showed that the frequency of embryos with significantly increased TNF-$ alpha$ mRNA expression corresponded to the incidence of murine embryo abortion. In addition, the results showed that increased TNF-$ alpha$ mRNA was simultaneously expressed with iNOS mRNA suggesting a potential role for TNF-$ alpha$ in the triggering of decidual macrophages.<br>In summary, we demonstrated the presence of activated decidual macrophages in murine placentas, and that inducible nitric oxide produced by these macrophages was responsible for embryo death. We further showed that IFN-$ gamma$ was responsible for the priming of decidual macrophages, and that the expression of TNF-$ alpha$, a potential secondary signal was associated with decidual macrophage activation, NO production, and subsequent embryo loss.
29
Nzoumbou-Boko, Romaric. "Caractérisation d’une voie Immunomodulatrice impliquant l’arginase dans les Trypanosomoses." Thesis, Bordeaux 2, 2013. http://www.theses.fr/2013BOR22053/document.
Full textAbstract:
Une nouvelle voie d’immunomodulation, l’induction de l’arginase par les trypanosomes chez leurs hôtes, a été identifiée et caractérisée. Pour éviter la réponse cytotoxique de l’activation « classique » M1 des macrophages et bénéficier de leur activation « alternative » M2, les parasites induisent l’arginase, qui produit la L-ornithine, indispensable à leur développement. Cette voie d’immunomodulation mise en évidence chez la souris infestée par son parasite naturel, Trypanosoma musculi, est également présente dans d’autres trypanosomoses, en particulier la trypanosomose humaine africaine (THA). Une augmentation de l’arginase, retrouvée dans le sérum de patients trypanosomés, se normalise après un traitement efficace. T. brucei gambiense, parasite de l’homme, induit l’arginase au niveau des macrophages murins et des leucocytes humains. T. lewisi, parasite du rat, induit également l’arginase. Au cours de leur longue coévolution avec leurs hôtes, les trypanosomes extracellulaires ont sélectionné un procédé favorisant leur croissance, l’induction de l’arginase, par des facteurs d’excrétion/sécrétion. Nous avons produit un anticorps monoclonal dirigé contre ce facteur inducteur. Il bloque l’induction de l’arginase par T. musculi in vitro et in vivo. Chez la souris infectée, son injection diminue considérablement la parasitémie. Il a permis l’identification du facteur inducteur, une kinésine orpheline. Cet anticorps, inhibant l’induction de l’arginase par différents trypanosomes, reconnaîtrait une région conservée de la kinésine induisant l’arginase. Cette kinésine se lie à des récepteurs de la membrane des macrophages. In vitro, l’addition de mannose à des co-cultures macrophages-parasites bloque l’induction de l’arginase et la multiplication des parasites. Chez la souris infestée par T. musculi, l’injection de mannose diminue la parasitémie, qui est également réduite chez les souris Mrc1-/-, KO pour le récepteur mannose. L’utilisation de molécules ciblant la voie inductrice de l’arginase et/ou ce récepteur peut représenter une nouvelle approche thérapeutique dans les trypanosomoses<br>Arginase induction, a mechanism of immunomodulation elaborated by trypanosomes has been identified. To avoid cytotoxic classical M1 macrophage activation, trypanosomes induce alternative M2 macrophage activation, which leads to L-ornithine production, essential for parasite growth. This immunomodulation pathway has been evidenced in a natural murine trypanosomiasis provoked by Trypanosoma musculi. This mechanism is also evidenced in human African trypanosomiasis (HAT). An increase in serum arginase is measured in HAT patients. A return to normal values is obtained after an efficacious treatment. Trypanosoma brucei gambiense, the causative agent of HAT, induces arginase in mouse macrophages and human leucocytes. T. lewisi, a rat parasite, also induces macrophage arginase.During host-parasite co-evolution, extracellular trypanosomes have selected a growth promoting mechanism, macrophage arginase induction by excreted secreted factor (ESF). We have produced a monoclonal antibody which inhibits trypanosome-induced arginase. This antibody blocks in vitro and in vivo T. musculi-induced arginase. Its injection into infected mice provokes a decrease in parasite load. This monoclonal antibody has allowed the identification of an orphan kinesin as the arginase inducing factor. The arginase inducing region of kinesin seems conserved among extracellular trypanosomes. Kinesin binds to macrophage membrane receptors. In vitro, addition of mannose to macrophage-parasite cocultures blocks arginase induction and parasite multiplication. Mannose injection decreases parasite load in infected mice. Compared to WT mice, parasite load is highly reduced in infected Mrc1 -/- KO mice. In trypanosomiasis, molecules targeting arginase pathway and/or mannose receptor, highly conserved in evolution, might represent new therapeutic approaches
30
Sundling, Niklas, and Lisa Lü. "Characterization of Macrophage Activation Induced by Leukotoxin from Aggregatibacter actinomycetemcomitans." Thesis, Umeå universitet, Institutionen för odontologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-143900.
Full textAbstract:
ABSTRACT Aggregatibacter actinomycetemcomitans (Aa), is a gram-negative, facultative anaerobe, non-motile coccobacilli colonizing the human oral cavity and is strongly associated with localized aggressive periodontitis (LAP). Aa possesses several virulence mechanisms, among others; Lipopolysaccharide (LPS), an endotoxin found in the outer membrane of Aa and Leukotoxin (LtxA), an exotoxin attached to the bacterial cell surface or in outer membrane vesicles and which has been correlating with periodontal disease mostly. LtxA specifically targets human leukocytes, causing imbalance in the host inflammatory response. It is involved in the activation of a cellular pathway, starting with ATP release from the cell, possibly through Pannexin-1(Panx-1) channels, Caspase-1 activation and release of bioactive interleukin-1β (IL-1β) from leukocytes. In the case of periodontitis, inflammatory cytokines like IL-1β will stimulate periodontal tissue breakdown. The aim of the present study was to examine the involvement of Panx-1 in LtxA induced activation and cytotoxicity of human macrophages. To determine viability of the macrophages the release of LDH and the accumulation of neutral red was quantified. The release of IL-1β was analysed by ELISA analyses of the cell culture supernatants. Results showed that macrophages treated with Cbx and exposed to LtxA was still sensitive to LtxA, but showed a decrease in the IL-1β release. In opposite, macrophages exposed to LPS showed increased IL-1β release in presence of Cbx. The conclusion of our study is that Panx-1 channels are partially involved in the cellular pathway leading to IL-1β release on LtxA exposed cells.
31
Gross, Antoine. "Activation et inhibition du macrophage lors de l'infection par "Brucella"." Montpellier 2, 1998. http://www.theses.fr/1998MON20216.
Full textAbstract:
Brucella est responsable d'infections chroniques chez l'homme et les ruminants domestiques ; elle n'infecte pas naturellement la souris. Afin d'analyser les phenomenes permettant a brucella d'infecter et de se maintenir chroniquement chez l'homme, nous avons etudie et compare differents processus impliques dans l'interaction de brucella avec les macrophages humains et murins a l'interieur desquels elle se multiple. Cette these presente quatre aspects de cette problematique : 1) nous avons caracterise une induction de la inos lors de l'infection du macrophage murin par brucella et montre que no est un composant de l'activite microbicide contre cette bacterie. Contrairement a la cellule murine, le macrophage humain dans lequel une activite inos fonctionnelle a ete mise en evidence, ne produit pas de no lorsqu'il est infecte par brucella. 2) l'etude des cytokines secretees au cours de l'infection revele que brucella inhibe specifiquement la secretion de tnf- par le macrophage humain. Ce phenomene n'est jamais observe dans le modele murin. Cette activite inhibitrice ne conduit pas a une desactivation complete de la cellule infectee. L'inhibition de la secretion du tnf resulte d'un facteur soluble pouvant etre libere dans le milieu de culture et considere comme un facteur de virulence chez l'homme. 3) malgre l'absence de tnf-, l'infection par brucella confere une resistance a l'apoptose aux monocytes/macrophages humains. Cette resistance implique un processus suppletif a l'absence de tnf-, favorisant la survie de la cellule hote et le developpement de la bacterie. 4) les cannabinoides affectent le macrophage en modulant la production de cytokines. Stimules par sr 141716a, un antagoniste des recepteurs cb1 aux cannabinoides, les macrophages humains controlent la multiplication intracellulaire de brucella. Toutefois, cet effet n'implique pas une reactivation de la production de tnf- et est retrouve lors de l'infection de macrophages murins.
32
Afroun-Talantikite, Samia. "Activation des macrophages péritonéaux murins : modifications dans le profil de glycosylation des protéines, et dans l'activité bactéricide vis-à-vis du BCG." Paris 11, 1988. http://www.theses.fr/1988PA112165.
Full textAbstract:
Le macrophage est une des cellules effectrices des réactions de défense de l'organisme contre les infections. Mais les macrophages ne sont capables de s’opposer à la multiplication des microbes à developpement intacellulaire et les cellules tumorales que s'ils sont dans un état activé. Nous avons montré que l'action cytotoxique des macrophages activés vis-à-vis de cellules de nastocytome P815 dépend de l'intégrité des structures membranaires spécialement susceptibles à la trypsine. Nous avons d'autre part recherché les modifications apportées au profil de glycosylation des protéines macrophagiques lors. Du phénomène d'activation nous avons démontré que l'activation s'accompagne d'une réduction de 30 à 40 du taux d'acide sialique; 2) d'une réduction, hezles protéines N-glycosylées, des chaines deglycanes detypecomplexe au profit deglycanes hybrides ou oligomannosidiques. Une augmentation du nombre de résidus mannose et de galactose exposés à la surface des macrophages pourrait modifier leur capacité d'interaction avec les parasites et les cellules tumorales. Pour l'expression d'une activité cytotoxique, les macrophages sont activés, par l'application séquentielle de 2 stimuli (injection de dimycolate de tréhalose (TOM) puis traitement in vitro par le LPS). Nous avons recherché quelle était la contribution propre de chacun de ces 2 signaux pour l'induction d'une activité microbicide vis-à-vis d'une bactérie à croissance intracellulaire comme le BCG: le TOM induit une activité anti-BCG qui s'exprime in de façon transitoire; le traitement par le LPS renforce et/ou prolonge l'activité microbicide des macrophages. L'eau oxygénée que les macrophages-TOM sont capables d'émettre ne semble pas très responsable de l'arrêt de la croissance du BCG; par contre, les lysats de macrophages activés ont une activité bactériostatique.
33
GROELL, VALERIE. "Immunotherapie du cancer par transfert adoptif de macrophages actives in vitro." Strasbourg 1, 1990. http://www.theses.fr/1990STR15048.
Full text
34
Schroder, Kate. "Mechanisms of IFN[gamma] priming of macrophage activation by CpG DNA /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18684.pdf.
Full text
35
Menzies, Fiona Mary. "The influence of sex and pregnancy associated hormones on macrophage activation." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501658.
Full textAbstract:
Stimulation of macrophages with LPS alone or in combination with IFN-y is termed 'innate' and 'classical' activation, respectively. This is associated with the expression of nos2 and p40 (IL-12/IL-23). Stimulation of macrophages with IL-4 or IL-13 is termed 'alternative' activation and is associated with expression of argI, dectin-1, mrc-1 ,fizz1 and ym1. Recent studies demonstrate that arg1 is expressed in some innate activated macrophages.
36
Schonberg, David L. "Formation of New Oligodendrocytes in the Spinal Cord Following Macrophage Activation." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1261419807.
Full text
37
Beidelschies, Michelle. "Orthopaedic Wear Particle-Induced Activation of Macrophages." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1228363163.
Full text
38
Burgess, Matthew. "Effects of diabetes and Hoxa3 upon macrophage function." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/effects-of-diabetes-and-hoxa3-upon-macrophage-function(049743d6-7449-458a-981e-267a3e112d6c).html.
Full textAbstract:
Chronic non-healing wounds commonly present in patients with diabetes. These wounds are characterised by elevated numbers of immature leukocytes and M1 macrophages and reduced numbers of endothelial cells and M2 macrophages, impairing wound healing resolution. Topical treatment of murine diabetic wounds with a Hoxa3 gene expression vector redresses the balance of inflammatory and pro-healing cells within the lesion, reducing excessive inflammation and rescuing the wound healing phenotype. In this thesis I present experiments to further understanding of how diabetes alters the macrophage phenotype and how this may cause the decreased endothelial cell and M2 macrophage numbers in the diabetic wound. In vitro culture was used to characterize the intrinsic changes of diabetic macrophages isolated from the environmental effects of the diabetic wound milieu. These same systems were used to develop a cell culture system for the promotion of monocytic to endothelial transdifferentiation. Finally the in vitro macrophage culture system was used to assess the effects of Hoxa3 treatment upon diabetic macrophages and how Hoxa3 transcriptional activity in macrophages may contribute to the restoration of wound healing. In vitro cultured diabetic macrophages were observed to raise an increased response to classical and alternative activation signals that may contribute to the excessive inflammatory state of diabetic cutaneous wounds. Treatment of these macrophages for four days with a Hoxa3 conditioned medium protein transduction system upregulated the expression of the plasminogen activator urokinase receptor gene Plaur and enhanced the expression of macrophage maturation markers. These macrophages also exhibit an enhanced response to classical activation stimuli, a reduced alternative activation response. In an in vitro neovascularisation assay Hoxa3 treated macrophages inhibit vessel growth. These effects of Hoxa3 treatment of diabetic macrophages are unexpected based on the rescue of the inflammatory phenotype with Hoxa3 treatment of diabetic wounds. Non-diabetic macrophages were also treated for four days with a Hoxa3 conditioned medium and exhibited upregulation of macrophage maturation markers. These macrophages showed no difference in activation state polarisation compared to macrophages grown in a control conditioned medium but did upregulate activation markers in unstimulated cells. This may be indicative of a priming for response to low levels of activation stimuli. The Hoxa3 treated non-diabetic cells also promoted the formation of vessel networks in a neovascularisation co-culture assay, possibly through the promotion of angiogenesis. These results suggest that diabetes directly effects the maturation and inflammatory phenotype of macrophages and that Hoxa3 treatment rescues the impaired maturation phenotype and may stimulate macrophage populations to a pro-angiogenic state.
39
Malik, Divya. "MicroRNAs in the regulation of alternatively activated macrophages." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20385.
Full textAbstract:
Macrophages play a key role in maintaining the balance and efficiency of the immune response. TH2 cytokines IL-4 & IL-13, through shared IL-4Rα signalling, trigger a state of alternative activation in macrophages and also drive their proliferation. Alternatively activated macrophages (AAMΦ) are involved in the control of helminth infections and have also been implicated in tissue repair. However, TH2 weighted imbalance can result in inflammatory disorders such as asthma and fibrosis. Hence, macrophage responses must be tightly regulated. MicroRNAs, a short (~22nt) class of non-coding RNA, are one such immunomodulatory feedback mechanism that can regulate gene expression by targeting the 3’ UTR of mRNA resulting in destabilisation of the mRNA and/or inhibition of translation. With their ability for vast gene regulation, it was hypothesised that microRNAs could play a crucial role in the regulation of AAMΦ by targeting genes and pathways critical for their induction, maintenance & proliferation. Previously generated microarrays in the lab have allowed us to identify microRNAs differentially expressed in AAMΦ. In an effort to determine which microRNAs are genuinely associated with alternative activation, the first part of this project examined the expression profiles of ten shortlisted microRNA candidates under varying conditions of alternative activation, ranging from a reductionist in vitro IL-4/13 stimulation of macrophage cell lines to a complex in vivo TH2 mouse model of filarial infection. Profiling of microRNA expression under these conditions revealed that the expression of two IL-4Rα dependent microRNAs, namely miR-199b-5p and miR-378, along with another microRNA, miR-146, was highly regulated and consistently associated with alternative activation. The subsequent chapters of this thesis investigated the contribution of these microRNAs in regulating AAMΦ responses. Interestingly, we identified miR-199b-5p as being highly expressed in AAMΦ in vivo but not in vitro. Pathway analysis identified insulin signalling and other proliferative pathways such as PI3K/AKT as being highly targeted by miR-199b-5p. Overexpression of miR-199b-5p in RAW 264.7 cells resulted in a reduction in the rate of proliferation and a change in the levels of Insulin Receptor Substrate -1 (IRS-1), suggesting that miR-199b- 5p might regulate macrophage proliferation via insulin signalling. An alteration in the expression of YM-1 and RELM-α, markers characteristic of alternative activation, was also observed. MiR-199b-5p was successfully delivered to the lung and overexpressed in alternatively activated alveolar macrophages. No effect was observed on IL-4 induced proliferation, potentially due to the lack of significant insulin receptor and IRS-1 expression in alveolar macrophages. However, secreted levels of YM-1, but not RELM-α, were significantly reduced. MiR-378 is a microRNA that has previously been shown to be associated with AAMΦ through targeting of AKT-1; however, a direct influence of this microRNA on the regulation of this phenotype is yet to be determined. In this thesis, we have provided direct evidence of the impact of miR-378 deficiency on the regulation of AAMΦ and their responses using miR-378 KO mice. The ability of macrophages isolated from WT and KO animals to alternatively activate was studied in various systems both in vitro and in vivo. The influence of miR-378 deficiency on IL-4 induced proliferation was also addressed in vivo. Although the lack of miR-378 had no significant effect on IL-4 driven macrophage proliferation, results from this chapter support a role for miR-378 in the regulation of alternative activation through regulation of YM-1 and RELM-α expression. Lastly, to determine whether this regulation by miR-378 had functional consequences, we also utilised Litomosoides sigmodontis, a murine model of filarial infection. Due to experimental limitations, a concrete role for miR-378 in the context of infection could not be established. The final chapter of this thesis focuses on examining the role of miR-146 in the regulation of AAMΦ. MiR-146a is a highly studied microRNA that has previously been linked strongly to TH1 immune responses, especially classical activation of macrophages. However, a role for this microRNA in regulating AAMΦ is yet to be determined. Expression levels of miR-146a and miR-146b, the two isoforms of miR-146, were found to be differentially regulated upon alternative activation, with a decrease in miR-146a and increase in miR-146b expression in response to IL-4 both in vitro and in vivo. Based on this difference in expression and their known functions in suppressing excessive proinflammatory responses, it was hypothesised that miR-146a/b serve to regulate proinflammatory molecules (and signals) in a fine balance to allow efficient alternative activation to occur. However, the high sequence similarity between these two isoforms proved to be a hindrance to test this hypothesis in terms of shared targets. Therefore, the latter half of this chapter was devoted to the generation and optimisation of a stable cell line for the identification of microRNA targets using CLASH (cross-linking, ligation and sequencing of hybrids). In summary, the results from this thesis provide an important foundation for further studies of the functional role of microRNAs in the regulation of AAMΦ. Firstly, it characterises the expression profiles of ten different microRNAs differentially expressed during alternative activation. Secondly, for the first time, it identifies a role for miR-199b- 5p in the regulation of macrophage proliferation and activation. Thirdly, this thesis has provided direct evidence for the effect of miR-378 deficiency on AAMΦ responses. Lastly, it identifies and demonstrates the robust differential expression of two separate isoforms of the same microRNA (miR-146) under varying conditions of alternative activation, whose functional properties as regulators of the AAMΦ phenotype await further investigation.
40
Lakritz, Jessica Robyn. "Monocyte / Macrophage Activation and Traffic Mediates HIV and SIV – Associated Peripheral Neuropathy." Thesis, Boston College, 2016. http://hdl.handle.net/2345/bc-ir:107213.
Full textAbstract:
Thesis advisor: Tricia H. Burdo<br>Human immunodeficiency virus-associated peripheral neuropathy (HIVPN) continues to be a prevalent comorbidity of HIV infection, despite virologic control due to effective antiretroviral therapy (ART). Symptoms include bilateral tingling, numbness, and pain in distal extremities. Severity of symptoms is associated with a loss of intraepidermal nerve fiber density (IENFD) in the feet. Damage to the dorsal root ganglia (DRG) has also been observed in postmortem tissue analysis from patients with HIV-PN. Treatment options are limited due to a lack of understanding of the disease pathogenesis. Chronic monocyte activation and accumulation of macrophages in peripheral nervous system (PNS) tissues has been reported but few studies have directly demonstrated the role of monocyte/macrophage activation and traffic in the pathogenesis of HIV-PN. The central hypothesis of this thesis is that monocyte activation and traffic mediates PNS neuronal damage. We addressed this hypothesis in several ways. In chapter 2, we describe pathology seen in a rapid disease progression animal model of HIV-PN. We found that an early loss of IENFD preceded a loss of small diameter DRG neurons. In chapter 3, we associated DRG pathology with an accumulation of inflammatory macrophages surrounding DRG neurons. Increased monocyte traffic to the DRG was associated with severity of DRG pathology and with a loss of IENFD. In chapter 4, we directly tested the impact of monocyte traffic on DRG pathology by blocking leukocyte traffic with an anti-VLA-4 antibody, natalizumab. Blocking cell traffic reduced accumulation of macrophages in the DRG and improved pathology. Next we treated animals with methylglyoxal-bisguanylhydrazone (MGBG) to specifically target myeloid cells and reduce their activation. MGBG treatment improved DRG pathology and reduced accumulation of macrophages in tissues. Having demonstrated the role of monocyte traffic and activation, we aimed to identify signaling proteins and inflammatory proteins associated with PNS pathology. We found elevated monocyte chemoattractants in DRG tissue and elevated markers of monocyte activation in plasma that were associated with a loss of IENFD. Together, these studies demonstrate that systemic monocyte activation, macrophage accumulation in DRG tissue, and monocyte traffic plays a major role in SIV-PN pathogenesis. These studies provide novel insight into immune mechanisms that impact neuronal loss during SIV infection. Thus, modulating macrophage activation and reducing monocyte traffic may have therapeutic benefits to patients suffering from or at risk of developing HIV-PN<br>Thesis (PhD) — Boston College, 2016<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Biology
41
Liu, Yu. "The role of suppressors of cytokine signalling 1 and 3 in macrophage activation." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=24848.
Full text
42
Weintz, Gabriele Maria. "Phosphoproteome analysis of the macrophage response to toll-like receptor (TRL)-activation." kostenfrei, 2010. https://mediatum2.ub.tum.de/node?id=807143.
Full text
43
Parsa, Roham. "Macrophage activation phenotypes in type 1 diabetes pathogenesis and therapy : Master thesis." Thesis, KTH, School of Biotechnology (BIO), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10210.
Full textAbstract:
<p>Macrophages are an important key effector cell in the immune system which can practically be found in every tissue. Macrophages have for a long time been considered a population of cells only responsible for pro-inflammatory responses and anti-microbial activities. But over the past decade, many have come to realize the amazing plasticity of macrophages in response to different stimulations. The anti-microbial and pro-inflammatory macrophage is known as classically activated macrophages but newly discovered phenotypes have been revealed named wound-healing macrophages and regulatory macrophages. Through systematic screening we have identified an inducible macrophage activation state which has both wound-healing and regulatory capabilities activated by the novel cytokine combination IL-4/IL-10 with or without TGF-β.</p>
44
Eklund, Daniel. "Mycobacterium tuberculosis and the human macrophage : shifting the balance through inflammasome activation." Doctoral thesis, Linköpings universitet, Avdelningen för mikrobiologi och molekylär medicin, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-100890.
Full textAbstract:
Mycobacterium tuberculosis is a very successful pathogen and tuberculosis constitutes a major threat to global health worldwide. The World Health Organization (WHO) estimates that almost nine million new cases and 1.5 million deaths occur annually and the situation is worsened by increased antibiotic resistance and an extreme synergism with the HIV pandemic. M. tuberculosis primarily affects the lungs where the infection can lead to either eradication of the bacteria or the initiation of an immune response that culminates in the formation of a large cluster of immune cells termed granulomas. In these granulomas, the bacteria can either replicate and cause disease with the ultimate goal of spreading to new hosts or cause latent tuberculosis, which can persist for decades. The tools available to manage the disease are currently suboptimal and include lengthy antibiotic treatments and an inefficient vaccine resulting in poor protection. On a cellular level, M. tuberculosis primarily infects the cell designed to recognize, ingest and eradicate bacteria, namely the human macrophage. Following recognition, the macrophage phagocytoses the bacterium and tries to kill it using an array of different effector mechanisms including acidification of the bacterium-containing vacuole, different degradative enzymes and the generation of radicals. However, the bacterium is able to circumvent many of these harmful effects, leading to a tug-of-war between the bacterium and host macrophage. This thesis aims at studying the interaction between the human macrophage and M. tuberculosis to identify host factors critical for controlling growth of the bacteria. More specifically, it focuses on the role of an intracellular receptor protein called NLRP3 and its downstream effects. NLRP3 is activated in human macrophages infected by M. tuberculosis and upon activation it forms a multi-protein complex known as the inflammasome. This protein complex is known to induce the production of the proinflammatory cytokine IL-1β and specialized forms of macrophage cell death. We hypothesized that stimulating this pathway would have a beneficial effect for the host macrophage during infection with M. tuberculosis. To allow us to follow interaction between M. tuberculosis and the human macrophage, we first developed a luminometry-based method of measuring bacterial numbers and following bacterial growth over several days in infected cells. With this new assay we showed that low numbers of bacteria induced very low levels of IL-1β and failed to induce any type of cell death in the macrophage. However, when a critical number of bacteria were reached, the infected macrophages underwent necrosis, which was accompanied by high levels of IL-1β. We were also able to show that addition of vitamin D, which has been implicated as an important factor for increased killing capacity of infected macrophages, increased the production of IL-1β, which coincided with increased killing of M. tuberculosis. This effect was seen specifically in cells from patients with active tuberculosis, suggesting that these cells are primed to respond to vitamin D and increased levels of IL-1β. Furthermore, we also showed that increasing production of IL-1β by stimulating infected macrophages with apoptotic neutrophils in turn drives the production of other proinflammatory cytokines. Lastly, we showed that gain-of-function polymorphisms in inflammasome components linked to increased inflammasome activation and IL-1β production promotes bacterial killing in human macrophages. In conclusion, the work presented in this thesis shows that by enhancing the functions of the inflammasome, it is possible to tip the balance between the human macrophage and M. tuberculosis in favor of the host cell.
45
McDaid, John Patrick. "The role of protein tyrosine kinases in macrophage activation and cytokine responses." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411796.
Full text
46
Benslimane, Fatiha. "Effect of dietary fat on lipid accumulation and macrophage activation in vivo." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/34072/.
Full textAbstract:
The rat was used as a model for the assessment of a high fat diet (HFD) and HFD/streptozotocin (STZ) induced Type II diabetes upon lipid deposition and development of inflammation in metabolically active tissues. HFD feeding for a period of 10 weeks did not induce significant weight gain in animals compared to those fed on normal chow (NC). There was also no significant effect of HFD feeding upon blood glucose and insulin levels. Adipose and skeletal muscle tissues showed minimal effects of HFD feeding at both the histological and molecular level. Histological assessment of liver tissue revealed marked steatosis in HFD fed animals. Molecular studies showed that genes involved in lipid and glucose metabolism and insulin signalling were decreased while genes involved in endoplasmic reticulum (ER) stress were elevated. Liver triglyceride fatty acid profiles resembled those of the diet with no significant differences in lipoprotein triglyceride levels observed between experimental groups. STZ injection induced hypoinsulinemia and hyperglycaemia. The changes observed at the molecular level were related to insulin depletion. Pioglitazone intervention did not cause any major changes in the STZ treated animals. The main conclusion was that HFD induces liver steatosis due to increase lipid flux from the diet despite the absence of weight gain or increased adipose tissue or skeletal muscle lipid content. This suggests that consumption of a high fat diet may cause the development of fatty Liver disease in the absence of weight gain or overt obesity.
47
Schmierer, Ann E. "Macrophage interactions with biomaterial surfaces and their effects on endothelial cell activation /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8047.
Full text
48
Clemons-miller, Annette R. "Tnf(alpha)-dependent and Tnf(alpha)-independent Activation of Macrophage Effector Function." Digital Commons @ East Tennessee State University, 1998. https://dc.etsu.edu/etd/2894.
Full textAbstract:
Tumor necrosis factor α (TNFα) is a pleiotropic cytokine that is predominantly produced by activated macrophages. The effects of TNFα are as diverse as the cells with which it interacts, e.g., stimulating fibroblast growth, exerting cytotoxic/cytostatic; activity against various human and murine cell lines, promoting inflammation through upregulation of endothelial adhesion molecules and IL-8 production. Yet TNFα is best known, and in fact was originally described, for its role in the bacterial-induced hemorrhagic necrosis of tumors and exacerbation of septic shock in which aberrant TNFα production leads to vascular collapse, cachexia, multiple organ failure, and ultimately death in as many as 100,000 people each year in the United States alone. LPS, a component of the outer cell wall of gram-negative bacteria, is the principal inducer of macrophage TNFα production. TNFα production can be enhanced by IFNγ which also induces upregulation of TNFα receptors allowing for the establishment of a TNFα autocrine loop. It has been hypothesized that autocrine TNFα stimulation plays a critical role in the induction of macrophage effector function, e.g., nitric oxide production. This dissertation represents efforts to evaluate the respective roles of the TNFα receptors in the induction of macrophage effector function, in addition to examining the mechanism by which autocrine TNFα exerts its effects on macrophages. Exploiting the species specificity of the murine TNFα receptor type 2 (TNF-R2), splenic macrophages were stimulated with human TNFα (which binds to TNF-R1 but not TNF-R2), in the presence of IFNγ. Human TNFα was effective in the induction of nitric oxide production, albeit at concentrations 12.5-fold greater than those required by murine TNFα to achieve the same result. Addition of anti-TNF-R1 completely inhibited the murine TNFα mediated induction of macrophage effector function. However, treatment with anti-TNF-R2 resulted in partial inhibition of macrophage activation. Taken together this data suggests that the primary TNFα mediated signals involved in macrophage activation are transduced through TNF-R1, although TNF-R2 appears to contribute to the intensity of the macrophage response. To evaluate the role of autocrine TNFα signaling in the induction of macrophage effector function, immortalized macrophages from normal C57Bl/6J mice (B6/J2) and C57Bl/6J mice containing gene targeted disruptions of the TNF-R1 and TNF-R2 genes (TRN) were stimulated under CD14-dependent and CD14-independent conditions. Although the B6/J2 and TRN clones mounted similar NO responses to LPS in the presence of serum, the TRN macrophages generated a weak nitric oxide response as compared to B6/J2 when stimulated with LPS under serum-free conditions. The involvement of TNFα autocrine stimulation in the CD14-independent activation was corroborated by the ability of soluble TNF-R1 to inhibit the response of B6/J2 macrophages to LPS in serum-free medium. CD14-independent LPS stimulation of TRN and B6/J2 resulted in equivalent levels of IL-1β, TNFα, and NOS gene expression, as determined by RT-PCR, and in release of equivalent amounts of biologically active TNFα. However, western blot analysis revealed that NOS protein production by TRN was as much as 50% less than that produced by B6/J2. These results indicate that autocrine TNFα stimulation contributes to the signaling pathways initiated by ligation of CD14-independent LPS receptors and may be involved in NOS post-transcriptional regulation.
49
Redente, Elizabeth Frances. "Macrophage and bone marrow derived monocyte activation during mouse lung tumorigenesis and chronic inflammation /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2008.
Find full textAbstract:
Thesis (Ph.D. in Toxicology) -- University of Colorado Denver, 2008.<br>Typescript. Includes bibliographical references (leaves 224-253). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
50
Sharif, Rubina Qasour. "Macrophage activating factor (MAF) in rainbow trout (Oncorhynchus mykiss) : biological activity and molecular source." Thesis, University of Stirling, 2003. http://hdl.handle.net/1893/26687.
Full textAbstract:
This study investigated the biological activity of a macrophage activating factor (MAF) produced by activated lymphocytes from the rainbow trout (Oncorhynchus mykiss) and attempts to discover its molecular source. Peripheral blood lymphocytes were shown to release factors with MAF activity following incubation with a variety of stimulants and were subsequently shown to activate macrophages using at least two different methods, the nitroblue tetrazolium (NBT) colourimetric assay and the luminol-dependent chemiluminescent assay. The latter technique detected an immediate response which decayed over a 40 minute period on the addition of cell-free supernatants from activated lymphocytes to macrophages. A number of molecular approaches, including degenerate PCR primer amplification, DNA cross-hybridisation and cDNA library screening were used in this study to try to isolate any cytokine genes from Oncorhynchus mykiss. As a control β-actin cDNA was successfully amplified from Oncorhynchus mykiss using primers based on the salmon sequence. The Oncorhynchus mykiss orthologue of IFN-y was initially targeted. However, although a PCR product of the appropriate size was amplified using degenerate primers based on mammalian and avian IFN-y sequences, the sequence was not related to IFN-y or any other known Oncorhynchus mykiss sequence. A similar strategy was used to try and amplify the Oncorhynchus mykiss orthologue of mammalian IL-15. Again despite amplification of a DNA fragment of approximately the correct size there appeared to be no relationship between it and the known IL-15 sequences. As an alternative strategy a cDNA library from stimulated peripheral blood lymphocytes (PBLs) was constructed and screened using cDNA probes derived from stimulated and non-stimulated PBLs in order to detect mRNAs which might have been upregulated as a result of in vitro stimulation. A number of positive clones were obtained from the differential screening of the library including cDNAs showing similarity to other unidentified fish sequences as well as to a number of proteins predicted to be involved in regulation of cell proliferation, neocorticogenesis and embryo development. Additionally. the library was also screened using ovine cytokine cDNA probes. although no positively hybridising clones were obtained. The ovine IFN-y gene was also used to probe genomic DNA from Oncorhynchus mykiss. but unlike previous studies with human IFN-y gene no hybridisation between the ovine IFN-y gene and Oncorhynchus mykiss DNA was observed. This investigation highlights the potential difficulties of using various molecular strategies such as DNA cross-hybridisation or PCR techniques for the cloning of fish cytokine sequences. Consequently, future strategies for cloning fish cytokine genes may require targeting the biological activity through expression libraries.