A fibrose hepática é uma patologia que acompanha outras doenças crônicas do fígado como a cirrose e o hepatocarcinoma. As células estreladas hepáticas (HSC, do inglês hepatic stellate cells) compõem uma população celular heterogênea que se caracteriza por transitar entre dois fenótipos. As células com fenótipo quiescente possuem a capacidade de armazenar vitamina A em gotas lipídicas. Os insultos ao fígado desencadeiam uma resposta inflamatória que gera estímulos parácrinos e autócrinos mediados por citocinas e espécies reativas. Neste contexto, as HSC assumem um fenótipo ativado fibrogênico e tornam-se responsáveis pela cicatrização hepática. Danos crônicos ao fígado levam a uma deposição de matriz extracelular exagerada que configura o estado patológico da fibrose. O resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-estilbeno) é uma fitoalexina produzida por algumas espécies de plantas. Inúmeros efeitos benéficos à saúde são atribuídos ao RSV por causa do seu potencial antioxidante, antiinflamatório e pró-apoptótico. Estudos anteriores mostraram que tratamento da GRX, uma linhagem murina de HSC ativadas, com concentrações de RSV próximas as biodisponíveis (0,1 a 1 μM) resultou em parada do ciclo na fase S com consequente inibição de proliferação celular, um efeito associado à citotoxicidade e que pode favorecer a resolução da fibrose hepática. Neste estudo, por técnicas espectrofotométricas, foi demonstrado que tratamento da GRX por 24 horas com concentrações entre 0,1 a 50 μM de RSV promoveu um efeito pró-oxidante que causa uma citotoxicidade dependente da dose, bastante aumentada no grupo tratado com a concentração mais alta. Os efeitos citotóxicos atenuados encontrados nas células tratadas por 120 horas sugerem que a GRX pode se tornar resistente a estes efeitos. O potencial pró-oxidante do RSV foi o ponto de partida para investigar a possibilidade de que esta fitoalexina provocasse uma alteração no metabolismo mitocondrial da GRX. Para isso, os efeitos do RSV (1 a 50 μM) na função mitocondrial, na indução de morte mediada por estas organelas e na autofagia/mitofagia foram investigados por técnicas de espectrofotometria, de imunocitoquímica, de citometria de fluxo, de microscopia confocal e de microscopia eletrônica de transmissão em GRX tratadas por 24 e 120 horas. Foi demonstrado que todas as concentrações de RSV promovem apoptose por meio da ativação de caspases, alteram a dinâmica/função mitocondrial e induzem o aumento de autofagia/mitofagia na GRX. No entanto, o RSV provocou biogênese de mitocôndrias nos grupos tratados com 1 e 10 μM, enquanto que o tratamento com 50 μM causou dano celular evidente na GRX, sem induzir biogênese de mitocôndrias. Desta forma, é possível que a citotoxicidade “dose-dependente” do RSV, que causa a morte celular e dano oxidativo em 24 horas de tratamento, esteja relacionada com o desequilíbrio entre a indução concomitante de apoptose mediada por dano mitocondrial, autofagia/mitofagia e biogênese de mitocôndrias. Por fim, foi investigada a liberação de TNF-α, Interleucina-6 e Interleucina-10 pela GRX tratada por 24 e 120 horas com RSV (0,1 a 50 μM), considerando o papel antiinflamatório do RSV e o papel das HSC ativadas na sinalização autócrina que contribui para a modulação fenotípica destas células. Foi demonstrado que o tratamento da GRX com RSV por 24 e 120 horas induziu a redução da liberação de Interleucina-6; enquanto que a liberação de TNF-α e Interleucina-10 foi aumentada. Estes resultados confirmam um efeito antiinflamatório do RSV que deve contribuir na prevenção da ativação ou da perpetuação do estado ativado das HSC por meio de sinalização autócrina. Ainda que a concentração do RSV seja importante para efetivamente induzir a morte das HSC ativadas, o tratamento com esta fitoalexina pode ser promissor para a resolução da fibrose hepática por diminuir a população de células ativadas e, possivelmente, prevenir a perpetuação do estado fenotípico ativado. Estudos avaliando indicadores de quiescência em células tratadas são ainda necessários para desvendar completamente os efeitos do RSV quanto às possibilidades de inibição da perpetuação ou reversão fenotípica das HSC ativadas. / Liver fibrosis is a disease that accompanies other hepatic chronic diseases such as cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) are a heterogeneous cell population characterized by transiting between two phenotypes. Cells with a quiescent phenotype are able to store vitamin A into lipid droplets. Damage to the liver trigger an inflammatory response that generates paracrine and autocrine stimulation mediated by cytokines and reactive species. In this context, HSC assume an activated and fibrogenic phenotype responsive for hepatic wound-healing. Chronic insults to the liver lead to an excessive deposition of extracellular matrix that configures the pathological state of fibrosis. Resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-stilbeno) is a phytoalexin produced by some species of plants. Several beneficial effects are attributed to this molecule due to its antioxidant, antiproliferative and pro-apoptotic potential. Previous studies showed that treatment with bioavailable concentrations of RSV (0.1 to 1 μM) promoted an arrest cycle at the S phase in GRX, a murine activated HSC model, leading to cell proliferation inhibition, a cytotoxic effect that contributes to the liver fibrosis resolution. In this study, it was shown by spectrophotometric techniques that GRX treatment for 24 hours at concentrations between 0.1 to 50 μM of RSV promoted a fairly clear pro-oxidant effect that causes a dose-dependent cytotoxicity that was higher in the group treated with 50 μM. The attenuated cytotoxicity found after 120 hours of GRX treatment suggest that these cells became resistant to this effect. The pro-oxidant potential of RSV was the starting point for investigating the possibility that this phytoalexin would cause a change in the GRX mitochondrial metabolism. Thus, the effects of RSV (1 to 50 μM) on altering the mitochondrial function, on inducing mitochondrial-mediated cell death, and autophagy/mitofagia were investigated in GRX treated for 24 and 120 hours by spectrophotometric techniques, immunocytochemistry, flow cytometry, confocal microscopy, and transmission electron microscopy. All the RSV concentrations promote cell apoptosis through caspases activation, alter the mitochondrial dynamics and function, and induce an increase of autophagy/mitofagia. Curiously, only 1 and 10 μM of RSV induced mitochondrial biogenesis in GRX, while the highest concentration caused an evident cell damage without inducing mitochondrial biogenesis. Thus, it is possible that the "dose-dependent" cytotoxicity of RSV, which causes cell death and oxidative damage in 24 hours of treatment, is related to an imbalance between the concomitant induction of mitochondrial-mediated apoptosis, autophagy/mitofagia, and mitochondrial biogenesis. Finally, it was investigated the release of TNF-α, Interleukin-6 and Interleukin-10 by GRX treated for 24 and 120 hours with RSV (0.1 to 50 μM), considering the anti-inflammatory role of RSV and the autocrine signalling role of HSC that contributes to the perpetuation of its activated phenotype. It was demonstrated that GRX treatment with RSV for 24 and 120 hours reduced the release of Interleukin-6 in the culture medium; whereas the release of TNF-α and Interleukin-10 was increased. These results confirm the anti-inflammatory properties of RSV and may contribute to the prevention of HSC activation through autocrine signalling. Although RSV concentration is important to effectively induce activated HSC death, cells treatment with this phytoalexin may be promising for liver fibrosis resolution through decreasing the population of activated cells or through preventing the perpetuation of activated state of HSC. Future studies evaluating the quiescence indicators of GRX under RSV treatment are still needed to fully unravel the effects of this phytoalexin on inhibiting the perpetuation of activated HSC or reversing its activated phenotype.

B. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Cardiovascular diseases (CVDs) are the leading cause of death worldwide, and the prevalence thereof is on the rise in developing countries due to the demographic transition and urbanization. The inflammatory process, atherosclerosis, is at the root of the majority of CVDs and is caused by unresolved inflammation. Various cardiovascular risk factors such as hyperglycaemia, dyslipidaemia, hypertension, smoking and aging stimulate the development of atherosclerosis through triggering inflammation. Being in a state of chronic low-grade inflammation therefor places an individual at higher risk of developing CVD, with inflammation playing a cause and effect role. The aim of this study was to investigate the inflammatory status of an elderly black South African population by analysis of inflammatory markers HS-CRP, TNF-α and IL-6, as well as the genetic polymorphism C174G associated with increased serum levels of IL-6 in some populations. The research was conducted in the field of Biomedical Sciences as a quantitative, cross-sectional, analytical observational design. The study was ethically approved and involved collection of 84 blood samples from volunteers in a purposively selected population as part of a larger collaborative study. Serum was used to analyse HS-CRP, TNF-α and IL-6 and DNA was extracted from whole blood for analysis of the C174G polymorphism. The median serum HS-CRP of 6.44mg/L (IQR = 2.82 - 9.86mg/L) fell within the highest risk (>5mg/L) of CVD and 75% of participants were at high (3.01-5mg/L) or very high (>5mg/L) risk. The median TNF-α of 0.00pg/mL was within the normal range and only 2.6% of participants had high serum TNF-α levels. The median serum IL-6 level was 1.92pg/mL and was also within the normal range with only 2.6% of participants who had high serum IL-6 levels. For the C174G polymorphism analysis, 98.6% had the GG, 1.4% the GC genotype and no participants had the CC genotype. The median serum IL-6 level of the homozygous GG group was 6.51mg/L, higher than the 4.13mg/L serum IL-6 of the heterozygous GC group. The difference in IL-6 should be considered with caution as only one participant had the C allele. A highly significant (p=0.001) correlation was found between HS-CRP and IL-6, as well as between IL-6 and TNF-α (p = 0.048). The elderly black Sharpeville community is in an increased inflammatory state which puts them at risk of CVD. The prevalence of the C allele in the C174G polymorphism is low in this population. Further research could be conducted as intervention studies to decrease the inflammatory state of the population and influence health policy changes to improve prevention of CVD.

L’apparition de plusieurs maladies, telles que le cancer, le diabète, l'hypertension artérielle et la propagation d'infections de type virus mutagènes peuvent être liées à la qualité et au mode de vie que nous menons aujourd’hui. En effet, plusieurs études sur les facteurs déclenchant ces maladies dites "morbides" à long ou à court terme, sont liées au stress et à la qualité des aliments consommés, qu'ils soient d'origine végétale ou animale. Ces maladies deviennent un phénomène courant, elles touchent différentes races et toutes les catégories de la société. D'après les recherches ethnobotaniques, les substances d’origine naturelle, ont permis à des civilisations de survivre à des maladies mortelles. A titre d'exemple, on retrouve ainsi des références à des périodes de fièvre paludique en Chine et à des symptômes de cette maladie dans le «Huangdi Neijiang» Le Canon de Médecine datant des environs du premier siècle avant notre ère, plus de 2000 ans, qui relate de l'emploi de plantes médicinales, pour soulager les fièvres (Desgrouas et al., 2014).Vers 186 avant J.-C. apparaît, dans certaines régions de Chine, l'utilisation en tisane, du Qing hao su, appelé plus tard artémisinine en Occident et extrait d'une plante médicinale utilisée comme antipyrétique appelée "Qing hao", Artemisia annua ou Armoise annuelle. L'artemisinine bloque une enzyme qui permet au parasite de pomper le calcium et l'empêche ainsi de se développer. Au jour d'aujourd'hui l’Artemisinin-based combination therapy, en français Thérapie combinée à base d'artémisinine et en sigle ACT, est une thérapie et une prévention tertiaire dans les cas de paludisme simple.Dans cette optique notre étude vient s'ajouter à une longue série d'études menées sur les plantes médicinales et les substances naturelles extraites. Elle a pour objectif de révéler de nouvelles biomolécules, de mettre en évidence leurs activités biologiques grâce à des techniques de biotechnologies d'une part. D'autre part ces investigations permettront de valoriser les ressources naturelles qui se distinguent par leur endémicité.Pour se faire, notre choix s'est porté sur deux plantes médicinales endémiques à l'Algérie Cyclamen africanum Boiss. & Reuter et Zygophyllum cornutum Coss. , après une recherche ethnobotanique sur la pharmacopée traditionnelle du Nord de l'Afrique, et qui a révélé l’efficacité de ces plantes dans les problèmes inflammatoires minimes chez les autochtones, nous avons entrepris des investigations pharmaco- biochimiques.Ces dernières nous ont permis d'isoler : cinq composés à partir de l'extrait méthanolique des racines de l'espèce Cyclamen africanum Boiss. & Reuter, deux nouvelles saponines triterpéniques de type Oleanane, Afrocyclamin A et B (1, 2), ainsi que trois saponines triterpénoïdes connus sous le nom de lysikokianoside (3), deglucocyclamin I (4) et de son dérivé d'acide dicrotalique (5); et Sept saponosides connus à partir de l'extrait méthanolique de la plante entière de Zygophyllum cornutum Coss., ces saponosides sont de type ursane, ce type de triterpène est rapporté dans cette espèce pour la première fois et peuvent être considérés comme un marqueur chimio-taxonomique (chemotype) du genre Zygophyllum. Les structures ont été élucidées, sur la base de l'analyse des spectres de l'expérience RMN-1D et RMN- 2D (COSY, TOCSY, NOESY, HMBC et HSQC) et spectrométrie de masse en source FAB mode ion négatif. Des activités biologiques, des fractions saponosidiques Fr.1 et Fr.2, ont été testées sur des lignées de Rats mâles et femelles, de la race Winstar pour évaluer l'activité anti inflammatoire.La fraction saponosidique Fr.1 de Cyclamen africanum à la dose 5 mg, a montré un effet significatif sur l'inflammation causé par la carragénine, en réduisant l'oedème et la réponse immunitaire, qui s'est traduite par la concentration des protéines de la réponse inflammatoire (PRI) à travers leurs action sur les pro-médiateurs de l'inflammation (COX-2, PGE2, TNF -α, iNOS). / The appearance of several diseases, such as cancer, diabetes, high blood pressure and spread of infections mutagenic virus type can be linked to the quality and lifestyle that we lead today. Indeed, several studies on the factors triggering these so-called "morbid" long-or short-term illnesses are related to stress and quality of food consumed, whether of plant and animal origin. These diseases are becoming a common occurrence, they affect different races and all classes of society. According ethnobotanical research, naturally occurring substances, allowed civilizations to survive deadly diseases. For example, we thus find references to periods of malarial fever in China and one of the symptoms of this disease in the "Huangdi Neijiang" The Canon of Medicine dating from around the first century BC, more than 2000 years, which relates to the use of herbal medicines to relieve fevers (Desgrouas et al., 2014).Around 186 BC appears, in some parts of China, the use in herbal tea, Qing hao su, later known as artemisinin in the West and extracted from a medicinal plant used as antipyretic called "Qing hao" Artemisia annua or annual wormwood. Artemisinin blocks an enzyme which enables the parasite to pump calcium and prevents it from developing. As of today the Artemisinin-based combination therapy in French Combination therapy of artemisinin and ACT acronym, is a therapy and tertiary prevention in cases of uncomplicated malaria.From this perspective our study adds to a long series of studies on medicinal plants and natural substances extracted. It aims to reveal new biomolecules, highlighting their biological activities through techniques of biotechnology on the one hand. Moreover, these investigations will develop natural resources that are characterized by endemic.To do this, our choice is focused on two endemic medicinal plants in Algeria Cyclamen africanum Boiss. & Reuter and Zygophyllum cornutum Coss. After an ethnobotanical research on traditional medicine in Northern Africa, which showed the effectiveness of these plants in minimal inflammatory problems among Aboriginal, we undertook biochemical pharmacological investigations.The latter allowed us to isolate, five compounds from the methanol extract of the roots of the species Cyclamen africanum Boiss. Reuter & two new oleanane triterpene saponins type, Afrocyclamin A and B (1, 2) and three triterpenoid saponins known lysikokianoside of (3), deglucocyclamin I (4) and its derivative dicrotalique acid (5) September and known from the methanol extract saponins from the whole plant of Zygophyllum cornutum Coss. these saponins are ursane type, type triterpenes are reported in this species for the first time and can be considered a chemotherapy marker Taxonomic (chemotype) of Zygophyllum kind. The structures were elucidated on the basis of the analysis of NMR spectra of the experience-1D and 2D-NMR (COSY, TOCSY, NOESY, HSQC and HMBC) and mass spectrometry method negative ion FAB source. The biological activities of saponosidiques FR.1 and Fr.2 fractions were tested on lines of male and female rats of the Winstar rats to evaluate the anti-inflammatory activity. The saponosidique fraction FR.1 Cyclamen africanum the 5 mg dose, showed a significant effect on inflammation caused by carrageenan, reducing edema and immune response, which resulted in the concentration of protein the inflammatory response (PRI) through their action on the pro-inflammatory mediators (COX-2, PGE2, TNF -α, iNOS). The fraction of Fr.2 saponosidique Zygophyllum dose 20 mg did not show a significant effect on inflammation in general.

No description available.

Les cellules du système immunitaire sont programmées pour reconnaître et éliminer les cancéreuses, pourtant les cellules tumorales ont la capacité de mettre en œuvre les divers moyen pour échapper à la mort induite par les effecteurs du système immunitaire. Au cours de cette thèse, nous avons étudié plus particulièrement PD-L1, qui est impliqué dans la protection des cellules tumorales contre une attaque du système immunitaire et induit au cours de la TEM. / EMT foster cancer progression by acting on mechanisms allowing tumors to exide immune surveillance. Recent clinical advances immunotherapy demonstrated that some cancer with established lymphocyte infiltrates, express immune checkpoint inhibitory molecules, such as PD-L1, to allow their progression. During this thesis, another link between EMT and immune escape, through the regulation of PD-L1 in non-smal cell lung caricinoma was established. A new role of IKKƐ in the regulation of PD-L1 during EMT was also been shown.

Background: Horses are much predisposed and susceptible to excessive and acute inflammatory responses that cause the recruitment and stimulation of polymorphnuclear granulocytes (PMN) together with peripheral blood mononuclear cells (PBMC) and the release of cytokines. The aim of the study is to develop easy, quick, cheap and reproducible methods for measuring tumor necrosis factor alpha (TNF-α) and interleukin-1 receptor antagonist (IL-1Ra) in the equine whole blood cultures ex-vivo time- and concentration dependently. Results: Horse whole blood diluted to 10, 20 and 50 % was stimulated with lipopolysaccharide (LPS), PCPwL (a combination of phytohemagglutinin E, concanavalin A and pokeweed mitogen) or equine recombinant TNF-α (erTNF-α). TNF-α and IL-1Ra were analyzed in culture supernatants, which were collected at different time points using specific enzyme-linked immunosorbent assays (ELISA). Both cytokines could be detected optimal in stimulated 20 % whole blood cultures. TNF-α and IL-1Ra releases were time-dependent but the kinetic was different between them. PCPwL-induced TNF-α and IL-1Ra release was enhanced continuously over 24–48 h, respectively. Similarly, LPS-stimulated TNF-α was at maximum at time points between 8–12 h and started to decrease thereafter, whereas IL-1Ra peaked later between 12–24 h and rather continued to accumulate over 48 h. The equine recombinant TNF-α could induce also the IL-1Ra release. Conclusions: Our results demonstrate that similar to PCPwL, LPS stimulated TNF-α and IL-1Ra production time-dependently in whole blood cultures, suggesting the suitability of whole blood cultures to assess the release of a variety of cytokines in health and diseases of horse.

Ce travail examine les mécanismes de l’immunité innée impliqués dans l’hépatite aiguë virale du modèle murin d’infection par le virus de l’hépatite virale murine de type 3 (MHV-3). Afin de déterminer le rôle du TLR2 dans l’aggravation de l’hépatite, des infections avec le virus MHV-3 ont été réalisées in vivo chez des souris C57BL/6 et des souris déficientes pour le gène tlr2 et in vitro dans des macrophages et des hépatocytes infectés avec le virus MHV-3 et le virus moins virulent MHV-A59. Les niveaux de transcription et de traduction des senseurs microbiens, des interférons (IFN) de type I, des cytokines et/ou des chimiokines ont été évalués par qRT-PCR et ELISA. Les cellules ont été traitées avec des petits ARNs interférants (siRNAs) pour le TLR2 et le CEACAM1a ou mises en présence d’inhibiteurs des voies d’endocytose. Les résultats révèlent le rôle stimulateur du TLR2 pour la réplication virale, la production de cytokines pro-inflammatoires IL-6 et TNF-α et des chimiokines CXCL1, CXCL10 et CCL2. Un nouveau mécanisme d’échappement aux senseurs viraux dépendant du TLR2 a également été mis en évidence dans les macrophages et les hépatocytes lors de l’infection de ces cellules avec le virus MHV-3, et non pas avec le virus moins virulent MHV-A59. Ces différents travaux révèlent un nouveau rôle du TLR2 lors d’infections virales dans l'aggravation de la réponse inflammatoire tout en protégeant le virus des autres senseurs de la réponse immune innée. / This work investigates the innate immunity mechanisms involved in the Murine Hepatitis Virus type 3 (MHV-3) acute hepatitis disease model. In the goal of determining the role of the TLR2 receptor in aggravating the hepatitis disease, in vivo infections with the MHV-3 virus were performed on C57BL/6 mice or tlr2-/- gene knockout mice as well as in vitro infections of murine macrophages and hepatocytes with the MHV-3 and less virulent MHV-A59 serotypes. The levels of transcription and translation of different microbial sensors, type I interferons (IFN), cytokines and/or chemokines were measured by qRT-PCR and ELISA tests. Cells were treated with small interfering ARN (siRNA) for the TLR2 and/or CEACAM1a genes or treated with the different endocytosis inhibitors before infection. Our results reveal the stimulatory role of the TLR2 receptor on viral replication, production levels of the IL-6 and TNF-α cytokines and chemokines CXCL1, CXCL10 and CCL2. This study also reveals a new immune evasion mechanism via TLR2 in macrophages infected with MHV-3, but not with the lesser virulent MHV-A59 serotype. These different experiments have revealed a new role for the TLR2 receptor in viral infections wherein inflammatory responses are aggravated whilst shielding viral detection by other pathogens sensors of the innate immunity.

<p>Patients with peritonitis or malignant obstructive jaundice (HPB⁺) have an increased morbidity and mortality due to sepsis. An altered cell-mediated immunity in the intestinal mucosa might promote gut barrier failure, increased endotoxin and cytokine release and bacterial translocation (BT) in these conditions. A clinically relevant rat model of polymicrobial peritonitis induced sepsis by cecal ligation and puncture (CLP) was used. Septic animals demonstrated a superficial injury in the small intestinal mucosa, and a significant reduction in T lymphocytes in the villi, as well as increased number of macrophages in the villi and in the MLNs as compared to sham. CLP caused increased concentration of TNF-α and IL-6 in ascitic fluid. CLP + the immunomodulator Linomide decreased the TNF-α level, reduced mucosal damage and attenuated the changes in T lymphocytes and macrophages observed following CLP. CLP + selective cyclooxygenase (COX)-2 inhibitor (SC-236) or nonselective COX inhibitor (indometacin) decreased the amount of macrophages in the mucosa and the MLNs compared to untreated CLP. CLP + indometacin decreased T lymphocytes in the villi and MLNs. SC-236 + CLP reduced mucosal injury and cytokine release as compared to indometacin. An increased rate of apoptosis in both the mucosa and MLNs was seen following CLP; COX inhibitors enhanced this phenomenon in the MLNs.</p><p>BT occurred infrequently in patients with acute peritonitis and in HPB⁺ there was no evidence of BT. Peritonitis and HPB⁺causes significant inflammatory cellular reactions as increased endotoxin and cytokine plasma levels and an altered immune cell distribution in MLNs, in HPB⁺a high rate of apoptosis in MLNs was observed. </p><p>An altered pattern of immunocompetent cells within the mucosa and in MLNs was found in experimental and clinical peritonitis as in HPB⁺.Lymphocyte depletion may be a result of increased apoptosis, which could reduce the ability of septic or jaundice patients to eradicate infection.</p>

Patients with peritonitis or malignant obstructive jaundice (HPB+) have an increased morbidity and mortality due to sepsis. An altered cell-mediated immunity in the intestinal mucosa might promote gut barrier failure, increased endotoxin and cytokine release and bacterial translocation (BT) in these conditions. A clinically relevant rat model of polymicrobial peritonitis induced sepsis by cecal ligation and puncture (CLP) was used. Septic animals demonstrated a superficial injury in the small intestinal mucosa, and a significant reduction in T lymphocytes in the villi, as well as increased number of macrophages in the villi and in the MLNs as compared to sham. CLP caused increased concentration of TNF-α and IL-6 in ascitic fluid. CLP + the immunomodulator Linomide decreased the TNF-α level, reduced mucosal damage and attenuated the changes in T lymphocytes and macrophages observed following CLP. CLP + selective cyclooxygenase (COX)-2 inhibitor (SC-236) or nonselective COX inhibitor (indometacin) decreased the amount of macrophages in the mucosa and the MLNs compared to untreated CLP. CLP + indometacin decreased T lymphocytes in the villi and MLNs. SC-236 + CLP reduced mucosal injury and cytokine release as compared to indometacin. An increased rate of apoptosis in both the mucosa and MLNs was seen following CLP; COX inhibitors enhanced this phenomenon in the MLNs. BT occurred infrequently in patients with acute peritonitis and in HPB+ there was no evidence of BT. Peritonitis and HPB+ causes significant inflammatory cellular reactions as increased endotoxin and cytokine plasma levels and an altered immune cell distribution in MLNs, in HPB+ a high rate of apoptosis in MLNs was observed. An altered pattern of immunocompetent cells within the mucosa and in MLNs was found in experimental and clinical peritonitis as in HPB+. Lymphocyte depletion may be a result of increased apoptosis, which could reduce the ability of septic or jaundice patients to eradicate infection.

Mathematical models of signal transduction pathways are characterized by a large number of proteins and uncertain parameters, yet only a limited amount of quantitative data is available. The dissertation addresses this problem using two different approaches: the first approach deals with a model simplification procedure for signaling pathways that reduces the model size but retains the physical interpretation of the remaining states, while the second approach deals with creating rich data sets by computing transcription factor profiles from fluorescent images of green-fluorescent-protein (GFP) reporter cells. For the first approach a model simplification procedure for signaling pathway models is presented. The technique makes use of sensitivity and observability analysis to select the retained proteins for the simplified model. The presented technique is applied to an IL-6 signaling pathway model. It is found that the model size can be significantly reduced and the simplified model is able to adequately predict the dynamics of key proteins of the signaling pathway. An approach for quantitatively determining transcription factor profiles from GFP reporter data is developed as the second major contribution of this work. The procedure analyzes fluorescent images to determine fluorescence intensity profiles using principal component analysis and K-means clustering, and then computes the transcription factor concentration from the fluorescence intensity profiles by solving an inverse problem involving a model describing transcription, translation, and activation of green fluorescent proteins. Activation profiles of the transcription factors NF-κB, nuclear STAT3, and C/EBPβ are obtained using the presented approach. The data for NF-κB is used to develop a model for TNF-α signal transduction while the data for nuclear STAT3 and C/EBPβ is used to verify the simplified IL-6 model. Finally, an approach is developed to compute the distribution of transcription factor profiles among a population of cells. This approach consists of an algorithm for identifying individual fluorescent cells from fluorescent images, and an algorithm to compute the distribution of transcription factor profiles from the fluorescence intensity distribution by solving an inverse problem. The technique is applied to experimental data to derive the distribution of NF-κB concentrations from fluorescent images of a NF-κB GFP reporter system.