Introdução: Chlamydia trachomatis (CT) é causa da infecção sexualmente transmitida de origem bacteriana mais comum. Na mulher, a infecção genital pela CT pode causar cervicite, uretrite, endometrite, salpingite. Infecções persistentes ou recorrentes provavelmente representam um importante fator de risco para o desenvolvimento de sequelas associadas, como dor pélvica crônica, gravidez ectópica e infertilidade por fator tubário. A lectina ligadora de manose (MBL), componente doo sistema imune inato, tem importante papel na defesa antimicrobiana, reconhecendo vírus, fungos e patógenos bacterianos. O gene que codifica para a MBL é polimórfico, e a substituição de um único nucleotídeo resulta na produção de uma proteína instável, que é rapidamente degradada. Objetivo: Avaliar se mulheres brasileiras portadoras de um polimorfismo do gene da MBL apresentam diferentes susceptibilidades para a ocorrência de obstrução tubária, na presença ou ausência de uma infecção prévia por Chlamydia trachomatis. Métodos: Em estudo caso-controle, foram avaliadas 75 pacientes com obstrução tubária e 75 pacientes com tubas pérvias, atendidas na Divisão de Ginecologia do Hospital das Clínicas da Universidade de São Paulo (HCFMUSP). Anticorpos IgG anti-CT foram mensurados através de um ensaio de imunoabsorção enzimática para investigar uma infecção prévia pela CT. Para o polimorfismo, realizou-se coleta de células bucais e o DNA extraído foi analisado através de reação em cadeia da polimerase (PCR), digestão de endonuclease e gel de eletroforese, utilizando pares de primers específicos para a região polimórfica. Todo material foi mantido a -80°C e enviado em gelo seco para a Division of Immunology and Infectious Diseases da Weill Cornell Medicine em Nova York. Associações entre genótipos de MBL ou alelos e permeabilidade tubária foram analisadas pelo teste de qui-quadrado de Pearson com ou sem correção de Yates. Resultados: Não houve diferença na detecção de anticorpos da CT entre os grupos. Mulheres com tubas obstruídas tiveram uma prevalência maior do genótipo AB (36%) versus (16%), resultado estatisticamente significativo (p < 0,01). De maneira semelhante, a distribuição do alelo A e do alelo variante B também apresentaram diferenças significantes entre os grupos (p < 0,01). Conclusão: Os achados sugerem, que embora a exposição à Chlamydia trachomatis tenha sido semelhante em ambos os grupos, a presença do alelo variante B do gene que codifica para a MBL aumenta o risco de desenvolvimento da obstrução tubária, subsequente à infecção pela CT ou outros agentes infecciosos. Nas mulheres brasileiras avaliadas a presença de tal polimorfismo genético aumentou a probabilidade de obstrução tubária em consequência de uma infecção do trato genital / Introduction: Chlamydia trachomatis (CT) is the cause of the most common bacterial sexually transmitted infection. In women, genital CT infection may cause cervicitis, urethritis, endometritis, salpingitis. Persistent or recurrent infections probably represent an important risk factor for the development of associated sequelae, such as chronic pelvic pain, ectopic pregnancy and tubal factor infertility. Mannose-binding lectin (MBL), a component of the innate immune system, has an important role in antimicrobial defense, recognizing viral, bacterial and fungal pathogens. The gene coding for MBL is polymorphic and a single nucleotide substitution results in production of an unstable protein, that is rapidly degraded. Objective: To evaluate whether Brazilian women with a polymorphism in the MBL gene present different susceptibilities to the occurrence of fallopian tube damage, in the presence or absence of a previous infection by CT. Method: In a case-control study, 75 patients with tubal obstruction and 75 patients with patent tubes were studied, all seen at the Gynecology Division of the Hospital das Clínicas of the University of São Paulo (HCFMUSP). IgG anti-CT antibodies were measured by enzyme-linked immunoassay to investigate a previous CT infection. For the polymorphism analysis, buccal cells were collected and the extracted DNA was analyzed by polymerase chain reaction (PCR), endonuclease digestion and gel electrophoresis using primer pairs specific for the polymorphic region. All material was maintained at -80 ° C and sent on dry ice to the Division of Immunology and Infectious Diseases at Weill Cornell Medicine in New York. Associations between MBL genotypes or alleles and tubal permeability were analyzed by the Pearson chi-square test with or without Yates correction. Results: There was no difference in CT antibody detection between the two groups. Women with obstructed tubes had a higher prevalence of being positive for the heterogenous genotype AB (36%) versus (16%) (p < 0.01). Similarly, the distribution of the normal A allele and variant B allele were also significant different between the two groups (p < 0,01). Conclusion: The findings suggest that while exposure to CT was similar in both groups of women the presence of the variant MBL B allele increases the risk for development of tubal obstruction, subsequent to a CT or other infection. In the Brazilian women evaluated possession of this genetic polymorphism increased the likelihood that blocked fallopian tubes will be a consequence of a genital tract infection

Cryptococcus sp é um fungo saprófita, cosmopolita, que causa micose sistêmica, geralmente, subaguda ou crônica, conhecida, sobretudo, por sua localização meníngea, após aquisição da infecção por via respiratória Embora seja ubíquo, a criptococose ocorre predominantemente em indivíduos imunodeficientes e podendo ocorrer, também, em indivíduos imunocompetentes. Os estudos experimentais e em humanos avaliando a ativação do sistema complemento e a produção de anticorpos específicos mostram que a resposta inata e de anticorpos são importantes para a delimitação do processo infeccioso por Cryptococcus sp, como também, a administração de anticorpos monoclonais podem induzir uma resposta eficaz na disseminação da doença. O sistema complemento contribui para a defesa do organismo contra o Cryptococcus sp de diferentes maneiras: secretando opsoninas e fatores quimiotáticos e colaborando com a ação dos anticorpos específicos, aumentando a interação entre a imunidade inata e adquirida. Os anticorpos antiglicuroxilomanana (GXM) possuem numerosas atividades biológicas: a) opsonização para fagocitose, b) ativação da via clássica do complemento resultando na deposição precoce de fragmentos de C3 no fungo, c) supressão do excesso de acúmulo de C3 pela via alternativa; d) facilitação do clareamento do GXM do soro in vivo, resultando no maior acúmulo de GXM nos tecidos ricos em células do sistema fagocítico mononuclear; e) proteção em modelos murinos da criptococose e f) facilitação de vários aspectos da imunidade celular ao Cryptococcus sp. O objetivo desse estudo foi avaliar a resposta humoral ao GXM e às proteínas da parede celular (Ag S) avaliando a atividade do sistema complemento como também a produção de anticorpos específicos em amostras séricas de adultos com e sem neurocriptococose. Foram coletadas 106 amostras de soro e divididas em 3 grupos: grupo 1- 21 indivíduos com neurocriptococose e baixa exposição a levedura, grupo 2- foi composto por 23 indivíduos saudáveis com alta exposição ao fungo e HIV negativos, granjeiros da cidade de Jumirim localizada a 164 km de São Paulo, na região de Sorocaba e, o grupo 3- 60 indivíduos saudáveis, HIV negativos e com baixa exposição ao Cryptococcus sp. Dois pacientes foram excluídos do estudo por apresentarem tumores (timona e câncer de pulmão). O sistema complemento foi avaliado por ensaio hemolítico (CH 50 e AP 50) e, a dosagem da proteína ligadora de manose (MBL) foi feita por ELISA. Os valores de CH 50 estiveram dentro da normalidade em 17/21, 13/23, 59/60 indivíduos dos grupos 1, 2 e 3 respectivamente. A média dos valores de CH 50 foi diferente significativamente entre o três grupos (P < 0,0001). O grupo 2 mostrou níveis reduzidos significantes em comparação aos dois outros grupos. Os valores de AP 50 estiveram dentro da normalidade em 11/21; 21/23 e 60/60 indivíduos dos grupos 1, 2 e 3 respectivamente. Houve diferença nos valores de AP 50 (P = 0,0005) e apenas um paciente do grupo 1 apresentou valores indetectáveis desta via. Houve diferença significante na dosagem de MBL entre os três grupos (P = 0,0277). Anticorpos IgG anti-GXM foram quantificados por ELISA e expressos por densidade óptica (DO). IgG anti GXM foi detectado em todos os grupos com diferença significante entre eles (P= 0,0127). As médias de IgG anti- GXM (DO) foram: 1.191 (0,49 a 1.217) no grupo 1, 1.572 (0,815 a 2.479) no grupo 2 e 0,965 (0,321 a 1.295) no grupo 3. Dois indivíduos assintomáticos do grupo 2 tiveram títulos de GXM detectáveis (1/256 e 1/32). Quatro pacientes com neurocriptococose faleceram (19%) e seus resultados mostravam: CH 50 normal, 2/4 tinham valores de AP 50 baixo (12 UI/mL) e indetectável; 3/4 tinham altos níveis de MBL e apenas um tinha baixa DO de IgG anti-GXM. Baseado em nosso estudo, podemos concluir que a resposta humoral (sistema complemento e anticorpos) não é suficiente para explicar a susceptibilidade a neurocriptococose, porém a alta e constante exposição ao Cryptococcus sp pode prevenir o desenvolvimento de doença, ou seja, a constante e intensa exposição ao fungo induz a produção de anticorpos que previnem a doença clínica mas não a infecção. Por outro lado fatores genéticos que determinam as concentrações de MBL podem influenciar na susceptibilidade a neurocriptococose. Os anticorpos contribuem para o clearence de GXM, entretanto as concentrações séricas não se correlacionam com resistência à doença / Cryptococcus sp is a fungal pathogen with a worldwide distribution. Although it is ubiquitous in the environment, cryptococcal disease occurs predominantly in immunocompromised hosts and can also occur in apparently immunocompetent individuals. The innate immunity is of special relevance for the antifungal reaction, as it allows an immediate reaction and recognizes a broad variety of fungal pathogens. The host immune response is a major determinant of the outcome of cryptococcal infection; however, the antibodies response is poorly understood. In addition, most of the studies are experimental and there is restricted knowledge concerning the human immune response. Complement system has soluble factors, restrictive regulator proteins and cellular receptors involved in defense mechanism. Glucuroxylomannan (GXM) monoclonal antibodies (MAbs) have numerous biological activities: a) opsonization for phagocytosis, b) activation of the classical complement pathway leading to early deposition of C3 fragments on the yeast, c) suppression overall accumulation of C3 via the alternative pathway; d) clearance facilitation of GXM from serum in vivo, leading to increased accumulation of GXM in tissues rich in mononuclear phagocyte system; e) protection in murine models of cryptococcosis and f) facilitation of various aspects of cellular immunity to Cryptococcus sp. The goal of our study was to evaluate if the antibody response to GXM and cell wall proteins regarding specific antibodies as well as complement system in sera of immunocompetent adults with and without neurocryptococcosis. The aim of our research was to evaluate classical and alternative complement system pathway, to quantify mannose-binding lectin (MBL) as well antibody response to GXM and cell wall proteins (AgS) regarding specific antibodies in sera of immunocompetent adults with and without neurocryptococcosis. One hundred and six samples were collected and classified in 3 groups: group 1- 21 individuals with neurocryptococcosis and low exposure to the yeast; group 2- was composed by 23 healthy individuals, chicken farmings from Jurumirim, a town 164 km to São Paulo, and with high exposure to Cryptoccocus spp and HIV negative. The third group included 60 healthy HIV negative individuals with presumed low exposure to Cryptococcus. Two patients were excluded by report of previous malignancies (timoma and pulmonary cancer). The complement system was evaluated by hemolytic assay and ELISA to MBL. CH 50 and AP 50 values were within the normal range in 17/21; 13/23; 59/60 patients in groups 1, 2 and 3 respectivelly. Mean CH 50 values were significantly different among the three groups (P < 0,0001). Group 2 showed significantly reduced levels in comparison with groups 1 and 3. AP 50 values were within the normal range in 11/21; 21/23; 60/60 patients in groups 1, 2 and 3 respectivelly. There was difference in the AP 50 values (P=0,0005) and one no activation of this pathway in group 1. There was significant difference in MBL among the groups (P = 0,0277). GXM antibodies IgG was measured by ELISA and expressed as optical density (OD). GXM- IgG was detected in all the groups with significant difference among them (P = 0,0127). The means of IgG anti-GXM (OD) were: 1.191 (range 0,49 to 1.217) in group 1, 1.572 (range 0,815 to 2.479) in group 2 and 0,965 (range 0,321 to 1.295) in the group 3. Two of the group 2 individuals had low GXM titers (1/256 and 1/32) and no symptoms. Four patients (4/21; 19%) with neurocryptococcosis died and the results showed: normal classical pathway activation, 2/4 had low (12 UI/mL) or undetectable alternative pathway values ; 3/4 had high MBL concentrations and only one had low OD for IgG anti-GXM. In conclusion, our results suggest that constant and high exposure to Cryptococcus sp can prevent the development of cryptococcosis, i.e. constant and intensive fungal exposition induces protective antibodies to clinical disease but not to the infection. In the other side, genetic factors which determine MBL concentrations could influence the susceptibility to neurocryptococcosis. The antibodies contribute to GXM clearance, however, the concentrations did not correlate with the resistance to the disease

Proteins that recognise the sugar surface structures on cells have an enormous potential to be used as tools in the characterisation of these structures. A group of proteins, called lectins, have been identified that can bind to carbohydrate complexes on the receptors of cells. The crude extract from Grevillea robusta seeds was found to contain lectin-like proteins that were different from most other lectins, as they would specifically target the receptors of white blood cells and not those found on red blood cells. Therefore, the lectin isolated from G.robusta could be used as a tool to identify the specific surface structures on white blood cells. The lectin was isolated using affinity chromatography where a complex (oligosaccharide) matrix was used. Agglutination, binding and sugar inhibition assays confirmed the isolated protein was a lectin. The lectin was found in low amounts (up to 5% of the total protein content) within the seeds of G.robusta. As a result of this low yield, the identification of the lectin by PAGE was difficult because the levels of protein were beyond the detection limit of the commercial staining reagents. The lectin was called the GR2 protein and was characterised as a monocot mannose binding lectin based on its sugar specificity for only mannose. A serine protease inhibitor was isolated from the seeds of G.robusta using two different chromatography methods, reverse phase HPLC (GR1.HPLC) and gel filtration chromatography (GR1.GF). Ion exchange chromatography was used to initially separate the proteins in the crude extract and the fraction containing the GR1 protein was further purified using reverse phase HPLC (GR1.HPLC). N-terminal sequencing results of the GR1.HPLC protein, showed evidence of proteolytic cleavage during the extraction process, which lead to the second purification method being established. Protease inhibitors were added to the buffers prior to being purified by gel filtration chromatography, which resulted in the GR1 protein being isolated from the crude extract without the presence of the contaminating protein. Mass spectroscopy identified the molecular weight of the GR1 protein to be 6669Da and the full amino acid sequence was derived by cDNA techniques. Sequence alignment studies of the GR1 protein showed significant similarities with the Bowman-Birk inhibitor. The positioning of the cysteine residues were conserved throughout the Bowman-Birk superfamily, however these residues were not conserved within the GR1 protein. Competitive inhibition assays on the GR1 protein revealed the protein could inhibit both trypsin and chymotrypsin at similar levels to that seen for the Bowman-Birk inhibitor. Therefore, the GR1 protein was characterised as a member of the Bowman-Birk superfamily of serine protease inhibitors. The three-dimensional structure of the GR1 protein was determined using two-dimensional NMR spectroscopy. Computer programs such as XEASY, DYANA and SYBYL® were used to tabulate the information taken from the 2D experiments, generate structures and minimise these structures respectively. The solution structure of the GR1 protein was found to contain a region of antiparallel β-sheet structure that corresponded to the trypsin binding site and the remainder of the protein consisted of loops and turns that were held together by disulfide bridges (the chymotrypsin-binding region). Structural similarities between the GR1 protein and the Bowman-Birk inhibitor existed only in the trypsin-binding site of the Bowman-Birk inhibitor. The GR1 protein is the first member of the Proteaceae family to be characterised as a Bowman-Birk inhibitor. This thesis outlines the isolation and biochemical characterisation of the two proteins found within Grevillea robusta and also describes the steps involved and results obtained in determining the three-dimensional structure of the GR1 protein.

Aus hämatopoetischen Stammzellen (HSCs) können sich neben allen anderen Zellen des Immunsystems auch dendritische Zellen (DCs) entwickeln. DCs spielen eine zentrale Rolle sowohl bei der Induktion von Immunantworten als auch bei der Aufrechterhaltung peripherer Toleranz. Eine Beeinflussung von DCs zur therapeutischen Nutzung wäre wünschenswert, erfordert aber ein noch tieferes Verständnis über deren Entwicklung im humanen Organismus. Das erste Ziel dieser Arbeit war die Charakterisierung potentieller DC-Vorläuferzellen in humanen lymphatischen Geweben. In Immunfluoreszenzaufnahmen von Thymus, Milz und Tonsillen mit Stammzell-charakterisierenden Markern konnten sowohl die in der Literatur als „Hämatopoetisches Stammzellkompartiment“ beschriebene Zellpopulation als auch weitere Zwischenstufen der Entwicklungsreihe der HSCs detektiert werden. Als Nächstes wurde untersucht, ob die im Gewebe identifizierten CD34+ Zellen in der in vitro Kultur zu DCs differenziert werden konnten. Hierzu wurden zunächst Protokolle etabliert und weiterentwickelt, in denen CD34+ Stammzellen des Nabelschnurbluts zu DCs gereift wurden. In einem anschließenden Schritt wurde das Protokoll mit den besten Ausbeuten an DCs auf Thymuszellen angewendet. Somit gelang es, aus Thymusstammzellen eine DCSubpopulation zu generieren, die aufgrund ihrer Markerexpression den Langerhanszellen ähnelt. Auf ihnen konnten außer Langerin auch andere C-Typ Lektinrezeptoren (Clec9a, DCIR und CD205) detektiert werden. Diese Zellen sind daher interessante Ziele für Untersuchungen zur Antigenbeladung von DCs und deren Präsentation an das adaptive Immunsystem. Zur effektiven Antigenbeladung von DCs werden Antikörper gegen endozytotisch wirksame Oberflächenmoleküle benötigt. Für deren Produktion wurden im weiteren Verlauf der Arbeit His-tragende und Ig-Fusionsproteine von Clec9a, Langerin, Dectin-1 und Dectin-2 produziert, um diese zur Immunisierung und Antikörperproduktion einzusetzen. In Zukunft können diese Antikörper zur Charakterisierung verschiedenster DC-Subpopulationen und außerdem zur Antigenbeladung von DCs herangezogen werden.

Endotoxin or Lipopolysaccharide (LPS) is the invariant structural component of gram negative bacterial outer membranes and is the chief causative factor of Sepsis or endotoxic shock. Sepsis is a syndrome that has very high mortality rates even in this age of excellent therapeutics and critical patient care. The treatment for sepsis till date remains nonspecific and supportive due to lack of effective anti-endotoxic drugs. Sepsis is initiated when the circulating bacteria shed LPS from their cell envelopes. Shed LPS aggregates are recognized by LPS binding proteins and receptors, which activate the host's immune system. Uncontrolled and excessive stimulation of the host's immune system precipitates endotoxic shock which in advanced cases involving multiple system organ failure inevitably lead to patient's death. Many strategies have been tested out to combat this deadly affliction. One of the attractive clinical modalities in sepsis treatment is the use of peptides as LPS sequestering anti-endotoxic drugs. A classical peptide antibiotic of this class is Polymyxin B (PMB) a cyclic cationic acylated molecule, that recognizes LPS with a very high affinity. This thesis describes kinetics and thermodynamics of PMB-LPS interactions and applies these parameters over a framework of different models so as to gain insights into the structure-function relationships that govern the interactions of this peptide with endotoxin(s). Classical biophysical techniques like fluorescence, circular dichroism spectroscopy, stopped flow kinetics, titration calorirnetry (ITC) and the relatively new technique of Surface Plasmon Resonance (SPR) have been employed to dissect out the mechanism of the range of non-covalent forces that are involved in peptide-endotoxin recognition. Certain proteins that exhibit LPS binding activity have also been studied to gains insight about their mode of action. Implications of these studies for designing peptides that have better anti-endotoxic properties are also highlighted. The first chapter introduces and highlights the clinical features of sepsis. It also attempts to shed light on the LPS mediated signal transduction pathway that leads to endotoxic shock. This chapter also briefly explains the roles of many LPS receptors that are present in the human system and their specific roles in the signal transduction pathways. The second part of this chapter deals with the role of cationic peptides as anti-endotoxic drugs. Certain key functional aspects of these peptides, which impart in them, the desirable property of LPS recognition have also been discussed The second chapter describes the kinetic studies undertaken to unravel the exact mechanism of LPS-PMB interaction. The studies reveal that PMB recognizes LPS in a biphasic manner, with the second, unimolecular isomerization step of the reaction being the rate-limiting step. The initial reaction is shown to be influenced by the presence of salt in the reaction medium. The dissociation phase of this interaction also shows a biphasic pattern. These data allow us to speculate upon the exact mechanism by which PMB is able to recognize LPS. The studies also shed light on some structural aspects that govern and confer such high LPS binding activity to PMB. Based on these a model has been proposed to explain this recognition (C.J. Thomas et al, 1998). The second chapter discuses the mode of action of various PMB analogs. These analogs have been chosen in terms of their mode of action as well as their structural similarly to PMB. The affinities of these analogs to LPS and lipid A were quantified using the Surface plasmon resonance (SPR) method. SPR, a technique that relies on the quantification of change in mass during a binary binding process occurring between an immobilized entity and a flowing ligand, is a rapid and sensitive method to measure biologically relevant interactions. SPR studies provide us with the binding constants and thermodynamic parameters that allow evaluation of the affinities of these peptides towards LPS (C.J.Thomas and A.Surolia, 1999). The third chapter discusses a hitherto unknown mode by which PMB acts on a LPS lamellae. The results of this study wherein the binding affinities of PMB and its analogs were performed on monolayers and tethered liposomes, show that PMB is able to remove specifically LPS or lipid A from monolayers or bilayer assemblies such as tethered liposomes. The exact mode of action of PMB is deciphered in the light of these new studies, which allow us to posit on the observed efficacy of PMB in neutralizing the endotoxin as compared to peptides with nearly similar affinities for LPS (C.J Thomas et al 1999). In the fourth chapter a series of 23 residue peptides, based on the sequence corresponding to the anti-sense strand of magainin gene have been synthesized. Magainin an amphiphilic helical peptide obtained from frog skins plays a vital role in the innate immune defense mechanisms of these organisms. It also exhibits LPS binding activity that makes it an attractive target as an anti-endotoxic drug. Biochemical and biophysical characterization of these peptides reveal that they have the tendency to perturb both the inner and the outer membranes of E.coli. The peptides are amphiphilic and have helical structure in a membrane bound environment. Three of the peptides tested have high affinities for lipid A that approach the values shown by PMB. The kinetic parameters obtained by stopped flow and SPR studies in conjunction with the therrnodynamic parameters obtained using ITC studies allow us to highlight the key structural features that need to be exhibited by peptides that are designed to be LPS recognizers. The studies also project the fact that ionic forces play an important role in the initial recognition of LPS by these peptides. Fortification of the might of these ionic charges increases affinity for LPS where as the hydrophobic residues that interact at the next phase of binding are more amenable to disruptions in contiguity. These factors are discussed using the helical wheel diagram that shows the clear amphiphilicity displayed by these peptides. (C.J Thomas et al Manuscript under preparation, 2000) Chapter six discusses the mode of action of certain LPS binding proteins. Limulus anti endotoxic factor (LALF) plays a vital role in the innate immune based defense systems of the horseshoe crab. Galectin-3 is a metal ion independent, galactosc binding Icctin of human origin with unknown functions. Both these phylogcntically-unrclatcd proteins exhibit LPS/lipid A recognizing properties. ITC and SPR studies have been used to determine the binding constants displayed by these proteins for lipid A. LALF bind to lipid A with very high affinity than compared to Galectin-3 and is also able to take away selectively lipid A from both monolayers and tethered liposomes. Galectin-3 does not show this property of LALF, which might account for its lowered affinities. Also structurally LALF has amphiphilic nature that confers high lipid A binding activity, which is clearly lacking in Galectin-3. These studies in conjunction with the knowledge gained from the study of LPS-PMB interaction stress on the importance of amphiphilicity in LPS recognition. (C.J Thomas et al Manuscript under preparation, 2000). The final chapter is a general discussion that attempts to collate all these kinetic and thermodynamic observations in the pursuit of designing small easily manipulatable peptides that exhibit high LPS binding activity. These studies are aimed to act as rough guidelines to the design of LPS sequestering peptides that might have better therapeutic and pharmacokinetic properties. The appendix to the main body of work presented in thesis are two pieces of work pertaining to the elucidation the kinetics and mechanism of sugar lectin interactions, when sugars are presented as glycolipids in monolayers or bilaycrs liposomes. Mode of the presentation of sugars at cell-surfaces in the form of glycolipids as ligands influence their recognition by macromolecular receptors like lectins. Appendix 1 is a study of the mode of action of Ulex europeus I lectin binding to H-fucolipid containing tethered liposomes, by SPR. Fucosylated sugars are often used as key markers in histochemical analysis of malignant cancerous tissues. Ulex lectin plays a vital role as a marker for identification of these tissues. The kinetics and thermodynamic parameters that are obtained in this study throw some light on the mode of recognition of glycolipid receptor by Ulex europeus I lectin (C.J Thomas and A. Surolia 2000). Appendix 2 is a study, that attempts to quantify the initial kinetic parameters that correlate the recognition of glycolipid receptors with their inclination at the membrane surface and the influence of charge on them by soyabean agglutinin (SBA), Abrus agglutinin I and II. Studies on the soyabean agglutinin-globoside interaction highlights the divalent cation mediated reorientation of these receptors on their accessibility and recognition to the agglutinin. The divalent cations are speculated to orient the oligosaccharide head groups in a spatial geometry that allows a heightened kinetics of their interaction by SBA. These studies reveal that the reorganization of the binding pocket of a lectin can also have a profound influence on ihc rates of recognition of a glycospingolipid ligand by a lectin as exemplified by Abrus agglutinin II- GM1 interactions (C.J Thomas ct al, Manuscript under preparation).

Les progrès réalisés en immunologie ont orienté les recherches vers des approches et des stratégies de plus en plus prometteuses et innovantes afin de mieux manipuler la réponse immunitaire. Le but de nos recherches est la prévention et le traitement des maladies liées aux dysfonctionnements du système immunitaire, telles que les maladies auto-immunes, inflammatoires et malignes. Bien que l'inflammation constitue un processus physiologique indispensable au maintien de l'homéostasie suite à une infection ou à une lésion, elle est également associée à des pathologies infectieuses, auto-immunes et tumorales. Les stratégies thérapeutiques les plus utilisées pour traiter l'inflammation sont basées sur la neutralisation des médiateurs inflammatoires par des anticorps, des antagonistes moléculaires, des immunoglobulines intraveineuses, des corticostéroïdes, des médicaments anti-inflammatoires non stéroïdiens. En plus des traitements mentionnés, des produits issus de la phytothérapie ont été largement utilisés afin d'atténuer l'inflammation et la douleur dans plusieurs maladies inflammatoires et dans le cancer. Depuis des décennies, les préparations de Viscum album, connu sous le nom de " gui européen ", sont largement utilisées dans le traitement du cancer comme thérapie auxiliaire. Bien que les mécanismes d'action soient partiellement connus, plusieurs hypothèses ont été proposées. En effet, les mécanismes anti-tumoraux du Viscum album impliquent des propriétés induisant une cytotoxicité, l'apoptose, l'inhibition de l'angiogenèse et plusieurs autres mécanismes immunomodulateurs. Ce travail décrit un nouveau mécanisme anti-inflammatoire de Viscum album, qui participe à l'effet thérapeutique de ces préparations. De plus, l'effet bénéfique anti-inflammatoire observé est associé à l'inhibition des voies pro- inflammatoires de COX2 et PGE2 dans les cellules épithéliales issues d'adénocarcinome du poumon. Ce travail a identifié un des mécanismes moléculaires de Viscum album associé à son effet anti-inflammatoire participant à ses bénéfices thérapeutiques. Ainsi, ces préparations pourraient être utilisées en combinaison avec d'autres traitements dans des maladies inflammatoires et dans le cancer.

Dendritische Zellen (DCs) sind befähigt, als potenteste Antigen-präsentierende Zelle anti¬genspezifische Immunantworten zu initiieren und zu regulieren. Mittels in vivo Antigen¬beladung von spezifischen DC-Subpopulationen mit rekombinanten Antigen-gekoppelten Antikörpern gegen C-Typ-Lektinrezeptoren konnte im Mausmodell erfolgreich adaptive zelluläre und humorale Immunantworten hervorgerufen werden. Im Menschen kann dieser Ansatz therapeutisch noch nicht zum Einsatz kommen, da DC-Subpopulationen im humanen Gewebe momentan nicht ausreichend charakterisiert sind. Im Rahmen dieser Arbeit wurden humane Gewebe auf das Vorhandensein der im peripheren Blut beschriebenen DC-Subpopulationen (mDC-1 DCs: CD11c+BDCA1+, mDC-2 DCs: CD11clowBDCA3+ und pDCs: CD11c-CD123+BDCA2+) und die Expression von C-Typ-Lektinrezeptoren (DC-SIGN, MMR, Langerin, DCIR und DEC205) mittels Immun¬fluoreszenz untersucht. Anhand der vorge¬gebenen Marker im peripheren Blut konnten alle drei DC-Subpopulationen in der Milz, Thymus und Tonsillen detektiert werden. Zusätzlich konnte hier erstmalig eine vierte CD11c-CD123-BDCA2+ pDC-2 DC-Subpopulation in der Milz beschrieben werden, deren Funktion derzeit noch näher untersucht wird. Im Thymus konnte CD26 nach FACS-Analysen von Gordon Heidkamp als spezifischer Marker für mDC-2 DCs identifiziert und dies in der vorliegenden Arbeit auch durch Immun¬fluores¬zenzaufnahmen von Gewebeschnitten verifi¬ziert werden. CD26 stellt damit erstmalig einen Marker dar, der erfolgreich als alternativer Marker für BDCA3, welcher unspezifisch an Thrombomodulin bindet, zur Identifikation von mDC-2 DCs in der Immunfluoreszenz von Thymusproben eingesetzt werden könnte. Die getesteten Anti¬körper XCR-1 (monoklonal) und Clec9a (polyklonal) hingegen erschienen in der Immun¬fluoreszenz sowie in FACS-Analysen (Gordon Heidkamp) nicht geeignet. Weiterhin wurde die Expression ausgewählter C-Typ-Lektinrezeptoren (MMR, Langerin, DCIR, DC-SIGN und DEC205) im vorhandenen Gewebe näher betrachtet. Nach Auswertung der Immun¬fluoreszenzen konnte eine weit verbreitete Expression der untersuchten C-Typ-Lektin¬rezeptoren in humaner Milz und Thymus gefunden werden. Einzig hDCIR war auf vereinzelten Zellen exprimiert, und Langerin im Thymus nicht detektierbar. Um nicht verfügbare monoklonale Antikörper gegen C-Typ-Lektinrezeptoren zu produzieren und später Antigene an diese koppeln zu können, sollten lösliche Proteine einiger C-Typ-Lektinrezeptoren (humanes und murines Clec9a, Dectin-1 und -2, Langerin) produziert werden. Dabei gelang es bereits, lösliche Proteine der C-Typ-Lektinrezeptoren von humanem und murinem Dectin-1 zu generieren und diese zur weiteren Antikör¬per¬produktion einzusetzen.

Submitted by Leonardo Cavalcante (leo.ocavalcante@gmail.com) on 2018-04-23T23:19:25Z No. of bitstreams: 1 Arquivototal.pdf: 1967881 bytes, checksum: 7ca8d86d26370955fcc5937ad9344abc (MD5) / Made available in DSpace on 2018-04-23T23:19:25Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 1967881 bytes, checksum: 7ca8d86d26370955fcc5937ad9344abc (MD5) Previous issue date: 2017-05-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Sesbania virgata is a shrub belonging to a family Leguminosae whose fruit presents seeds with high protein content. Considering the potential of use of this species as a biotechnological tool, the objective this paper was to characterize the seeds of S. virgata (Cav.) Pers., as well as evaluate extracts and fractions for a presence of some biological activities of medical and pharmacological interest. For this, S. virgata seeds were collected in the city of João Pessoa, Paraíba, and had their morpho-physical-chemical characteristics determined. Afterwards, the seeds were delipidated, processed and solubilized in extractive solutions, obtaining 30 extracts and 10 protein fractions, allowing a characterization of the antinutritional factors; protein and amino acid profile; and biological activities. The nutritional characteristics of the seed flour emphasize its high protein content. The optimization of the production of extracts and fractions allowed obtaining the total crude extract (EBT), purification of the protein fraction with lectin activity (FPAL) and the determination of several antinutritional factors. The protein analyzes revealed 60.79% of total protein for the fine flour (FF), 49.34% for EBT and 55.84% for FPAL. With molecular weights between 31-225 kDa, FF, EBT and FPAL presented antioxidant activity. However, they did not present antibacterial activity against the strains investigated, but promoted the inhibition of Candida albicans, C. tropicalis, Aspergillus flavus and Penicillium citrinum. In addition to the high protein content and biological activities, it is important to incorporate new analyzes into the products so that, in the future, they will be viable in the food or pharmaceutical industry, by creating of topical drugs to control fungal contamination or reduction of the damage caused to human health by free radicals and other oxidants. / Sesbania virgata é um arbusto pertencente a família Leguminosae, cujo fruto apresenta sementes com elevados teores proteicos. Considerando o potencial de uso dessa espécie como ferramenta biotecnológica, objetivou-se caracterizar nutricional, antinutricional e bioquimicamente as sementes de Sesbania virgata (Cav.) Pers., bem como avaliar extratos e frações proteicas quanto a presença de algumas atividades biológicas de interesse médico e farmacológico. Para tal, sementes de Sesbania virgata foram coletadas na cidade de João Pessoa, Paraíba, e tiveram suas características morfo-físico-químicas determinadas. Posteriormente, as sementes foram delipidadas, processadas e solubilizadas em soluções extratoras, obtendo-se 30 extratos e 10 frações proteicas, permitindo a caracterização dos fatores antinutricionais, do perfil proteico e aminoacídico, e atividades biológicas. As características nutricionais da farinha enfatizaram seu elevado teor protéico. A otimização da produção dos extratos e frações permitiu a obtenção do extrato bruto total (EBT), a purificação da fração proteica com atividade lectínica (FPAL) e a determinação de fatores antinutricionais diversos. As análises proteicas revelaram 60,79% de proteína total para a farinha fina (FF), 49,34% para EBT e 55,84% para FPAL. Com massas moleculares entre 31-225 kDa, FF, EBT e FPAL apresentaram atividade antioxidante. Contudo, não apresentaram atividade antibacteriana contra as cepas investigadas, mas promoveram a inibição de Candida albicans, C. tropicalis, Aspergillus flavus e Penicillium citrinum. Ressalta-se, além do elevado teor proteico e atividades biológicas apresentados, a importância em incorporar novas análises aos produtos para que, futuramente, apresentem viabilidade de implementação na alimentação ou na indústria farmacêutica, mediante criação de fármacos tópicos para controle da contaminação fúngica ou redução dos danos causados à saúde humana pelos radicais livres e outros oxidantes.

GONÇALVES, Nidyedja Goyanna Gomes. Ação da lectina de Dioclea altissima sobre células tumorais: Citotoxidade e Perfil Proteômico da Linhagem PC3M. 2012. 106 f. Dissertação (Mestrado em Bioquímica)-Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-06-27T12:21:35Z No. of bitstreams: 1 2012_dis_ngggoncalves.pdf: 5791111 bytes, checksum: 5bb7d007364d7c5364b8faa3b419bf9c (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T20:07:30Z (GMT) No. of bitstreams: 1 2012_dis_ngggoncalves.pdf: 5791111 bytes, checksum: 5bb7d007364d7c5364b8faa3b419bf9c (MD5) / Made available in DSpace on 2016-08-02T20:07:30Z (GMT). No. of bitstreams: 1 2012_dis_ngggoncalves.pdf: 5791111 bytes, checksum: 5bb7d007364d7c5364b8faa3b419bf9c (MD5) Previous issue date: 2012 / Recently, plant lectins have attracted great interest due to their several biological activities of which stands out the antitumoral action in vivo and in vitro that in general result in inhibition of cell growth and induction of cell death by apoptosis. In the present study, it was investigated the effect of the Dioclea altissima (DAL) lectin, a legume alfa-D-mannose ligand lectin on A549 (lung cancer), OVCAR-8 (ovarian cancer) and PC3M (prostate cancer) and normal line PBMC (cell blood tissue). DAL was isolated and purified by affinity chromatography on a Sephadex G-50 column and its cytotoxicity was evaluated by MTT assay. DAL was selectively cytotoxic to cancer cells A549, PC3M after 48 and 72 hours of incubation, and OVCAR-8 after 72 hours of treatment with DAL (CI50 values between 23.0 e 55.7 μg/mL). Moreover, it was observed cell agglutination from 24 hours of incubation. Comet assay revealed DAL does not cause direct DNA damage. The line PC3M was selected for proteomic analysis by mass spectrometry (nanoUPLC® nanoESI-MSE) to present the best evidence of sensitivity to DAL. PC3M line was treated with various concentrations of DAL during 24, 48 e 72 hours, it was identified a total of 837 proteins, 140 (24h), 321 (48h) e 376 (72h). The study of differential protein expression of the DAL-treated PC3M cells compared to control demonstrated apoptotic effect generated, mainly, via ER stressed-dependent. / Nas últimas décadas, as lectinas vegetais têm atraído grande interesse devido às suas diversas atividades biológicas das quais se destaca a ação antitumoral in vivo e in vitro que, em geral, causa a inibição do crescimento celular e a indução da morte celular por apoptose. No presente estudo, foi investigado o efeito da lectina de Dioclea altissima (DAL), uma lectina de leguminosa, alfa-D-manose ligante, sobre as linhagens tumorais A549 (carcinoma pulmonar), OVCAR-8 (carcinoma de ovário) e PC3M (carcinoma de próstata) e linhagem normal CMSP (células do tecido sanguíneo). DAL foi isolada e purificada por cromatografia de afinidade em coluna de Sephadex G-50 e sua citotoxicidade foi avaliada através do ensaio do MTT. DAL foi seletivamente citotóxica para as células cancerígenas A549, PC3M, após 48 e 72 horas de incubação, e para OVCAR-8, após 72 horas de tratamento apresentando valores de CI50 entre 23,0 e 55,7 μg/mL, promovendo aglutinação celular a partir de 24 horas de incubação. DAL não se mostrou citotóxica para células normais. O teste do cometa revelou que DAL não causa dano direto ao DNA. A linhagem PC3M foi selecionada para análise proteômica por espectrometria de massas (nanoUPLC® nanoESI-MSE) por apresentar maior sensibilidade à DAL. Após tratamento das células com diversas concentrações de DAL, por 24, 48 e 72 horas, foi identificado um total de 837 proteínas válidas, 140 (24h), 321 (48h) e 376 (72h). O estudo das proteínas diferencialmente expressas das células tratadas com a lectina em relação ao controle definiu o efeito citotóxico de DAL em PC3M como apoptótico gerado, principalmente, via estresse do retículo endoplasmático.

Abstract Respiratory tract infections are the most common acute illnesses, and innate immunity and inflammation are important in defence against these infections. Mannose-binding lectin (MBL) mediates innate immune defences by recognising microbial structures. MBL deficiency caused by polymorphisms in the MBL2 gene has been associated with susceptibility to recurrent infections. Interleukin-6 (IL-6) is a mediator of inflammatory response. Polymorphisms in the IL-6 and IL-6 receptor (IL-6R) genes have been previously associated mainly with metabolic disorders and cardiovascular diseases. Chlamydia pneumoniae is a common pathogen in acute respiratory tract infections, but it also has a tendency to cause persistent infections, which have been associated with cardiovascular diseases and its risk factors, such as obesity. The aims of this study were to investigate if selected polymorphisms of the MBL2, IL-6 and IL-6R genes are associated with respiratory tract infections and markers of C. pneumoniae infection, and to study if persistent C. pneumoniae infection is connected with an elevated body mass index (BMI) in 893 Finnish male military conscripts. Respiratory tract infections were followed during their military service and serum samples were collected at the beginning and end of their service and during each infectious episode. A variation in serum MBL levels between different MBL2 genotypes and a MBL deficiency in homozygous exon 1 variant genotypes (at codons 52, 54 and 57) were observed. Low MBL levels and MBL2 polymorphisms in exon 1 and promoter region were found to be risk factors for susceptibility to respiratory tract infections as well as for positivity and a rise in C. pneumoniae antibodies during military service. Associations between IL-6R gene polymorphisms in the promoter region (-183G/A) and in intron 1 and respiratory tract infections were found. In addition, the IL-6 -174G/C polymorphism was associated with persistently elevated C. pneumoniae antibodies and with slightly elevated serum C-reactive protein (CRP) levels, pointing to chronic C. pneumoniae infection. Furthermore, persistent C. pneumoniae antibodies as a suggestive marker of chronic infection, and elevated serum CRP levels as a marker of systemic inflammation, were associated with an elevated BMI. In conclusion, the findings support the role for MBL in susceptibility to infections and provide new information about the association between MBL and common respiratory tract infections. The results also suggest that the 5’ area of the IL-6R gene may be a possible candidate region for respiratory tract infection susceptibility, and that IL-6 genetics may be associated with C. pneumoniae infection. The study also provides new information about the role of possible chronic C. pneumoniae infection in obesity. / Tiivistelmä Hengitystieinfektiot ovat yleisimpiä äkillisiä sairauksia, ja synnynnäisellä immuunivasteella ja tulehduksella on tärkeä rooli puolustuksessa näitä infektioita vastaan. Synnynnäiseen immuniteettiin kuuluva mannoosia sitova lektiini (MBL) tunnistaa infektioita aiheuttavien mikrobien rakenteita. MBL2-geenin polymorfismien aiheuttaman MBL-proteiinin puutteen on todettu altistavan toistuville infektioille. Interleukiini-6 (IL-6) on tulehduksen välittäjänä toimiva sytokiini. IL-6- ja IL-6-reseptori (IL-6R) -geenien polymorfismit on aikaisemmin yhdistetty lähinnä metabolisiin häiriöihin sekä sydän- ja verisuonitauteihin. Chlamydia pneumoniae eli keuhkoklamydia on yleinen hengitystieinfektioiden aiheuttaja, mutta se voi myös aiheuttaa kroonisia infektioita, jotka on yhdistetty sydän- ja verisuonitauteihin sekä niiden riskitekijöihin kuten lihavuuteen. Työn tarkoituksena oli tutkia tiettyjen MBL2-, IL-6- ja IL-6R-geenien polymorfismien yhteyttä hengitystieinfektiohin ja keuhkoklamydiavasta-ainetasoihin sekä keuhkoklamydiainfektion yhteyttä painoindeksiin 893 suomalaisella varusmiehellä. Hengitystieinfektioita seurattiin palveluksen aikana, ja seeruminäytteet kerättiin palveluksen alussa, lopussa ja jokaisen infektion aikana. Tutkimuksessa havaittiin vaihtelua seerumin MBL-pitoisuudessa eri MBL2-genotyyppien välillä sekä MBL:n puute homotsygooteissa eksoni 1 -alueen varianttigenotyypeissä (kodoneissa 52, 54 ja 57). Alhaiset MBL-tasot sekä MBL2-geenin polymorfismit eksoni 1 -alueella ja säätelyalueella olivat riskitekijöitä hengitystieinfektioalttiudelle sekä keuhkoklamydiavasta-aineiden esiintymiselle ja vasta-aineiden nousulle palveluksen aikana. IL-6R-geenin polymorfismit säätelyalueella (-183G/A) ja introni 1 -alueella liittyivät hengitystieinfektioihin. Lisäksi IL-6-geenin -174G/C polymorfismi oli yhteydessä jatkuvasti kohonneisiin keuhkoklamydiavasta-aineisiin sekä seerumin C-reaktiivisen proteiinin (CRP) tasoihin, jotka mahdollisesti osoittaisivat kroonista keuhkoklamydiainfektiota. Lisäksi krooniseen keuhkoklamydia-infektioon viittaavat vasta-ainetasot sekä tulehdukseen liittyvä kohonnut CRP-pitoisuus olivat yhteydessä ylipainoon. Tutkimuksen tulokset tukevat aikaisemmin havaittua MBL:n vaikutusta infektioalttiuteen ja lisäksi antavat uutta tietoa MBL:n yhteydestä tavallisiin hengitystieinfektioihin. Tulokset viittaavat myös siihen, että IL-6R-geenin 5’-alueella voi olla yhteyttä hengitystieinfektioalttiuteen ja että IL-6-polymorfismi olisi yhteydessä keuhkoklamydiainfektioon. Tutkimus antaa myös uutta tietoa mahdollisen kroonisen keuhkoklamydiainfektion liittymisestä ylipainoon.