A coleta de hemocomponentes por equipamentos de aférese tem aumentado muito nos últimos anos, sendo considerado um avanço na medicina transfusional, pois possibilita a retirada de um ou mais componentes de um doador único resultando em um hemocomponente padronizado e de alta qualidade. No entanto, os intervalos entre as doações de plaquetaférese em geral são curtos, podendo haver perda de células a cada doação e potencial desregulação do sistema hematopoiético. Pode ocorrer ainda um possível efeito patogênico após passagem das células pelo equipamento de aférese e ativação neutrofílica. Diante disso, há a preocupação se isso acarretaria riscos à saúde do doador em longo prazo. Objetivo: O objetivo deste estudo foi avaliar a perda da expressão de proteínas ancoradas ao glicosilfosfatidilinositol (GPI), presença de clone HPN (hemoglobinúria paroxística noturna) e ativação de neutrófilos em doadores de plaquetaférese de repetição. Métodos: Estudo de caso controle, sendo 44 amostras de doadores de plaquetaférese de repetição e 44 doadores de sangue total controle. Foram coletadas amostras de sangue periférico, marcadas com os anticorpos monoclonais CD157, CD45, CD64, CD10 e FLAER (do inglês, Fluorescent Aerolysin, aerolisina fluorescente) e analisadas por citometria de fluxo. Para análise de ativação de neutrófilos, foram analisadas 17 amostras de doadores de plaquetaférese de repetição e 17 amostras de doadores de sangue total marcadas com CD64. Conclusão: Não foram encontradas alterações significativas na expressão das proteínas ancoradas ao GPI e na expressão de CD64 entre os doadores de plaquetaférese de repetição e os controles. Sugere-se que a doação de plaquetaférese de repetição não altera a expressão de proteínas ancoradas ao GPI, não gera clone HPN tampouco altera a expressão de CD64. Palavras-chave: plaquetaférese, GPI, HPN, ativação de neutrófilos. / The collection of hemocomponents through apheresis equipment has increased much in recent years, which is considered an advance in transfusion medicine because it enables the withdrawal of one or more components from a single donor, resulting in a standardized and high-quality hemocomponent. Nonetheless, the intervals between the plateletpheresis donations are generally short, which can cause loss of cells in each donation and potential dysregulation of the hematopoietic system. What can also happen is a possible pathogenic effect after the transit of the cells through the apheresis equipment and neutrophilic activation. In light of this situation, there is the concern about whether that brings risks to the donor’s health, in the long term. Objective: the objective of this study was to evaluate the loss in the expression of some glycosylphosphatidylinositol-anchored (GPI-anchored) proteins, the presence of PNH clone and neutrophils activation in repeated plateletpheresis donors. Methods: Case-control study using 44 samples of donors of repeated plateletpheresis and 44 samples of donors of whole-blood donors as controls. Peripheral blood samples were collected into tubes containing EDTA, marked with CD157, CD45, CD64, CD10 and FLAER monoclonal antibodies, and analyzed by flow cytometry. For the analysis of neutrophil activation, 17 samples of repeated plateletpheresis donors and 17 samples of whole-blood donors, both marked with CD64 were analyzed. Conclusion: No alteration in the expression of glycosylphosphatidylinositol-anchored proteins and in the CD64 expression was found. It is suggested that repeated plateletpheresis donation does not alter the expression of GPI-anchored proteins, does not generate PNH clone and neither alters the expression of CD64.

A coleta de hemocomponentes por equipamentos de aférese tem aumentado muito nos últimos anos, sendo considerado um avanço na medicina transfusional, pois possibilita a retirada de um ou mais componentes de um doador único resultando em um hemocomponente padronizado e de alta qualidade. No entanto, os intervalos entre as doações de plaquetaférese em geral são curtos, podendo haver perda de células a cada doação e potencial desregulação do sistema hematopoiético. Pode ocorrer ainda um possível efeito patogênico após passagem das células pelo equipamento de aférese e ativação neutrofílica. Diante disso, há a preocupação se isso acarretaria riscos à saúde do doador em longo prazo. Objetivo: O objetivo deste estudo foi avaliar a perda da expressão de proteínas ancoradas ao glicosilfosfatidilinositol (GPI), presença de clone HPN (hemoglobinúria paroxística noturna) e ativação de neutrófilos em doadores de plaquetaférese de repetição. Métodos: Estudo de caso controle, sendo 44 amostras de doadores de plaquetaférese de repetição e 44 doadores de sangue total controle. Foram coletadas amostras de sangue periférico, marcadas com os anticorpos monoclonais CD157, CD45, CD64, CD10 e FLAER (do inglês, Fluorescent Aerolysin, aerolisina fluorescente) e analisadas por citometria de fluxo. Para análise de ativação de neutrófilos, foram analisadas 17 amostras de doadores de plaquetaférese de repetição e 17 amostras de doadores de sangue total marcadas com CD64. Conclusão: Não foram encontradas alterações significativas na expressão das proteínas ancoradas ao GPI e na expressão de CD64 entre os doadores de plaquetaférese de repetição e os controles. Sugere-se que a doação de plaquetaférese de repetição não altera a expressão de proteínas ancoradas ao GPI, não gera clone HPN tampouco altera a expressão de CD64. Palavras-chave: plaquetaférese, GPI, HPN, ativação de neutrófilos. / The collection of hemocomponents through apheresis equipment has increased much in recent years, which is considered an advance in transfusion medicine because it enables the withdrawal of one or more components from a single donor, resulting in a standardized and high-quality hemocomponent. Nonetheless, the intervals between the plateletpheresis donations are generally short, which can cause loss of cells in each donation and potential dysregulation of the hematopoietic system. What can also happen is a possible pathogenic effect after the transit of the cells through the apheresis equipment and neutrophilic activation. In light of this situation, there is the concern about whether that brings risks to the donor’s health, in the long term. Objective: the objective of this study was to evaluate the loss in the expression of some glycosylphosphatidylinositol-anchored (GPI-anchored) proteins, the presence of PNH clone and neutrophils activation in repeated plateletpheresis donors. Methods: Case-control study using 44 samples of donors of repeated plateletpheresis and 44 samples of donors of whole-blood donors as controls. Peripheral blood samples were collected into tubes containing EDTA, marked with CD157, CD45, CD64, CD10 and FLAER monoclonal antibodies, and analyzed by flow cytometry. For the analysis of neutrophil activation, 17 samples of repeated plateletpheresis donors and 17 samples of whole-blood donors, both marked with CD64 were analyzed. Conclusion: No alteration in the expression of glycosylphosphatidylinositol-anchored proteins and in the CD64 expression was found. It is suggested that repeated plateletpheresis donation does not alter the expression of GPI-anchored proteins, does not generate PNH clone and neither alters the expression of CD64.

Prostasin is expressed in normal prostate epithelial cells but down-regulated in prostate cancers, while prostasin re-expression in invasive prostate cancer cells reduced invasion. We examined prostasin expression and function in benign prostatic hyperplasia (BPH). We evaluated prostasin expression in 12 BPH specimens by immunohistochemistry, and evaluated the impact of prostasin silencing by siRNA on the expression of the inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), and cyclin D1, as well as on cell proliferation and invasion, using the BPH-1 human prostate epithelial cell line model. Prostasin expression was localized in the glands of BPH tissues by immunohistochemistry, in either the tall columnar-shaped or the flattened epithelial cells. We silenced prostasin expression by >50% at both the mRNA and protein levels using siRNA in the BPH-1 human prostate epithelial cell line, and this silencing of prostasin expression was associated with an induction of iNOS and ICAM-1 expression and a down-regulation of cyclin D1 expression. The protein expression of EGFR, a putative prostasin substrate, was not affected by prostasin silencing in this cell line. The prostasin-silenced cells displayed a reduced cell proliferation rate and reduced invasiveness, cell behaviors regulated by cyclin D1, iNOS, and ICAM-1 in the BPH-1 cells. We believe that this down-regulation of cyclin D1 is due to prostasin's augmentative effect on iNOS. We also believe that the decrease in cell motility is due to an increase in iNOS and ICAM-1 as well as a decrease in cyclin D1, since all of these molecules can play a role in cell motility. In conclusion, Prostasin is somehow involved in the regulation of inflammatory gene expression (iNOS and ICAM-1) in prostate epithelial cells, as well as cyclin D1 expression, cell proliferation and invasion, involving molecular mechanisms different than those in the prostate cancer cells. These studies suggest that prostasin is a player in the glandular components of benign prostatic hyperplasia.

No description available.

No description available.

Âncoras de glicosilfosfatidilinositol (GPI) são estruturas essenciais para a ancoragem de glicoconjugados e proteínas na superfície celular de protozoários. Trypanosoma cruzi produz uma gama de estruturas únicas de GPI, as quais ancoram mucinas e trans-sialidases, que participam de processos envolvidos na interação entre parasita e hospedeiro. Afim de estudar a biossíntese de âncora de GPI de T. cruzi e possivelmente utilizá-la como um potencial alvo anti-T.cruzi, este trabalho visa sintetizar análogos de âncoras de GPI e analisar o potencial destas moléculas como substratos da via biossintética de GPIs. Neste contexto, um pseudo-dissacarídeo 31 foi sintetizado através de O-glicosilação entre os doadores derivados de azido-glicopiranosídeo (32 ou 33a-d) e o acceptor de mio-inositol (34), preparados a partir de cloridrato de glucosamina (35) e metil-?-D-glucopiranósido (36), respectivamente, usando proteção/desproteção ortogonais. Cinco diferentes dadores de glicosídicos (32 e 33a-d) foram preparados para investigar a influcia dos seus grupos protetores na estereoselectividade da reações de O-glicosilação na presença de diferentes solventes para estudar o favorecimento da configuração ?, presente em GPIs. Ademais, a síntese do aceptor de mio-inositol 34 foi realizada em 12 etapas pela estratégia do rearranjo Ferrier para formar um derivado de ciclitol, além de diversas proteções/desproteções, funcionalizado que permite a introdução regiosselectiva da unidade de azido glicose (32-33a-d) e uma porção de fosfolípido no seu C-1 e posições C-6, respectivamente. Assim, O-glicosilação entre doador 33c e o acceptor 34, foi realizada utilizando TMSOTf como promotor para originar o composto 31c com boa estereoseletividade para ?, com elevado rendimento (~70%). Após a dealilação de 31c, a porção fosfodiéster contendo uma cadeia C-8 (87), preparada pela abordagem do H-fosfonato, foi anexada ao pseudo-dissacarídeo para gerar, após desprotecção global, o composto alvo 30a. A mesma estratégia sintética foi aplicada ao preparo do composto 91 contendo uma cadeia lateral alquil-naftil (90) que está em últmas etapas de desproteção para gerar o composto final 30c. Atualmente, o composto 30a está sendo testado como substrato da biossíntese de âncoras de GPI em membranas microssomais de Euglena gracilis, uma alga unicelular não patogênica, que pode potencialmente ser utilizada como modelo para parasitas humanos filogeneticamente relacionados. Após a incubação do potencial substrato de GPI 30a com membranas microssomais de E. gracilis para geração de metabólitos, será realizada análise do extrato por LC-MS e, eventualmente, isolamento dos produtos formados para posterior caracterização. Os produtos que apresentarem atividade como substrato ou como inibidores da biossíntese de GPI em E. gracilis serão também ensaiados na membrana microsomal do T. cruzi. / Glycosylphosphatidylinositol (GPI) anchors are essential molecules to attach glycoconjugates and proteins in protozoan\'s cell surface. Trypanosoma cruzi produces a range of unique GPI structures that anchor mucins and trans-sialidases which participate in important processes involved in the interaction between parasite and host. As an effort to study T. cruzi GPI anchor biosynthesis and possibly use it as a potential target for an antichagasic drug, this work aims to synthesize GPI anchor analogs (labelled or not) and analyze the potential of these molecules as substrates in the GPI biosynthetic pathway. In this context, a pseudo-disaccharide 31 was synthesized by O-glycosylation reaction between azide glycosyl donors (32 or 33a-d) and myo-inositol acceptor (34), prepared from glucosamine (35) hydrochloride and methyl ?-D-glucopyranoside (36), respectively, using orthogonal protection/ deprotection. Five different glycosyl donors (32 and 33a-d) were prepared to investigate the influence of their protective groups on the stereoselectivity of the O-glycosylation reaction in the presence of different solvents to afford the required GPI ?-linkage. In addition, the synthesis of the myo-inositol acceptor 34 was achieved using several protection/deprotection steps, besides the Ferrier rearrangement, to form a functionalized cyclitol derivative that enables the regioselective introduction of the azide glycoside unit and phospholipid moiety on its C-1 and C-6 positions, respectively. Then, O-glycosylation of acceptor 34 with donor 33c was accomplished in diethyl ether, using TMSOTf as promoter to give exclusively ?-anomer 31c in high yield. After deallylation of 31c, the phosphodiester moiety bearing an octyl chain (87), prepared by the H-phosphonate approach, was appended to the pseudo-disaccharide to yield, after deprotection, target compounds 30a. The same synthetic strategy was applied to the preparation of 30c, even though in the protective form, compound 91 bearing an alkyl-naphthyl side chain (90). Currently, compound 30a is being tested as substrates of GPI anchor biosynthesis in Euglena gracilis cell membranes, a non-pathogenic unicellular algae, which may potentially be used as a model for phylogenetically related human parasites. After incubation of the potential GPI substrate 30a with E. gracilis microsomal membranes for generation of metabolites, the analysis by LC-MS and, eventually, isolation of the products will be performed for further characterization. Products that show any substrate or inhibitory activities will be also assayed in T. cruzi microsomal membrane.

A relação evolutiva entre mamíferos e Plasmodium compreende infecções com reflexos adaptativos de ambos os lados. A evasão imune pelo parasita e a aquisição imune do hospedeiro contra antígenos importantes são extremos de um longo processo. Genes e antígenos variantes do parasita funcionam nesse processo desempenhando papel evasivo, de citoaderência e manutenção do processo infeccioso. Hospedeiros podem adquirir imunidade efetiva por vacinas contra antígenos variantes e antígenos de caráter reinvasivo. Testamos aqui três desenhos experimentais visando: 1- Definir se antigenos variantes BIR estão associados a citoadesão em infecção murina e se sua localização é em eritrócitos infectados. 2- O papel de um transgene controlado por um promotor de genes variantes no processo adaptativo infeccioso, frente a hospedeiros que diferem em apenas um único gene. 3- Criação de um modelo vacinal aplicável a qualquer antígeno relevante em infecções pelo gênero Plasmodium. Como resultados obtivemos que: 1- Antigenos BIR não parecem estar relacionados na cito adesão em modelo murino. Identificamos um outro grupo de antígenos com domínio LCCL que talvez desempenhe um papel de ligante. 2- promotores bir podem sofrer modulação em uma única infecção que difiere em somente um gene em hospedeiros. Os efeitos desencadeados foram maior parasitemia, anergia e tolerância imune sem afetar a morbidade da infecção de maneira nociva ao hospedeiro. Esse efeito parece ser mediado por subpopulações parasitarias usando exossomos entre parasita e hospedeiro. 3- Produzimos um sistema funcional de produção de proteínas recombinantes fusionadas a GPI que permite integração em lipossomos para usos vacinais. A prova de princípio foi o uso de antígenos PfRH5-GPI recombinantes em teste vacinal que conseguiram gerar anticorpos com alta atividade inibitória em cultivos de P. falciparum. Tomados em conjunto mostramos que o hospedeiro é capaz influenciar a expressão de transgenes controlados por promotores bir e que proteolipossomos contendo antígenos relevantes, como PfRH5, possuem potencial protetor quando vacinados contra malaria. / The relation between mammals and Plasmodium comprise infections with adaptive reflections for both sides. The immune evasion by parasites and immune acquisition by the host against important antigens are end points of a long process. Variant genes and proteins of the parasite can exert a role in this process by enbling immune evasion, cytoadherence resulting in the maintainence of the infective process. We tested three experimental approaches focusing on the following points:1-Show if variant BIR antigens are associated with cytoadherence during murine infections 2- The role of a transgene under the control of a variant gene promoter in adaptation to infection in hosts which express or not the transgene 3- Creation of a vaccine model applicable to any relevant antigen in infections with Plasmodium. As results we showed that: 1-BIR antigenes are likely not related to cito adhesion in the murine model. Cytoadherence in this model is probably related to exported parasite proteins with LCCL domains 2-bir promoters can be modulated during infection in hosts which which differ in one unique gene.The effects observed in this case was an increase in parasitemia, anergy and immune tolerance without affecting the morbidity of infection in the host. These effects are apparently mediated by parasite subpopulations producing exosomes that signal from the parasite to the host.3- We generated a system for recombinant protein production where antigens are fused to GPI and then integrated onto liposomes for vaccine usage. The proof of principle was the use of recombinant PfRH5-GPI as vaccine which elicited antibodies with strong blocking activity in P. falciparum cultures. Together we have shown that the host environment is capable of modulating the activity of variant bir gene promoters and that proteoliposomes loaded with relevant malarial antigens such as PfRH5, are potentially protective when used as malaria vaccine.

Candida albicans est un pathogène opportuniste présent à l'état commensal chez 75% de la population. Il s'agit du premier pathogène d'origine fongique (4ème cause d'infections nosocomiales) responsable d'infections superficielles chez les personnes immunocompétentes ou d'infections profondes chez les personnes immunodéprimées. Les protéines à ancre GPI (Glycosyl Phosphatidyl Inositol) de C. albicans, situées à l'interface entre la levure et les cellules de l'hôte, semblent être les plus aptes à moduler la réponse immunitaire. Au cours de cette étude, une banque de surexpression et de sécrétion d'une vingtaine de domaines fonctionnels putatifs issus de protéines à ancre GPI potentiellement exposées à la surface a été construite. Le crible réalisé a permis d'identifier sept polypeptides impliqués dans la modulation de la réponse des cellules macrophages et trois polypeptides ayant des propriétés immunogènes. Dans un deuxième projet, nous avons démontré que la protéine à ancre GPI Rbt1 spécifique des hyphes de C. albicans avait des propriétés d'adhésines aux substrats abiotiques et contribuait à la formation de biofilm et d'agrégats. La caractérisation de cette protéine a permis d'apporter des données nouvelles concernant l'exposition en surface de protéines membranaires suivant la forme morphologique de C. albicans. / C. albicans is an opportunistic pathogen present as commensal in 75% of the population. This is the first fungal pathogen (4th cause of nosocomial infections) responsible for superficial infections in immunocompetent patients or deep infections in immunocompromised patients. C. albicans GPI-anchored proteins (Glycosyl Phosphatidyl Inositol) present at the interface between the yeast and the host cells appear to be the proteins most capable of modulating the immune response. In this study, a library overexpressing and secreting twenty fonctionnal domains from GPI-anchored proteins potentially exposed to the surface was constructed. We identified seven polypeptides involved in the modulation of the macrophage response and three polypeptides with immunogenic properties. In a second project, we demonstrated the properties of the hyphae specific GPI-anchored protein Rbt1 in adhesion, biofilm formation and aggregation. The characterization of this protein gives us new data on surface exposure of membrane proteins depending to C. albicans morphological state.

Des variants récessifs touchant le gène PIGB, encodant une enzyme impliquée dans la biosynthèse des ancres GPI, ont récemment été décrits chez des patients présentant une déficience héritée des ancres GPI ainsi qu’une encéphalopathie épileptogène (EE), une forme d’épilepsie infantile sévère associée à des atteintes cognitives. Chez l’humain, plus de 150 protéines, dont certaines sont critiques pour la fonction neuronale, sont localisées à la membrane cellulaire grâce aux ancres GPI. Des données préliminaires du laboratoire Rossignol démontrent que la délétion embryonnaire du gène Pigb dans les interneurones GABAergiques (IN) dérivés de l’éminence ganglionnaire médiale (MGE) est suffisante pour induire des crises d’épilepsie spontanées et des déficits cognitifs chez la souris, suggérant un rôle critique de PIGB dans le développement de l’inhibition corticale. Toutefois, les mécanismes cellulaires et moléculaires sous-tendant les phénotypes cliniques associés aux délétions du gène PIGB sont inconnus. Compte tenu du rôle central joué par les molécules de guidage, dont certaines sont des protéines à ancrage GPI, lors de la migration des IN vers la plaque corticale, nous postulons que la perte sélective des ancres GPI, résultant d’une délétion conditionnelle de Pigb dans les IN, altère leur dynamique de migration, ce qui a pour conséquence de réduire leur nombre dans le cortex postnatal, menant à une désinhibition corticale et au développement de l’épilepsie. L’imagerie en temps réel d’explants cellulaires de MGE a révélé que la perte de fonction du gène Pigb dans les IN dérivés du MGE entraine un défaut de la migration tangentielle et des anomalies morphologiques se traduisant par une réduction de la densité des IN dans le cortex postnatal. Nous avons également démontré que la signalisation motogène EphA4-éphrineA2 est altérée dans les IN déficients en ancres GPI, contribuant au délai de migration observé. En somme, nos travaux ont permis de préciser les mécanismes physiopathologiques sous-tendant les EE associées à des variants pathogéniques du gène PIGB et d’approfondir notre compréhension du rôle des ancres GPI durant le neurodéveloppement et plus précisément, durant la migration des IN. / Recessive variants in the PIGB gene, encoding an enzyme involved in the biosynthesis pathway of GPI anchors, were recently described in children with an inherited GPI anchor defect and epileptic encephalopathy (EE), a neurodevelopmental disorder characterized by early-onset epilepsy with cognitive impairment. GPI anchors are critical for the membrane attachment of at least 150 human proteins, some of which are important for proper neuronal function. Preliminary data from the Rossignol group show that the embryonic deletion of Pigb in GABAergic interneurons (INs) emanating from the medial ganglionic eminence (MGE) causes spontaneous seizures and cognitive deficits in mice, suggesting a critical role of PIGB in the establishment of cortical inhibition. However, the cellular and molecular mechanisms leading to epilepsy remain unknown. Given the central role of guidance molecules, some of which are GPI-anchored proteins, during neuronal migration, we postulate that loss of GPI anchors following the conditional deletion of Pigb in MGE-derived INs disrupts chemotactic guidance and IN migration dynamics, leading to cortical disinhibition and epilepsy post-natally. Time-lapse live imaging of MGE explants revealed that the targeted deletion of Pigb impairs the tangential migration as well as the morphological development of MGE-derived INs, resulting in reduced IN densities in the postnatal cortex. We showed that the kinetic deficits are partly due to a loss of EphA4-ephrinA2 motogenic signaling in PigbcKO INs. In summary, our work helps clarify the physiopathology underlying PIGB associated-EE and deepens our understanding of the roles of GPI-anchor-related pathways in neurodevelopment and more specifically, in the migration of cortical INs.

Die Arbeit umfasst die Synthese von lipophilen Inositolen und Glycerollipiden, welche auf ihre Raftophilie getestet wurden. Des weiteren wurden eine Reihe neuer Ceramide synthetisiert und diese in Bioassays auf ihre Wirksamkeit gegenüber diversen Krankheiten wie Influenza getestet.