Orientador: Márcia Regina Brochetto Braga / Banca: Regina Barretto Cicarelli / Banca: Frederico Gonzalez Colombo Arnoldi / Resumo: Polybia paulista ou popularmente "paulistinha" é uma vespa social da família Vespidae. Possui hábitos urbanos e grande ocorrência no Sudeste do Brasil, especialmente no Estado de São Paulo, onde tem causado muitos acidentes de importância médica. Na composição de seu veneno encontra-se um potente alérgeno, a proteína Antígeno 5 (Ag5) e embora sua função biológica ainda seja desconhecida, este alérgeno é responsável por importantes reações imunológicas cruzadas com o Ag5 do veneno de outros insetos sociais e com outras proteínas de eucariotos. A importância da reatividade cruzada em pacientes alérgicos ao veneno de vespas sociais é inquestionável, pois estas interações têm impacto direto sobre o diagnóstico e a seleção da melhor conduta terapêutica. Os diagnósticos de alergia são baseados na detecção de anticorpos do tipo IgE específico ao veneno por testes cutâneos ou de sangue. No entanto, respostas falso-positivas decorrentes da reatividade cruzada e respostas falso-negativas provenientes da baixa quantidade de IgE detectada, dificultam a interpretação dos resultados. A sequência completa de cDNA (621 pb) do alérgeno Ag5 do veneno da vespa P. paulista, foi clonada e a análise dos nucleotídeos revelou uma similaridade de 99% com a vespa Polybia scutellaris. Anticorpos policlonais foram produzidos contra a fração eletroforética protéica do Ag5 (25 kDA) de P. paulista e analisados imunologicamente por Western blotting. Os resultados demonstraram que os anticorpos reconheceram especificamente o alérgeno Ag5 no veneno bruto de P. paulista bem como, desenvolveram maior reação imunológica cruzada com os alérgenos Ag5 do veneno das vespas do gênero Polybia, embora não se descarte a possibilidade de ocorrência de reação cruzada com venenos de outros insetos sociais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Polybia paulista, commonly known as "paulistinha", is a social wasp of the family Vespidae. This species occurs in urban areas and is frequent in the Southeastern Brazil, especially in the State of São Paulo, where it has been responsible for many accidents of medical significance. A potent allergen, the protein antigen 5 (Ag5), is an important compound of the wasp venom. Although its biological function remains unknown, this component is responsible for substantial cross-immunological reactions with the Ag5 of venoms of other social insects and with eukaryotic proteins. The importance of cross-reactivity in allergic patients to the wasp venoms is unquestionable, because these interactions present a direct impact on the diagnosis and on the selection of the therapeutic treatment. Allergenic diagnoses are based on the detection of IgE specific to the venom via cutaneous or blood tests. However, sometimes they are hampered by false-positive responses as a result of cross-reactivity and false-negative responses that can occur due to the low amount of IgE detected as consequence of the low sensitivity of the test. The fulllength cDNA (621 bp) from the venom allergen Ag5 wasp P. paulista was cloned and nucleotide analysis revealed 99% of similarity with the wasp Polybia scutellaris. Polyclonal antibodies were produced against the electrophoretic protein fraction of Ag5 (25 kDa) of P. paulista and immunologically analyzed by Western blotting. The results showed that the antibodies strongly recognized the allergen Ag5 in the venom of P. paulista and developed higher cross-immune reaction with the same allergen in wasp venoms of the genus Polybia, although the possibility of cross reaction with other insect venoms not tested in this study cannot be excluded. The model carried out for the Ag5 P. paulista revealed the... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:22:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-02Bitstream added on 2014-06-13T19:08:38Z : No. of bitstreams: 1 giratto_dt_me_rcla.pdf: 1764427 bytes, checksum: 1b64e9443f58235f6ad350ec38383d9a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Polybia paulista ou popularmente “paulistinha” é uma vespa social da família Vespidae. Possui hábitos urbanos e grande ocorrência no Sudeste do Brasil, especialmente no Estado de São Paulo, onde tem causado muitos acidentes de importância médica. Na composição de seu veneno encontra-se um potente alérgeno, a proteína Antígeno 5 (Ag5) e embora sua função biológica ainda seja desconhecida, este alérgeno é responsável por importantes reações imunológicas cruzadas com o Ag5 do veneno de outros insetos sociais e com outras proteínas de eucariotos. A importância da reatividade cruzada em pacientes alérgicos ao veneno de vespas sociais é inquestionável, pois estas interações têm impacto direto sobre o diagnóstico e a seleção da melhor conduta terapêutica. Os diagnósticos de alergia são baseados na detecção de anticorpos do tipo IgE específico ao veneno por testes cutâneos ou de sangue. No entanto, respostas falso-positivas decorrentes da reatividade cruzada e respostas falso-negativas provenientes da baixa quantidade de IgE detectada, dificultam a interpretação dos resultados. A sequência completa de cDNA (621 pb) do alérgeno Ag5 do veneno da vespa P. paulista, foi clonada e a análise dos nucleotídeos revelou uma similaridade de 99% com a vespa Polybia scutellaris. Anticorpos policlonais foram produzidos contra a fração eletroforética protéica do Ag5 (25 kDA) de P. paulista e analisados imunologicamente por Western blotting. Os resultados demonstraram que os anticorpos reconheceram especificamente o alérgeno Ag5 no veneno bruto de P. paulista bem como, desenvolveram maior reação imunológica cruzada com os alérgenos Ag5 do veneno das vespas do gênero Polybia, embora não se descarte a possibilidade de ocorrência de reação cruzada com venenos de outros insetos sociais... / Polybia paulista, commonly known as paulistinha, is a social wasp of the family Vespidae. This species occurs in urban areas and is frequent in the Southeastern Brazil, especially in the State of São Paulo, where it has been responsible for many accidents of medical significance. A potent allergen, the protein antigen 5 (Ag5), is an important compound of the wasp venom. Although its biological function remains unknown, this component is responsible for substantial cross-immunological reactions with the Ag5 of venoms of other social insects and with eukaryotic proteins. The importance of cross-reactivity in allergic patients to the wasp venoms is unquestionable, because these interactions present a direct impact on the diagnosis and on the selection of the therapeutic treatment. Allergenic diagnoses are based on the detection of IgE specific to the venom via cutaneous or blood tests. However, sometimes they are hampered by false-positive responses as a result of cross-reactivity and false-negative responses that can occur due to the low amount of IgE detected as consequence of the low sensitivity of the test. The fulllength cDNA (621 bp) from the venom allergen Ag5 wasp P. paulista was cloned and nucleotide analysis revealed 99% of similarity with the wasp Polybia scutellaris. Polyclonal antibodies were produced against the electrophoretic protein fraction of Ag5 (25 kDa) of P. paulista and immunologically analyzed by Western blotting. The results showed that the antibodies strongly recognized the allergen Ag5 in the venom of P. paulista and developed higher cross-immune reaction with the same allergen in wasp venoms of the genus Polybia, although the possibility of cross reaction with other insect venoms not tested in this study cannot be excluded. The model carried out for the Ag5 P. paulista revealed the... (Complete abstract click electronic access below)

Resumo: Os venenos dos insetos da ordem Hymenoptera contêm uma variedade de proteínas alergênicas. As ferroadas desses insetos podem induzir reações alérgicas e ocasionalmente, anafilaxias fatais. Há um crescente interesse nos componentes químicos dos venenos desses insetos, sobretudo no campo da alergia e imunologia clínica. As principais reações desses venenos são as reações inflamatórias e/ou imunológicas em suas vítimas, podendo ocorrer alguns efeitos sistêmicos. Dentre os Hymenoptera sociais, os venenos de abelhas e vespas têm sido extensivamente estudados e muitos de seus componentes moleculares já foram isolados e identificados. Fosfolipase, hialuronidase, antígeno-5 e serinoprotease são proteínas antigênicas de elevada massa molecular que, quando injetadas durante o ato de ferroar, iniciam uma resposta imune peculiar, sensibilizando alguns indivíduos. Porém, poucos estudos têm sido realizados para a identificação e o mapeamento dos epítopos desses alérgenos. O conhecimento sobre a interação molecular dos principais alérgenos destes venenos certamente deverá contribuir para o aperfeiçoamento dos diagnósticos de alergia, bem como para o desenvolvimento de tratamentos mais seletivos de reações alérgicas mediadas por IgE. No presente estudo identificamos e mapeamos os epítopos lineares de células-B do antígeno-5 do veneno da vespa social Polybia paulista. O antígeno-5 é conhecido como um dos principais alérgenos do veneno de Hymenoptera com massa molecular em torno de 23 kDa e função biológica desconhecida, porém muitos estudos demonstram a sua alergenicidade. Tendo conhecimento da sequência primária do antígeno-5, a identificação e o mapeamento dos epítopos foram realizados através da síntese múltipla de peptídeos, utilizando as técnicas do SPOT-Synthesis, imunodetecção e método indireto do ELISA com soro de pacientes sensíveis... (resumo completo, clicar acesso eletrônico abaixo) / Abstract: The venom insects of Hymenoptera order contain a variety of allergenic proteins. The stings of these insects can induce allergic reactions and occasionally fatal anaphylaxis. There is a growing interest in the knowledge about the chemical components of the venom of these insects, especially in the field of allergy and clinical immunology. The main reactions of these venoms are inflammation and / or the induction of immune process in the victims; sometimes systemic effects also may be observed. Among the social Hymenoptera, the venoms of bees and wasps have been extensively studied and many of their molecular components have been isolated and identified. Phospholipase, hyaluronidase, antigen-5 and serine protease are antigenic proteins of high molecular weight, which may initiate a peculiar immune response to sensitize some individuals. However, few studies have been performed for the identification and mapping of the epitopes these allergens. The knowledge about the molecular interaction of the major allergens of these venoms with IgG and/or IgE will certainly contribute for improving the diagnosis of allergy, as well as to develop more selective treatments of reactions IgE-mediated allergy. In this study we identified and mapped the linear epitopes of B-cells of the antigen-5 from the venom of the social wasp Polybia paulista. The antigen-5 is known as one of the major allergens from Hymenoptera venoms with molecular weight around 23 kDa and unknown biological function, but many studies show its allergenicity. The aim of this study was to identify and to map the linear epitopes of B-cells of this allergen. Taking into account the knowledge the primary sequence of antigen-5, the identification and mapping of epitopes was performed by using multiple synthesis of peptides with the combination of different protocols: SPOT-Synthesis, immunoblotting and indirect method of ELISA with the sera... (Complete abstract click electronic access below) / Orientador: Mario Sergio Palma / Coorientador: Lucilene Delazari dos Santos / Banca: Salvatore Giovanni de Simone / Banca: Luisa Karla de Paula Arruda / Mestre

Made available in DSpace on 2014-06-11T19:23:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-03Bitstream added on 2014-06-13T20:29:34Z : No. of bitstreams: 1 pinto_jras_me_rcla.pdf: 1057969 bytes, checksum: 2e29026d533c6190983ed253a062779d (MD5) / Os venenos dos insetos da ordem Hymenoptera contêm uma variedade de proteínas alergênicas. As ferroadas desses insetos podem induzir reações alérgicas e ocasionalmente, anafilaxias fatais. Há um crescente interesse nos componentes químicos dos venenos desses insetos, sobretudo no campo da alergia e imunologia clínica. As principais reações desses venenos são as reações inflamatórias e/ou imunológicas em suas vítimas, podendo ocorrer alguns efeitos sistêmicos. Dentre os Hymenoptera sociais, os venenos de abelhas e vespas têm sido extensivamente estudados e muitos de seus componentes moleculares já foram isolados e identificados. Fosfolipase, hialuronidase, antígeno-5 e serinoprotease são proteínas antigênicas de elevada massa molecular que, quando injetadas durante o ato de ferroar, iniciam uma resposta imune peculiar, sensibilizando alguns indivíduos. Porém, poucos estudos têm sido realizados para a identificação e o mapeamento dos epítopos desses alérgenos. O conhecimento sobre a interação molecular dos principais alérgenos destes venenos certamente deverá contribuir para o aperfeiçoamento dos diagnósticos de alergia, bem como para o desenvolvimento de tratamentos mais seletivos de reações alérgicas mediadas por IgE. No presente estudo identificamos e mapeamos os epítopos lineares de células-B do antígeno-5 do veneno da vespa social Polybia paulista. O antígeno-5 é conhecido como um dos principais alérgenos do veneno de Hymenoptera com massa molecular em torno de 23 kDa e função biológica desconhecida, porém muitos estudos demonstram a sua alergenicidade. Tendo conhecimento da sequência primária do antígeno-5, a identificação e o mapeamento dos epítopos foram realizados através da síntese múltipla de peptídeos, utilizando as técnicas do SPOT-Synthesis, imunodetecção e método indireto do ELISA com soro de pacientes sensíveis... / The venom insects of Hymenoptera order contain a variety of allergenic proteins. The stings of these insects can induce allergic reactions and occasionally fatal anaphylaxis. There is a growing interest in the knowledge about the chemical components of the venom of these insects, especially in the field of allergy and clinical immunology. The main reactions of these venoms are inflammation and / or the induction of immune process in the victims; sometimes systemic effects also may be observed. Among the social Hymenoptera, the venoms of bees and wasps have been extensively studied and many of their molecular components have been isolated and identified. Phospholipase, hyaluronidase, antigen-5 and serine protease are antigenic proteins of high molecular weight, which may initiate a peculiar immune response to sensitize some individuals. However, few studies have been performed for the identification and mapping of the epitopes these allergens. The knowledge about the molecular interaction of the major allergens of these venoms with IgG and/or IgE will certainly contribute for improving the diagnosis of allergy, as well as to develop more selective treatments of reactions IgE-mediated allergy. In this study we identified and mapped the linear epitopes of B-cells of the antigen-5 from the venom of the social wasp Polybia paulista. The antigen-5 is known as one of the major allergens from Hymenoptera venoms with molecular weight around 23 kDa and unknown biological function, but many studies show its allergenicity. The aim of this study was to identify and to map the linear epitopes of B-cells of this allergen. Taking into account the knowledge the primary sequence of antigen-5, the identification and mapping of epitopes was performed by using multiple synthesis of peptides with the combination of different protocols: SPOT-Synthesis, immunoblotting and indirect method of ELISA with the sera... (Complete abstract click electronic access below)

Le paludisme, première endémie parasitaire mondiale ayant engendré près d’un demi-million de morts en 2017 (d’après l’OMS), est due à une infection par un parasite du genre Plasmodium. Cet apicomplexe infecte, au cours de son cycle de vie, un hôte définitif, un moustique femelle du genre Anopheles, et un hôte intermédiaire homéotherme (l’Homme pour au moins 6 espèces). Chez ce dernier, après une phase de développement hépatique, le parasite envahit puis lyse les érythrocytes. L’accroissement exponentiel de la parasitémie engendre les symptômes du paludisme et permet la production de formes sexuées (gamétocytes) qui seront transmises au vecteur arthropode, permettant ainsi la complétion du cycle de vie du parasite.Plasmodium a co-évolué avec ses hôtes et mis en place divers modes de régulation de l’expression de ses gènes. La phosphorylation est l’une des modifications post-traductionnelles majeures et rapides qu’il utilise pour répondre aux changements environnementaux auxquels il est confronté au cours de son cycle de vie. Nombre de ses kinases et phosphatases jouent un rôle essentiel dans l’invasion de cellules hôtes, la croissance et la division cellulaires, ainsi que la motilité de certains stades. En revanche, le rôle des cinq pseudokinases de Plasmodium dans son développement n’a jusqu’ici pas été exploré.Durant ma thèse, j’ai caractérisé l’unique pseudo-Tyrosine Kinase-like (pTKL) de Plasmodium et étudié son rôle au cours du cycle intra-érythrocytaire du parasite.L’annotation de la pTKL de P. falciparum (PfpTKL) m’a permis d’identifier différents domaines et motifs, et notamment un domaine SAM (Sterile Alpha Motif), deux motifs RVxF (connus pour leur capacité d’interaction avec la Protéine Phosphatase de type 1, PP1) et un pseudo-domaine kinase appartenant à la famille des Tyrosine Kinases-like (TKL). Nous avons montré que ce pseudo-domaine kinase est capable de lier l’ATP de manière cation-indépendante, mais est dépourvu d’activité enzymatique. Des études d’interaction in vitro couplées à l’utilisation de modèles hétérologues (Levure, ovocytes de Xénope) m’ont permis d’identifier deux protéines parasitaires partenaires de PfpTKL : le domaine SAM de PfpTKL interagit directement avec la pseudo-protéase PfSERA5 (SErine Repeat Antigen 5), alors que les deux régions de la protéine contenant les motifs RVxF de PfpTKL interagissent avec PfPP1c (phosphatase majeure de Plasmodium). De façon intéressante, le deuxième motif RVxF est directement impliqué dans l’interaction avec PP1c et serait capable de moduler l’activité de cette dernière de manière allostérique.La localisation de la pTKL de P. berghei (PbpTKL) a ensuite été étudiée par immunofluorescence et confirmée par des expériences de fractionnement cellulaire. Nous avons ainsi observé que PbpTKL est exportée dans l’érythrocyte infecté au stade trophozoïte, puis retenue dans le parasite et la vacuole parasitophore au stade schizonte. L’étude de l’interactome de PbpTKL par IP/MS au stade trophozoïte a montré que PbpTKL s’associe à diverses protéines impliquées dans l’organisation du cytosquelette de l’érythrocyte, ainsi que dans l’érythropoïèse et l’homéostasie cellulaire. Ces observations suggèrent que pTKL joue un rôle, direct ou via ses partenaires, à l’interface entre le parasite et sa cellule hôte.Enfin, afin d’approcher la fonction de pTKL chez le parasite, nous avons généré différentes lignées génétiquement modifiées. L’étude phénotypique des souches de P. berghei KO et iKD pour pTKL a montré qu’elle était dispensable pour la complétion du cycle intra-érythrocytaire, l’expression des gamétocytes ainsi que l’activation des gamétocytes mâles. Ces données suggèrent que pTKL est dispensable pour ces stades de développement ou que l’expression de gènes redondants compense son absence. Quoi qu’il en soit, il est important de poursuivre les recherches sur le rôle de cette protéine aux autres stades de développement du parasite, notamment du zygote aux stades hépatiques. / Malaria is the first endemic parasitic disease in the world with nearly half million deaths in 2017 according to the WHO. This disease is the result of an infection by an agent belonging to the Plasmodium genus. This apicomplexan parasite infects two hosts over its complex life cycle: a definitive one – a mosquito belonging to the Anopheles genus – and a homoeothermic intermediate host. At least six Plasmodium species can infect humans. In its intermediate host, Plasmodium first replicates in hepatocytes before releasing erythrocyte-infectious stages in the bloodstream. Once there, parasites invade and replicate within erythrocytes, before lysing them to release other infectious stages. This triggers an exponential rise in the parasitemia, as well as malaria symptoms. Sexual stages, called gametocytes, are produced over this intra-erythrocytic cycle to be transmitted to the arthropod vector, thus allowing the completion of the parasite life cycle.Plasmodium co-evolved with its hosts and set up diverse gene expression regulation pathways accordingly. Phosphorylation is one of the major and fastest post-translational modifications used by the parasite to respond to environmental changes. Many of its kinases and phosphatases play key roles in host cell invasion, cellular growth and division, as well as motility of specific developmental stages. However, the role of the five pseudo-kinases expressed by Plasmodium has not been explored yet.During my PhD project, I have performed the characterization of the unique Plasmodium pseudo-Tyrosine Kinase-like (pTKL) and explored its role over the parasite intra-erythrocytic cycle.P. falciparum pTKL (PfpTKL) in silico annotation allowed the delineation of the protein domains. Notably, a SAM (Sterile Alpha Motif) domain, two RVxF motifs (known for their binding potential with the major protein phosphatase type 1, PP1) and a pseudo-kinase domain belonging to Tyrosine Kinase-like (TKL) family were found. This pseudo-kinase domain was found to be able to bind ATP in a cation-independent way although devoid of kinase activity. Two parasite protein partners of PfpTKL have been identified using in vitro protein-protein interaction studies together with heterologous models (yeast, Xenopus ovocytes). First, PfSERA5 (SErine Repeat Antigen 5) specifically and strongly interacts with PfpTKL SAM domain and second, PfPP1c binds the two RVxF-containing regions of PfpTKL. Interestingly, the second RVxF motif, which is located within the pseudo-kinase domain, directly binds PfPP1c and seems to be involved in the allosteric regulation of the phosphatase activity. The subcellular localization of P. berghei pTKL (PbpTKL) was studied by IFA as well as sequential lysis of erythrocytes followed by immunoprecipitation assays. PbpTKL was shown to be exported to the host cell cytosol at the trophozoite stage, but retained in the parasitophorous vacuole and the parasite cytosol at the schizont stage. Furthermore, our interactome analysis conducted at the trophozoite stage by IP/MS showed that PbpTKL binds many host cell proteins involved in erythrocyte cytoskeleton organization, as well as erythropoiesis and cell homeostasis. These data suggest that pTKL plays a role at the parasite/host interface, either directly or via its protein partners.Finally, in an attempt to understand the role of pTKL for the parasite development, we generated genetically modified P. berghei strains. The phenotypic study of PbpTKL KO and iKD strains did not show any difference between the defective parasites and the parental wild type ones during the intra-erythrocytic cycle, gametocyte expression and male gametocyte activation. These data suggest the dispensability of pTKL or the expression of redundant gene(s) with similar functions in these parasite stages. Whatever the explanation, it is still important to follow up this investigation in other parasite stages, from zygotes to hepatic stages.