A partir de uma biblioteca de cDNA de glândulas de veneno de Micrurus corallinus (cobra-coral), uma serpente da Família Elapidae bastante representada no Brasil e muito comum em áreas florestais tropicais, foram gerados 1.438 Expressed Sequences Tags (ESTs), agrupados em 611 clusters. O banco representa os genes mais expressos na glândula de veneno de M. corallinus. Os transcritos relacionados às toxinas apresentaram ao redor de 46% de representação nesse banco de seqüências. A composição geral das toxinas inclui: toxinas de três dígitos (3FTx) (24%), fosfolipases A2 (PLA2) (16%), lectinas do tipo C (5%), entre outros. O banco permitiu não somente a identificação de possíveis toxinas, mas também de transcritos celulares, sendo a maioria envolvida nas funções fisiológicas de células da glândula de veneno. A maior parte dessas moléculas apresenta um envolvimento na expressão gênica e protéica, o que reflete uma alta especialização do tecido para a síntese de toxinas. A análise do transcriptoma de glândulas de veneno de M. corallinus possibilitou a identificação de alguns candidatos antigênicos para um anti-soro antielapídico alternativo. Cinco candidatos antigênicos foram selecionados por meio da análise do transcriptoma obtido: Atg1 (Grupo das neurotoxinas Homolog 8), Atg2 (Grupo das neurotoxinas Homolog 7/3/1), Atg3 (Outras neurotoxinas 1), Atg4 (Outras neurotoxinas 2) e Atg5 (fosfolipase do tipo A2). Avaliamos a viabilidade de imunização com o DNA desses candidatos. Para isso, os cinco grupos de antígenos foram clonados, primeiramente em pGEM-T e, posteriormente, em pSecTag2A, que é um vetor de expressão em células de mamíferos. As clonagens foram inicialmente testadas em células do tipo COS (transfecção transiente), entretanto não ficou clara a capacidade dessas células em expressar os antígenos. Para a análise da resposta imunológica da vacina de DNA, proteínas recombinantes produzidas em E. coli foram utilizadas para o coating de ELISA para detectar anticorpos presentes no soro primário proveniente da imunização com DNA. Os resultados mostraram que o soro dos animais imunizados foi capaz de reconhecer os antígenos recombinantes. Isso indica que a imunização por DNA em camundongos poderia ser uma boa alternativa em relação à imunização do veneno puro de serpente, que é custosa e muito depende da disponibilidade do veneno. Apesar da necessidade de testes complementares, esse é um resultado promissor, já que a produção de anticorpos pode ser alcançada por via de imunização intramuscular, mais prática para objetivos de produção. / Micrurus corallinus(coral snake) is a tropical forest snake belonging to the Elapidae Family, and is very common in Brazil. From the cDNA library of its venom glands, 1.438 Expressed Sequences Tags (ESTs) were generated and grouped into 611 clusters. This database contains the most expressed genes in the M. corallinus venom glands. The transcripts related to toxins represent approximately 46% of the total genes in this database. The toxin compound consists of: three finger toxins (24%), phospholipases A2 (PLA2s) (16%), type-C lectins (5%), among others. This database allowed not only the identification of possible toxins, but also the identification of cellular transcripts, most of which seems to be involved in physiological functions of venom gland cells. The majority of these molecules are involved in gene and protein expression, revealing the high level of specialization of the tissue for toxin synthesis. The analysis of the M. corallinus venom gland transcriptome allowed the identification of some antigenic candidates for an alternative antielapidic antiserum. Five antigenic candidates were selected after analysing the transcriptome: Atg1 (Homolog group 8), Atg2 (Homolog group 7/3/1), Atg3 (Other neurotoxins 1), Atg5 (A2-type phospholipase). These five antigenic groups were used for DNA immunization. Then they were first cloned in pGEM-T and, after, in pSecTag2A, which is an expression vector in mammal cells. The cloning was tested in COS-type cells (transient transfection), without signs of expression. To analyze the immunological response, recombinant proteins were produced in E. coli and used for ELISA coating to react with the primary serum deriving from the DNA immunization. The results showed that the serum from the immunized animals was able to recognize the recombinant antigens, indicating that the DNA immunization in mice could be a feasible alternative regarding the traditional immunization with crude snake venom, which is costly and heavily dependent on the availability of the venom. Regardless the need for additional tests, this is a promising result, because the antibody production can be achieved by intramuscular immunization, a more effective method when aiming for downstream production.

O Papaya ringspot virus (PRSV) é uma espécie do gênero Potyvirus, sendo que a maioria dos isolados pertence a duas estirpes distintas: "papaya" (P) e "watermelon" (W). O Papaya ringspot virus - estirpe W (PRSV-W) tem sido considerado um dos vírus mais importantes no cultivo de cucurbitáceas pela predominância e pelos prejuízos significativos que causa no Brasil. O controle do mosaico da abobrinha-de-moita, causado pelo PRSV-W, tem sido obtido de forma satisfatória através da premunização com as três estirpes fracas, designadas PRSV-W-1, PRSV-W-2 e PRSV-W-3. O principal objetivo desse estudo foi comparar essas estirpes fracas com estirpes severas PRSV-W-C, PRSV-W-PR e PRSV-W-PE, com base na seqüência de nucleotídeos do gene que codifica a proteína da capa protéica e na mobilidade dessa proteína em SDS-PAGE. A seqüência de nucleotídeos da capa protéica das estirpes fracas PRSV-W-1 e PRSV-W-2 apresentou 100 % de homologia. Quando comparadas com a estirpe fraca PRSV-W-3, a homologia foi de 98 %. As estirpes fracas PRSV-W-1 e PRSV-W-2 apresentaram 95 % de homologia com as estirpes severas PRSV-W-C e PRSV-W-PE. Essas duas estirpes severas, por sua vez, apresentaram respectivamente, 93 e 95 % de homologia com a estirpe fraca PRSV-W-3. O alinhamento das seqüências de nucleotídeos entre as estirpes fracas e as severas evidenciou a inserção de 6 nucleotídeos na região conservada desse gene nas estirpes fracas. Essa inserção refletiu na adição de dois amino ácidos (Asn e Asp) na seqüência de amino ácidos deduzidos dessa proteína. A mobilidade da capa protéica em SDS-PAGE foi semelhante para todas as estirpes estudadas. / Papaya ringspot virus (PRSV), a species of the enus Potyvirus, is classified into two strains: "papaya" (P) and "watermelon" (W). Papaya ringspot virus - type W (PRSV-W) has been considered one of the most important viruses infecting cucurbits in Brazil due to its predominance and significative damage caused on the crops. The control of the disease caused by this virus has been efficiently achieved by means of cross protection with three mild strains, namely PRSV-W-1, PRSV-W-2, and PRSV-W-3. The main purpose of the present study was to compare these mild strains with the severe strains PRSV-W-C, PRSV-W-PR, and PRSV-W-PE, based on the nucleotide sequence of the coat protein gene and on the mobility of the capsid protein in SDS-PAGE. The nucleotide sequence of the coat protein gene of the mild strains PRSV-W-1 and PRSV-W-2 showed 100 % of homology. When compared with the coat protein gene of the mild strain PRSV-W-3, the homology was 98 %. The mild strains PRSV-W-1 and PRSV-W-2 showed 95 % of homology with the severe strains PRSV-W-C and PRSV-W-PE. These two severe strains, otherwise, showed respectively, 93 and 95 % of homology with the mild strain PRSV-W-3. The alignment of the nucleotide sequences of the mild and the severe strains indicated an insertion of 6 nucleotides in the conserved region of the coat protein gene of the mild strains. This insertion reflected on the addition of two amino acids (Asn e Asp) in the amino acid deduced sequence of this protein. The mobility of the coat protein in SDS-PAGE was similar for all the strains studied.

O objetivo com o presente trabalho foi avaliar o efeito do preparado de anticorpos policlonais (PAP) contra bactérias ruminais específicas (Streptococcus bovis e Fusobacterium necrophorum) sobre o consumo de matéria seca, digestibilidade aparente total da dieta, parâmetros de fermentação ruminal e contagem ruminal de protozoários, em animais adaptados ou não a dietas com alta proporção de carboidratos fermentescíveis. Foram utilizadas 6 vacas fistuladas no rúmen em dois quadrados latinos 3x3, em arranjo fatorial de tratamentos 3x2 referentes a dois aditivos PAP pó (PAPP) e PAP líquido (PAPP), mais o grupo controle e 2 tipos de manejo de adaptação à dieta. O primeiro quadrado latino recebeu uma adaptação gradual à dieta: do D0 ao D4 100% forragem; D5 ao D9 30% de concentrado e do D10 ao D14 60% de concentrado. O segundo quadrado latino recebeu 100% de forragem do D0 ao D14. Nos dias D15 e D16, todos os animais receberam uma dieta com 80% de concentrado. Para as análises, amostras de líquido ruminal foram coletadas diariamente às 3 h após a alimentação matinal. Os dados foram analisados pelo procedimento MIXED do SAS com nível de significância de 0,05. A variável consumo de matéria seca apresentou efeito de interação entre tempo e adaptação à dieta com alta proporção de carboidratos prontamente fermentescíveis (P<0,0001), onde o grupo adaptado apresentou consumo mais elevado em relação aos não adaptados (12,4 vs 6,6, respectivamente) do D0 ao D17. Para a variável digestibilidade da MS foi observado efeito de adaptação (P<0,0001), sendo que nos animais adaptados, a digestibilidade da MS foi superior (65,9%) à dos não adaptados (55,3%). Foi também observado efeito de aditivo (P=0,0186), onde o tratamento com PAPL apresentou maior digestibilidade da MS (63,6%), quando comparados aos tratamentos PAPP e controle (58,4% e 59,6%, respectivamente). A digestibilidade da PB apresentou efeito de interação entre proporção de carboidratos na dieta e o tipo de adaptação (P<0,0001), onde os animais adaptados apresentaram maior digestibilidade da PB (83,2%) em comparação aos não adaptados (79,3%), ambos recebendo 100% de forragem. Quando os animais adaptados receberam 60% de concentrado na dieta, este grupo apresentou menor digestibilidade da PB (69,4%), quando comparado ao grupo de animais não adaptados (83,6%). Já para a variável digestibilidade da FDN, os animais adaptados apresentaram maior digestibilidade da FDN (40,6%) em relação aos não adaptados (36,3%) (P=0,0332). Quanto ao efeito de aditivo (P=0,0248), os animais tratados com o aditivo PAPL apresentaram maior digestibilidade da FDN (44,0%), quando comparados aos tratados com PAPP (36,2%) e o grupo controle (35,4%). Quanto à digestibilidade do amido, foi observada interação entre dieta e adaptação (P=0,05), onde, na segunda semana, o grupo dos adaptados apresentou maior digestibilidade (92,8%) quando comparado ao grupo dos não adaptados (73,9%). Para a digestibilidade de carboidratos totais, foi observado efeito de adaptação (P<0,0001) e de aditivo (P=0,0312), onde o grupo dos adaptados apresentou maior digestibilidade quando comparados aos não adaptados (66,4% vs. 55,5, respectivamente), e os animais tratados com PAPL, apresentaram maior digestibilidade (63,9%) de carboidratos totais, que os tratados com PAPP (59,0%) e controle (59,9%). Ocorreu interação entre tempo e adaptação para a variável pH (P <0,0001), sendo que o grupo adaptado apresentou menor pH (6,40) quando comparado ao grupo dos não adaptados (6,77) entre o D2 e o D16. Ainda, foi verificado efeito de aditivo sobre a variavel pH ruminal (P=0,0432), onde o grupo PAPL apresentou maiores valores (6,62) quando comparado ao grupo PAPP (6,57) e ao controle (6,56). Ocorreu interação entre tempo e adaptação (P<0,0001) para a concentração AGCCt, onde os animais adaptados apresentaram valores mais elevados que o grupo dos não adaptados (100,3 vs. 77,7, respectivamente). Para a variável relação acetato:propionato (Ac:Pr), houve efeito de interação entre tempo e adaptação (P<0,0001). No D2, 5, 6 e D7, o grupo dos animais adaptados apresentou menor relação Ac:Pr quando comparados aos animais não adaptados (2,29 vs. 1,96, respectivamente). Porém, nos dias 12 a 16, houve inversão desta relação e os animais adaptados passaram a apresentar maior relação Ac:Pr (2,87) quando comparados ao grupo dos não adaptados (2,41). Não foi observado efeito de adaptação (P>0,05) bem como aditivo (P>0,05) para a variável concentração de lactato no líquido ruminal. A concentração de N-NH3 apresentou interação entre tempo e adaptação (P=0,0003), onde o grupo dos adaptados apresentou maiores valores quando comparado ao dos não adaptados (24,68 vs 15,97 mg/dL, respectivamente) entre o D1 e D15. Quanto as populações de protozoários, observou-se interação entre tempo, adaptação e aditivo para as populações de Dasytricha sp (P=0,0305) e Entodinium sp (P=0,0398), sendo observada manutenção das populações de Dasytricha sp (P=0,0188) nos animais não adaptados e decréscimo nos animais adaptados. Conseqüentemente, para a população de Entodinium sp, foi observado aumento nos animais adaptados (80,78%) e manutenção nos não adaptados (45,3%). Nos animais tratados com PAPL, a população de Dasytricha sp foi superior (38,3%) quando comparados às populações dos tratados com PAPP (31,50%) e grupo controle (34,7%), sem diferença entre estes últimos dois grupos. Quanto a população de Entodinium sp, os animais tratados com PAPL apresentaram menor porcentagem deste gênero de protozoários (58,5%) quando comparados ao grupo controle (64,0%) e ao PAPP (66,7%). A partir dos resultados obtidos foi possível concluir que o preparado de anticorpos policlonais tanto na apresentação líquida como em pó não alterou o consumo de matéria seca bem como a concentração AGCCt, proporção molar de acetato, propionato e butirato, assim como a concentração ruminal de lactato e N-NH3. O preparado de anticorpos policlonais na apresentação líquida melhorou a digestibilidade da MS, FDN e carboidratos totais. Quanto ao pH ruminal, o PAP na apresentação líquida, se mostrou mais eficiente, em evitar a sua redução, quando comparado ao preparado na apresentação em pó e que o grupo controle durante o pico de fermentação. A adaptação melhorou a digestibilidade da MS, PB, EE, FDN, FDA e carboidratos totais, assim como aumentou as concentrações de AGCCt, sem que ocorresse aumento nas concentrações de lactato. / The objective with the present work was to evaluate the polyclonal antibody preparation (PAP) against specific rumen bacteria (Streptococcus bovis and Fusobacterium necrophorum) on dry matter intake, total apparent digestibility of diet, ruminal fermentation patterns and ruminal protozoa counting on adapted and non-adapted animals to highly fermentable carbohydrates diets. Six ruminally cannulated cows were used in two Latin squares 3x3, in a factorial arrangement of treatments 3x2 regarding two feed additives (PAP in powder presentation (PAPP) and PAP in liquid presentation (PAPL)) plus control group (CON) and two managements of diets adaptation. The first Latin square received a step-up diet adaptation: from D0 to D4 100% forage; D5 to D9 30% of concentrates and D10 to D14 60% of concentrates. The second Latin square received 100% forage from D0 to D14. On D15 and D16, all animals received a diet with 80% of concentrates. For analysis, rumen fluid samples were daily collected 3h after morning meal. Data were analyzed by MIXED procedure with a significance level of 0.05. The variable dry matter intake presented interaction between time and adaptation to highly fermentable carbohydrate diets (P<0.0001), where the adapted group had greater DMI compared with non-adapted animals (12.4 vs. 6.6, respectively) from D0 to D17. For DM digestibility, it was observed effect of adaptation (P<0.0001), where the adapted group had greater values (65.9%) compared with the non-adapted group (55.3%). It was also observed effect of additive for this variable (P=0.0186), where the treatment PAPL had greater DM digestibility (63.6%) compared with treatments PAPP and control (58.4% and 59.6%, respectively). Crude protein digestibility had effect of interaction between carbohydrate proportion in diet and type of adaptation (P<0.0001), where the adapted animals had greater CP digestibility (83.2%) in relation to non-adapted animals (79.3%), both receiving 100% of forage. When the adapted animals received 60% of concentrates in diet, this group had lower CP digestibility (69.3%) compared with non adapted group (83.6%). For NDF digestibility, adapted animals had greater values (40.6%) in relation to non-adapted animals (36.3%) (P=0.0332). It was also observed an additive effect (P=0.0248), where the animals in PAPL group had greater NDF digestibility (44.0%) compared with PAPP (36.2%) and control (35.4%) groups. For starch digestibility, it was observed interaction between diet and adaptation (P=0.05), where, in the second week, the adapted group had greater digestibility (92.8%) compared with non-adapted group (73.9%). For total carbohydrates digestibility, it was observed effect of adaptation (P<0.0001) and additive (P=0.0312), where the adapted group had greater values compared with non-adapted animals (66.4% vs. 55.5, respectively), and the animals in PAPL group had greater total carbohydrates digestibility (63.9%) than PAPP (59.0%) and control (59.9%) groups. It was observed an interaction between time and adaptation for ruminal pH (P <0.0001), where the adapted group had lower pH (6.40) compared with non-adapted group (6.77) between D2 and D16. Moreover, it was verified additive effect for ruminal pH (P=0.0432), where PAPL group had higher values (6.62) compared with PAPP (6.57) and control (6.56) groups. It was observed an interaction between time and adaptation (P<0.0001) for total concentration of short chain fatty acids (SCFA), where the adapted animals had greater values than non-adapted animals (100.33 vs. 77.72, respectively). For acetate:propionate ratio (Ac:Pr), there was effect of interaction between time and adaptation (P<0.0001). At D2, 5, 6 and D7, the group of adapted animals had lower Ac:Pr ratio than non-adapted group (2,29 vs. 1,96, respectively). However, at D12 to D16, there was an inversion of this relation and the adapted animals had greater Ac:Pr ratio (2.87) when compared with non-adapted animals (2.41). It was not observed effect of adaptation (P>0.05) as well as effect of additive (P>0.05) for ruminal lactate concentration. The concentration of N-NH3 showed interaction between time and adaptation (P=0.0003), where the adapted group had greater values compared with non-adapted group (24.7 vs. 16.0 mg/dL, respectively) between D1 and D15. For rumen protozoa population, it was observed an interaction between time, adaptation and additive for Dasytricha sp (P=0.0305) and Entodinium sp (P=0.0398), where the number of Dasytricha sp (P=0.0188) population was maintained in non-adapted animals and decreased in adapted animals. Consequently, for Entodinium sp population, it was observed increase in its number in adapted animals (80.8%) and maintenance of its number in non-adapted animals (45.3%). In animals treated with PAPL, the population of Dasytricha sp was greater (38.3%) when compared with the animals treated with PAPP (31.5%) and control group (34.7%), without difference between these last two groups. For Entodinium sp population, the animals treated with PAPL had lower percentage of these protozoa (58.5%) when compared with control (64.0%) and PAPP (66.7%) groups. From these results, it was possible to conclude that polyclonal antibody preparation both in liquid or powder presentation did not alter dry matter intake, total concentration of SCFA, molar proportion of acetate, propionate and butyrate as well as ruminal concentration of lactate and NH3-N. Polyclonal antibody presentation in liquid presentation improved DM, NDF and total carbohydrates digestibility. For ruminal pH, PAP in liquid presentation was more efficient in preventing its reduction, when compared with PAP in powder presentation and control group during the peak of fermentation. Adaptation to highly fermentable carbohydrate diets improved DM, CP, EE, NDF, NDA and total carbohydrates digestibility even as increased total concentration of SCFA without increase in lactate concentration.

Resumo: O presente ensaio de pesquisa objetivou avaliar o preparado de anticorpos policlonais contra as bactérias ruminais precursoras de distúrbios nutricionais (Streptococccus bovis, Lactobacillus ssp. e Fusobacterium necrophorum) na forma sólida, como aditivo alimentar preventivo à acidose ruminal em bovinos e substituto à monensina. Nove vacas canuladas no rúmen com 677±98 kg de peso vivo médio foram agrupadas em baias individuais através de delineamento inteiramente casualizado com dois períodos de 20 dias. Separaram-se os animais em três tratamentos: controle (CTL), preparado de anticorpos policlonais (PAP) e monensina sódica (MON). Nos primeiros cinco dias de cada período, os animais receberam apenas cana e úreia como alimento. Em seguida, foi fornecida a dieta desafio com aproximadamente 74% de concentrado por 15 dias, com o intuito de causar acidose ruminal. Houve um tempo de 15 dias entre cada período para a readaptação dos animais à dieta de volumoso. As variáveis experimentais foram: ingestão de matéria seca (em kg, IMKG; % do peso vivo, IMPV; e metabólico, IMPM, respectivamente), flutuação da ingestão de matéria seca (FIMS) dos dias subseqüentes ao desafio com a dieta de concentrado e os parâmetros de fermentação ruminal (pH do líquido ruminal, lactato ruminal, concentração de ácidos graxos de cadeia curta, nitrogênio amoniacal e lactato ruminal). Não houve efeito de tratamento (P > 0.05) tanto para a ingestão de matéria seca quanto para a flutuação da ingestão de matéria seca. Os animais tratados com monensina apresentaram pH mais alto (P < 0.0001) que os demais tratamentos (MON = 6.06 vs. PAP = 5.89 e CTL = 5.91), independente de tempo. A concentração ruminal de lactato permaneceu baixa (0.23 mM), mesmo após o desafio com concentrado. A concentração de N-amoniacal do CTL foi menor (P = 0.0039), comparado à MON e PAP... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study was designed to evaluate the potential of the dry form of a multivalent polyclonal antibody preparation against several nutritional disturbs precursors ruminal bacteria (Streptococccus bovis, Fusobacterium necrophorum and Lactobacillus ssp.), as acidosis preventative feed additive to high concentrate fed cattle and as an alternative to monensin. It was used nine cannulated cows (677±98 kg of BW) allocated in a completely randomized desing with two periods of 20 d. Animals were separated in three treatments: control (CTL), multivalent polyclonal antibody preparation (PAP) and monensin sodium (MON). During the first five days of each period, animals were fed all forage diet. Ruminal acidosis was induced by an abrupt diet switch to a 74% concentrate diet during 15 d. An interval of 15 d was considered as ruminal washout in the meantime of the two periods, when animals were refed all forage diet to restablish normal ruminal pH conditions and cellulolitic microbial population. Ruminal acidosis evaluation parameters were: dry matter intake (kg/d, % of BW and % of BW0,75; DMIK, DMIB and DMIM respectivelly), dry matter intake fluctuations (DMIF) during the subsequent days after concentrate challenge, ruminal fermentation (pH; SCFAs, lactate and NH3-N concentrations). There were no treatment main effects (P > 0.05) for DMIK, DMIB, DMIM or DMIF. Higher pH was measured (P < 0.0001) in MON, compared to the other two treatments (MON = 6.06 vs. PAP = 5.89 and CTL = 5.91). Ruminal lactate concentration remained low (0.23 mM) throughout the entire experimental period. Ruminal ammoniacal-N concentration of CTL was lower (P = 0.0039), compared to MON and PAP (14.74 and 13.64 vs. 11.20 mg/dl, for MON, PAP and CTL, respectivelly). Molar concentration of acetate was not affected (P = 0.3288) by treatments. However, an interaction day x treatment (P = 0.0079) for propionate molar concentration was... (Complete abstract click electronic access below) / Orientador: Mário de Beni Arrigoni / Coorientador: Paulo Henrique Mazza Rodrigues / Banca: Jane M. Ezequiel / Banca: Paulo Roberto Meirelles / Banca: Carolina T. Marino / Banca: Paulo Roberto Lemes / Doutor

Le développement des anticorps monoclonaux thérapeutiques est en plein essor notamment à cause de leur bénéfice important pour le traitement des cancers. Cependant, à l’heure actuelle, aucun anticorps monoclonal sur le marché ou en phase III ne cible de RCPGs, en dépit de l’implication grandissante de ces récepteurs dans la carcinogenèse. Parmi les RCPGs les plus pertinents pour l’oncologie, souvent cités dans la littérature et dont certains inhibiteurs chimiques sont en phase clinique avancée, on trouve les deux sous-types de récepteurs des endothélines ETAR et ETBR. Dans ce contexte, mon projet de thèse a consisté à produire des anticorps monoclonaux capables de lier spécifiquement les récepteurs des endothélines, puis à les caractériser dans le but d’évaluer leur potentiel antitumoral. Grâce à une stratégie d’immunisation génique, un ensemble de 27 anticorps monoclonaux, tous spécifiques de la forme native d’ETBR, a été obtenu. Un de ces anticorps, nommé rendomab-B1, a fait l’objet d’une caractérisation précise et s’est révélé être un puissant inhibiteur allostérique d’ETBR. De plus, cette propriété antagoniste a permis de bloquer l’action autocrine antiapoptotique de l’ET-1 sur des cellules endothéliales vasculaires, suggérant ainsi que le rendomab-B1 pourrait être utilisé comme agent thérapeutique afin d’inhiber les effets tumorigènes liés à la suractivation de l’axe ET1/ETBR au niveau de l’endothélium vasculaire tumoral. Par ailleurs, le rendomab-B1 a également été testé sur des lignées de mélanomes humains ; l’absence de fixation de l’anticorps malgré la présence de récepteurs ETB fonctionnels à la surface de ces cellules suggère l’existence d’une forme moléculaire atypique du récepteur, potentiellement spécifique aux mélanomes. A la lumière de ces résultats, le rendomab-B1 apparaît comme un outil prometteur, à la fois pour l’étude structurale et fonctionnelle d’ETBR, mais aussi pour une éventuelle thérapie anticancéreuse. Enfin, les 26 autres anticorps monoclonaux anti-ETBR, actuellement en cours de caractérisation, constituent également des molécules potentiellement intéressantes pour un usage fondamental ou thérapeutique impliquant ETBR. Pour conclure, ces travaux ont démontré l’intérêt de la méthode d’immunisation génique pour la production d’anticorps monoclonaux anti-RCPGs à visée thérapeutique. / For a decade, monoclonal antibodies have become increasingly important for the biotherapeutic management of cancer. However, none of the monoclonal antibodies currently on the market or in late stage clinical trial do target a G-protein coupled receptor in spite of the emerging role of these receptors in tumor progression. Among the therapeutically relevant GPCRs for oncology, the endothelin receptors (ETAR and ETBR) are particularly attractive considering their overexpression in a wide range of tumors and their involvement in various stages of tumorigenesis. In this context, my PhD project consisted in producing and characterizing monoclonal antibodies directed against endothelin receptors with a view to use them as anti-tumor agents. Using an original DNA immunization strategy, we produced a panel of 27 monoclonal antibodies which selectively recognized ETBR expressed at the surface of transfected cells. One of these antibodies, named rendomab-B1, was extensively characterized and proved to be a potent allosteric antagonist of ETBR. Moreover, rendomab-B1 was able to disrupt the autocrine ET1-mediated survival loop on vascular endothelial cells, suggesting that this antibody could be used to prevent the pro-tumorigenic effect due to ET-1 and ETBR upregulation in the tumor-surrounding endothelium. Furthermore, rendomab-B1 binding onto ETBR was also assessed on melanoma cell lines and revealed that a tumor-specific form of ETBR may exist, as illustrated by the poor fixation of rendomab-B1 on these cells in spite of the presence of functional ETB receptors. Together, these results present rendomab-B1 as promising agent, not only for the structural and functional study of ETBR, but also for its therapeutic modulation in the case of cancer for instance. Finally, the other 26 monoclonal antibodies, whose characterization is still ongoing, also constitute potential tools for fundamental or therapeutic applications involving ETBR. To conclude, this work has highlighted the relevance of the DNA immunization approach to generate monoclonal antibodies against the native form of GPCRs.

Les anticorps monoclonaux représentent aujourd’hui un outil de choix en thérapeutique et en diagnostic. Les anticorps thérapeutiques sont des biomédicaments en plein essor depuis les années 1970 et représentent 10% du marché des produits pharmaceutiques. Les anticorps monoclonaux sont utilisés dans divers domaines : en cancérologie, pour lutter contre les maladies auto-immunes ou en infectiologie. Le nombre des anticorps monoclonaux en développement ne cesse d’augmenter. Les premiers anticorps monoclonaux utilisés en thérapie étaient d’origine murine et leur administration à l’Homme est susceptible de déclencher des effets secondaires. De nouveaux anticorps visant à limiter voir faire disparaitre ces effets indésirables tels que d’abord les anticorps chimériques, puis les anticorps humanisés et enfin les anticorps totalement humains ont été développés. 9 anticorps totalement humains sont actuellement sur le marché et d’autres sont en cours de développement. Le phage display, les souris transgéniques et l’utilisation de lymphocytes B humains sont les trois stratégies mises en œuvre pour produire des anticorps totalement humains. L’utilisation des lymphocytes B humains, peu étudiée à cause d’un faible rendement et de problèmes de stabilité, a connu ces dernières années un regain d’intérêt grâce à l’immortalisation virale par le virus Epstein-Barr et à la découverte de myélomes humains. Dans ce contexte, l’objectif de mon projet de thèse a été la production d’anticorps monoclonaux humains à partir de lymphocytes B humains. Pour ce faire, deux approches basées sur l’immortalisation virale par le virus Epstein-Barr couplée ou non à une immortalisation cellulaire par des myélomes ont été mises en œuvre. La première approche utilise des lymphocytes B mémoires isolés de sang périphérique de donneurs infectés ou vaccinés. L’entérotoxine B de Staphylococcus aureus (SEB) a été utilisée comme modèle.La deuxième approche implique une immunisation in vitro de lymphocytes B naïfs extraits de sang périphérique. Cette stratégie pourrait permettre la production d’anticorps humains contre des antigènes pour lesquels il n’existe pas de donneurs infectés ou vaccinés. Deux modèles, le peptide N-terminal de la neurotoxine A de Clostridium Botulinium A (BoNT/A) et la protéine de fusion ZZTat101, comportant le domaine ZZ de Staphylococcus aureus lié covalemment à la protéine transactivatrice Tat du virus de l’immunodéficience humaine VIH-1, ont été employés. Nous avons réussi à obtenir des IgMs dirigés contre la neurotoxine Clostridium Botulinium A, ainsi que des IgMs (et peut-être des IgGs) dirigés contre la protéine Tat. L’immortalisation par Epstein-Barr, nous a permis d’isoler 7 lignées de lymphocytes immortalisés sécrétant des anticorps IgMs anti-TBA-Nter humains. L’immunisation in vitro produisant essentiellement des IgMs, la possible production d’IgGs après stimulation par la protéine ZZTat101 se révèle un résultat très intéressant. Nous avons montré que la production d’anticorps par ZZTat101 impliquait les 7 cystéines, la région 22-57 et la liaison aux héparanes sulfates de Tat. / The number of monoclonal antibodies used as drug or under clinical investigation increases rapidly. The first murine monoclonal antibodies (mAbs) used in therapy induces human anti-mouse antibodies (HAMAs) when administered to patients. Such HAMAs hamper the therapeutic efficacy of mAbs and induce side effects. To limit these effects, new antibodies were developed during the, last 30 years. Chimeric, humanized and fully human antibodies were engineered. The use of human monoclonal antibodies (hAbs) appears ideal to solve the problem of HAMAs. Nowadays 9 fully human antibodies are available and others are evaluated in clinical trials or currently investigated in research labs. Three methods exist to produce fully human antibodies: the phage display, the transgenic mice and the use of human B lymphocytes. The majority of fully human antibodies resulted from the phage display and the transgenic mice methods. The use of human B lymphocytes is less investigated due to a poor yield and stability problems. These last years, the immortalization process, thanks to the involvement of the Epstein-Barr virus and human myeloma, induced a rise of interest for human B lymphocytes. In this context we decided to develop fully human monoclonal antibodies using human B lymphocytes through immortalization using the Epstein-Barr virus followed or not by an immortalization with a human/mouse heteromyeloma HM. The first approach is based on hAbs production from peripheral blood memory B lymphocytes isolated from infected or vaccinated donors. The Staphylococcus aureus enterotoxine B (SEB) was used as a model. Memory B lymphocytes were purified and cultured in the presence of Epstein-Barr virus (EBV). The transformation of memory B lymphocytes by EBV allowed the generation of immortalized B lymphocytes lines producing IgGs antibodies directed against SEB. We succeeded in isolating 6 EBV-immortalized memory B lymphocytes lines secreting anti-SEB IgGs antibodies. After many attempts to immortalize EBV immortalized memory B lymphocytes lines secreting anti-SEB antibodies with myeloma, the fusion of a EBV immortalized memory B lymphocytes with the human/mouse heteromyeloma HM led to an hybridoma. Unfortunately this hybridoma has rapidly lost its capacity to secrete d’IgGs anti-SEB. In the second approach the hAbs production implies the in vitro immunization of peripheral blood naïve lymphocytes. This strategy could allow the hAbs production against antigens for which no infected or vaccinated donors may be available. The Clostridium Botulinum neurotoxin A (BoNT/A), the most powerful toxin, and its N-terminal peptide (TBA-Nter) or the fusion protein ZZTat101 were used as models. ZZTat101 is a fusion between the ZZ domain of Staphylococcus aureus and the Tat protein of the human immunodeficiency virus HIV-1. Monocytes, B lymphocytes and T lymphocytes were isolated from human PBMC depleted of Natural killer. These cells were tools to develop efficient in vitro immunization protocols. IgMs directed against TBA-Nter and also IgMs (and possibly IgGs) directed against Tat were obtained. The use of the Epstein-Barr virus induced 7 EBV immortalized lines secreting anti-TBA-Nter IgMs antibodies. Unfortunately, after fusion with the heteromyeloma HM no hybridoma was isolated against TBA-Nter and Tat. The ZZTat101 mechanism involved on humoral response was studied, showing that the 7 cysteines, the region 22-57 and the ability of Tat to bind heparane sulfate are necessary to trigger the humoral response.

Anticorpos (Ac) anti-oxLDL estão envolvidos no desenvolvimento da lesão aterosclerótica. Induzimos a produção desses Ac através da imunização com oxLDL. Avaliamos os perfis lipídico e de Ac anti-oxLDL e anti-pepD (pepD é um peptídeo derivado da apoB). Animais apoE-/- possuem maiores níveis de lípides sorológicos em comparação com animais C57Bl/6, exceção da HDL. A imunização oxLDL não alterou este perfil. A imunização aumentou os títulos dos Ac IgM, IgG e IgG1 anti-oxLDL. Animais C57Bl/6, mas não os apoE-/- tiveram aumento dos Ac IgM anti-pepD após a imunização. Acreditamos que o aumento de anticorpos IgG1 deve-se ao adjuvante usado. A aterosclerose pode ocorrer com maior freqüência, em indivíduos portadores de doenças renais crônicas. Para estudar essa interferência submetemos os animais a um modelo de isquemia e reperfusão renal (I/R). A I/R promoveu aumento da concentração de TG, podendo agravar a aterosclerose. O aumento de Ac IgG anti-oxLDL promovidos pela I/R sugere que o processo inflamatório desencadeado por este procedimento, aumenta a oxidação de LDL. Desta forma, concluímos que a I/R pode ser considerado um procedimento pró-aterosclerótico que não pode ser revertido pela imunização com oxLDL. / Oxidized LDL (oxLDL) antibodies (Ab) are involved in the development of the atherosclerotic lesion. We induced the formation of such Ab through immunization with oxLDL. We evaluate the lipids and antibody (anti-oxLDL and anti-pepD pep D is a peptide derived from apolipoprotein B) profile. The apoE-/- mice used have higher seric levels of most lipids than C57Bl/6 animals, the exception being HDL. The oxLDL immunization does not change this profile. The immunization increased anti-oxLDL Ab e IgM, IgG and IgG1 titers. Anti-pepD IgM Ab increased with immunization in C57Bl/6 animals only, and not in apoE-/-. We believe the increased IgG1 Ab due to the adjuvant used. Atherosclerosis has a higher incidence in individuals with chronic renal conditions. In order to study such interference, we submitted the animals to a renal ischemia and reperfusion model (I/R). The I/R procedure increased TG concentration, what can make atherosclerosis more severe. The increase in IgG anti-oxLDL antibody caused by I/R suggests that the inflammation process set by the procedure increases LDL oxidation. This way, we conclude that the I/R can be considered a pro-atherosclerotic procedure. The oxLDL immunization was not able to revert the atherogenic effect caused by I/R model.

This thesis investigates the development of the Brazilian vaccine industry. This industry has experienced a sharp growth in the last decades supported by public policies and a protected and fast-growing public market. In addition, this development is apparently characterized by continuous processes of technology acquisition, rather than indigenous R&D, as the main source of its technological knowledge, and by other specificities in the vaccine context. The research draws on studies of the dynamics of technological capability building in catching-up industries of latecomer contexts, especially during the transition period when they are approaching the innovation frontier. It also draws on those studies focusing on new directions/paths as an alternative strategy adopted to overcome barriers and disadvantages to develop. It has been argued that the specificities of the Brazilian context and, of the vaccine sector, may be determining a particular pattern of technological accumulation to this industry, and that interpreting its pattern of development may be useful to understand how and if this industry has overcome its constraints to develop. A framework based on linear approaches of catching-up, and that integrates the innovation transition approach was built as a benchmark model for the search for similarities and differences in the pattern of development of this industry. The findings show similarities and new directions in the process of technological accumulation of the industry, suggesting that, more recently, it has actually developed through a distinct pattern. They also show the strong role of the government and its public market as one of the drivers of this new path. Distinct roles of the technology acquisition strategy and a high level of technological capabilities currently developed are also revealed. Finally, they show that the technology acquisition strategy has effectively contributed to the development of this industry and that the constraints to the completion of the transition phase is linked less to technical and scientific issues and more to managerial and policy ones.

Made available in DSpace on 2014-06-11T19:31:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-29Bitstream added on 2014-06-13T20:40:58Z : No. of bitstreams: 1 silva_vk_dr_jabo.pdf: 1506111 bytes, checksum: 562838af0ec5f22ad837aa2904b5851a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dois experimentos foram conduzidos com o objetivo de avaliar os efeitos da ingestão contínua de pectina. No primeiro experimento, foram avaliados a digestibilidade da ração, a viscosidade e o tempo de trânsito intestinal. Para isso, 240 frangos de corte macho Cobb® foram distribuídos em delineamento inteiramente casualizado (DIC), em 4 tratamentos (0, 1, 3 e 5% de pectina) compostos por 6 repetições de 10 aves por unidade experimental. As análises foram realizadas em duas fases: inicial (14 a 18 dias) e crescimento (27 a 31 dias). Os resultados mostraram que com a ingestão de pectina houve melhora da digestibilidade dos nutrientes na fase inicial dos frangos e piora na fase de crescimento, aumento na viscosidade e no tempo de trânsito intestinal e redução na umidade da excreta. No segundo experimento, foram analisados o desempenho e rendimento de cortes aos 35 e 42 dias de idade, o desenvolvimento semanal das aves e o consumo de água, parâmetros bioquímicos plasmáticos, morfometria do tecido adiposo abdominal, morfometria do fígado e teor de lipídio total hepático e dos músculos peitoral maior e gastrocnêmio. Foram utilizados 720 pintos machos Cobb® distribuidos em DIC, composto por 4 tratamentos (0, 1, 3 e 5% de pectina) e 6 repetições de 30 aves por unidade experimental. Na última semana, o consumo de água aumentou com o aumento do nível de pectina na ração. O consumo de até 1% de pectina na ração mantém o desempenho das aves. Aos 42 dias de idade ocorreu redução nos valores de proteína total plasmática com a ingestão de pectina. Os níveis de 3 e 5% reduziram as concentrações de colesterol total e, o nível de 5% reduziram os níveis de HDL. A ingestão de pectina proporcionou diminuição na concentração de lipídio hepático e menor relação entre peso corporal e gordura abdominal com a ingestão de 5% de pectina aos 42 dias. As concentrações... / Two experiments were conducted to evaluate the effects of continuous pectin intake. In the first experiment evaluated the digestibility of feed, the viscosity and intestinal transit time. For this, 240 male Cobb® broilers were distributed in a randomized design in four treatments (0, 1, 3 and 5% pectin) formed by 6 repetitions of 10 birds each. Analyses were performed in two stages: early (14 to18 days) and growth (27 to 31 days). The results showed that the ingestion of pectin had improved the digestibility of nutrients in the initial phase of chickens and worsens during growth, increase in viscosity and intestinal transit time and reduction in moisture of excreta. The second experiment analysed the performance and yield of the 35 and 42 days old, the weekly development of birds and water consumption, biochemical parameters, morphometry of abdominal adipose tissue, liver morphology and hepatic, pectoralis major and gastrocnemius lipid content. We used 720 male Cobb® chicks distributed in a completely randomized design with 4 treatments (0, 1, 3 and 5% pectin) consisting of six replicates of 30 birds each. In the last week, water consumption increased with increase level of pectin in the diet. The consumption up to 1% pectin keeps the performance of broilers.. At 42 days of age there was a reduction in total plasma protein values with the intake of pectin. The levels of 3 and 5% reduced the levels of total cholesterol and the level of 5% reduced levels of HDL. The intake of pectin resulted in decreased hepatic lipid content and lower ratio of body weight and abdominal fat with intake of 5% pectin and 42 days. The lipid concentration in the pectoralis major and gastrocnemius muscles were not influenced by levels of pectin in the same age

Estudos sobre imunização do desamparo aprendido apresentam resultados contraditórios quando utilizam estímulos apetitivos na fase de imunização. Uma análise dos procedimentos utilizados nesses estudos sugere que eles diferem no grau de controle e previsibilidade da liberação do estímulo apetitivo. Além disso, foi demonstrado que quando a previsibilidade do estímulo é manipulada ela produz efeitos dependentes do sexo do sujeito. O presente estudo teve por objetivos avaliar se: 1) a previsibilidade e a controlabilidade de estímulos apetitivos na fase de imunização são variáveis críticas para imunizar ratos contra o desamparo; 2) esses efeitos são dependentes do sexo. Em paralelo, buscou-se explorar alguns efeitos das variáveis hormonais nesses comportamentos. Um Estudo Piloto demonstrou não haver diferença quanto ao desamparo em fêmeas nas fases de estro e diestro do ciclo estral. Quanto à imunização (Experimento 1), foi utilizado reforçamento positivo combinando-se as variáveis de controle (VI e VT) e previsão (com ou sem sinal antecedendo a disponibilização do reforço), utilizando-se grupos (n=16) com ratos machos e fêmeas em igual proporção. Em seguida esses animais foram submetidos a choques incontroláveis e por fim a um teste de fuga. Outro grupo de machos e fêmeas passou apenas pelas duas últimas fases e um grupo apenas pela fase final. Os resultados mostraram que o sexo dos animais não é uma variável importante para o desamparo, mas que essa é uma variável que interfere na imunização do desamparo aprendido. Fêmeas expostas a estímulos previsíveis e controláveis na fase de imunização apresentam um comportamento muito semelhante as fêmeas e machos do Grupo não choque. Por outro lado, apenas metade dos machos expostos a estímulos apetitivos previsíveis e controláveis na fase de imunização aprenderam a resposta de fuga no teste. Esses resultados sugerem que o sexo é uma variável que precisa ser mais investigada em experimentos que estudam o comportamento. No Experimento 2 as fêmeas foram distribuídas em dois grupos (castradas e sham), foram retirados os ovários dos animais do primeiro grupo, responsáveis pela produção do estrógeno, hormônio que as diferencia dos machos. Após a recuperação da cirurgia os animais de ambos os grupos foram expostos ao mesmo procedimento de imunização do Grupo imprevisível e controlável do Experimento 1, o único em que foram obsevadas diferenças estatísticas entre machos e fêmeas. Os resultados mostraram aproximadamente metade das fêmeas, de ambos os grupos, aprenderam fuga apresentando latências semelhantes entre si, sugerindo que a presença ou ausência do hormônio sexual em fêmeas não foi, aparentemente, o fator determinante da diferença de gênero na imunização. Discute-se a relevância dos estudos comportamentais entre gêneros mostrando a interação de fatores ambientais com orgânicos / Studies on immunization against learned helplessness have different results when using appetitive stimuli during immunization. An analysis of these studies procedures suggests that they differ in the degree of control and predictability of the release of appetitive stimulus. Furthermore, it was shown that when the predictability of the stimulus is manipulated it produces effects that depend of the subjects sex. The objective of the present study was to evaluate : 1) if the appetitive stimuli predictability and controllability during immunization are critical variables to immunize rats against learned helplessness; and if 2) these effects are sex dependent. In parallel, we explored t some effects of hormonal variables on these behaviors. A pilot study showed no difference regarding learned helplessness in estrus and diestrus phases of the estrous cycle. Concerning immunization (Experiment 1), positive reinforcement was used combining the variables of control (VI and VT) and predictability (with or without signal preceding the availability of reinforcement), using groups (n = 16) with equal proportion of male and female rats. Then these animals were subjected to uncontrollable shock and finally to an escape test. Another group with males and females was submitted only to the last two phases and a last group only to the final phase. The results showed that sex is not an important variable concerning learned helplessness, but it interferes with the immunization against learned helplessness. Females exposed to predictable and controllable stimuli during immunization showed similar behavior with females and males of Non Shock Group. On the other hand, only half of the males exposed to predictable and controllable appetitive stimuli during immunization phase learned the escape response during the test. These results suggest that sex is a variable that needs to be better investigated in behavior experiments. In Experiment 2, females were distributed into two groups (castrated and sham), the ovaries of the animals of the first group were removed, they are responsible for the estrogen production, a hormone that differentiates males from females. After recovery from surgery, both groups were exposed to the same immunization procedure of the unpredictable and controllable group from Experiment 1, the only group that statistical differences between males and females were observed. Females in both groups showed similar escape latencies suggesting that the presence or absence of sex hormone in females was apparently not the determining factor of gender difference in immunization. It is discussed the relevance of behavioral sex differences studies showing the interaction of environmental with organic factors