O desenvolvimento de vacinas contra o vírus do papiloma humano (HPV) representa uma importante alternativa para o controle da infecção sexualmente transmissível e do câncer cervical. Neste trabalho exploramos uma estratégia vacinal inédita contra tumores induzidos pelo HPV-16 empregando a proteína E7 obtida após fusão genética com a glicoproteína D do vírus herpes tipo 1, uma proteína com propriedades adjuvantes para linfócitos T. A proteína recombinante gDE7 foi expressa em bactérias e em células de inseto e purificada por cromatografia de afinidade. A proteína gerada em bactérias foi administrada nas formas insolúvel e solúvel como vacina em camundongos. A gDE7 insolúvel conferiu 80% de proteção profilática para o crescimento tumoral, a gDE7 que manteve a forma solúvel após refolding protegeu 100% dos animais nas mesmas condições. Já a proteção terapêutica alcançou 30% dos animais. Além disso, verificamos o potencial neutralizante dos soros gerados frente ao HSV-1. As condições de obtenção das proteínas expressas em células de inseto também foram estabelecidas. / The development of vaccines against human papillomavirus (HPV) represents an important alternative to control the sexually transmitted infection and cervical cancer. In this paper we explored a novel vaccine strategy against tumors induced by HPV-16 using the E7 protein obtained after genetic fusion to the glycoprotein D of herpes virus type 1, a protein with adjuvant properties for T lymphocytes. The recombinant protein gDE7 was expressed in bacteria and in insect cells and purified by affinity chromatography. The protein generated in bacteria was administered in soluble and insoluble forms as a vaccine in mice. The insoluble gDE7 gave 80% prophylactic protection for tumor growth, the gDE7 that kept the soluble form after refolding protected 100% of the animals under the same conditions. The therapeutic protection reached 30% of the animals. We also verified the neutralizing potential of sera generated against the HSV-1. The conditions for obtaining the proteins expressed in insect cells were also established.

Forma epimastigotas de T. cruzi são aglutinadas especificamente por baixas concentrações de concanavalina A. A aglutinação é linear com o tempo até aproximadamente10 minutos, para um número de células maior que 1 x 108 células/ml. Nessas condições a aglutinação é dependente da concentração de con A. As formas tripomastigotas sanguícolas e matecíclicas não são aglutináveis por con A. O complexo glicoproteico isolado de formas epimastigotas de T. cruzi por tratramentofenólico de extrato celular, apresenta na sua composição ácida siálico, glicosamina, galactose, glicose e manose, além de xilose em algumas frações. Os aminoácidos constituintes são principalmente lisina, ácido aspártico (e/ou asparagina), alanina, treonina, ácido glutâmico (e/ou glutamina). serina, prolina e glicina. Esse complexo pode ser separado em três componentes em colunas de DEAE-celulose. Dois desses componentes, selecionados para estudo, inibem a reação de aglutinação por con A das formas epimastigotas, assim como a fração não cromatografada. Essas frações isoladas fornecem quatro componentes glicoproteicos por eletroforese em gel de poliacrilamida na presença de SDS. / Epimastigote forms of T. cruzi are agglutinated by low con A concentrations. The agglutinabillity is linear up to 10 minutes. Under these conditions the agglutination is dependent on the con A concentration providing the cell density is 108/ml or higher. The blood forms and culture trypomastigotes are not agglutinated by con A. A glycoprotein complex was isolated from epimastigote forms of T. cruzi by aqueous phenol extraction. This complex is composed by sialic acid, glucosamine, galactose, glucose, mannose and xylose. The latter appears only in some fractions of the complex. The amino acids found are lysine, aspartic acid (and/or asparagine), alanine, threonine, glutamic acid (and/or glutamine), serine, proline and glycine. The glycoproteins render three components in DEAE-cellulose columns (peaks 1, 2 and 3). The peaks 2 and 3 are able to inhibit the agglutination of epimastigotes by con A. These fractions are separated in four glycoprotein components by polyacrylamide gel electrophoresis in the presence of SDS.

A matriz extracelular (MEC) pode ser definida como um complexo de proteínas e glicoproteínas que envolve as células nos mais diversos tecidos e tem papel importante na diferenciação e atividade celular, bem como no processo de mineralização e nos processos neoplásicos. Os componentes não colágenos da MEC têm sido abundantemente estudados, visando conhecer os minuciosos detalhes da biologia dos tecidos e assim entender os mecanismos envolvidos em suas patologias. Neste contexto, o presente trabalho tem como objetivo estudar a expressão e distribuição dos seguintes componentes não colágenos da MEC dos tecidos dentais: biglican, decorin, fibromodulin, osteonectina (ONC), osteopontina (OPN), sialoproteína óssea (BSP) e osteocalcina (OCC) no ameloblastoma e no tumor odontogênico cístico calcificante (cisto de Gorlin). Para ta nto foi utilizada a técnica da imunoistoquímica, com o método da estreptavidina-biotina-peroxidase, e anticorpos contra as proteínas anteriormente citadas. Os resultados mostraram que o biglican, o decorin e a BSP foram expressos somente nas células epiteliais metaplásicas, nas células fantasmas e células fantasmas em processo de calcificação, no estroma dos ameloblastomas e no ectomesênquima neoplásico do tumor odontogênico cístico calcificante. Já o fibromodulin e a OC foram predominantemente negativos no componente epitelial e no mesenquimal, com exceção para as células fantasmas, células fantasmas em processo de calcificação e áreas de hialinização próximas ao epitélio. A ONC foi positiva na maioria das células epiteliais, com exceção das células estrelárias dos ameloblastomas folicular e acantomatoso, e também no componente mesenquimal de ambas neoplasias. Já a OPN apresentou positividade somente nos focos de calcificação presentes no tumor odontogênico cístico calcificante. As proteínas estudadas apresentaram distribuição semelhante em neoplasias caracterizadas por padrões de crescimento diferentes, levando a crer que, apesar de participarem ativamente do mecanismo de crescimento neoplásico intra-ósseo, isoladamente não exercem papel decisivo na determinação do tipo de padrão de crescimento. Outro fato digno de relevância é a baixa expressão dessas proteínas nas células epiteliais neoplásicas quando comparada com a expressão no estroma e ectomesênquima, levando-nos a crer que as células epiteliais atuem principalmente como estimuladores da expressão dessas proteínas, que, por sua vez, podem atuar de forma agonista ou antagonista ao crescimento neoplásico. / The extracellular matrix (ECM) can be defined as a complex of proteins and glycoproteins that involves the cells in all tissues. It has a key role in cell differentiation and activity, as well as in mineralization and neoplastic processes. The non-collagenous components of the ECM have been abundantly studied to know the details of the biology of tissues and thus to understand the mechanisms involved in its pathologies. The aim of the present work is to study the expression and distribution of the following noncollagenous components of the ECM of dental tissues: biglycan, decorin, fibromodulin, osteonectin (ONC), osteopontin (OPN), bone sialoprotein (BSP) and osteocalcin (OCC) in ameloblastoma and the calcifying cystic odontogenic tumour. The streptavidin-biotinperoxidase method of immunohistochemistry was used with antibodies against the antigens previously cited. The results show that biglican, decorin and BSP had been expressed only in metaplastic epithelial cells, in ghost cells and ghost cells in calcification process, stroma of ameloblastomas and neoplastic ectomesenchyma of the calcifying cystic odontogenic tumour. The fibromodulin and the OCC showed predominantly negative expression in the epithelial and mesenchymal components, with exception for the ghost cells, ghost cells in calcification process and hyalinization areas next to the epithelium. The ONC was positive in the majority of the epithelial cells, with exception of the central cells of follicular and acanthomatous ameloblastomas, and also in the mesenchymal component of both tumours. OPN presented positivity only in the calcification focus of the calcifying cystic odontogenic tumour. The proteins studied presented similar distribution in tumours characterized by different patterns of growth, leading to believe that although they participate actively of the mechanism of intraosseous growth, separately they do not exert a key role in the determination of the type of growth pattern. Another relevance fact is the low expression of these proteins in the neoplastic epithelial cells when compared to the expression in stroma and ectomesenchyma, which make us believe that the epithelial cells act mainly as stimulators of the expression of these proteins, which in turn can act as agonist or antagonist to the tumour growth.

A matriz extracelular (MEC) pode ser definida como um complexo de proteínas e glicoproteínas que envolve as células nos mais diversos tecidos e tem papel importante na diferenciação e atividade celular, bem como no processo de mineralização e nos processos neoplásicos. Os componentes não colágenos da MEC têm sido abundantemente estudados, visando conhecer os minuciosos detalhes da biologia dos tecidos e assim entender os mecanismos envolvidos em suas patologias. Neste contexto, o presente trabalho tem como objetivo estudar a expressão e distribuição dos seguintes componentes não colágenos da MEC dos tecidos dentais: biglican, decorin, fibromodulin, osteonectina (ONC), osteopontina (OPN), sialoproteína óssea (BSP) e osteocalcina (OCC) no ameloblastoma e no tumor odontogênico cístico calcificante (cisto de Gorlin). Para ta nto foi utilizada a técnica da imunoistoquímica, com o método da estreptavidina-biotina-peroxidase, e anticorpos contra as proteínas anteriormente citadas. Os resultados mostraram que o biglican, o decorin e a BSP foram expressos somente nas células epiteliais metaplásicas, nas células fantasmas e células fantasmas em processo de calcificação, no estroma dos ameloblastomas e no ectomesênquima neoplásico do tumor odontogênico cístico calcificante. Já o fibromodulin e a OC foram predominantemente negativos no componente epitelial e no mesenquimal, com exceção para as células fantasmas, células fantasmas em processo de calcificação e áreas de hialinização próximas ao epitélio. A ONC foi positiva na maioria das células epiteliais, com exceção das células estrelárias dos ameloblastomas folicular e acantomatoso, e também no componente mesenquimal de ambas neoplasias. Já a OPN apresentou positividade somente nos focos de calcificação presentes no tumor odontogênico cístico calcificante. As proteínas estudadas apresentaram distribuição semelhante em neoplasias caracterizadas por padrões de crescimento diferentes, levando a crer que, apesar de participarem ativamente do mecanismo de crescimento neoplásico intra-ósseo, isoladamente não exercem papel decisivo na determinação do tipo de padrão de crescimento. Outro fato digno de relevância é a baixa expressão dessas proteínas nas células epiteliais neoplásicas quando comparada com a expressão no estroma e ectomesênquima, levando-nos a crer que as células epiteliais atuem principalmente como estimuladores da expressão dessas proteínas, que, por sua vez, podem atuar de forma agonista ou antagonista ao crescimento neoplásico. / The extracellular matrix (ECM) can be defined as a complex of proteins and glycoproteins that involves the cells in all tissues. It has a key role in cell differentiation and activity, as well as in mineralization and neoplastic processes. The non-collagenous components of the ECM have been abundantly studied to know the details of the biology of tissues and thus to understand the mechanisms involved in its pathologies. The aim of the present work is to study the expression and distribution of the following noncollagenous components of the ECM of dental tissues: biglycan, decorin, fibromodulin, osteonectin (ONC), osteopontin (OPN), bone sialoprotein (BSP) and osteocalcin (OCC) in ameloblastoma and the calcifying cystic odontogenic tumour. The streptavidin-biotinperoxidase method of immunohistochemistry was used with antibodies against the antigens previously cited. The results show that biglican, decorin and BSP had been expressed only in metaplastic epithelial cells, in ghost cells and ghost cells in calcification process, stroma of ameloblastomas and neoplastic ectomesenchyma of the calcifying cystic odontogenic tumour. The fibromodulin and the OCC showed predominantly negative expression in the epithelial and mesenchymal components, with exception for the ghost cells, ghost cells in calcification process and hyalinization areas next to the epithelium. The ONC was positive in the majority of the epithelial cells, with exception of the central cells of follicular and acanthomatous ameloblastomas, and also in the mesenchymal component of both tumours. OPN presented positivity only in the calcification focus of the calcifying cystic odontogenic tumour. The proteins studied presented similar distribution in tumours characterized by different patterns of growth, leading to believe that although they participate actively of the mechanism of intraosseous growth, separately they do not exert a key role in the determination of the type of growth pattern. Another relevance fact is the low expression of these proteins in the neoplastic epithelial cells when compared to the expression in stroma and ectomesenchyma, which make us believe that the epithelial cells act mainly as stimulators of the expression of these proteins, which in turn can act as agonist or antagonist to the tumour growth.

Mise en oeuvre de microréseaux de lectines naturelles et recombinantes dédiés au suivi de production des glycoprotéines d’intérêt thérapeutiqueLes anticorps thérapeutiques, biomédicaments dont le marché est en pleine expansion, sont des glycoprotéines obtenues en bioproduction dans des cellules eucaryotes. Leur N-glycosylation, cruciale pour la modulation des fonctions effectrices des anticorps, confère un effet pro-inflammatoire ou anti-inflammatoire aux anticorps. Les anticorps thérapeutiques recombinants actuellement commercialisés présentent des glycosylations dites tronquées (GlcNAc terminaux) ou non humaines (α-Gal, NeuGc) rendant les anticorps immunogènes et, par conséquent, réduisant notablement leur efficacité. Les Agences de Santé exigent de réduire cet effet secondaire. La société SiaMed’Xpress a développé un savoir-faire pour obtenir une glycosylation complète, incluant la sialylation terminale des N-glycanes par ingénierie des cellules eucaryotes. Il est nécessaire de disposer d’outils d’analyse permettant de suivre la qualité de la N-glycosylation au cours de la production.La modification du milieu de culture par ajout de suppléments nutritionnels permet une modulation supplémentaire de la glycosylation. L’utilisation de suppléments nutritionnels commerciaux augmentent le taux de production mais bloquent la glycosylation au stade G0(F) (GlcNAc terminaux) alors que l’utilisation d’un supplément propre à SiaMed’Xpress permet de poursuivre jusqu’à la galactosylation et la sialylation, mettant ainsi en évidence un carrefour métabolique clé dans la glycosylation. Pour suivre les modifications de glycosylation dans différentes conditions de production, un test utilisant des lectines a été développé. Un jeu de treize lectines naturelles et recombinantes a été sélectionné par analyse bio-informatique et intégré dans un glycotest. L’utilisation de ce glycotest pour l’analyse de la glycosylation de trois anticorps produits en présence de différents suppléments nutritionnels permet d’obtenir de façon rapide, fiable et reproductible les profils de glycosylation des anticorps. Ainsi, le glycotest développé est fonctionnel et permet de caractériser la glycosylation des anticorps thérapeutiques recombinants. / Development of natural and recombinant lectin microarrays for monitoring the production of glycosylated protein drugsTherapeutic antibodies, biologic drugs whose market is growing, are glycoproteins obtained though bioproduction in eukaryotic cells. Their N-glycosylation, which is crucial for the modulation of effector functions, confers a pro-inflammatory or anti-inflammatory effect to antibodies. Currently, marketed therapeutic recombinant antibodies have truncated (terminal GlcNAc) or non human (α-Gal, NeuGc) glycosylation, inducing immunologic reaction and, consequently, reducing their effectiveness. Health agencies demand to reduce such secondary effects. SiaMed’Xpress developped a knowledge to obtained a complete glycosylation, including terminal sialylation of N-glycans by engineering eukaryotic cells for production. It is now necessary to develop analysis tools to monitor the quality of the N-glycosylation during bioproduction.Modification of culture media with feeds allows to further modulate glycosylation. The use of marketed feeds increase the production rate but block the glycosylation process in the G0(F) state (terminal GlcNAc) whereas SiaMed’Xpress feed allows for galactosylation and sialylation, highlighting a metabolic key point during the glycosylation. To follow the glycosylation modifications under different conditions of production, an assay using lectins has been developed. A panel of 13 lectins, recombinants and naturals, has been determined by bio-informatic analysis and integrated into a glycotest. The use of this glycotest to analyse glycosylation of 3 antibodies produced with different feeds allows fast, reliable and reproductible glycosylation profils of these antibodies. So, this developped glycotest is functionnal and this using permits to monitore therapeutic recombinant antibody glycosylation during bioproduction.

Arenaviruses and hantaviruses are human pathogens that cause significant morbidity and mortality. The current lack of vaccines and treatment options for these viruses is a global concern. Despite producing only 4 proteins, these viruses are able to maintain a persistent and asymptomatic infection in wild rodents while being continuously shed into the environment. In humans, these viruses cause a spectrum of diseases ranging from aseptic meningitis to severe hemorrhagic fever syndromes. Little is known about how arenavirus and hantavirus proteins engage and interact with the human proteome during the complex process of viral biogenesis, or how the interactions with human proteins contribute to viral propagation as well as the onset and progression of disease. This dissertation provides a road map of the protein interactions formed between a prototypic envelope glycoprotein encoded by either an arenavirus or hantavirus, and the human proteome. The viral envelope glycoprotein (GP) decorates the surface of the virion. The primary function of the GP is to mediate attachment of the virus to specific cellular receptors, and after internalization of the virion, fuse the viral membrane with an internal endosomal membrane. In order to carry out these specific tasks, the viral GPs must first co-opt the extensive machinery found within the cellular secretory pathway to coordinate the proper glycosylation, folding, proteolytic maturation, and targeting of the GP during its biosynthesis. We identified a human protein with a conserved interaction amongst these two groups of viral GPs termed the Endoplasmic Reticulum (ER)-Golgi Intermediate Compartment Protein of 53 kiloDaltons (ERGIC-53). ERGIC-53 is an intracellular cargo receptor that normally cycles within the early secretory pathway of cells, where it is responsible for ferrying a small subset of cellular glycoproteins, most notably the coagulation factors FV and FVIII, from the ER to the Golgi apparatus. Herein we describe a novel role for ERGIC-53 in the propagation of not only arenaviruses, but also coronaviruses and filoviruses. Following infection with an arenavirus, ERGIC-53 leaves the early secretory pathway and becomes incorporated into the virus as it pinches off from the cell surface. Newly formed viruses lacking ERGIC-53 are no longer infectious due, in part, to a defect in their ability to attach to host cells. We suggest that ERGIC-53 represents a promising broad-spectrum antiviral target because of its association with the GPs from many families of pathogenic viruses, as well as its ability to exert control over their infectivity; and finally, because ERGIC-53 itself is not required for human health. The discovery of ERGIC-53 outside of its normal location inside of cells suggests that it may have additional unknown functions. Lastly, by revealing the importance of the cellular protein in controlling viral infectivity, we provide insight into the ongoing co-evolution of virus and host.

Includes bibliographical references (leaves 355-403) / 403 leaves : plates (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dental School, 2002

Graduation date: 1993

Graduation date: 1993

The goal of our research is to generate cryopreservation agents derived from antifreeze glycoproteins. One postulated mechanism of cell cryo-injury is ice recrystallization. It is known that simple saccharides and cryopreservation agents (DMSO) display ice recrystallization inhibition (IRI). This study assessed the cytotoxicity and cryopreservation ability of these sugars in relation to their IRI. It was determined that compounds with greater IRI have increased cytotoxicity yet confer cryoprotection. To further investigate how structure is affecting IRI activity, several galactopyranoside derivatives were synthesized. A series of deoxy and α-Callyl- deoxy galactopyranoses were prepared. Testing determined that removal of any hydroxyl group removes IRI. 3-deoxy-β-thiophenyl galactose was also synthesized and had surprisingly better IRI than β-thiophenylgalactose. Also, 6-azido galactose had similar IRI to 6-deoxy galactose. Lastly, a series of β- thioalkylgalactosides was synthesized and testing gave contradicting results which suggest that predicting IRI based on hydrophilicity is more complicated than initially hypothesized.