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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Chimerinių pelių poliomos viruso paviršiaus VP1 baltymų, eksponuojančių HCV epitopus, konstravimas / Construction of chimeric mouse polyomavirus surface vp1 proteins exhibiting hcv epitopes

Sabaliauskaitė, Rasa 25 November 2010 (has links)
Magistrinio darbo metu sukonstruotos mielių plazmidės, turinčios pelių poliomos viruso pagrindinį kapsidės baltymą VP1 su jame įterptais hepatito C viruso apvalkalo baltymų peptidais. Šiomis plazmidėmis buvo transformuotos S. cerevisiae mielės. Transformuotos mielės sintetina chimerinius baltymus: MPyV-VP1-BC-E2 [384-414], MPyV-VP1-HI-E2 [384-414], MPyV-VP1-BC-E1 [310-329], MPyV-VP1-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447], MPyV-VP1-HI-E2 [412-i447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-i447], MPyV-VP1-BC-E2 [412-447]-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447]-HI-E1 [310-329]. Į virusus panašias daleles (VPD) renkasi tik MPyV-VP1-BC-E2 [384-414], MPyV-VP1-HI-E2 [384-414], MPyV-VP1-BC-E1 [310-329] baltymai. Kiti baltymai: MPyV-VP1-BC-E1 [310-329], MPyV-VP1-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447], MPyV-VP1-HI-E2 [412-i447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-i447], MPyV-VP1-BC-E2 [412-447]-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447]-HI-E1 [310-329] nesirinko į VPD. / In the present study, plasmids for expression of major capsid proteins VP1 of murine polyomavirus with inserted sequences from Hepatitis C virus envelope proteins in yeast S. cerevisiae were constructed. The plasmids were used to transform yeast cells. The transformed yeast produced proteins: MPyV-VP1-BC-E2 [384-414], MPyV-VP1-HI-E2 [384-414], MPyV-VP1-BC-E1 [310-329], MPyV-VP1-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447], MPyV-VP1-HI-E2 [412-i447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-i447], MPyV-VP1-BC-E2 [412-447]-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447]-HI-E1 [310-329]. Virus-like particles (VLPs) composed MPyV-VP1-BC-E2 [384-414], MPyV-VP1-HI-E2 [384-414], MPyV-VP1-BC-E1 [310-329]. Other proteins: MPyV-VP1-BC-E1 [310-329], MPyV-VP1-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447], MPyV-VP1-HI-E2 [412-i447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-447], MPyV-VP1-BC-E1 [310-329]-HI-E2 [412-i447], MPyV-VP1-BC-E2 [412-447]-HI-E1 [310-329], MPyV-VP1-BC-E2 [412-i447]-HI-E1 [310-329] did not form VLPs.
2

Expressão e caracterização das proteínas VP1 e VP2 de parvovírus humano B19 em Pichia pastoris. / Expression and characterization of VP1 and VP2 proteins of the human parvovirus B19 in Pichia pastoris.

Silva Filho, Claudionor Gomes da 10 December 2007 (has links)
O parvovírus B19 é o agente causador de eritemas infecciosos em crianças, hidropsia fetal em mulheres gestantes, esse vírus pode causar anemia crônica e crise aplástica transitória respectivamente. A levedura P. pastoris é um sistema de expressão usado na produção de várias proteínas heterólogas. O objetivo deste trabalho foi expressar as proteínas VP1 e VP2 do parvovírus humano B19 em levedura P. pastoris. As seqüências gênicas VP1 e VP2 foram amplificadas por PCR, usando DNA do vírus B19, os produtos obtidos foram inicialmente subclonados no vetor pGEM-TEasy. Os fragmentos de DNA foram digeridos com enzima de restrição EcoRI e NotI , purificados e inseridos no vetor de expressão e excreção pPIC9K de P. pastoris, entre os sítios EcoRI e NotI. Para expressão das proteínas recombinantes VP1 e VP2 de parvovírus humano B19, os transformantes foram crescidos em glicerol e induzidos pela adição de metanol. As expressões dos antígenos recombinantes foram analisadas por SDS-PAGE e atividade biológica foram confirmadas pelos ensaios imunológicos ELISA, Dot-Blot e Western Blot. / Human Parvovirus B19 is the causative agent of erythema infectiosum in children, hydrops fetalis in pregnant women, B19 may cause chronic anemia and aplastic crisis, respectively. The yeast P. pastoris expression system is being used for the production of various recombinant heterologous proteins. The objective of this work was to express the VP1 and VP2 proteins of the human parvovirus B19 in the yeast Pichia pastoris. The coding sequence of VP1 and VP2 were amplified by PCR, using DNA virus of B19. PCR-products were initially subcloned in the vector pGEM-TEasy. The DNA fragment EcoRI and NotI was excised, purified, and inserted between the sites EcoRI and NotI of P. pastoris expression-secretion vector pPIC9K.For heterologous expression of the proteins VP1 and VP2 Human parvovirus B19, the transformants were growth on glycerol and induced by the addition of methanol. The expressed recombinant antigens VP1 and VP2 were analyzed by SDS-PAGE and its biological activity were confirmed through Enzyme immunoassay EIA, Dot-Blot e Western Blot.
3

Monokloninių antikūnų prieš Hendra ir Nipah virusų nukleokapsidės baltymus gavimas ir charakterizavimas / Production and characterization of monoclonal antibodies against Hendra and Nipah virus nucleocapsid proteins

Kairytė, Ieva 25 June 2008 (has links)
Šio darbo tikslas buvo gauti monokloninius antikūnus prieš Hendra ir Nipah virusų nukleokapsidės baltymus. Dėl didelės Henipavirus genties virusų nukleokapsidės baltym�� homologijos sunku gauti monokloninius antikūnus, specifiškus konkretaus viruso nukleokapsidės baltymui. Siekiant išspręsti šią problemą, buvo panaudoti chimeriniai rekombinantiniai baltymai, sukonstruoti pelės poliomos viruso pagrindinio kapsidės baltymo VP1 pagrindu, į kurį buvo įterptos nehomologiškos Nipah ir Hendra virusų nukleokapsidės baltymų sekos. Imunizacijoms panaudojus tokius chimerinius baltymus, buvo nustatyta, kad jie sukelia stiprų imuninį atsaką. Buvo sukurti nauji monokloniniai antikūnai, specifiški tik Nipah viruso nukleokapsidės baltymui ir nereaguojantys su Hendra viruso nukleokapsidės baltymu. Taip pat buvo sukurti monokloniniai antikūnai prieš baltymą-nešiklį – pelės poliomos viruso pagrindinį kapsidės baltymą VP1. Naujai sukurtų antikūnų specifiškumas buvo patvirtintas imunofermentinės analizės ir imunoblotingo metodais. Monokloninių antikūnų prieš Hendra viruso nukleokapsidės baltymą gauti nepavyko. / The aim of this study was to generate monoclonal antibodies against Hendra and Nipah virus nucleocapsid proteins. There is high homology between nucleocapsid proteins of Henipavirus genus members, therefore it is difficult to generate monoclonal antibodies that do not show any cross-reactivity with both antigens. This problem was solved by using recombinant chimeric proteins designed by insertion of non-homological segments of Hendra and Nipah virus nucleocapsid proteins into the mouse polyomavirus capsid protein VP1. Mice were immunized with these chimeric proteins and it was determined that they induce a strong immune response. Monoclonal antibodies against Nipah virus nucleocapsid protein as well as carrier protein – mouse polyomavirus capsid protein VP1 – were generated. The specificities of newly developed monoclonal antibodies were confirmed by ELISA and immunoblot. The generation of specific monoclonal antibodies against Hendra virus nucleocapsid protein failed.
4

Expressão heteróloga de proteínas do vírus da Hepatite A e avaliação da imunogenicidade

Silva Junior, Haroldo Cid da January 2015 (has links)
Made available in DSpace on 2016-05-02T13:06:58Z (GMT). No. of bitstreams: 2 haroldo_junior_ioc_dout_2015.pdf: 2633312 bytes, checksum: 02a75ad07873abdb519b939eb64b351c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / O vírus da Hepatite A (HAV) é o principal agente etiológico das hepatites virais agudas e estima-se que ocasione 1,5 milhão de novas infecções no mundo anualmente. Apesar da eficácia apresentada pelas vacinas comerciais, a replicação do HAV em cultura de células é lenta e apresenta baixo rendimento, o que torna a sua produção difícil e dispendiosa. Nesse contexto, o uso de proteínas recombinantes do HAV pode representar uma alternativa ao modelo de vacina existente. O presente trabalho teve como objetivo expressar e avaliar a imunogenicidade das partículas virais destituídas de ácido nucleico (VLPs) e da proteína VP1 do HAV. As VLPs foram geradas a partir do sistema baculovírus/células de inseto através da infecção de células de inseto com baculovírus recombinantes contendo as regiões P1-2A e P3 do genoma do HAV. A poliproteína P1-2A foi expressa, clivada e se organizou em estruturas que continham epitopos conformacionais de neutralização. Partículas com características similares ao HAV foram identificadas por microscopia eletrônica, sugerindo que as proteínas expressas se montaram em VLPs. Em paralelo, a VP1 foi expressa nos sistemas baculovírus/células de inseto e Escherichia coli Níveis mais elevados de expressão foram obtidos em E. coli, o que consequentemente aumentou a taxa de recuperação da proteína purificada. A VP1 derivada de E. coli foi utilizada nos ensaios de antigenicidade e mostrou reatividade frente aos soros de pacientes infectados pelo HAV, o que demonstra seu potencial como um marcador para diagnóstico. Para os estudos de imunogenicidade, a VP1 derivada de E. coli foi combinada a dois adjuvantes, o hidróxido de alumínio (A1(OH)3) e o adjuvante a base de saponina. A formulação VP1+A1(OH)3 induziu polarização da resposta Th2, enquanto que a formulação VP1r+saponina gerou um balanço maior entre as respostas Th1 e Th2. O adjuvante saponina permitiu a administração de uma dose menor da VP1 sem afetar a intensidade da resposta. Resultados preliminares sugerem que os anticorpos anti-VP1 induzidos pela formulação com saponina apresentaram reatividade cruzada com o HAV. Além disso, testes iniciais indicam que os camundongos imunizados com a VP1 em associação com ambos os adjuvantes apresentaram resposta anamnéstica contra o HAV. Os resultados aqui apresentados sugerem que a VP1 e as VLPs podem ser úteis para o desenvolvimento de uma nova vacina contra a Hepatite A / The hepatitis A virus (HAV) is the primary etiological agent of acute viral hepatitis and it is estimated to cause 1.5 million of new infections each year worldwide. Despite the effectiveness of commercial vaccines, the replication of HAV in cell culture is slow and has low yield, which makes it difficult and expensive to manufacture. In this context, the use of recombinant HAV proteins could represent an alternative model to the existing vaccines. This study aimed to express and evaluate the immunogenicity of virus-like-particles (VLPs) and VP1 protein of HAV. The VLPs were generated using the baculovirus/insect cell expression system by the infection of insect cells with recombinant baculovirus containing HAV P1-2A and P3 regions. The P1-2A polyprotein was successfully expressed, cleaved and organized into structures that contained neutralizing conformational epitopes. HAV-like particles were identified by electron microscopy, suggesting that the expressed proteins were assembled into VLPs. In parallel, VP1 was expressed in both baculovirus/insect cell and Escherichia coli expression systems. Higher protein levels were obtained in E. coli, which consequently increased the recovery rate after protein purification. The E. coli-derived VP1 was then used in antigenicity assays and showed reactivity against sera from patients infected with HAV, demonstrating its potential as a diagnostic marker. For immunogenicity studies, the E. coliderived VP1 was combined with two adjuvants, aluminum hydroxide (Al(OH)3) and the saponin-based adjuvant. The VP1+Al(OH)3 induced Th2 polarization, while VP1+saponin generated a Th1 and Th2 balanced immune response. Saponin-based adjuvant formulations allowed the administration of lower dose of VP1 without affecting the intensity of the response. Preliminary results suggest that the anti-VP1 antibodies induced by saponin-based adjuvant showed cross-reactivity with HAV. Furthermore, initial tests indicate that immunization of mice with VP1 in association with both adjuvants generated anamnestic response against HAV. The results presented here suggest that VP1 and VLPs might be useful to develop a new vaccine against hepatitis A. / 2016-07-10
5

Role acetylace proteinů v životním cyklu Polyomavirů / The role of proteins acetylation in life cycle of Polyomaviruses

Dostalík, Pavel January 2020 (has links)
Capsid of mouse polyomavirus (MPyV) is composed from three structural proteins: major structural protein VP1 and minor structural proteins VP2 and VP3. Posttranslational modifications may affect functions of proteins. This work deals with acetylation of MPyV structural proteins and its impact on the viral replication cycle. First part of the thesis is focused on acetylation of VP1. We showed that the VP1 protein is acetylated in viral particles and that interaction of VP1 with minor proteins supports VP1 acetylation. Further, we showed that cytoplasmatic deacetylase, histone deacetylase 6 (HDAC6), is important for virus infectivity. Overexpression of HDAC6 decreased MPyV infectivity, also decreased infectivity was exhibited by virus isolated from HDAC6 knock out cells. In addition, VP1 protein of virus from HDAC6 knock out cells was more acetylated in comparison with virus from parental cell line. These data suggest that VP1 is substrate for HDAC6. Second part of the thesis is focused on the characterization of N-terminal acetylation of VP3 minor structural protein. It has been previously shown that VP3 protein is N-terminally acetylated and MyPV with mutated (unacetylated) form of VP3 protein is non-infectious. The main aim of this part is to prove the hypothesis that N-terminal acetylation is...
6

Studium interakcí hlavního strukturního proteinu polyomavirů se strukturami hostitelských buněk / Major structural protein of Polyomaviruses: Interactions with host cell structures

Mrkáček, Michal January 2018 (has links)
The main structural protein VP1 is the product of late polyomaviral genes and it is the largest and the most abundant protein of the whole polyomaviral capsid. Because of the low coding capacity of the polyomaviral genomes, it is considered that in addition to its structural role the VP1 protein might have some additional functions in the late phase of the infectious cycle. This diploma thesis is exactly on these additional functions. In the case of the VP1 protein of mouse polyomavirus, it was observed that the protein is capable of binding to the structure of cellular microtubules. The first objective of this work was to test whether pentamers of the VP1 protein are able of this binding without the participation of other cellular (or viral) proteins. Based on an in vitro experiment, we showed that protein VP1 binds to the structure of microtubules very inefficiently. The second objective of this work was to prepare a detection system that would allow an identification of potential interaction partners of BK polyomavirus VP1 protein. Therefore, expression plasmids producing the N and C-terminally tagged VP1 protein were prepared. These tagged proteins had the property of being biotinylated whilst being produced in the transfected cells. By using affinity chromatography, the entire protein complexes...
7

Mise au point et évaluation d'une technique de PCR permettant la détection et le typage des entérovirus directement à partir de produits pathologiques ou d'échantillons environnementaux / Development and evaluation of a PCR technique for detection and typing of enteroviruses directly from pathological product or environmental samples

Ibrahim, Wafa 11 April 2014 (has links)
Les entérovirus (EV) humains, membres de la famille des Picornaviridae, comprennent plus de 100 génotypes appartenant à 4 espèces : Enterovirus A, B, C et D. Ces virus sont à l’origine de pathologies très variées et occupent une place importante en santé publique. La méthode conventionnelle de typage des EV consiste en une réaction de séroneutralisation avec des antisérums spécifiques à partir de souches isolées en culture cellulaire ; cette technique est longue, coûteuse et limitée par sa capacité à identifier correctement les variants antigéniques et les nouveaux génotypes. De plus, elle est limitée aux génotypes cultivables. De nouvelles méthodologies de typage moléculaire par séquençage partiel du génome ont été récemment développées ; elles consistent à analyser une partie variable de la région codant une des protéines de capside (VP1 ou alternativement VP2 ou VP4). Cependant ces techniques sont le plus souvent réalisées à partir de souches isolées en culture cellulaire. Le but de ce travail a été de développer une technique de typage des EV directement sur des prélèvements cliniques en se basant sur le séquençage partiel de la région VP2 dont le laboratoire avait montré précédemment l’intérêt (Nasri et al., 2007). Pour le dessin des amorces, nous avons utilisé la stratégie CODEHOP (COnsensus DEgenerate Hybrid Oligonucleotide Primer) de manière à améliorer à la fois la spécificité et la sensibilité de la méthode d’amplification. Nous présentons ici un premier article décrivant la nouvelle technique de typage VP2 et rapportons son application au typage d’échantillons cliniques trouvés positifs par une PCR ciblant la région 5’ non codante du génome des EV sur une période de trois ans. Le deuxième article présente pour la première fois l’application d’une technique de typage direct à des échantillons environnementaux d’eaux usées. Le troisième article montre l’intérêt de coupler deux techniques de typage ciblant des régions différentes (VP1 et VP2) pour l’identification de souches d’EV isolées par culture cellulaire en Centre-Afrique. Malgré des problèmes de sensibilité, cette nouvelle technique de typage directement à partir d’échantillons peut rendre de grands services tant en clinique humaine que pour la surveillance environnementale / Human enteroviruses (EV), members of the Picornaviridae family, comprise more than 100 genotypes belonging to four species: Enterovirus A, B, C and D. These viruses are responsible for a wide range of pathologies and play an important role in Public Health. The classic method for typing EVs consists in a seroneutralisation assay with specific antisera using strains isolated by cell culture; this technique is cumbersome, expensive and unable to type currently antigenic variants and new serotypes. In addition, it is limitated to culturable serotypes. New methods of molecular typing by partial sequencing of the genome have been recently developed; they consist in analysing a variable part of the region coding for capsid protein (VP1 or alternatively VP2 or VP4). However, these techniques are usually performed on strains isolated by cell culture. The aim of this work was to develop a typing method able to work from clinical specimens by partial sequencing of the VP2 region, which had been shown to exhibit a good typing performance (Nasri et al., 2007). For the design of primers, we used the CODEHOP (COnsensus DEgenerate Hybrid Oligonucleotide Primer) strategy on order to improve the sensitivity and the specificity of the amplification assay. We present herein a first article that describes in details the new VP2 typing method and requests its use for typing clinical specimens found positive by a PCR assay targeting the 5’ non coding region of EVs over a period of three years. The second paper describes for the first time the direct use of a typing method on environtmental wastewater samples. The third article shows the interest of coupling 2 typing techniques targeting different regions (VP1 and VP2) of the EV genome for the identification of strains isolated by cell culture in Republic of Central Africa. Despite a loss of sensitivity, the new VP2 typing method used directly on specimens was found to be of great help both for human diagnosis and environmental surveillance
8

Denitrifikationsmöjligheter hos lakvattnet på Bredemads avfallsdeponi i Ljungby / Denitrification potential of the leachate on Bredemads landfill in Ljungby

Samuelsson, Stina January 2014 (has links)
I examensarbetet har möjlig denitrifikationshastighet för lakvattnet på Bredemads avfallsdeponi i Ljungby undersökts. Denitrifikationshastigheten har tagits fram i satsvisa och kontinuerliga försök där Reppos 40T och Brenntaplus VP1 har jämförts som externa kolkällor. De satsvisa försöken har genomförts i temperaturerna 15 °C, 20 °C och 22,5 °C och de kontinuerliga försöken har genomförts med reningsmetoden ”Moving Bed Biofilm Reactor” (MBBR) med bärare som hade en skyddad yta på 500 m2/m3. Denitrifikationshastigheten i g/(dygn•m2) med Reppos 40T var 0,45 och med Brenntaplus VP1 1,05. I reaktorn med Reppos 40T var fyllnadsgraden 48 % och denitrifikationshastigheten 4,5 g/(h•m3). I reaktorn med Brenntaplus VP1 var fyllnadsgraden 41 % och denitrifikationshastigheten 9,1 g/(h•m3).
9

Hlavní strukturní protein myšího polyomaviru: interakce s buněčnými strukturami / Major capsid protein of mouse polyomavirus: interaction with cellular structures

Horníková, Lenka January 2012 (has links)
Mouse polyomavirus (MPyV) is small non-enveloped DNA virus. Although this virus has been studied for almost 60 years, it still remains unclear, how can virus transport its genetic information to the cell nucleus. Also, the mechanism of virion morphogenesis is not well understood. First part of this work is focused on endocytic pathway which is used by MPyV for trafficking toward the cell nucleus. Using dominant negative mutant of caveolin-1 we showed that caveolin-1dependent endocytic pathway, described for SV40, is not used by MPyV for productive infection. MPyV is transported to early endosomes. Acidic milieu of endosomes is indispensable for productive infection. Preventing virus localisation into early endosomes (dominant negative mutant of Rab 5 GTPase) or endosomes alkalisation (by ammonium chloride or bafilomycin A1) led to dramatic decrease of virus infectivity. Alkalisation of endosomes entailed retention of MPyV in early endosomes. It indicates that virus is further transported to late endosomes. Finally, we confirmed by FRET that MPyV is in perinuclear space localized into recycling endosomes. Another poor characterized process is virion morphogenesis. To characterize the participation of cellular proteins in virion precursor complexes, nuclear as well as whole-cell lysates of infected cells or...
10

Evaluation and implementation of a molecular-based protocol for the identification of enteroviruses at the Florida Department of Health - Tampa Laboratory

Smith, Matthew Adams 01 January 2003 (has links)
The Enterovirus genus within the family Picornaviridae contains over 100 serotypes, of which sixty-four are known to be human pathogens. Infection with this group of RNA viruses produces a myriad of clinical conditions including poliomyelitis, meningitis, encephalitis, respiratory illnesses, and hand-foot-and-mouth disease. Outbreaks have been documented worldwide; significant morbidity and mortality exist to warrant laboratory surveillance. Traditionally, enteroviruses have been identified to the level of serotype by the serum neutralization assay. However, numerous problems are associated with this assay. The serum neutralization assay is labor intensive, results are often ambiguous, and reagents are becoming difficult to obtain. Recently, molecular-based typing protocols have been described that are cost effective and produce results that are more reliable. The overall objective of this thesis was to implement a molecular-based typing protocol to replace the serum neutralization method currently used. Three specific aims were identified to reach this objective. First, a database cataloging all enteroviruses isolated at the Florida Department of Health - Tampa Branch Laboratory from 1981 through 2002 was created. Serotype prevalence, specimen submission rates, and temporal trends were analyzed to demonstrate the public health importance of enterovirus surveillance. Next, five oligonucleotide primer sets were compared with respect to sensitivity, specificity, and overall utility in molecular typing protocols developed to accurately determine enterovirus type. Finally, the most effective molecular assay was used to conduct two basic molecular epidemiological analyses of intratypic variation of Coxsackievirus B5 isolates, and of intratypic variation of successive Echovirus 9 passages. The results from this study show that implementation of a molecular-based typing system for enteroviruses would be an improvement over current enterovirus serotyping methods. Results are obtained more rapidly and are more reliable. The implementation of such a system would improve the surveillance capabilities of the State of Florida Department of Health.

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