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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.
21

O papel dos miRNA na infecção de leucócitos esplênicos de cão por Leishmania Infantum /

Melo, Larissa Martins. January 2018 (has links)
Orientador: Valéria Marçal Félix de Lima / Resumo: A leishmaniose visceral canina (LV) no Brasil representa um grave problema de saúde pública. Na LV a supressão imune celular é determinante da progressão da doença. Estudos mostraram que a regulação da resposta imune depende de miRNAs. O objetivo deste estudo foi a caracterização dos miRNAs em leucócitos esplênicos (LE) de cães naturalmente infectados por L. infantum. Este estudo foi realizado em Araçatuba, região endêmica para LV canina (LVC). Um grupo de 4 cães saudáveis e 8 cães com LVC foi estudado. O RNA foi extraído do LE usando o Kit Mirvana (Invitrogen™) de acordo com as recomendações do fabricante. O RNA foi quantificado usando um fluorômetro (Qubit 3.0, Invitrogen™) o grau de pureza realizado por eletroforese capilar (Bioanalyser, Agilent ™), as amostras foram então armazenadas a -80°C. O miRNA foi preparado para o microarranjo usando o FlashTag Biotina HSR RNA Labeling Kit (Affymetrix ™). O microarranjo foi realizado usando o Affymetrix ™ miRNA 4.1 Strip de acordo com as recomendações do fabricante. A produção de cDNA foi realizada usando o kit miScript RT II (Qiagen™). Os miRNAs diferencialmente expressos foram validados por qPCR utilizando iniciadores para miRNAs de cães inventariados (Qiagen™) de acordo com recomendação do fabricante. Os miRNAs validados foram analisados no programa Ingenuity Pathway Analysis (IPA, Qiagen™). Após a análise das vias, os LE de cães infectados foram transfectados com miR21 usando miScript miRNA Mimics e Inhibitor (Qiagen™) de acord... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Canine visceral leishmaniasis (VL) in Brazil represents a serious public health problem. In VL cellular immune suppression is determinant of disease progression. Studies have shown that the regulation of the immune response depends on miRNAs. The objective of this study was the characterization of the miRNAs in spleen leukocytes (SL) from dogs naturally infected by L. infantum. This study was carried out in Araçatuba, an endemic region for canine LV (LVC). A group of 4 healthy dogs and 8 dogs with VL was studied. Total RNA was extracted from SL using Mirvana Kit (Invitrogen®) according to manufacturer’s recommendations Total RNA was quantified using a fluorometer (Qubit 3.0, Invitrogen®) the degree of purity performed by capillary electrophoresis (Bioanalyser, Agilent®), the samples were then stored at -80°C. Total RNA was prepared for the microarray using the FlashTag Biotin HSR RNA Labeling Kit (Affymetrix®). The microarray was performed using the Affymetrix ™ miRNA 4.1 Strip according to manufacturer’s recommendations. cDNA production was performed using the miScript RTII kit (Qiagen®). Differentially expressed miRNAs were validated by qPCR was performed using the inventoried dog miRNAs (Qiagen®) and SYBR Green (kit miScript SYBR Green PCR, Qiagen®), according to the manufacturer's recommendation. The validated miRNAs were analyzed in the program Ingenuity Pathway Analysis (Qiagen®). After analysis of the pathways, then the LS from infected dogs were transfected with miR21... (Complete abstract click electronic access below) / Doutor
22

Investigation of functionalized carbon nanotubes as a delivery system for enhanced gene expression with implications in developing DNA vaccines for hepatitis C virus

Chen, Wenting 13 January 2009
Hepatitis C virus (HCV) causes a significant health problem worldwide due to the lack of effective vaccines. It has been recognized that a rapid, vigorous, and broadly targeted cell-mediated immune response (Th1-like) is often associated with the clearance of HCV infections. DNA vaccines represent a promising means for HCV vaccination because they tend to induce a Th1-biased cell-mediated response in the host cell. Currently, the delivery of DNA vaccine for HCV in large animals as well as in humans is not as effective as in small animals. Nano delivery systems would be a promising approach to overcome this problem. Carbon nanotubes (CNTs) have been extensively studied for delivering drugs, proteins, peptides, and nucleic acids including plasmid DNA to cells and organs with varying degrees of success, but few of them have been applied to DNA vaccine for HCV.<p> This thesis presents a study of using functionalized CNTs (f-CNTs) to improve the efficacy of plasmid DNA vaccine delivery for HCV. First, CNTs were functionalized via 1,3-dipolar cycloaddition reaction with the appropriate amino acids and aldehydes. NMR and TEM results suggested that the CNTs were successfully functionalized and became soluble in water. Then plasmid DNAs which encode green fluorescence protein reporter gene, luciferase reporter gene, and HCV core protein, respectively, were delivered into human hepatoma cells via calcium phosphate precipitation method, f-CNT delivery system, and a combination of f-CNT and calcium phosphate method, respectively. The result showed that f-CNTs, in combination with the calcium phosphate method, significantly enhanced the gene expression in human hepatoma cells.<p> Consequently, this study concludes that the f-CNT can significantly enhance gene expression in liver cells conferred by a plasmid DNA when combined with calcium phosphate precipitation method. Even though the mechanisms of this enhancement await further investigation, the results of this thesis may have important implications in developing DNA vaccines for infectious diseases in general and for hepatitis C in particular.
23

Investigation of functionalized carbon nanotubes as a delivery system for enhanced gene expression with implications in developing DNA vaccines for hepatitis C virus

Chen, Wenting 13 January 2009 (has links)
Hepatitis C virus (HCV) causes a significant health problem worldwide due to the lack of effective vaccines. It has been recognized that a rapid, vigorous, and broadly targeted cell-mediated immune response (Th1-like) is often associated with the clearance of HCV infections. DNA vaccines represent a promising means for HCV vaccination because they tend to induce a Th1-biased cell-mediated response in the host cell. Currently, the delivery of DNA vaccine for HCV in large animals as well as in humans is not as effective as in small animals. Nano delivery systems would be a promising approach to overcome this problem. Carbon nanotubes (CNTs) have been extensively studied for delivering drugs, proteins, peptides, and nucleic acids including plasmid DNA to cells and organs with varying degrees of success, but few of them have been applied to DNA vaccine for HCV.<p> This thesis presents a study of using functionalized CNTs (f-CNTs) to improve the efficacy of plasmid DNA vaccine delivery for HCV. First, CNTs were functionalized via 1,3-dipolar cycloaddition reaction with the appropriate amino acids and aldehydes. NMR and TEM results suggested that the CNTs were successfully functionalized and became soluble in water. Then plasmid DNAs which encode green fluorescence protein reporter gene, luciferase reporter gene, and HCV core protein, respectively, were delivered into human hepatoma cells via calcium phosphate precipitation method, f-CNT delivery system, and a combination of f-CNT and calcium phosphate method, respectively. The result showed that f-CNTs, in combination with the calcium phosphate method, significantly enhanced the gene expression in human hepatoma cells.<p> Consequently, this study concludes that the f-CNT can significantly enhance gene expression in liver cells conferred by a plasmid DNA when combined with calcium phosphate precipitation method. Even though the mechanisms of this enhancement await further investigation, the results of this thesis may have important implications in developing DNA vaccines for infectious diseases in general and for hepatitis C in particular.
24

Biochemical modulation and stem cell therapy for irradiated mandible

Zhang, Wenbiao, January 2009 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 117-191). Also available in print.
25

Regulation of dendritic spine proliferation

Johnson, Orenda Lyons. Ouimet, Charles C. January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Chalres C. Ouimet, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains x, 83 pages. Includes bibliographical references.
26

Analise do padrão de metilação da região promotora do gene humano PAX9 (-947 - +251) e analise in vitro da sua atividade transcricional / New insights into methylation pattern and transcriptional activity of human PAX9 gene (-947 - +251) in vitro

Saito, Cristiane Pereira Borges 12 August 2018 (has links)
Orientador: Sergio Roberto Peres Line / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-12T22:28:51Z (GMT). No. of bitstreams: 1 Saito_CristianePereiraBorges_D.pdf: 2404829 bytes, checksum: ef69d02f749dac4b0974b53ad416de6d (MD5) Previous issue date: 2009 / Resumo: O gene PAX9 é um regulador chave durante o processo de desenvolvimento dentário e, particularmente em humanos, mutações neste gene estão associadas a fenótipos peculiares como agenesias dentárias. O objetivo deste estudo foi descobrir novas coordenadas acerca da atividade transcricional do promotor desse gene e de um possível padrão de metilação. Quanto ao estudo da metilação, foram avaliadas amostras de DNA genômico extraído da papila dentária de embriões humanos através de enzimas de restrição sensíveis à metilação e através da amplificação por Reação da Polimerase em Cadeia-PCR com oligos específicos. A extração de DNA de amostras incluídas em parafina foi padronizada no laboratório de Morfologia da Faculdade de Odontologia de Piracicaba, FOP-UNICAMP. Amostras de DNA extraídas de saliva humana foram usadas como controle. Para os ensaios de transcrição, foram amplificados através de ensaios com a transcriptase reversa, transcritos do gene Pax9 de Células Embrionárias de Rato, bem como de Células Odontoblastóides de Camundongo- MDPC-23 (Mouse Odontoblast Cell-like-23). Esses transcritos foram quantificados através de PCR semi-quantitativa. A região promotora do gene PAX9 humano íntegra (-947 - +251) e deletada (-485 - +22), recombinada com o vetor de expressão pGL3Basic, contendo o gene repórter luciferase após a região promotora, foi transfectada em cultura de Células Embrionárias de Rato. Todas as placas de cultura foram submetidas à ação de duas drogas: Ácido Retinóico (AR) e Dexametasona (Dex). Após a lise das células, os níveis relativos de expressão da proteína luciferase foram analisados, utilizando o kit Dual-Glo Luciferase (Promega), em um luminômetro. Os resultados mostram que: (1) O gene PAX9 encontra-se metilado in vitro; (2) O AR inibiu a síntese de RNA mensageiro transcrito pelas Células Embrionárias Rato. O promotor do gene humano PAX9 clivado nos sítios -485 e +22 e que não continha 507pb não foi afetado pelos receptores do AR. O Promotor PAX9 íntegro foi ativado na presença do AR na maior concentração da droga ; (3) A Dex estimulou a transcrição do gene Pax9 no grupo de células MDPC-23 e influenciou positivamente ambas as versões do promotor do gene PAX9 com as concentrações: 0.1µM e 1nM. Esses resultados demonstraram que os receptores dos hormônios esteróides AR e Dex podem se ligar diretamente a sequências do gene Pax9 em ratos e camundongos e que a região contendo 507pb retirada do promotor do gene PAX9 humano pode conter sítios de ligação para receptores do AR. Além disso, o sítio de metilação encontrado na região promotora do gene PAX9 humano resultou em novas perspectivas acerca do seu padrão de funcionamento em células normais. / Abstract: PAX9 is a key regulator during tooth development and plays an essential role in the patterning of murine and human dentition. In humans, mutations in PAX9 are associated with unique phenotypes of familial tooth agenesis that mainly involve posterior teeth. The objectives of this study were to gain new insights into the transcriptional activity and DNA methylation within the promoter region of human PAX9 gene in vitro. The methylation pattern was examined by studying PAX9 gene promoter in Dental Papilla of human Embryos through methylation-sensitive restriction enzyme and PCR amplified with specific oligos. DNA extractions from paraffin-embedded tissue sections were well established in Morphology Laboratory, Piracicaba Dental School. DNA samples from Buccal Epithelial Cells were used as control. In the present study, we have PCR amplified cDNAs encoding Rat Pax9 and Mouse Pax9 from Primary embryonic cell culture obtained from 13 day-old Wistar Rat and Mouse odontoblast cell-like culture-23 (MDPC-23) respectively and quantified by Semi-quantitative PCR technique. Furthermore, we examined the transcriptional activity of human Pax9 gene promoter: (-947 - +251) full Pax9 promoter and the promoter lacking 507bp (-485 - +22) through recombination into pGL3Basic expression vector and transfection in primary rat embryonic cells. Cell cultures were all submitted to selective regulation of both drugs: Retinoic Acid (RA) and Dexamethasone (Dex). Relative luciferase expression units were obtained by dual luciferase assay kit (Promega). Our results showed that: (1) human PAX9 promoter region is methylated in vitro; (2) RA inhibited Pax9 mRNA synthesis in Primary Rat embryonic cells while PAX9 promoter lacking 507bp (-485 - +22) was not activated by RA receptors. Human PAX9 full promoter activation was improved by RA treatment at the greater concentration; (3) Dex stimulated Pax9 mRNA activity in MDPC-23 and influenced positively both PAX9 promoter versions with 0.1µM and 1nM concentrations. The present experiments suggest that a 507bp region in PAX9 promoter may contain binding sites for RA receptors and that Dex and RA steroid hormone receptors may be directly bind to the sequences of murine Pax9 gene. The methylation pattern finding give rise to new perspectives on PAX9 patterning in normal cells phisiology. / Doutorado / Histologia e Embriologia / Doutor em Biologia Buco-Dental
27

Investigação funcional de ANKHD1 nas neoplasias malignas / Functional investigation of ANKHD1 in malignant neoplasms

Rodrigues, Patricia Cristina 16 August 2018 (has links)
Orientador: Sara Teresinha Olalla Saad / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-16T01:25:11Z (GMT). No. of bitstreams: 1 Rodrigues_PatriciaCristina_D.pdf: 2756759 bytes, checksum: c32a31ef7786358790e9e69edaf2c2db (MD5) Previous issue date: 2010 / Resumo: A proteína humana ANKHD1 (Ankyrin Repeat Single KH Domain containing 1) foi inicialmente descrita em células de adenocarcinoma de próstata humano (LNCaP), e sua expressão também é observada em diversas linhagens leucêmicas. ANKHD1 é homóloga a proteína Mask (Multiple Ankyrin repeat and single KH domain) de Drosophila melanogaster, relacionada com diferenciação, sobrevivência e proliferação de fotorreceptores dos olhos de drosófila. Interações diretas entre ANKHD1 e SHP2, proteína que exerce um papel crítico na hematopoiese, foram descritas nas linhagens mielóide K562, de adenocarcinoma de próstata, LNCaP, e em linhagem de mieloma múltiplo RPM1 8226. Porém pouco se sabe sobre a função de ANKDH1 e seu papel na leucemogênese. O objetivo do presente estudo foi investigar o envolvimento da ANKHD1 em processos biológicos relacionados com a leucemogênese. Para tal utilizamos duas abordagens metodológicas principais: inibição e hiperexpressão de ANKHD1. A inibição de ANKHD1 em linhagem LNCaP foi seguida de rastreamento das demais alterações gênicas associadas através de microarray. O microarray realizado mostrou 706 genes cuja expressão foi aumentada e 159 genes cuja expressão foi diminuída. Os genes foram agrupados em 26 classes funcionais, sendo que diversos genes conhecidos por regularem ciclo celular e apoptose tiveram seu perfil de expressão alterada. Importante ressaltar que a inibição de ANKHD1 resultou em aumento significativo da expressão de um grande número de Histonas, sugerindo seu papel no controle epigenético. Dentre as modulações validadas, algumas foram verificadas também em amostras provenientes de portadores de leucemia. Neste estudo, foi demonstrada a baixa expressão gênica de ANKHD1 em amostras de 38 pacientes com diagnóstico de leucemia aguda, quando comparadas às células de medula óssea normal. Uma vez que esta amostra leucêmica se mostrou como um modelo natural de inibição de ANKHD1, a expressão de outros genes modulados no array foi testada, e o gene BMF, que se mostrou aumentado no array, se mostrou também mais expresso em amostras de leucemias, confirmando a oposição de expressão destes dois genes. Simultaneamente, células de leucemia aguda e mielodisplasia foram submetidas à ação de diversas drogas usadas no tratamento dessas doenças mostrando aumento de expressão de ANKHD1. Estes dados em conjunto com os observados no microarray sugerem a participação da ANKHD1 na via de JAK/STAT1 e vias de controle epigenético. A segunda abordagem utilizada neste trabalho foi a hiperexpressão ANKHD1, isoformas 1 e 2, em linhagens tumorais, seguidas da detecção de expressão protéica de ANKHD1 em cotransfecção com os genes Siva e Vpr. As proteínas Siva e Vpr foram recentemente descritas como capazes de interagir fisicamente com as isoformas 1 e 2 de ANKHD1 respectivamente. Tanto a proteína a Siva quanto a Vpr foram atribuídos papéis de indução de apoptose em linfócitos T. Observou-se que ao cotransfectarmos Siva ou Vpr com ANKHD1 houve diminuição de expressão de ANKHD1 tanto para a isoforma 1 quanto para isoforma 2 (western blotting) e também se observou que a isoforma 1 de ANKHD1 é citoplasmática assim como ocorre com a Mask de drosófila, porém a isoforma 2 se mostrou predominantemente nuclear em microscopia de fluorescência. A análise funcional da hiperexpressão de ANKHD1 seguida de análise por FACS sugere diminuição de apoptose em células leucêmicas. Em conclusão, o presente estudo identificou diversos possíveis participantes da via de sinalização de ANKHD1 por análise microarray, relatou a diminuição da sua expressão em amostras de pacientes portadores de leucemia, bem como o aumento de sua expressão em linhagens leucêmicas sob a ação de diversos tratamentos correntemente utilizados no combate de desordens hematopoiéticas. Descrevemos também o aumento de expressão da expressão do gene BMF nas mesmas amostras em que há diminuição de ANKHD1, corroborando os dados encontrados no microarray da inibição de ANKHD1. Descrevemos também pela primeira vez a localização nuclear da isoforma 2 de ANKHD1, confirmando todas as previsões computacionais de localização de ANKHD1. Os resultados aqui descritos sugerem que ANKHD1 esteja envolvida com o fenótipo anormal da célula leucêmica e permitirão direcionar novos estudos com o objetivo de melhor elucidar as funções específicas de ANKHD1 na hematopoiese / Abstract: The human protein ANKHD1 (Ankyrin Repeat Single KH Domain containing 1) was initially described in Human prostate adenocarcinoma cells (LNCaP), and can also be expressed in many different leukemic cell lines. ANKHD1 is homologous to the Drosophila melanogaster Mask protein (Multiple Ankyrin repeat and single KH domain), related to differentiation, proliferation and survival in photoreceptors of Drosophila eyes. Direct interactions between ANKHD1 and SHP2, a protein that plays a critical role in hematopoiesis, have been described in the myeloid cell line K562, in prostate adenocarcinome, LNCaP, and in multiple myeloma cell line RPM1 8226. Nevertheless, little is known of the function of ANKDH1 and its role in leukemogenesis. The purpose of this work was to investigate the involvement of ANKHD1 in biological processes related to leukemogenesis. For this purpose, we used two main methodological approaches: ANKHD1 inhibition and overexpression. The inhibition of ANKHD1 in LNCaP cell lines was followed by the tracking through microarray of the remaining associated genetic alterations. Microarray revealed 706 genes with upregulated expression and 159 genes with downregulated expression; the genes were gathered in 26 functional groups and many genes, known for regulating cell cycle and apoptosis, had alterations in their expression profile. Importantly, inhibition of ANKHD1 resulted in significant increase in the expression of a large number of Histones, suggesting its role in epigenetic control. Among the validated modulations, some were also observed in the samples collected from leukemia patients. In this study, the downregulation of ANKHD1 was demonstrated in samples collected from 38 acute leukemia patients when compared to normal bone marrow cells. As this leukemic sample represented a natural model of inhibition of ANKHD1, the expression of other genes processed through array were tested, and the BMF gene, which was upregulated in the array, was also more elevated in leukemia samples. Simultaneously, cells of acute leukemia and myelodysplasia were subjected to the action of various drugs used to treat these diseases showing increased expression of ANKHD1. These data together with those observed in the microarray suggest the participation of ANKHD1 towards JAK/STAT1 and pathways of epigenetic control. The second approach used in this work was the ANKHD1overexpression, isoforms1 and 2, in tumor lines, followed by the detection of protein expression in cotransfection with Siva and Vpr genes. The proteins Siva and Vpr have been recently described as being capable of physical interaction with the isoforms 1 and 2 of ANKHD1, respectively. The role of inducing apoptosis in T lynphocytes was attributed to both Siva and Vpr. By cotrasfecting Siva and Vpr with ANKHD1 a reduction of ANKHD1 expression to isoform 1 as well as to isoform 2 (western blotting) was obtained and isoform 1 of ANKHD1 was observed to be citoplasmatic, such as occurs with drosophila Mask, although isoform 2 happened to be predominantly nuclear in the fluorescence microscope. Functional analysis of overexpression of ANKHD1 followed by FACS analysis suggests reduction of apoptosis in leukemic cells. Finally, this study identified many possible participants in the signaling pathway of ANKHD1 by microarray analysis, and related the reduction of its expression in leukemia patients, as well as the increasing of its expression in leukemic cell lines under the effect of many different treatments currently used against hematopoietic disorders. We also described the increasing of BMF expression in the same samples where we found a reduction of ANKHD1, corroborating all the data we obtained from the ANKHD1 inhibition microarray. In addition, we described, for the first time, the nuclear location of ANKHD1's isoform 2, confirming all the computer-aided predictions regarding the location of ANKHD1. The results herein described suggest that ANKHD1 could be involved with the abnormal phenotype of leukemic cells and these results could guide further studies towards elucidating the specific functions of ANKHD1 in hematopoiesis / Doutorado / Biologia Estrutural, Celular, Molecular e do Desenvolvimento / Doutor em Fisiopatologia Medica
28

A Microfluidic Device for Transfection of Mammalian Cells Using Adjustable Shear Stress

Cencen, Veronika January 2016 (has links)
Microfluidic technology is a rapidly progressing tool in biomedical engineering. Microfluidic devices are appreciated for their simplicity and production efficiency potential. Our research focuses on developing a microfluidic device capable of transfecting cells by applying shear stress to cause temporary membrane damage. The advantage of this physical method of transfection is the possibility of incorporating large molecules that cannot be inserted with more traditional chemical transfection methods, while avoiding the large fall in viability seen with other physical methods such as electroporation. Unlike previous groups, our device incorporates the use of microfluidic valves to allow tunability, and impedance sensing for cell membrane damage analysis. We achieve (95±5)% cell viability and up to (68±5)% efficiency in transfecting 3T3 cells with DNA-sized molecules. In future stages, we intend to add the device onto an existing cell-encapsulation device that is tasked with preparing therapeutic cells to be used in regenerative medicine applications.
29

Chitosan-mediated transfection and the role of cell surface interactions

Venkatesh, Savitha 01 January 1997 (has links)
Transfection is the process of introducing DNA into cells and expression of the gene contained in the DNA. The DNA itself could be a functional gene, part of a gene, or a gene with the regulatory and transcribed sequences intact. The ability to transfect mammalian cells is a powerful tool that can be used to study the function and control of mammalian genes. Transfection of DNA into eukaryotic cells can be done in several ways. One of the methods of introducing foreign DNA into mammalian cells is known as cationic liposome-mediated transfection. Preliminary studies involved the development of a cationic lipid-mediated transfection method using HeLa cells and a plasmid that codes for ~-galactosidase. The cationic lipid used was Transfectam. Transfectam is a commercially available, cationic lipopolyamine. Chitosan, a cationic polymer of glucosamine, was used as an alternative transfecting agent and as a binding agent for polyanions. The transfection efficiency of chitosan was compared to that of Transfectam. Chitosan was found to be comparable to Transfectam in this regard. Polyanions of different chemical structures were used in a chitosan binding study. These include aurin tricarboxylic acid, calf thymus DNA and methyl green DNA. The kinetics of the binding interactions suggest that ionic interactions predominated. Based upon these findings, studies were performed to determine the nature of chitosan interactions with the cell surface. Chitosan beads were prepared to determine the interaction of chitosan with the cell membrane of He La cells and for the isolation of membrane proteins. Membrane proteins which bound to chitosan beads could be effectively eluted with a-0-mannopyranoside but not sodium chloride. Furthermore, HeLa cells bound to the chitosan beads could be eluted with aD- mannopyranoside but not sodium chloride. The results suggested that membrane bound proteins interact with chitosan through carbohydrate moiety interactions which may facilitate the transfection process.
30

Mechanisms of Mononegavirales gene expression

Hayward, Oliver James 10 October 2019 (has links)
The Mononegavirales order unifies the non-segmented negative sense viruses (nsNSVs), including Marburgvirus (MARV) of the Filoviridae family and respiratory syncytial virus (RSV) of the Pneumoviridae. The mechanism of action of these viruses and how they infect cells are very similar, especially when focusing on their polymerases, which are distinct from those of eukaryotes and therefore possible targets for antiviral drugs. nsNSVs utilize a RNA-dependent RNA polymerase to either replicate the viral RNA genome or transcribe it into positive sense mRNA. Despite this, these two viruses result in very different, but equally devastating, effects in humans. Whereas MARV virus often results in rare but fatal hemorrhagic fevers, RSV is a common seasonal virus that can result in long term negative effects to respiratory health. These negative effects on public health demand extensive research in these two fields and a need to develop new technology and methods in order to uncover the missing pieces of viral gene expression. Specifically, the development of a MARV minigenome system would allow for increased testing of this virus outside of the confines of the biosafety level 4 (BSL-4) setting. By replacing MARV genes with reporter genes, but retaining the characteristic leader, intergenic, and trailer regions of the genome, tests involving site directed mutagenesis would reveal new insights into the crucial genomic elements needed for successful gene expression. Coupled with the transfection of the minigenome with plasmids coding for the crucial MARV proteins, artificial changes to the genome would lead to the presence of absence of translated bioluminescent reporter proteins. Using these two viruses, this study attempted to find commonalities across families. Specifically, the goals of this research were twofold, to find the optimal ratio of MARV plasmids in the minigenome system to understand the effects of the stem-loop secondary structure of MARV mRNA transcripts as well as determine the tail length of the poly(A) tail of RSV mRNA transcripts using digestion and probing primers. Calculating the RSV poly(A) tail length would allow for further research into determining whether the MARV and RSV polymerase polyadenylates before or after it releases the transcript. Despite multiple failed attempts, transfections using pCAGGS plasmids and the eGFP monocistronic minigenome in a 6-well plate qualitatively demonstrated the need for pCAGGS-L plasmid concentration of 1000 ng/µl. Due to time constraints, the poly(A) tail length of the RSV NS-1 mRNA transcript could not be determined. Overall, this study focused on gaining new insights on the techniques and procedures necessary for conducting virus research in a biosafety level 2 (BSL-2) setting, as well as developing troubleshooting skills in approaching fail experiments.

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