Orientador: Jorge Vega / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-20T18:10:06Z (GMT). No. of bitstreams: 1 Baptista_CeliaRegina_M.pdf: 10046267 bytes, checksum: 9f4cdc2c74acd2b3cc7ebea8e3d6983b (MD5) Previous issue date: 1995 / Resumo: Com o objetivo de estudar o efeito quimioterápico de Virazole (1-ß-Dribofuranosil -1,2,4 - triazol-3 - carboxamida) in vitro sobre vírus de plantas, dois modelos de estudo foram realizados. No primeiro utilizou-se calos de videira Vitis vinifera, Seibel 2, infectados com o vírus do enrolamento da folha da videira (VEFV), e calos de fumo Nicotiana tabacum "TNN" e Gomphrena globosa L. infectados com o vírus do anel do pimentão (VAP). No segundo, foi utilizado um modelo aplicado, visando a obtenção de plantas de limoeiro Galego Citrus aurantifolia (Christm.) Swing) livres do vírus da tristeza dos citros "citrus tristeza virus" (CTV). Os objetivos específicos foram: 1) Testar o efeito do Virazole em calos cultivados in vitro, comparando: a) diferentes tipos de vírus (closterovirus e tobravirus) e b) efeito do. Virazole sobre um mesmo vírus em duas espécies de plantas hospedeiras. 2) Avaliar a possibilidade do uso de Virazole para obtenção de plantas cítricas livres do CTV por minienxertia realizada in vitro. Os resultados mostraram que o Virazole inibiu a multiplicação dos 3 vírus em estudo (VEFV, VAP e CTV), pertencentes a dois grupos distintos: closterovirus (VEFV e CTV) e tobravirus (V AP). A utilização de calos infectados com vírus e tratados com Virazole in vitro, mostrou ser um modelo de estudo eficiente para avaliar o efeito desse composto quimioterápico sobre vírus de planta. A indexação serológica; das amostras coletadas a cada subcultura dos calos permitiu acompanhar a evolução do conteúdo de vírus no decorrer de várias subculturas sucessivas. Os resultados mostraram de modo geral, que a quantidade de vírus presente varia muito pouco nas culturas de calos mantidas em ausência de Virazole. As concentrações mais baixas utilizadas não inibiram a multiplicação dos vírus, ao passo que concentrações mais altas do produto provocaram uma diminuição progressiva da concentração de vírus a cada subcultura até que as partículas virais não foram mais detectadas nos testes serológicos. O desenvolvimento da cultura foi afetado por concentrações altas de Virazole, sendo que algumas concentrações foram fitotóxicas, dependendo da planta e do tecido tratado. Em calos de videira infectados com VEFV o significativa a replicação do vírus. A inibição foi proporcional Virazole inibiu de maneira à concentração do produto utilizada. À 50 ppm não foram detectadas partículas virais nos testes serológicos. O Virazole atuou rapidamente em diminuir a concentração do VEFV à um nível baixo em calos em proliferação, porém, um longo período de incubação foi necessário para obter completa supressão dos vírus. Esses resultados são consistentes com a possibilidade de que a atividade antiviral do Virazole se manifesta por sua ação na síntese de novas partículas mais do que uma inativação direta dos vírus existentes. O Virazole foi capaz de inibir a multiplicação do V AP em calos de fumo, mas não em calos de G. globosa. Em fumo a concentração de 200 ppm eliminou os vírus presentes nos calos, enquanto que em calos de G. globosa o Virazole não foi efetivo em nenhuma das concentrações testadas. Possivelmente essas plantas apresentam vias metabólicas alternativas para a replicação do RNA viral ( e não aquela inibida pelo Virazole). A eficiência do Virazole em eliminar o V AP foi também dependente do estágio de desenvolvimento dos tecidos tratados. O Virazole inibiu a multiplicação de vírus quando pedaços de folhas foram utilizados como explantes, porém, ocorreu pouca ou nenhuma inibição quando células de calos não organizados foram tratadas com Virazole. O Virazole inibiu a multiplicação do CTV à concentração de 200 ppm. Essa inibição foi verificada pela ausência de sintomas específicos do vírus da tristeza nas plantas obtidas. As plantas cresceram tão bem quanto as plantas sadias. O Virazole não foi efetivo à 100 ppm. Nessa concentração o vírus provocou paralisação do crescimento das plantas e as folhas apresentaram sintomas de palidez das nervuras, específicos da doença. Esses resultados foram confirmados por ELISA e "Western-blot". Com bases nesses resultados, conclui-se que o Virazole é um quimioterápico eficiente para a obtenção de plantas livres de vírus, dependendo da espécie vegetal, do vírus envolvido e das condições de tratamento / Mestrado / Fisiologia Vegetal / Mestre em Ciências Biológicas

Orientador : Otavio Henrique de Oliveira Pavan / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-15T06:29:39Z (GMT). No. of bitstreams: 1 Rodrigues_JaquelineJosiSama_M.pdf: 3116550 bytes, checksum: de31678246d3e695389ba76cef95ea7e (MD5) Previous issue date: 1989 / Resumo: Foram realizadas cinco passagens seriadas do Vírus de Poliedrose Nuclear de Autographa californica (VPNAc) no hospedeiro alternativo Diatraea saccharalis, sendo que o inoculo inicial foi uma variante genética deste vírus (E2). Quatro isolados virais foram obtidos (IV-1, IV-2, IV-3 e IV-4), além do VPNAc original ( E2 ). Foram analisados dados de mortalidade, tempo de ação do vírus, estrutura morfológica do cristal viral, produção de vírus por inseto e proteínas estruturais do vírus. Os principais resultados e conclusões foram: a) O VPNAC foi capaz de infectar, multiplicar-se e produzir cristais infectivos no hospedeiro alternativo Diatraea saccharallis.b) A virulência do VPNAc para lagartas de D. saccharalis, medida através da DL50 aumentou progressivamente em cerca de 1000 vezes. c) Alguns cristais virais apresentaram forma cúbica ao invés da poliédrica normal, sendo que no último isolado obtido (IV-4) estes perfizeram 20% do total de cristais. d) Os poliedros de IV-4 foram cerca de 2 vezes maior em volume do que os poliedros do primeiro isolado inoculado (E2). e) Houve uma redução gradual da produção de vírus por larvas infectadas. Esta diminuição da produção foi de 16 vezes após a 4ª passagem do vírus por O.saccharalis e, após a 5ª passagem, ocorreu uma quase ausência de cristais virais. f) Os isolados de VPNAc apresentaram diferenças quanto a seus polipeptídeos estruturais quando analisados em gel de SDS e paliacrilamida. g) Dentre os cincos isolados virais estudados, foram identificados três grupos, E2/IV-1, IV-2 e IV-3/IV-4, quanto à atividade biológica e padrões eletroforéticos de suas proteínas estruturais, observando-se um aumento de virulência acompanhado por uma progressiva alteração dos peptídeos. O isolado IV-2 apresentou características intermediárias entre os outros dois grupos, E2/IV-1 e IV-3/IV-4. h) O tratamento adicional com SDS e 2-mercaptoetanol na purificação dos vírus não permitiu que se evidenciassem as diferenças nos padrões eletroforéticos dos cinco isolados virais. i) As alterações que ocorrem com o VPNAc provavelmente devem ter sido causadas por modificações do DNA viral provocadas pela passagem do vírus, originalmente uma variante geneticamente homogênea, em larvas do hospedeiro alternativo D. Saccharalis. j) A passagem seriada em hospedeiro alternativo é um método que permite fácil manipulação genética e seleção de isolados virais e um importante instrumento na compreensão do complexo sistema patógeno-inseto / Abstract: The genetic variant E2 from the Autographa californica Nuclear Polyedrosis Virus (AcNPV) was serially passed for five generations in its alternate host Oiatraea saccharalis the sugarcane borer. From these passages four isolates were obtained besides the original inoculum (IV-I, IV-2, IV-3, IV-4 and E2). These isolates were compared to each other considering larval mortality, mode and timing of action, morphology of the polyhedra, polyhedral production and protein profile. As a result of this analysis the following results and conclusions were reached: a) The AcNPV-E2 was able to infect and produce infective polyhedra in its alternate host Diatraea saccharalis. b) A drastic and progressive increase in the virulence of the AcNPV isolates, indicated by thousand fold reduction of the LD50 values, was observed for D. saccharalis larvae. c) The increasing presence of abnormal larger cubic shaped polyhedra opposed to the regular polyhedra in the forth generation of the virus isolate (IV-4). d) A two fold increase in the number of polyhedral volume was observed when comparing the original (E2) and the selected inoculum (IV-4) e) A 16 fold reduction in the number of polyhedra produced per gram of infected larvae was observed when comparing the original inoculum (E2) and the forth generation (i. e. virus produced by inoculum IV-3). The inoculation of IV-4 resulted in an almost total absence of polyhedra in the infected larvae. f) The AcNPV isolates presented differences in the protein profile in the SDS polyacrilamide gel electrophoresis (SDS-PAGE). g) Based on the protein profile and biological activity the five isolates can be separated in the three groups, E2/IV-1, IV-2 e IV-3/ IV-4, indicating a growing virulence followed by an progressive alteration of peptides. The IV-2 isolate in both perspectives represents an intermediate group. h) The protein differences were not observed with the treatment of SDS and 2-mercaptoethanol in the purification procedure / Mestrado / Genetica / Mestre em Ciências Biológicas

Orientador : Avelino Rodrigues de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-15T17:34:48Z (GMT). No. of bitstreams: 1 Garcia_SaraPolido_M.pdf: 2495523 bytes, checksum: abc0b1d0f7ad966722417f684c3d617d (MD5) Previous issue date: 1980 / Resumo: Cinco técnicas de purificação do vírus do mosaico dourado do tomateiro (VMDT) foram testadas, visando obter antígenos para o preparo de antissoros específicos. As técnicas empregadas foram xilol, tetracloreto de carbono, eliminação dos cloroplastos e polietilenoglicol. A avaliação da eficiência dessas técnicas, através de testes de infectividade das frações finais, observações ao microscópio eletrônico e testes serológicos comos antissoros preparados, mostrou que polietilenoglicol é técnica adequada para os fins propostos. Frações do VMDT purificado segundo a técnica do polietilenglicol mostraram-se ativas biologicamente nos testes de inoculação mecânica em plantas de Nicotiana glutinosa L. e N. tabacum L. e exibiram alta concentração de partículas com diâmetro em torno de 14 nm. Antissoros preparados com essa fração apresentaram, em testes de dupla difusão em agar, linha de precipitação que permite diagnosticar a presença do VMDT em hospedeiras de N. glutinosa e N. tabacum / Abstract: In order to prepare specific antisera to the tomato golden mosaic virus (TGMV), a whytefly-transmitted agent, five purification methods were tried. The techiques used in this work were: xylol, carbon tetrachloride, butanol, chloroplasts elimination, and polyethylene glycol. Bio-assays and serological tests have shown that the polyethylene glycol technique was the best for purification. It was carried out, as follows: infected leaves of Nicotiana glutinosa L. And N. Tabacum L. Were homogenized in 0.02M potassium phosphate buffer at pH 7.0 plus 0.02M Na2SO3; the clarification was carried out with 7% chloroform combined with n-butanol and TGMV precipitated with 10% PEG (Carbowax-6.000)-0.25M NaC1, followed by low-speed centrifugation. TCMV is an immunogenic virus type and double diffusion tests performed with purified preparations against their antisera showed a precipitin line (line b), seen in Fig. 5,6 / Mestrado / Biologia Celular / Mestre em Ciências Biológicas

Orientador: Avelino Rodrigues de Oliveira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-18T01:59:17Z (GMT). No. of bitstreams: 1 Moraes_WalkyriaBuenodeCamargo_D.pdf: 6399767 bytes, checksum: ceb637122aeabfe9f1048e27d1ba4a8e (MD5) Previous issue date: 1973 / Resumo: Uma substância extraída de folhas de Abutilon striatum Dicks. Inibe a infecção causada pelo vírus do mosaico do fumo *TMV), quando inculado em folhas de glutinosa ( Nicotiana glutinosa L. ). A substância termoestável, não dialisável e de alto peso molecular (5000-10000) é de natureza polissacarídica, podendo ser retida pelo carvão ativo, não se alterando em pH alcalino ou quando submetida a tratamento para desproteinização. Não é degradada pelos tratamentos com diastase ou pectinase. Possue duas bandas características de absorção a ultravioleta, nas regiões compreendidas entre 260-276nm e 320 nm. A presença do inibidor não altera a capacidade de reação do TMV com seu antissoro específico, em testes de dupla- difusão em Agar. O inibidor forma complexo instável com TMV, podendo ser separado deste por ultracentrifugação. As eletromicrografias sugerem que o inibidor recubra as partículas de vírus, além de promover o agregamento, fragmentação e deformações das mesmas. Mantendo-se constante a concentração do TMV a porcentagem de inibição da infectividade deste é função logarítmica da concentração do inibidor. A redução da infectividade do vírus, quando empregado em diferentes concentrações, é inversamente proporcional às concentrações do mesmo, sob ação de uma determinada concentração do inibidor.O inibidor reduz a infectividade do TMV inoculado em N. glutinosa ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Na inhibitory substance present in leaves of Abutilon striatum reduced the infectivity of tobacco mosaic vírus (TMV) when assayed on leaves of Nicotiana glutinosa. The inhibitory substance presented the following characteristics: it was not dialyzable, it was stable in high temperature and high pH (11). It was retained by active charcoal. The substance was unaffected by treatments to inactivate proteins, and seemed to be a polysaccharide of high molecular weight (5000-10000). It was unaffected by enzymatic preparations of diastase and pectinase. The ultraviolet spectra showed two characteristic bands: I (260-276nm) and II (310-320nm). In serological agar double-diffusion tests, the presence of the inhibitor did not interfere with the capacity of reaction between the TMV and its specific antisserum. The TMV- inhibitor bounds could be disrupted by ultracentrifuging the mixture without loss of activity of any of the components.Studies on the fine-structure of the complex virus-inhibitor suggested that the virus particles were recovered by the inhibitor which promoted their aggregation, fagmentation and distortion. At constant TMV-concentration, the percentage of reduction of infectivity was a logarithmic function of inhibitor concentration.Under the action of a constant inhibitor concentration the reduction of TMV infectivity was inversely proportional to the virus concentration.The infectivity of TMV was inhibited when inoculated on N...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Doutorado / Doutor em Ciências Biológicas

Orientador: Alvaro S. Costa / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-20T01:41:00Z (GMT). No. of bitstreams: 1 Vega_Jorge_M.pdf: 4286431 bytes, checksum: e5da9b352c4959d8d12cdc78b7aec1f8 (MD5) Previous issue date: 1985 / Resumo: Em células do parênquima fotossintetizante de folhas de soja {Glycine max (L.) Merr.}, invadidas sistematicamente pelo vírus do mosaico comum de soja ('soybean mosaic virus'), foi observado que uma importante fração das inclusões lamelares (IL) induzidas pelo vírus aparecem em contato com os peroxisomas. Esta organela foi identificada pela reação da diaminobenzidina para localização citoquímica da catalase. Os peroxisomas são deformados pelo contrato com as inclusões. Não ocorre aumento desta atividade enzimática nas folhas inoculadas, nas quais não foi observada a associação entre inclusões e peroxisomas. A peroxidase, uma enzima não peroxisomal, é incrementada tanto nas folhas inoculadas como nas invadidas sistemicamente. Na variedade de soja Santa Rosa, muito suscetível ao VMCS, foi observado um decréscimo aparente no número de peroxisomas visíveis ao microscópio óptico, por corte de células, nas folhas infectadas. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Most cytoplasmic inclusions induced by soybean mosaic virus were observedassociated with peroxisomes in mesophyll cells of systemically infected leaves of soybean {Glycine max (L.) Merr.}. Peroxisomes, identified by the diaminobenzidine reaction for catalase, become misshapen because of deep invaginations at the region of contact with the lamellar inclusions. Aggregates ofperoxisomes, formed around the lamellar inclusions, are frequent. The catalase activity, a peroxisomal enzyme, increases in leaves with systemi symptoms, apparently as a result of the peroxisome-inclusin association. Catalase activity was not increased in inoculated leaves, nor them. The peroxidase activity, which is not localized in the peroxisome, is increased in either systemic or locally infected leaves. ...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Mestre em Biologia Vegetal

Tesis de Magíster en Bioquímica, Área de Especialización en Toxicología y Diagnóstico Molecular / La infección de transmisión sexual más común a nivel mundial, tanto en hombres como en mujeres es la producida por el Virus Papiloma Humano (HPV). Los diferentes HPV que afectan la zona anogenital se dividen en dos grupos: bajo y alto riesgo carcinogénico. La infección con HPV-AR ha sido detectada en más del 99,7% de los casos de cáncer cérvico-uterino. Este cáncer ocupa el sexto lugar dentro de las neoplasias malignas femeninas, produciendo alrededor de 600 muertes al año en Chile. En la actualidad no se dispone de biomarcadores adecuados para estimar el pronóstico de la infección viral en los pacientes. Por lo anterior, en esta investigación se evaluó la utilidad de la medición de la carga viral como predictor de progreso de la infección en mujeres infectadas con HPV-16. La hipótesis planteada fue que las pacientes infectadas con HPV-16 y con lesiones cervicales de alto grado presentan una mayor carga viral cuantificada a través de la amplificación de segmentos de los genes L1 y E7 en comparación con aquellas infectadas y con lesiones de bajo grado. El estudio se realizó con muestras cervicales de 60 mujeres controladas ginecológicamente en el Hospital San Juan de Dios. Todas las pacientes presentaban un examen citológico alterado: 40 estaban infectadas con HPV-16 y 20 fueron negativas a la presencia del virus. En todas las muestras se cuantificó la carga de DNA viral mediante PCR en tiempo real. El 28,3%, 18,3% y 53,3% de las pacientes presentaron lesiones NIE I, NIE II y NIE III, respectivamente. En las pacientes infectadas con HPV-16 se determinó que la mediana de la carga viral del ensayo utilizando L1 en LIBG es 1,4 veces mayor en comparación con la obtenida en las LIAG. La carga viral obtenida al amplificar un segmento del gen E7 se encontró que es 1,5 veces mayor en LIBG en comparación con LIAG. Además, los niveles de los amplicones de ambos genes en los diferentes grados de lesión mostraron una correlación lineal positiva. Estos resultados muestran que en LIBG existe una mayor carga viral en comparación con aquellas con lesiones LIAG / The most common worldwide sexually transmitted disease in both men and women is Human Papillomavirus (HPV). Different HPV infect the anogenital area and they are divided into two groups: low and high carcinogenic risk. High risk HPV have been found in 99,7% of cervical cancer cases. This cancer ranks sixth in female malignancies, causing about 600 deaths a year in Chile. Currently there are no good biomarkers to predict the viral infection in patients. Therefore, this study evaluated the usefulness of viral load as a predictor of disease progression in HPV-16-infected women. The hypothesis was that patients infected with HPV-16 and with high-grade cervical lesions have a higher viral load quantified through the amplification of segments of L1 and E7 genes compared to those infected with low-grade lesions. We studied vaginal samples of 60 women attending a gynecological control at San Juan de Dios Hospital. All patients had an altered cytology testing: 40 of them were HPV-16 infected and 20 non infected. Viral load of L1 and E7 genes were quantified in all samples by real time PCR. The overall detection of cervical intraepithelial neoplasia NIEI, NIEII and NIEIII was 28,3%, 18,3% and 53,3%, respectively. In LIBG patients infected with HPV-16 it was determined that the median viral load assay using L1 is 1,4 times higher compared with that obtained in LIAG. The viral load obtained by amplifying a segment of the E7 gene was found to be 1,5 times higher in patients with LIBG than LIAG. Furthermore, levels of L1 and E7 genes show a positive lineal correlation in all cervical lesions. These results indicate that lesions with low severity have higher viral load than high severity

Background: The human immunodeficiency virus (HIV) is the cause of the acquired immunodeficiency syndrome (AIDS). AIDS is fatal if not treated appropriately. Although there are treatment options for the infection, there are many problems associated with it, including non-compliance to prescribed treatments due to toxicity and side effects, leading to drug resistance. There is therefore a need to develop novel drugs that are less toxic. This study contributes to the fight against HIV/AIDS by recommending new metallodrugs able to address the shortcomings of existing treatments. Metals have previously demonstrated potential in targeting HIV-1, mostly with activity against the enzymes reverse transcriptase and protease. The current study investigated the effects of metal-based complexes against viral entry into host cells. Methods: Three metal-based complexes; Aryl-1H-1,2,3- triazole-based cyclometalated Ruthenium (II) complex (A), Aryl-1H-1,2,3- triazole-based cyclometalated Iridium (III) complex (B) and Aryl-1H-1,2,3- triazole-based cyclometalated Osmium (II) complexes (C) were investigated for potential HIV entry inhibition and their activity was compared to that of the ligand which did not contain the metal component. The study analysed the toxicity of the complexes in TZM-bl cells and Peripheral blood mononuclear cells (PBMCs). Three pseudo-viruses (CAP 210, Du 156 and Q 23) were created using transformation and transfection methods and a luciferase reporter gene assay was used to analyse the inhibitory effects of the complexes on the pseudo-virus infection of TZM bl cells. Active complexes were further analysed for a potential mechanism of action through in silico docking. Results and discussion: The complexes were found to have lower CC50 values in PBMCs compared to TZM-bl cells. In both cell lines, B had the lowest CC50 value, which can be attributed to the increased hydrolysis of the chloride atom bound to the iridium as well as the increased uptake into the cells. Based on the luciferase reporter gene assay all three of the metal-based complexes had inhibition of viral infection with IC50 values ranging from 5.34 – 7.41 µM for A, 2.35 – 8.09 µM for B and 2.59 to 4.18 µM for C. The ligand was only analysed for any inhibitory activity on one of the pseudo-viruses (Du 156) and was found to have no significant inhibition. Selectivity index (SI) values indicated the complexes were effective at non-toxic concentrations with values ranging from 1.61 – 4.56 for B, 3.29 – 4.56 for A and 7.03 – 11.26 for C. In silico docking analysis of the proteins involved in viral entry indicated that inhibition possibly occurred through interaction with the CCR5 co-receptor, as the docking scores for this protein were the most negative indicative of favourable interactions between proteins and ligands. Conclusion: The metal-based complexes showed inhibition with IC50 values in the low micromolar range, while the ligand had no statistically significant inhibition. This suggests that the presence of the metal ion enhances viral inhibition. Furthermore, inhibition was through the interaction of the complexes with CCR5, in a manner similar to that of Maraviroc, a clinically utilized CCR5 inhibitor. This study identified novel metal-based HIV-1 entry inhibitors which were effective against HIV-1 subtype A and C at non-toxic concentrations. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2021. / Biochemistry / MSc (Biochemistry) / Unrestricted

The main aims of diploma thesis were: 1) The sequence analysis of the Czech isolate of Potato virus M (PVM) VIRUBRA 4/009 and phylogenetic analysis of PVM coat proteins sequences 2) The bacterial expression of recombinant triple gene block protein 1 (TGB1) of PVM derived from the Czech isolate VIRUBRA 4/007 3) The construction of expression cassette of Potato leafroll virus (PLRV) coat protein and its transformation into A. tumefaciens for transgenic PLRV resistant plant formation In theoretical part of the thesis the taxonomic classification, morphology, genomic structure and virus transmission are discussed. Furthermore, the main rules concerning the bacterial expression of recombinant proteins and construction of transgenic plants using A. tumefaciens are described. Methodical part is devoted to description of generally used molecular biological and immunochemical methods. The following results were obtained in the thesis: The complete nucleotide sequences of open reading frames coding for three movement proteins (Triple gene block -TGB), coat protein and NA-binding protein of PVM isolate VIRUBRA 4/009; phylogenetic analysis was performed; the TGB1 protein was expressed in bacterial cells and will be used for polyclonal antibodies raising. Finally, the expression cassette containing the PLRV...

Oncolytic viruses (OVs) are an emerging cancer therapy that use an oncotropic virus to selectively infect and kill cancer cells, as well as stimulate long-lasting anti-tumor immune responses. In order to achieve high therapeutic efficacy, OVs need sufficient replication within the tumor tissue to mediate these effects. However, OV’s infectivity varies between different tumors and the host’s immune system can rapidly clear the virus, hampering treatment efficiency. Oncolytic virus sensitizers are chemical compounds that specifically enhance OV’s infectivity and efficacy. In our lab, I found that treatment of various cancer cell lines with BI-D1870, a pan-RSK (ribosomal S6 kinase) inhibitor, resulted in augmented Herpes Simplex Virus-1 (HSV1) and Vesicular Stomatitis Virus (VSVΔ51) infectivity. I also demonstrated that the effects of BI-D1870 on viral infection are virus-specific, and that RSK inhibition is not the primary target causing the enhancement of HSV1 and VSVΔ51 infection. Finally, BI-D1870 structural analogs were generated in an attempt to enhance the efficacy and selectivity of BI-D1870-based OV sensitizers. One of the analogs synthesized, KA-019, showed an improvement in the augmentation of OV infection over BI-D1870. As a genetically engineered strain of HSV1 has been approved by FDA for treatment of melanoma, the results of my project propose a novel viral sensitizer to improve viral replication within tumour cells with the hope of improving therapeutic efficacy.

Soybean (Glycine max L. Merr.) is one of the most important crops of the world. Among the various viruses infecting soybean, peanut mottle virus is most commonly found on soybeans in areas where they are grown in close proximity to peanuts. This research was conducted with the primary objective of identifying new genes for resistance to peanut mottle virus. To assign a gene symbol to the resistance gene in cultivar CNS, it was crossed with 'Peking'. Both the F2 and F2:3 lines segregated in a ratio which is expected when one dominant and one recessive gene at two different loci are segregating. Previous studies indicate the presence of one dominant gene in CNS and one recessive gene in Peking for resistance against PMV. This clearly suggests that Peking and CNS possess different resistance genes, which are non-allelic to each other. Now that, all the allelism tests are complete, the resistance gene in CNS can be assigned a gene symbol of Rpv3. PI 486355, a resistant line, was crossed with susceptible cultivars Lee 68 and Essex to study the mode of inheritance of resistance. This PI was found to possess two independent dominant genes for resistance to peanut mottle virus. It was also crossed with 'York' and CNS which are known to have resistance genes at the Rpv1 and Rpv3 loci, respectively. Data from inoculations of F2 and F2:3 progenies indicated that one gene was allelic to Rpv1 and the other is at a locus different from both Rpv1 and Rpv3. PI 398593 was crossed with Lee 68, York, Peking and CNS for studying the nature of resistance genes present in it. No certain conclusions can be drawn regarding the nature of the resistance gene(s) at this stage because of inconsistent behavior of the PI itself. The F2 data of the crosses of PI 398593 with Lee 68, York and CNS supported a recessive nature of the resistance gene present in the PI. F2 plants of the cross PI 398593 x Peking segregated but, not in the expected ratio. F2:3 data of only one cross (PI 398593 x York) supported the recessive nature of the PI resistance gene whereas the other two crosses (PI 398593 x CNS and PI 398593 x Peking) did not support these findings. From the data available it appears that the resistance is at least partially influenced by the environment. The mode of inheritance of resistance in PI 96983, 'Kwanggyo', 'Toano', 'Jizuka', 'Raiden' and 'Suweon 97' was studied by crossing these cultivars with PMV susceptible cultivars and inoculating the F2 populations of these crosses. In all these cultivars resistance is governed by a single dominant gene. PI 96983, Toano, Jizuka and Suweon 97 were also crossed with York to determine the allelic relationships. Resistance genes in all these cultivars were found to be allelic to Rpv1. Since each of the cultivars also has a single dominant gene at the same locus for resistance to soybean mosaic virus, it is possible that resistance to both viruses is controlled by the same gene. / Master of Science