Optimization of expression yield in a stable cell line expressing a novel mutated chimeric tissue plasminogen activator (mt-PA)

Abstract The development of stable cell lines producing recombinant proteins is very time-consuming and laborious. One of the practical approaches successfully performed is Fluorescence-Activated Cell Sorting (FACS). A mutated chimeric tissue plasminogen activator (mt-PA) was developed by removing the first three domains of t-PA, insertion of GHRP sequence and mutation toward resistance to plasminogen activator inhibitor-1 (PAI-1). In the current study, a new stable CHO-DG44 cell line producing mt-PA was developed by two sequential clonal selections: FACS and clonal-selection by limiting dilution. Furthermore, the expression was more evaluated using two different expression media. Finally, the high-producing clones were selected based on the dot blot and amidolytic activity test. The transfection efficiency of CHO-DG44 cells was 38% as measured by flow cytometry on green fluorescent protein (GFP). After performing FACS on stable cell pools, the expression yield was increased to fifty-fold. In terms of growth profile, CD-DG44 showed higher viability and cell density results than ProCHO5 medium. The expression of mt-PA was significantly higher in CD-DG44 than in ProCHO5, 765 and 280 IU/mL, respectively. Our data indicated that selection of an appropriate expression medium played a critical role in the development of potent producing stable cells by FACS.

Composição volátil das uvas ao espumante da cv. Chardonnay em diferentes condições de manejo no sul de Minas Gerais (Brasil) / Volatile composition from grapes to sparkling wine of Chardonnay vine in different management conditions in southern of Minas Gerais (Brazil)

O aroma é um dos fatores mais importantes na determinação da qualidade e do caráter do vinho. Isso se deve à presença de compostos voláteis que estão associados às suas características organolépticas ou diferentes proporções entre estes compostos que podem ser influenciadas por fatores vitícolas (clima, solo, cultivar, manejo) e enológicos (maturação da uva, fermentação, tratamentos pósfermentativos). A região do sul de Minas Gerais vem se destacando na produção de espumantes de qualidade, e, nesse contexto, o presente trabalho teve como objetivo conhecer a influência do manejo da videira no desenvolvimento do aroma, da baga até o espumante, a fim de estabelecer associações com a qualidade do produto final. Os experimentos foram realizados com a cultivar Chardonnay em diferentes condições de manejo, em que foram avaliados clones, porta-enxertos, sistemas de condução e densidades de plantio. Foram analisados os compostos voláteis livres por HS-SPME/GC-MS das bagas, mostos, vinhos base e espumantes nas safras 2016, 2017 e 2018. O trabalho foi dividido em quatro partes para a apresentação dos resultados. A primeira consistiu em verificar a influência do material genético na composição volátil da cv. Chardonnay com os experimentos de clones e portaenxertos; a segunda parte avaliou a composição volátil do clone 809 até o espumante; a terceira, em analisar as vinificações dos diferentes sistemas de condução; e a quarta, em avaliar a evolução dos compostos voláteis da baga ao espumante e analisar os aromas que as densidades de plantio podem conferir ao espumante. As principais classes de compostos aromáticos identificados nas matrizes foram: C6-C9 aldeídos, álcoois superiores, aldeídos ramificados, benzenoides, monoterpenoides, norisoprenoides, sesquiterpenoides, cetonas e ácidos graxos. Os resultados mostraram que os clones e os porta-enxertos apresentaram perfis voláteis diferentes, indicando que a variabilidade entre os clones e que a enxertia têm influência no metabolismo da baga; o clone 809 apresenta maior abundância de compostos monoterpenoides, confirmando o seu caráter moscato, das uvas aos espumantes; os diferentes sistemas de condução e densidades de plantio alteram o metabolismo da14 baga, refletindo no perfil volátil dos espumantes nas safras estudadas. Dessa forma, os dados indicam que a composição volátil sofre influência do manejo da videira ao espumante

Aroma is one of the most important factors in determining the quality and character of wine. This is due to the presence of volatile compounds that are associated with their organoleptic characteristics or different proportions among these compounds that can be influenced by viticultural (climate, soil, cultivar, management) and oenological factors (grape maturation, fermentation, post fermentation treatments). The southern region of Minas Gerais has been standing out in the production of quality sparkling wines, and in this context, the purpose of the present work was to learn about the influence of grapevine management on the development of aroma, from berry to sparkling wine, in order to establish associations with the quality of the final product. The experiments were carried out with the Chardonnay cultivar under different management conditions, in which clones, rootstocks, trellising systems and planting densities were evaluated. The free volatile compounds by HS-SPME/GC-MS of the berries, musts, base and sparkling wines in the 2016, 2017 and 2018 harvests were analyzed. The work was divided into four parts in order to present the results. The first part consisted of verifying the influence of genetic material on the volatile composition of the cv. Chardonnay with the experiments on clones and rootstocks; the second part evaluated the volatile composition of clone 809 up to the sparkling wine; the third one part analyzed the vinification of the different trainig systems; and the fourth part evaluated the evolution of the volatile compounds from the berry to the sparkling wine and analyzed the aromas that the planting densities can confer to the sparkling wine. The main classes of aromatic compounds identified in the matrices were: C6-C9 aldehydes, higher alcohols, branched aldehydes, benzenoids, monoterpenoids, norisoprenoids, sesquiterpenoids, ketones and fatty acids. The results showed that the clones and the rootstocks have different volatile profiles, indicating that variability among clones and that grafting have great relevance to the berry secondary metabolism; the 809 clone presents a greater abundance of monoterpenoid compounds, confirming its muscat character, from grapes to sparkling wines; the different training systems and planting densities alter the berry´s metabolism, reflecting16 in the volatile profile of sparkling wines in the studied harvests. The data indicate that the volatile composition is influenced by the management of the berry to the sparkling wine

T cell clones from Schistosoma haematobium infected and exposed individuals lacking distinct cytokine profiles for Th1/Th2 polarisation

T cell clones were derived from peripheral blood mononuclear cells of Schistosoma haematobium infected and uninfected individuals living in an endemic area. The clones were stimulated with S. haematobium worm and egg antigens and purified protein derivative. Attempts were made to classify the T cell clones according to production of the cytokines IL-4, IL-5 and IFN-gamma. All the T cell clones derived were observed to produce cytokines used as markers for the classification of Th1/Th2 subsets. However, the 'signature' cytokines marking each subset were produced at different levels. The classification depended on the dominating cytokine type, which was having either Th0/1 or Th0/2 subsets. The results indicated that no distinct cytokine profiles for polarisation of Th1/Th2 subsets were detected in these S. haematobium infected humans. The balance in the profiles of cytokines marking each subset were related to infection and re-infection status after treatment with praziquantel. In the present study, as judged by the changes in infection status with time, the T cell responses appeared to be less stable and more dynamic, suggesting that small quantitative changes in the balance of the cytokines response could result in either susceptibility or resistant to S. haematobium infection