Publications by authors named "Marcela Cristina Correa de Freitas"

Filamentous fungus Purpureocillium lilacinum is an emerging pathogen that infects immunocompromised and immunocompetent individuals and is resistant to several azole molecules. Although azole resistance mechanisms are well studied in Aspergillus sp. and Candida sp.

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Article Synopsis
  • The study aimed to create recombinant factor IX (FIX) variants that have enhanced clotting activity for hemophilia B treatment.
  • Three new FIX variants were developed (FIX-YKALW, FIX-ALL, and FIX-LLW), which had lower antigen expression levels compared to the wild-type but exhibited significantly higher biological activity in clotting assays.
  • Among the variants, FIX-YKALW showed the best results in promoting clotting and providing hemostatic protection in mice models, indicating potential for clinical use in protein replacement therapy.
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  • Gamma-carboxylated proteins require vitamin K for their normal biosynthesis and include key coagulation factors like factor VII, IX, X, and prothrombin.
  • These proteins undergo posttranslational modifications, making their production suitable in mammalian cell lines.
  • The chapter outlines methods for generating human cell lines to effectively produce these proteins, detailing steps from modifying the cell lines to adapting them for vitamin K use.
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Recombinant factor VII (rFVII) is the main therapeutic choice for hemophilia patients who have developed inhibitory antibodies against conventional treatments (FVIII and FIX). Because of the post-translational modifications, rFVII needs to be produced in mammalian cell lines. In this study, for the first time, we have shown efficient rFVII production in HepG2, Sk-Hep-1, and HKB-11 cell lines.

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  • Factor IX (FIX) is a key protein for treating Hemophilia B, and researchers studied its production using two human cell lines: 293T and SK-Hep-1.
  • SK-Hep-1 cells produced more biologically active FIX, although they showed slower growth compared to their non-FIX counterparts, while 293T cells did not have their growth affected by gene integration.
  • The study indicated that while 293T cells can efficiently carboxylate FIX (important for its activity), only a fraction is active; in contrast, SK-Hep-1 cells secrete high amounts of active protein, making them a promising platform for producing recombinant FIX.
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Ligation-mediated-PCR was performed followed by the mapping of 177 and 150 integration sites from HepG2 and Hek293 transduced with chimera vector carrying recombinant human Factor IX (rhFIX) cDNA, respectively. The sequences were analyzed for chromosome preference, CpG, transcription start site (TSS), repetitive elements, fragile sites and target genes. In HepG2, rhFIX was had an increased preference for chromosomes 6 and 17; the median distance to the nearest CpG islands was 15,240 base pairs and 37 % of the integrations occurred in RefSeq genes.

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The most important properties of a protein are determined by its primary structure, its amino acid sequence. However, protein features can be also modified by a large number of posttranslational modifications. These modifications can occur during or after the synthesis process, and glycosylation appears as the most common posttranslational modification.

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The industrial production of recombinant proteins preferentially requires the generation of stable cell lines expressing proteins in a quick, relatively facile, and a reproducible manner. Different methods are used to insert exogenous DNA into the host cell, and choosing the appropriate producing cell is of paramount importance for the efficient production and quality of the recombinant protein. This review addresses the advances in recombinant protein production in mammalian cell lines, according to key patents from the last 30 years.

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Objective: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO) and baby hamster kidney cells (BHK). Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.

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