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Quilici LS, Silva-Pereira I, Andrade AC, Albuquerque FC, Brigido MM, Maranhão AQ. A minimal cytomegalovirus intron A variant can improve transgene expression in different mammalian cell lines. Biotechnol Lett 2012; 35:21-7. [PMID: 22955677 DOI: 10.1007/s10529-012-1043-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 08/21/2012] [Indexed: 11/28/2022]
Abstract
The expression enhancement by cytomegalovirus promoter and different intron A (IA) variants were evaluated in CHO-K1, HepG2, HEK-293 and COS-7 cells by assessing the levels of luciferase activity. This data along with mRNA levels measurement indicated that the construct harboring an IA variant with a 200-nucleotide deletion (Δ200) had the greatest impact on increasing luciferase expression among all constructs evaluated. Based on these results, we redesigned pCMV-IA variants and cloned them into plasmids expressing a humanized antibody. These plasmids were then used to transfect CHO-K1 cells. Production of the antibody was not augmented with the Δ200 promoter variant. The 600-nucleotide deletion (Δ600) and whole IA promoter variants expressed similar levels of the recombinant protein. These data indicate that the IA-based enhanced expression of transgenes depends on a small region within the intron.
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Affiliation(s)
- L S Quilici
- Instituto de Ciências Biológicas, Departamento de Biologia Celular, Laboratório de Imunologia Molecular, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, Brazil
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Vieira CU, Bonetti AM, Simões ZLP, Maranhão AQ, Costa CS, Costa MCR, Siquieroli ACS, Nunes FMF. Farnesoic acid O-methyl transferase (FAMeT) isoforms: conserved traits and gene expression patterns related to caste differentiation in the stingless bee, Melipona scutellaris. Arch Insect Biochem Physiol 2008; 67:97-106. [PMID: 18076110 DOI: 10.1002/arch.20224] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Farnesoic acid O-methyl transferase (FAMeT) is the enzyme that catalyzes the formation of methyl farnesoate (MF) from farnesoic acid (FA) in the biosynthetic pathway of juvenile hormone (JH). This work reports the cloning, sequencing, and expression of FAMeT gene from the stingless bee Melipona scutellaris (MsFAMeT). The MsFAMeT in silico analysis showed that greatest sequence similarity is found in Apis mellifera and other insects, while relatively less similarity is shown in crustaceans. Evidence of alternative splicing of a 27 nucleotide (nt) microexon explains the presence of the detected isoforms, 1 and 2. The expression analysis of the two isoforms showed a marked difference when castes were compared, suggesting that they could be involved differently in the JH metabolism in M. scutellaris, providing new insights for the comprehension of female plasticity.
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Affiliation(s)
- Carlos U Vieira
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brasil.
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Tavares AHFP, Silva SS, Dantas A, Campos EG, Andrade RV, Maranhão AQ, Brígido MM, Passos-Silva DG, Fachin AL, Teixeira SMR, Passos GAS, Soares CMA, Bocca AL, Carvalho MJA, Silva-Pereira I, Felipe MSS. Early transcriptional response of Paracoccidioides brasiliensis upon internalization by murine macrophages. Microbes Infect 2007; 9:583-90. [PMID: 17387029 DOI: 10.1016/j.micinf.2007.01.024] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 01/17/2007] [Accepted: 01/30/2007] [Indexed: 11/15/2022]
Abstract
Paracoccidioides brasiliensis, a thermal dimorphic fungus, is the etiologic agent of the most common systemic mycosis in Latin America, paracoccidioidomycosis. The yeast form of P. brasiliensis acts as a facultative intracellular pathogen being able to survive and replicate within the phagosome of nonactivated murine and human macrophages. This ability has been proposed to be crucial to the development of disease. Thus, P. brasiliensis may have evolved mechanisms that counteract the constraints imposed by phagocytic cells. By using cDNA microarray technology we evaluated the early transcriptional response of this fungus to the environment of peritoneal murine macrophages in order to shed light on the mechanisms used by P. brasiliensis to survive within phagocytic cells. Of the 1152 genes analyzed, we identified 152 genes that were differentially transcribed. Intracellularly expressed genes were primarily associated with glucose and amino acid limitation, cell wall construction, and oxidative stress. For the first time, a comprehensive gene expression tool is used for the expression analysis of P. brasiliensis genes when interacting with macrophages. Overall, our data show a transcriptional plasticity of P. brasiliensis in response to the harsh environment of macrophages which may lead to adaptation and consequent survival of this pathogen.
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Affiliation(s)
- Aldo Henrique F P Tavares
- Departamento de Biologia Celular, Laboratório de Biologia Molecular, Universidade de Brasília-Unb Brasília, Campus Darcy Ribeiro-Asa Norte 70910-900, Brasília, DF, Brazil
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Felipe MSS, Andrade RV, Arraes FBM, Nicola AM, Maranhão AQ, Torres FAG, Silva-Pereira I, Poças-Fonseca MJ, Campos EG, Moraes LMP, Andrade PA, Tavares AHFP, Silva SS, Kyaw CM, Souza DP, Pereira M, Jesuíno RSA, Andrade EV, Parente JA, Oliveira GS, Barbosa MS, Martins NF, Fachin AL, Cardoso RS, Passos GAS, Almeida NF, Walter MEMT, Soares CMA, Carvalho MJA, Brígido MM. Transcriptional Profiles of the Human Pathogenic Fungus Paracoccidioides brasiliensis in Mycelium and Yeast Cells. J Biol Chem 2005; 280:24706-14. [PMID: 15849188 DOI: 10.1074/jbc.m500625200] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, a disease that affects 10 million individuals in Latin America. This report depicts the results of the analysis of 6,022 assembled groups from mycelium and yeast phase expressed sequence tags, covering about 80% of the estimated genome of this dimorphic, thermo-regulated fungus. The data provide a comprehensive view of the fungal metabolism, including overexpressed transcripts, stage-specific genes, and also those that are up- or down-regulated as assessed by in silico electronic subtraction and cDNA microarrays. Also, a significant differential expression pattern in mycelium and yeast cells was detected, which was confirmed by Northern blot analysis, providing insights into differential metabolic adaptations. The overall transcriptome analysis provided information about sequences related to the cell cycle, stress response, drug resistance, and signal transduction pathways of the pathogen. Novel P. brasiliensis genes have been identified, probably corresponding to proteins that should be addressed as virulence factor candidates and potential new drug targets.
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Affiliation(s)
- Maria Sueli S Felipe
- Departamento de Biologia Celular, Universidade de Brasília, 70910-900, Brasília, DF, Brazil.
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Dantas-Barbosa C, Brígido MM, Maranhão AQ. Construction of a human Fab phage display library from antibody repertoires of osteosarcoma patients. Genet Mol Res 2005; 4:126-40. [PMID: 16110435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Osteosarcoma is the commonest type of primary malignant bone tumor, frequently found in adolescents at sites of rapid bone growth. Despite current management protocols, up to half of the patients succumb to this disease. Moreover, there is no well-characterized molecular marker for diagnosis and prognosis. Since phage display methodology allows the selection of human antibody fragments with potential use in clinical applications, we applied this procedure to construct a recombinant Fab (antigen binding fragment) library from patients with osteosarcoma. We used peripheral blood lymphocyte total RNA from 11 osteosarcoma patients and cloned recombinant Fab representing the micro, gamma and kappa chain antibody repertoires of these individuals. The resulting library was cloned in the pComb3X vector and attained 1.45 x 10(8) different functional forms. BstO I fingerprinting and DNA sequencing analysis of randomly selected clones revealed the diversity of the library, demonstrating that Fab harbors Vkappa chains from subgroups I to V, biased towards the A27 fragment, as normally reported for the human repertoire. Analysis of the VH repertoire revealed that our library has a slight bias towards the VH4 family, instead of the usually reported VH3. This is the first description of a phage display library from osteosarcoma patients. We believe these human Fab fragments will provide a valuable tool for the study of this neoplasia and could also contribute to improvements in the diagnosis of this disease.
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Affiliation(s)
- Carmela Dantas-Barbosa
- Laboratório de Genética Molecular, Patologia, Rede Sarah de Hospitais de Reabilitação, 70330-150 Brasília, DF, Brazil
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Felipe MSS, Andrade RV, Petrofeza SS, Maranhão AQ, Torres FAG, Albuquerque P, Arraes FBM, Arruda M, Azevedo MO, Baptista AJ, Bataus LAM, Borges CL, Campos EG, Cruz MR, Daher BS, Dantas A, Ferreira MASV, Ghil GV, Jesuino RSA, Kyaw CM, Leitão L, Martins CR, Moraes LMP, Neves EO, Nicola AM, Alves ES, Parente JA, Pereira M, Poças-Fonseca MJ, Resende R, Ribeiro BM, Saldanha RR, Santos SC, Silva-Pereira I, Silva MAS, Silveira E, Simões IC, Soares RBA, Souza DP, De-Souza MT, Andrade EV, Xavier MAS, Veiga HP, Venancio EJ, Carvalho MJA, Oliveira AG, Inoue MK, Almeida NF, Walter MEMT, Soares CMA, Brígido MM. Transcriptome characterization of the dimorphic and pathogenic fungus Paracoccidioides brasiliensis by EST analysis. Yeast 2003; 20:263-71. [PMID: 12557278 DOI: 10.1002/yea.964] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Paracoccidioides brasiliensis is a pathogenic fungus that undergoes a temperature-dependent cell morphology change from mycelium (22 degrees C) to yeast (36 degrees C). It is assumed that this morphological transition correlates with the infection of the human host. Our goal was to identify genes expressed in the mycelium (M) and yeast (Y) forms by EST sequencing in order to generate a partial map of the fungus transcriptome. Individual EST sequences were clustered by the CAP3 program and annotated using Blastx similarity analysis and InterPro Scan. Three different databases, GenBank nr, COG (clusters of orthologous groups) and GO (gene ontology) were used for annotation. A total of 3,938 (Y = 1,654 and M = 2,274) ESTs were sequenced and clustered into 597 contigs and 1,563 singlets, making up a total of 2,160 genes, which possibly represent one-quarter of the complete gene repertoire in P. brasiliensis. From this total, 1,040 were successfully annotated and 894 could be classified in 18 functional COG categories as follows: cellular metabolism (44%); information storage and processing (25%); cellular processes-cell division, posttranslational modifications, among others (19%); and genes of unknown functions (12%). Computer analysis enabled us to identify some genes potentially involved in the dimorphic transition and drug resistance. Furthermore, computer subtraction analysis revealed several genes possibly expressed in stage-specific forms of P. brasiliensis. Further analysis of these genes may provide new insights into the pathology and differentiation of P. brasiliensis.
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Affiliation(s)
- M S S Felipe
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade de Brasília, 70910-900 Brasília, DF, Brasil.
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Abstract
We describe the expression of an anti-Z-DNA single chain variable region antibody fragment (scFv) on a filamentous phage surface. Four vectors for phage display were constructed. Two of them are able to display multiple copies of the antibody fragment, and the others can be used to make monovalent libraries. The vectors use different promoter/leader sequences to direct the expression of the fused proteins. All were able to promote the assembly of fusion virion particles. In this paper we also show the affinity selection (biopanning) of those phage-antibodies based on the capacity of their products to recognize the antigen. We used biotinylated Z-DNA and the selection was performed in a solution phase fashion. The data presented here indicate that these vectors can be further used to construct anti-nucleic acid antibody fragment libraries that can be used to study the basis of nucleic acid-protein interaction and its role in autoimmunity mechanisms.
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Affiliation(s)
- A Q Maranhão
- Departamento de Biologia Celular, Instituto de Biologia, Universidade de Brasília, Brasília, DF, Brasil
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Abstract
The pAC92 plasmid is a direct screening cloning vector which allows positive selection of recombinant clones (re-clones). This new high-copy-number plasmid vector encodes ampicillin resistance and carries the Bacillus subtilis alpha-amylase (alpha-Amy)-encoding gene (amy) containing a multiple cloning site. The pAC92 plasmid confers to Escherichia coli transformants an amylolytic phenotype easily detected by iodine vapor staining. The re-clones are identified by insertional inactivation of alpha-Amy activity. During pAC92 construction, a bacterial growth defect was observed in host cells after some modifications of the promoter region that caused the increase in the amy expression. This suicide characteristic permitted the positive selection of re-clones. A second transformation step was performed to enhance the rate of re-clones per plate.
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Affiliation(s)
- E V Barros
- Laboratory of Molecular Biology, Department of Cellular Biology, University of Brasilia, Brazil
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