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França RKA, Studart IC, Bezerra MRL, Pontes LQ, Barbosa AMA, Brigido MM, Furtado GP, Maranhão AQ. Progress on Phage Display Technology: Tailoring Antibodies for Cancer Immunotherapy. Viruses 2023; 15:1903. [PMID: 37766309 PMCID: PMC10536222 DOI: 10.3390/v15091903] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The search for innovative anti-cancer drugs remains a challenge. Over the past three decades, antibodies have emerged as an essential asset in successful cancer therapy. The major obstacle in developing anti-cancer antibodies is the need for non-immunogenic antibodies against human antigens. This unique requirement highlights a disadvantage to using traditional hybridoma technology and thus demands alternative approaches, such as humanizing murine monoclonal antibodies. To overcome these hurdles, human monoclonal antibodies can be obtained directly from Phage Display libraries, a groundbreaking tool for antibody selection. These libraries consist of genetically engineered viruses, or phages, which can exhibit antibody fragments, such as scFv or Fab on their capsid. This innovation allows the in vitro selection of novel molecules directed towards cancer antigens. As foreseen when Phage Display was first described, nowadays, several Phage Display-derived antibodies have entered clinical settings or are undergoing clinical evaluation. This comprehensive review unveils the remarkable progress in this field and the possibilities of using clever strategies for phage selection and tailoring the refinement of antibodies aimed at increasingly specific targets. Moreover, the use of selected antibodies in cutting-edge formats is discussed, such as CAR (chimeric antigen receptor) in CAR T-cell therapy or ADC (antibody drug conjugate), amplifying the spectrum of potential therapeutic avenues.
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Affiliation(s)
- Renato Kaylan Alves França
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.F.); (M.M.B.)
- Graduate Program in Molecular Pathology, University of Brasilia, Brasilia 70910-900, Brazil
| | - Igor Cabral Studart
- Oswaldo Cruz Foundation, Fiocruz Ceará, Eusébio 61773-270, Brazil; (I.C.S.); (M.R.L.B.); (L.Q.P.); (A.M.A.B.); (G.P.F.)
- Graduate Program in Biotechnology of Natural Resources, Federal University of Ceará, Fortaleza 60440-970, Brazil
| | - Marcus Rafael Lobo Bezerra
- Oswaldo Cruz Foundation, Fiocruz Ceará, Eusébio 61773-270, Brazil; (I.C.S.); (M.R.L.B.); (L.Q.P.); (A.M.A.B.); (G.P.F.)
- Graduate Program in Biotechnology of Natural Resources, Federal University of Ceará, Fortaleza 60440-970, Brazil
| | - Larissa Queiroz Pontes
- Oswaldo Cruz Foundation, Fiocruz Ceará, Eusébio 61773-270, Brazil; (I.C.S.); (M.R.L.B.); (L.Q.P.); (A.M.A.B.); (G.P.F.)
- Graduate Program in Biotechnology of Natural Resources, Federal University of Ceará, Fortaleza 60440-970, Brazil
| | - Antonio Marcos Aires Barbosa
- Oswaldo Cruz Foundation, Fiocruz Ceará, Eusébio 61773-270, Brazil; (I.C.S.); (M.R.L.B.); (L.Q.P.); (A.M.A.B.); (G.P.F.)
- Graduate Program in Applied Informatics, University of Fortaleza, Fortaleza 60811-905, Brazil
| | - Marcelo Macedo Brigido
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.F.); (M.M.B.)
| | - Gilvan Pessoa Furtado
- Oswaldo Cruz Foundation, Fiocruz Ceará, Eusébio 61773-270, Brazil; (I.C.S.); (M.R.L.B.); (L.Q.P.); (A.M.A.B.); (G.P.F.)
- Graduate Program in Biotechnology of Natural Resources, Federal University of Ceará, Fortaleza 60440-970, Brazil
| | - Andréa Queiroz Maranhão
- Molecular Immunology Laboratory, Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil; (R.K.A.F.); (M.M.B.)
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Antonelli ACB, Almeida VP, de Castro FOF, Silva JM, Pfrimer IAH, Cunha-Neto E, Maranhão AQ, Brígido MM, Resende RO, Bocca AL, Fonseca SG. In silico construction of a multiepitope Zika virus vaccine using immunoinformatics tools. Sci Rep 2022; 12:53. [PMID: 34997041 PMCID: PMC8741764 DOI: 10.1038/s41598-021-03990-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 12/01/2021] [Indexed: 01/02/2023] Open
Abstract
Zika virus (ZIKV) is an arbovirus from the Flaviviridae family and Flavivirus genus. Neurological events have been associated with ZIKV-infected individuals, such as Guillain-Barré syndrome, an autoimmune acute neuropathy that causes nerve demyelination and can induce paralysis. With the increase of ZIKV infection incidence in 2015, malformation and microcephaly cases in newborns have grown considerably, which suggested congenital transmission. Therefore, the development of an effective vaccine against ZIKV became an urgent need. Live attenuated vaccines present some theoretical risks for administration in pregnant women. Thus, we developed an in silico multiepitope vaccine against ZIKV. All structural and non-structural proteins were investigated using immunoinformatics tools designed for the prediction of CD4 + and CD8 + T cell epitopes. We selected 13 CD8 + and 12 CD4 + T cell epitopes considering parameters such as binding affinity to HLA class I and II molecules, promiscuity based on the number of different HLA alleles that bind to the epitopes, and immunogenicity. ZIKV Envelope protein domain III (EDIII) was added to the vaccine construct, creating a hybrid protein domain-multiepitope vaccine. Three high scoring continuous and two discontinuous B cell epitopes were found in EDIII. Aiming to increase the candidate vaccine antigenicity even further, we tested secondary and tertiary structures and physicochemical parameters of the vaccine conjugated to four different protein adjuvants: flagellin, 50S ribosomal protein L7/L12, heparin-binding hemagglutinin, or RS09 synthetic peptide. The addition of the flagellin adjuvant increased the vaccine's predicted antigenicity. In silico predictions revealed that the protein is a probable antigen, non-allergenic and predicted to be stable. The vaccine’s average population coverage is estimated to be 87.86%, which indicates it can be administered worldwide. Peripheral Blood Mononuclear Cells (PBMC) of individuals with previous ZIKV infection were tested for cytokine production in response to the pool of CD4 and CD8 ZIKV peptide selected. CD4 + and CD8 + T cells showed significant production of IFN-γ upon stimulation and IL-2 production was also detected by CD8 + T cells, which indicated the potential of our peptides to be recognized by specific T cells and induce immune response. In conclusion, we developed an in silico universal vaccine predicted to induce broad and high-coverage cellular and humoral immune responses against ZIKV, which can be a good candidate for posterior in vivo validation.
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Affiliation(s)
- Ana Clara Barbosa Antonelli
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Rua 235 s/n, sala 335, Setor Universitário, Goiânia, GO, 74605-050, Brazil
| | - Vinnycius Pereira Almeida
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Rua 235 s/n, sala 335, Setor Universitário, Goiânia, GO, 74605-050, Brazil
| | - Fernanda Oliveira Feitosa de Castro
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Rua 235 s/n, sala 335, Setor Universitário, Goiânia, GO, 74605-050, Brazil.,Departament of Master in Environmental Sciences and Health, School of Medical, Pharmaceutical and Biomedical Sciences, Pontifical Catholic University of Goiás, Goiânia, Brazil
| | | | - Irmtraut Araci Hoffmann Pfrimer
- Departament of Master in Environmental Sciences and Health, School of Medical, Pharmaceutical and Biomedical Sciences, Pontifical Catholic University of Goiás, Goiânia, Brazil
| | - Edecio Cunha-Neto
- Heart Institute (InCor), School of Medicine, University of São Paulo, São Paulo, Brazil.,Institute for Investigation in Immunology (iii) - National Institute of Science and Technology (INCT), São Paulo, Brazil
| | - Andréa Queiroz Maranhão
- Department of Cell Biology, University of Brasília, Brasília, Brazil.,Institute for Investigation in Immunology (iii) - National Institute of Science and Technology (INCT), São Paulo, Brazil
| | - Marcelo Macedo Brígido
- Department of Cell Biology, University of Brasília, Brasília, Brazil.,Institute for Investigation in Immunology (iii) - National Institute of Science and Technology (INCT), São Paulo, Brazil
| | | | | | - Simone Gonçalves Fonseca
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Rua 235 s/n, sala 335, Setor Universitário, Goiânia, GO, 74605-050, Brazil. .,Institute for Investigation in Immunology (iii) - National Institute of Science and Technology (INCT), São Paulo, Brazil.
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Maranhão AQ, Silva HM, da Silva WMC, França RKA, De Leo TC, Dias-Baruffi M, Burtet RT, Brigido MM. Discovering Selected Antibodies From Deep-Sequenced Phage-Display Antibody Library Using ATTILA. Bioinform Biol Insights 2020; 14:1177932220915240. [PMID: 32425512 PMCID: PMC7218273 DOI: 10.1177/1177932220915240] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/03/2020] [Indexed: 11/20/2022] Open
Abstract
Phage display is a powerful technique to select high-affinity antibodies for different purposes, including biopharmaceuticals. Next-generation sequencing (NGS) presented itself as a robust solution, making it possible to assess billions of sequences of the variable domains from selected sublibraries. Handling this process, a central difficulty is to find the selected clones. Here, we present the AutomaTed Tool For Immunoglobulin Analysis (ATTILA), a new tool to analyze and find the enriched variable domains throughout a biopanning experiment. The ATTILA is a workflow that combines publicly available tools and in-house programs and scripts to find the fold-change frequency of deeply sequenced amplicons generated from selected VH and VL domains. We analyzed the same human Fab library NGS data using ATTILA in 5 different experiments, as well as on 2 biopanning experiments regarding performance, accuracy, and output. These analyses proved to be suitable to assess library variability and to list the more enriched variable domains, as ATTILA provides a report with the amino acid sequence of each identified domain, along with its complementarity-determining regions (CDRs), germline classification, and fold change. Finally, the methods employed here demonstrated a suitable manner to combine amplicon generation and NGS data analysis to discover new monoclonal antibodies (mAbs).
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Affiliation(s)
- Andréa Queiroz Maranhão
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil.,Instituto de Investigação em Imunologia, Instituto Nacional de Ciência e Tecnologia (iii-INCT), São Paulo, Brazil
| | - Heidi Muniz Silva
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil
| | - Waldeyr Mendes Cordeiro da Silva
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil.,NEPBio, Federal Institute of Goiás, Formosa, Brazil
| | - Renato Kaylan Alves França
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil
| | - Thais Canassa De Leo
- School of Pharmaceutical Sciences of Ribeirão Preto, USP, Ribeirão Preto, Brazil
| | - Marcelo Dias-Baruffi
- School of Pharmaceutical Sciences of Ribeirão Preto, USP, Ribeirão Preto, Brazil
| | - Rafael Trindade Burtet
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil
| | - Marcelo Macedo Brigido
- Department of Cellular Biology, Institute of Biological Science, University of Brasília, Brasília, Brazil.,Instituto de Investigação em Imunologia, Instituto Nacional de Ciência e Tecnologia (iii-INCT), São Paulo, Brazil
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Sousa IG, do Almo MM, Simi KCR, Bezerra MAG, Andrade RV, Maranhão AQ, Brigido MM. MicroRNA expression profiles in human CD3 + T cells following stimulation with anti-human CD3 antibodies. BMC Res Notes 2017; 10:124. [PMID: 28292330 PMCID: PMC5351193 DOI: 10.1186/s13104-017-2442-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 03/01/2017] [Indexed: 02/07/2023] Open
Abstract
Background Anti-CD3 therapy can induce immunosuppression by several non mutually exclusive mechanisms that have been proposed to explain the therapeutic effect the administration anti-CD3 mAb, but its immunoregulatory mechanism is still not completely clear. In T cells, microRNAs (miRNAs) regulate several pathways, including those associated with immune tolerance. Here, we report changes in miRNA expression in T cells following treatment with anti-human CD3 antibodies. Peripheral blood mononuclear cells were cultured in the presence of the monoclonal antibody OKT3 or a recombinant fragment of humanized anti-CD3. Following these treatments, the expression profiles of 31 miRNA species were assessed in T cells using TaqMan arrays. Results Eight of the tested miRNAs (miR-155, miR-21, miR-146a, miR-210, miR-17, miR-590-5p, miR-106b and miR-301a) were statistically significantly up- or down-regulated relative to untreated cells. Conclusions Stimulation of T cells with anti-human CD3 antibodies alters miRNA expression patterns, including of miRNA species associated with immune regulatory pathways. Electronic supplementary material The online version of this article (doi:10.1186/s13104-017-2442-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Isabel Garcia Sousa
- Molecular Pathology Graduation Program, Medicine Faculty, University of Brasilia, Brasilia, Brazil
| | - Manuela Maragno do Almo
- Molecular Pathology Graduation Program, Medicine Faculty, University of Brasilia, Brasilia, Brazil
| | | | | | | | - Andréa Queiroz Maranhão
- Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil.,Institute for Immunology Investigation, A National Institute of Science and Technology, Brasilia, Brazil
| | - Marcelo Macedo Brigido
- Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil. .,Institute for Immunology Investigation, A National Institute of Science and Technology, Brasilia, Brazil.
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de Sousa CS, Serrão JE, Bonetti AM, Amaral IMR, Kerr WE, Maranhão AQ, Ueira-Vieira C. Insights into the Melipona scutellaris (Hymenoptera, Apidae, Meliponini) fat body transcriptome. Genet Mol Biol 2013; 36:292-7. [PMID: 23885214 PMCID: PMC3715298 DOI: 10.1590/s1415-47572013000200022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 03/11/2013] [Indexed: 12/21/2022] Open
Abstract
The insect fat body is a multifunctional organ analogous to the vertebrate liver. The fat body is involved in the metabolism of juvenile hormone, regulation of environmental stress, production of immunity regulator-like proteins in cells and protein storage. However, very little is known about the molecular mechanisms involved in fat body physiology in stingless bees. In this study, we analyzed the transcriptome of the fat body from the stingless bee Melipona scutellaris. In silico analysis of a set of cDNA library sequences yielded 1728 expressed sequence tags (ESTs) and 997 high-quality sequences that were assembled into 29 contigs and 117 singlets. The BLAST X tool showed that 86% of the ESTs shared similarity with Apis mellifera (honeybee) genes. The M. scutellaris fat body ESTs encoded proteins with roles in numerous physiological processes, including anti-oxidation, phosphorylation, metabolism, detoxification, transmembrane transport, intracellular transport, cell proliferation, protein hydrolysis and protein synthesis. This is the first report to describe a transcriptomic analysis of specific organs of M. scutellaris. Our findings provide new insights into the physiological role of the fat body in stingless bees.
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Affiliation(s)
- Cristina Soares de Sousa
- Laboratório de Genética, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
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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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De Souza GRL, Prudencio CR, Cardoso R, Almeida JF, Capparelli FE, Freschi APP, Maranhão AQ, De Macedo Brígido M, De Lima LM, bemquerer M, Goulart LR. Construction of an antibodies library (scFv) for selection and characterization of Boophilus microplus antigens. Vet Immunol Immunopathol 2009. [DOI: 10.1016/j.vetimm.2008.10.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Vaz de Andrade E, Freitas SM, Ventura MM, Maranhão AQ, Brigido MM. Thermodynamic basis for antibody binding to Z-DNA: comparison of a monoclonal antibody and its recombinant derivatives. Biochim Biophys Acta Gen Subj 2005; 1726:293-301. [PMID: 16214293 DOI: 10.1016/j.bbagen.2005.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [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: 05/27/2005] [Revised: 08/24/2005] [Accepted: 08/31/2005] [Indexed: 10/25/2022]
Abstract
Antibody engineering represents a promising area in biotechnology. Recombinant antibodies can be easily manipulated generating new ligand and effector activities that can be used as prototype magic bullets. On the other hand, an extensive knowledge of recombinant antibody binding and stability features are essential for an efficient substitution. In this study, we compared the stability and protein binding properties of two recombinant antibody fragments with their parental monoclonal antibody. The recombinant fragments were a monomeric scFv and a dimeric one, harboring human IgG1 CH2-CH3 domains. We have used fluorescence titration quenching to determine the thermodynamics of the interaction between an anti-Z-DNA monoclonal antibody and its recombinant antibody fragments with Z-DNA. All the antibody fragments seemed to bind DNA similarly, in peculiar two-affinity states. Enthalpy-entropy compensation was observed for both affinity states, but a marked entropy difference was observed for the monomeric scFv antibody fragment, mainly for the high affinity binding. In addition, we compared the stability of the dimeric antibody fragment and found differences favoring the monoclonal antibody. These differences seem to derive from the heterologous expression system used.
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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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