23 research outputs found

    Identification and characterization of expressed retrotransposons in the genome of the Paracoccidioides species complex

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    Background: Species from the Paracoccidioides complex are thermally dimorphic fungi and the causative agents of paracoccidioidomycosis, a deep fungal infection that is the most prevalent systemic mycosis in Latin America and represents the most important cause of death in immunocompetent individuals with systemic mycosis in Brazil. We previously described the identification of eight new families of DNA transposons in Paracoccidioides genomes. in this work, we aimed to identify potentially active retrotransposons in Paracoccidioides genomes.Results: We identified five different retrotransposon families (four LTR-like and one LINE-like element) in the genomes of three Paracoccidioides isolates. Retrotransposons were present in all of the genomes analyzed. P. brasiliensis and P. lutzii species harbored the same retrotransposon lineages but differed in their copy numbers. in the Pb01, Pb03 and Pb18 genomes, the number of LTR retrotransposons was higher than the number of LINE-like elements, and the LINE-like element RtPc5 was transcribed in Paracoccidioides lutzii (Pb01) but could not be detected in P. brasiliensis (Pb03 and Pb18) by semi-quantitative RT-PCR.Conclusion: Five new potentially active retrotransposons have been identified in the genomic assemblies of the Paracoccidioides species complex using a combined computational and experimental approach. the distribution across the two known species, P. brasiliensis and P. lutzii, and phylogenetics analysis indicate that these elements could have been acquired before speciation occurred. the presence of active retrotransposons in the genome may have implications regarding the evolution and genetic diversification of the Paracoccidioides genus.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Minas Gerais, Inst Ciencias Biol, Dept Microbiol, BR-31270901 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Programa Posgrad Bioinformat, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilUniv Brasilia, Inst Ciencias Biol, Lab Biol Mol, BR-70910900 Brasilia, DF, BrazilUniv Fed Goias, Inst Ciencias Biol, Lab Biol Mol, BR-74001970 Goiania, Go, BrazilFIOCRUZ Minas, Ctr Pesquisas Rene Rachou, Grp Informat Biossistemas, BR-30190002 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Dept Biol Geral, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilFAPEMIG: APQ-01661-13CNPq: 301652/2012-0CNPq: 486618/2013-7Web of Scienc

    Antibody Phage Display Libraries: Contributions to Oncology

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    Since the advent of phage display technology, dating back to 1985, antibody libraries displayed on filamentous phage surfaces have been used to identify specific binders for many different purposes, including the recognition of tumors. Phage display represents a high-throughput technique for screening billions of random fusion antibodies against virtually any target on the surface or inside cancer cells, or even soluble markers found in patient serum. Many phage display derived binders targeting important tumor markers have been identified. Selection directed to tumoral cells’ surfaces lead to the identification of unknown tumoral markers. Also the improvement of methods that require smaller amounts of cells has opened the possibility to use this approach on patient samples. Robust techniques combining an antibody library displayed on the phage surface and protein microarray allowed the identification of auto antibodies recognized by patient sera. Many Ab molecules directly or indirectly targeting angiogenesis have been identified, and one of them, ramucirumab, has been tested in 27 phase I–III clinical trials in a broad array of cancers. Examples of such antibodies will be discussed here with emphasis on those used as probes for molecular imaging and other clinical trials

    Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

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    Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen

    The glycosylation of anti-rhIFN-α2b recombinant antibodies influences the antigen-neutralizing activity

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    Objectives: The influence of glycosylation on the antigen-neutralizing ability of two potential biotherapeutic anti-human IFN-α2b antibodies composed by murine and humanized single-chain Fv fused to human Fcγ1 (chimeric and humanized scFv-Fc, respectively) was studied. Results: Chimeric antibodies produced in CHO-K1 and HEK293 mammalian cells showed no differences in the antigen–antibody affinity but demonstrated differences in the in vitro neutralization of IFN-α2b activity. On the other hand, the humanized antibodies produced in the same cell types showed differences in both the antigen–antibody affinity and the antigen-neutralizing ability. These differences are due to the scFv domain, as evidenced by its expression in CHO-K1 and HEK293 cells. In order to determine if the Fc glycosylation influences the antigen binding ability, both parameters were analyzed on chimeric and humanized deglycosylated scFv-Fc. Surprisingly, no differences in the antigen–antibody affinity were observed, but differences in the antigen-neutralizing ability of both chimeric and humanized antibodies, and their respectively deglycosylated glycoforms were found. Conclusions: Fc glycosylation influences the antigen neutralization ability of two anti-rhIFN-α2b recombinant antibodies. Although affinity is the widely accepted parameter to analyze antibody antigen binding, it does not appear to be sufficient to describe the behavior of recombinant antibodies in vitro. This work contributes with a high impact knowledge to develop therapeutic recombinant antibodies where glycosylation and producer cell lines must be taken into account for their influence on the antigen binding capacity and not only for their impact on the effector properties as it has been historically considered for antibodies.Fil: Attallah, Carolina Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Aguilar, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Forno, Angela Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. R&D Zelltek S.A; ArgentinaFil: Etcheverrigaray, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Brigido, Marcelo De Macedo. Universidade do Brasília; BrasilFil: Queiroz Maranhão, Andrea. Universidade do Brasília; BrasilFil: Roggero, Marcos Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin
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