Navegando por Palavras-chave "Paracoccidiodes brasiliensis"
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- ItemSomente MetadadadosAntigenic relationship between Loboa loboi and Paracoccidioides brasiliensis as shown by serological methods(Blackwell Science Ltd, 1998-12-01) Camargo, Zoilo Pires de [UNIFESP]; Baruzzi, Roberto Geraldo [UNIFESP]; Maeda, Solange Miki [UNIFESP]; Floriano, Marcos César [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Lobomycosis and paracoccidioidomycosis are two different mycoses caused by Loboa loboi and Paracoccidioides brasiliensis, respectively. To verify cross-antigenicity between them, lobomycosis sera were tested by immunoblotting, ELISA and capture-EIA against crude exo-antigen, 'cell-free antigen' and gp43 from P. brasiliensis. the majority of lobomycosis serum samples recognized crude exo-antigens and gp43 from P. brasiliensis. Gp43 was eluted from an affinity column prepared with IgG from a patient with active lobomycosis. in lower frequencies and intensities, lobomycosis sera also recognized proteins of 29 kDa, 36 kDa, 39 kDa, 52 kDa, 63 kDa, 70 kDa, 83 kDa, and 108 kDa from P. brasiliensis.
- ItemSomente MetadadadosAvaliação de peptídeos sintéticos selecionados por phage display para o sorodiagnóstico da Paracoccidioidomicose(Universidade Federal de São Paulo, 2017-06-29) Portes, Leticia da Silva [UNIFESP]; Xander, Patricia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Paraccocidioidomycosis (PCM) is a systemic granulomatous disease caused by the thermo-dimorphic fungus from complex Paraccocidioides. The disease diagnosis uses both direct detection of the fungus in biological samples and serological tests, which have also important role to follow disease progression and response to treatment. Currently, the use of synthetic peptides in the serological diagnosis of infectious diseases may represents a valuable strategy since, in comparison with natural or recombinant antigens, assays using these molecules are cheaper, simple, reproducible, and in some cases more specific and sensitive. Thus, the aim of this study was to screen and to identify peptides reactive against sera from patients with PCM by using Phage Display approach. First, a selection using immunoglobulins purified from sera of individuals without PCM (normal) were performed to eliminate phages clones not specific to the fungus. Then, positive selection was carried out against immunoglobulins purified from pool of sera from patients with PCM. The binding-phages were sequenced and tested in a binding assay to evaluate the interaction between the selected phages and the sera of normal individuals and patients with PCM. LP2 and LP15 samples showed higher affinity with sera of patients with PCM, compared to normal sera. The synthetic peptides were tested by ELISA and the LP15 peptide was recognized by sera of patients with PCM. The detection was higher when we used a mixture of LP15 and P2 peptide (mimetope of gp75 of P. brasiliensis). Thus, the Phage Display technology were useful to identify peptides with potential applications in PCM serodiagnosis.
- ItemSomente MetadadadosC-Npys (S-3-nitro-2-pyridinesulfenyl) and peptide derivatives can inhibit a serine-thiol proteinase activity from Paracoccidioides brasiliensis(Elsevier B.V., 2007-04-20) Matsuo, Alisson L.; Carmona, Adriana K.; Silva, Luiz S.; Cunha, Carlos E. L.; Nakayasu, Ernesto S.; Almeida, Igor C.; Juliano, Maria A.; Puccia, Rosana; Universidade Federal de São Paulo (UNIFESP); Univ TexasThe inhibitory capacity of C-Npys (S-[3-nitro-2-pyridinesulenyl]) derivatives over thiol-containing serine proteases has never been tested. in the present work we used an extracellular serine-thiol protemase activity from the fungal pathogen Paracoccidio ides brasiliensis (PbST) to describe a potent inhibitory capacity of Bzl-C(Npys)KRLTL-NH2, and Bzl-MKRLTLC(Npys)-NH2. the assays were performed with PbST enriched upon affinity chromatography in a p-aminobenzamidine (pABA)-Sepharose column. Although PbST can cleave the fluorescence resonance energy transfer peptide Abz-MKRLTL-EDDnp between L-T, the C(Npys) derivatives were not substrates nor were they toxic in a cell detachment assay, allowing therapeutic use. the best inhibitor was Bzl-C(Npys)KRLTL-NH2 (K-i = 16 nM), suggesting that the peptide sequence promoted a favorable interaction, especially when C(Npys) was placed at a further position from the L-T bond, at the N-terminus. Inhibition was completely reverted with dithioerythritol, indicating that it was due to the reactivity of the C(Npys) moiety with a free SH- group. (c) 2007 Elsevier Inc. All rights reserved.
- ItemAcesso aberto (Open Access)Caracterização de marcadores de virulência em Paracoccidioides brasiliensis(Universidade Federal de São Paulo (UNIFESP), 2009-06-24) Kioshima, Érika Seki [UNIFESP]; Lopes, Jose Daniel [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Paracoccidioidomycosis (PCM) is a human systemic granulomatous disease, prevalent in South America, caused by a thermodimorphic fungus, Paracoccidioides brasiliensis. This fungus presents complex antigenic structure and some of these components have been related with its pathogenicity, of which little is known. The virulence recovery of isolates by passage in vivo was performed in our laboratory. Attenuated and virulent Pb18 isolates were analyzed from various angles to confirm this change. The results of the survival curve, the number of CFUs and histology, showed clear differences in pathogenicity pattern of these isolates. Other features were also evaluated as morphology, growth curve and cell ultrastructure. Analysis of differential gene expression profile showed positive regulation genes related to metabolisms of proteins, lipids and amino acids. Some molecules, previously described as putative virulence factors, were positive regulated, among which calmodulin, kex-like protein and Hsp70. However, the number of defined virulence factors for dimorphic fungal pathogens, up to now, is relatively small. Several techniques have unsuccessfully been employed to characterize these elusive antigenic structures. Using phage display methodology, three peptide-displaying phages that bound preferentially to virulent isolates of P. brasiliensis were selected. By binding assay, p04 phage distinguished predefined degrees of virulence of isolates. Using confocal microscopy, the homologue synthetic peptide (pep04), labeled with 6-FAM, was internalized by only virulent isolate yeast cells. Sequential optical section imaging indicated that the labeling was within the intracellular milieu and frequently close or overlapping DAPI staining. These results showed that both, phage p04 and pep04, can be considered as biomarkers of virulence in PCM since both bound to virulent P. brasiliensis. To evaluate the consequences of interactions between the biomarkers and fungal cells, in vitro and in vivo experiments were performed. The latter demonstrated that p04 phage was sufficient to prevent the implantation of the fungus in the lungs and its migration to spleen and liver. In addition, this phage reduced colony-forming units in the lungs of mice infected with P. brasiliensis as compared to controls. In vitro experiments showed that pep04 exhibited fungicidal activity only against virulent P. brasiliensis, leaving unaltered the growth of the attenuated isolate. Therefore, these biomarkers may be useful tools for prognosis in PCM and may be possibly used in the routine clinical practice as therapeutic drug adjuvants.
- ItemSomente MetadadadosCloning and characterization of a LON gene homologue from the human pathogen Paracoccidioides brasiliensis(Wiley-Blackwell, 2001-07-01) Barros, Tânia Fraga [UNIFESP]; Puccia, Rosana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)A LON gene homologue from the human pathogen Paracoccidioides brasiliensis (PbLON) has been cloned, sequenced and characterized. It encodes a putative ATP-dependent proteinase Lon, which in Saccharomyces cerevisisae (PIM1) is a heat-inducible protein involved in the degradation of abnormal or short-lived proteins in the mitochondria. the PbLON ORF is within a 3369 bp fragment interrupted by two introns located in the 3 ' segment. the 5 ' and 3 ' regions flanking the ORF contain sequences which resemble known transcription elements. Several transcription binding factor motifs have also been found, including sites for heat shock/stress response and nitrogen control, the deduced protein consists of 1063 residues containing a mitochondrial import signal at the N-terminus and conserved ATP-binding (GPPGVGKT) and serine catalytic (KDGPSAG) sites. It shares high identity with Lon homologues from S. cerevisiae (73%), Homo sapiens (62%) and Escherichia coli (56%). in P. brasiliensis, an MDJ1 putative gene has also been partially sequenced adjacent to PbLON, possibly sharing divergently orientated promoter elements, This chromosomal organization is interesting, since Mdj1p is a heat shock chaperone essential for substrate degradation by PIM1 in yeast. the LON nucleotide and flanking sequence regions have been submitted to GenBank under Accession No. AF239178, Copyright (C) 2001 John Wiley & Sons, Ltd.
- ItemSomente MetadadadosGP43 from Paracoccidioides brasiliensis inhibits macrophage functions. An evasion mechanism of the fungus(Elsevier B.V., 2002-07-01) Popi, Ana Flavia [UNIFESP]; Lopes, Jose Daniel [UNIFESP]; Mariano, Mario [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Macrophages constitute one of the primary cellular mechanisms that impairs parasite invasion of host tissues. The phagocytic and microbicidal properties of these cells can be modulated by specific membrane receptors involved in cell-microorganism interactions. Gp43, the main antigen secreted by Paracoccidiodes brasiliensis (Pb), the causative agent of Paracoccidioidomycosis, is a high mannose glycoprotein. The role played by gp43 in the pathogenesis of the disease is not completely known. Here, we describe the influence of this molecule on the interaction between peritoneal murine macrophages and Pb. Phagocytosis of Pb, live or heat-killed, by adherent peritoneal cells from both, B10.A (susceptible) and A/Sn (resistant) mice, was evaluated. Addition of different concentrations of gp43 to the culture medium inhibited, in a dose-dependent pattern, phagocytosis of live or heat-killed Pb by peritoneal macrophages from both B10.A and A/Sn mice. Gp43 also inhibits phagocytosis of zymosan particles but did not interfere with the uptake of opsonized sheep red blood cells. It was also shown that both gp43 and heat-killed Pb have an inhibitory effect on the release of NO by zymosan stimulated macrophages. Finally, we demonstrated that gp43 inhibits the fungicidal ability of macrophages from both lineages. Based on these data, it is suggested that gp43 can be considered one of the evasion mechanisms for the installation of primary infection in susceptible hosts. (C) 2002 Elsevier Science (USA). All rights reserved.
- ItemSomente MetadadadosParacoccidioidal Infection in HIV Patients at an Endemic Area of Paracoccidioidomycosis in Brazil(Springer, 2012-03-01) Sarti, Elaine Cristina Fernandes Baez; Oliveira, Sandra Maria do Valle Leone de; Santos, Liara Ferreira dos; Camargo, Zoilo Pires de [UNIFESP]; Paniago, Anamaria Mello Miranda; Universidade Federal de Mato Grosso do Sul (UFMS); Univ Anhanguera Uniderp; Universidade Federal de São Paulo (UNIFESP)The association between paracoccidioidomycosis (PCM) and AIDS is relatively rare in contrast to the higher incidence of other systemic mycosis. the explanation may be that AIDS is still predominantly an urban disease, and the PCM is endemic in Latin American rural areas. the aim of this study was to detect the prevalence of Paracoccidioides brasiliensis infection in HIV-positive patients at an endemic area of paracoccidioidomycosis in Brazil. Skin test with purified 43 kD glycoprotein (gp43) was performed in 90 HIV/AIDS patients. the prevalence found was 12.2% and it may be even greater, considering that HIV/AIDS patients may not respond to the intradermal test, which depends on cellular immunity for its positivity.
- ItemSomente MetadadadosParacoccidioidomycosis vaccine(Landes Bioscience, 2012-10-01) Travassos, Luiz Rodolpho [UNIFESP]; Taborda, Carlos Pelleschi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Paracoccidioidomycosis is a granulomatous pulmonary infection that is generally controlled by chemotherapy. the efficacy of treatment, however, is limited by the status of the host immune response. the inhibition of a Th-2 immunity or the stimulation of Th-1 cytokines generally increases the efficacy of antifungal drugs.(1) This has been achieved by immunization with an internal peptide of the major diagnostic antigen gp43 of Paracoccidioides brasiliensis. Peptide 10 (QTLIAIHTLAIRYAN) elicits an IFN-gamma rich Th-1 immune response that protects against experimental intratracheal infection by this fungus. the combination of chemotherapy with P10 immunization showed additive protective effect even after 30 d of infection or in anergic mice, rendering in general, increased production of IL-12 and IFN-gamma and reduction of IL-4 and IL-10. Immunotherapy with P10 even in the absence of simultaneous chemotherapy has been effective using various protocols, adjuvants, nanoparticles, P10-primed dendritic cells, and especially a combination of plasmids encoding the P10 minigene and IL-12. Gene therapy, in a long-term infection protocol succeeded in the virtual elimination of the fungus, preserving the lung structure, free from immunopathological side effects.