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1.
Immunology ; 165(1): 110-121, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34458991

RESUMO

Decades of studies on antibody structure led to the tenet that the V region binds antigens while the C region interacts with immune effectors. In some antibodies, however, the C region affects affinity and/or specificity for the antigen. One example is the 3E5 monoclonal murine IgG family, in which the mIgG3 isotype has different fine specificity to the Cryptococcus neoformans capsule polysaccharide than the other mIgG isotypes despite their identical variable sequences. Our group serendipitously found another pair of mIgG1/mIgG3 antibodies based on the 2H1 hybridoma to the C. neoformans capsule that recapitulated the differences observed with 3E5. In this work, we report the molecular basis of the constant domain effects on antigen binding using recombinant antibodies. As with 3E5, immunofluorescence experiments show a punctate pattern for 2H1-mIgG3 and an annular pattern for 2H1-mIgG1; these binding patterns have been associated with protective efficacy in murine cryptococcosis. Also as observed with 3E5, 2H1-mIgG3 bound on ELISA to both acetylated and non-acetylated capsular polysaccharide, whereas 2H1-mIgG1 only bound well to the acetylated form, consistent with differences in fine specificity. In engineering hybrid mIgG1/mIgG3 antibodies, we found that switching the 2H1-mIgG3 hinge for its mIgG1 counterpart changed the immunofluorescence pattern to annular, but a 2H1-mIgG1 antibody with an mIgG3 hinge still had an annular pattern. The hinge is thus necessary but not sufficient for these changes in binding to the antigen. This important role for the constant region in antigen binding could affect antibody biology and engineering.


Assuntos
Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Cápsulas Bacterianas/química , Cápsulas Bacterianas/imunologia , Cryptococcus neoformans/imunologia , Imunoglobulina G/química , Imunoglobulina G/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Sítios de Ligação de Anticorpos , Células CHO , Linhagem Celular , Cricetulus , Criptococose/imunologia , Epitopos/química , Epitopos/imunologia , Camundongos , Proteínas Recombinantes de Fusão , Relação Estrutura-Atividade
2.
J Immunol ; 202(9): 2782-2794, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30894426

RESUMO

Abs exert several of their effector functions by binding to cell surface receptors. For murine IgG3 (mIgG3), the identity of its receptors (and the very existence of a receptor) is still under debate, as not all mIgG3 functions can be explained by interaction with FcγRI. This implies the existence of an alternate receptor, whose identity we sought to pinpoint. We found that blockage of integrin ß1 selectively hampered binding of mIgG3 to macrophages and mIgG3-mediated phagocytosis. Manganese, an integrin activator, increased mIgG3 binding to macrophages. Blockage of FcγRI or Itgb1 inhibited binding of different mIgG3 Abs to variable extents. Our results are consistent with the notion that Itgb1 functions as part of an IgG receptor complex. Given the more ancient origin of integrins in comparison with FcγR, this observation could have far-ranging implications for our understanding of the evolution of Ab-mediated immunity as well as in immunity to microorganisms, pathogenesis of autoimmune diseases, and Ab engineering.


Assuntos
Imunoglobulina G/imunologia , Integrina beta1/imunologia , Macrófagos/imunologia , Fagocitose , Receptores de IgG/imunologia , Animais , Imunoglobulina G/genética , Integrina beta1/genética , Camundongos , Camundongos Knockout , Receptores de IgG/genética
3.
Fungal Genet Biol ; 138: 103367, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32198121

RESUMO

Filamentous fungi are well known for producing secondary metabolites applied in various industrial segments. Among these, lovastatin and itaconic acid, produced by Aspergillus terreus, have applications in the pharmaceutical and chemical industries. Lovastatin is primarily used for the control of hypercholesterolemia, while itaconic acid is a building block for the production of synthetic fibers, coating adhesives, among others. In this study, for the first time, 35 strains of Aspergillus sp. from four Brazilian culture collections were evaluated for lovastatin and itaconic acid production and compared to a reference strain, ATCC 20542. From an initial screening, the strains ATCC 20542, URM 224, URM1876, URM 5061, URM 5254, URM 5256, URM 5650, and URM 5961 were selected for genomic comparison. Among tested strains, the locus corresponding to the lovastatin genomic cluster was assembled, showing that all genes essential for lovastatin biosynthesis were present in producing URM 5961 and URM 5650 strains, with 100% and 98.5% similarity to ATCC 20542, respectively. However, in the no producing URM 1876, URM 224, URM 5254, URM 5061, and URM 5256 strains, this cluster was either fragmented or missing. Among the 35 strains evaluated for itaconic acid production in this study, only three strains had titers above 0.5 g/L, 16 strains had production below 0.5 g/L, and the remaining 18 strains had no production, with the highest production of itaconic acid observed in the URM 5254 strain with 2.2 g/L. The essential genes for itaconic acid production, mttA, cadA msfA were also mapped, where all three genes linked to itaconic acid production were found in a single contig in the assembly of each strain. In contrast to lovastatin loci, there is no correlation between the level of itaconic acid production and genetic polymorphisms in the genes associated with its biosynthesis.


Assuntos
Aspergillus , Lovastatina , Succinatos , Aspergillus/genética , Aspergillus/metabolismo , Biodiversidade , Brasil , Genes Fúngicos , Variação Genética , Genoma Fúngico , Lovastatina/biossíntese , Lovastatina/genética , Filogenia , Succinatos/metabolismo
4.
Fungal Genet Biol ; 140: 103395, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32325168

RESUMO

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.


Assuntos
Variação Genética/genética , Genômica , Paracoccidioides/genética , Paracoccidioidomicose/genética , Argentina/epidemiologia , Ecossistema , Genética Populacional , Genoma Fúngico/genética , Genótipo , Humanos , Paracoccidioides/classificação , Paracoccidioides/patogenicidade , Paracoccidioidomicose/classificação , Paracoccidioidomicose/epidemiologia , Paracoccidioidomicose/microbiologia , Paraguai/epidemiologia , Filogenia
5.
Biotechnol Lett ; 41(12): 1391-1401, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31659577

RESUMO

OBJECTIVE: To select potential ligands of ALS3 for drug development with anti-adhesion and/or anti-biofilm activities. METHODOLOGY: ALS3 model was considered stable by DM. The main features of protein flexibility were represented by two conformers which were used in the virtual screening. Twenty-four small molecules were selected for in vitro assays. Five of them presented the best biological activity with ability to inhibit the adhesion and C. albicans biofilm formation on abiotic surface. RESULTS: To select potential ligands of ALS3 for drug development with anti-adhesion and/or anti-biofilm activities. CONCLUSION: In silico tools application was able to select promising compounds with anti-adhesion activity, opening a new perspective of medical device treatment.


Assuntos
Antifúngicos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Adesão Celular/efeitos dos fármacos , Descoberta de Drogas/métodos , Proteínas Fúngicas/antagonistas & inibidores , Simulação de Acoplamento Molecular/métodos , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Proteínas Fúngicas/química , Ligação Proteica , Conformação Proteica
6.
Appl Microbiol Biotechnol ; 100(9): 4015-25, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26695160

RESUMO

The thioredoxin system plays a critical role in maintaining the cytoplasm redox state, participating in functions that are important to the cellular viability of fungi. Although functional and structural information on targets in human pathogenic fungi has been scarcely described in the literature, such studies are essential for in silico drug design and biotechnological applications. Therefore, the aims of the present study were to produce recombinant proteins of the thioredoxin system from Candida albicans and evaluate their possible use as prophylactic or alternative therapies against the most important pathogenic fungus associated with nosocomial infections. We focused on biochemical and structural analyses of recombinant thioredoxin reductase from C. albicans with His-tag (CaTrxR-His) for further biotechnology applications. Heterologous CaTrxR-His was efficiently expressed in the soluble fraction of the Escherichia coli lysate. CaTrxR-His was obtained with a high level of purity and presented specific enzymatic activity. Conformational changes of the protein were observed at different pHs and temperatures, with higher thermal stability at pH 8.0. The CaTrxR-His vaccine was shown to effectively induce high levels of CaTrxR-specific immunoglobulin G antibodies in Balb/c mice and reduce the renal fungal burden of experimental disseminated candidiasis in mice. These data may greatly impact future development strategies for vaccine and drug designs against C. albicans infection.


Assuntos
Candida albicans/enzimologia , Tiorredoxina Dissulfeto Redutase/imunologia , Tiorredoxina Dissulfeto Redutase/metabolismo , Animais , Anticorpos Antifúngicos/sangue , Antígenos de Fungos/genética , Antígenos de Fungos/metabolismo , Candida albicans/genética , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Concentração de Íons de Hidrogênio , Imunoglobulina G/sangue , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Temperatura , Tiorredoxina Dissulfeto Redutase/genética
7.
Eukaryot Cell ; 14(2): 158-69, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25480940

RESUMO

Sporotrichosis is one of the most frequent subcutaneous fungal infections in humans and animals caused by members of the plant-associated, dimorphic genus Sporothrix. Three of the four medically important Sporothrix species found in Brazil have been considered asexual as no sexual stage has ever been reported in Sporothrix schenckii, Sporothrix brasiliensis, or Sporothrix globosa. We have identified the mating type (MAT) loci in the S. schenckii (strain 1099-18/ATCC MYA-4821) and S. brasiliensis (strain 5110/ATCC MYA-4823) genomes by using comparative genomic approaches to determine the mating type ratio in these pathogen populations. Our analysis revealed the presence of a MAT1-1 locus in S. schenckii while a MAT1-2 locus was found in S. brasiliensis representing genomic synteny to other Sordariomycetes. Furthermore, the components of the mitogen-activated protein kinase (MAPK)-pheromone pathway, pheromone processing enzymes, and meiotic regulators have also been identified in the two pathogens, suggesting the potential for sexual reproduction. The ratio of MAT1-1 to MAT1-2 was not significantly different from 1:1 for all three Sporothrix species, but the population of S. brasiliensis in the outbreaks originated from a single mating type. We also explored the population genetic structure of these pathogens using sequence data of two loci to improve our knowledge of the pattern of geographic distribution, genetic variation, and virulence phenotypes. Population genetics data showed significant population differentiation and clonality with a low level of haplotype diversity in S. brasiliensis isolates from different regions of sporotrichosis outbreaks in Brazil. In contrast, S. schenckii isolates demonstrated a high degree of genetic variability without significant geographic differentiation, indicating the presence of recombination. This study demonstrated that two species causing the same disease have contrasting reproductive strategies and genetic variability patterns.


Assuntos
Genes Fúngicos Tipo Acasalamento/genética , Reprodução Assexuada , Sporothrix/genética , Esporotricose/transmissão , Animais , Brasil , Gatos , Surtos de Doenças , Humanos , Sistema de Sinalização das MAP Quinases , Polimorfismo Genético , Sporothrix/patogenicidade , Sporothrix/fisiologia , Esporotricose/veterinária , Virulência/genética
8.
BMC Genomics ; 16: 376, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25962381

RESUMO

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.


Assuntos
Regulação Fúngica da Expressão Gênica , Genoma Fúngico/genética , Paracoccidioides/genética , Retroelementos/genética , Análise por Conglomerados , Etiquetas de Sequências Expressas/metabolismo , Genômica , Anotação de Sequência Molecular , Paracoccidioides/classificação , Filogenia , Sequências Repetidas Terminais/genética , Transcrição Gênica
9.
Nucleic Acids Res ; 41(15): 7387-400, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23761445

RESUMO

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector-human and vector-parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi.


Assuntos
Anopheles/genética , Genoma de Inseto , Insetos Vetores/genética , Animais , Anopheles/classificação , Brasil , Cromossomos de Insetos/genética , Elementos de DNA Transponíveis , Evolução Molecular , Feminino , Variação Genética , Interações Hospedeiro-Parasita , Proteínas de Insetos/genética , Insetos Vetores/classificação , Resistência a Inseticidas , Inseticidas/farmacologia , Malária/parasitologia , Masculino , Anotação de Sequência Molecular , Filogenia , Sintenia , Transcriptoma
10.
Fungal Biol Biotechnol ; 11(1): 5, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38715132

RESUMO

BACKGROUND: Candida albicans is one of the most prevalent fungi causing infections in the world. Mnt1 is a mannosyltransferase that participates in both the cell wall biogenesis and biofilm growth of C. albicans. While the cell wall performs crucial functions in pathogenesis, biofilm growth is correlated with sequestration of drugs by the extracellular matrix. Therefore, antifungals targeting CaMnt1 can compromise fungal development and potentially also render Candida susceptible to drug therapy. Despite its importance, CaMnt1 has not yet been purified to high standards and its biophysical properties are lacking. RESULTS: We describe a new protocol to obtain high yield of recombinant CaMnt1 in Komagataella phaffii using methanol induction. The purified protein's identity was confirmed by MALDI-TOF/TOF mass spectroscopy. The Far-UV circular dichroism (CD) spectra demonstrate that the secondary structure of CaMnt1 is compatible with a protein formed by α-helices and ß-sheets at pH 7.0. The fluorescence spectroscopy results show that the tertiary structure of CaMnt1 is pH-dependent, with a greater intensity of fluorescence emission at pH 7.0. Using our molecular modeling protocol, we depict for the first time the ternary complex of CaMnt1 bound to its two substrates, which has enabled the identification of residues involved in substrate specificity and catalytic reaction. Our results corroborate the hypothesis that Tyr209 stabilizes the formation of an oxocarbenium ion-like intermediate during nucleophilic attack of the acceptor sugar, opposing the double displacement mechanism proposed by other reports. CONCLUSIONS: The methodology presented here can substantially improve the yield of recombinant CaMnt1 expressed in flask-grown yeasts. In addition, the structural characterization of the fungal mannosyltransferase presents novelties that can be exploited for new antifungal drug's development.

11.
Nat Commun ; 15(1): 3190, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609393

RESUMO

Coccidioidomycosis, listed as a priority mycosis by the WHO, is endemic in the United States but often overlooked in Central and South America. Employing a multi-institutional approach, we investigate how disease characteristics, pathogen genetic variation, and environmental factors impact coccidioidomycosis epidemiology and outcomes in South America. We identified 292 cases (1978-2021) and 42 outbreaks in Piauí and Maranhão states, Brazil, the largest series outside the US/Mexico epidemic zone. The male-to-female ratio was 57.4:1 and the most common activity was armadillo hunting (91.1%) 4 to 30 days before symptom onset. Most patients (92.8%) exhibited typical acute pulmonary disease, with cough (93%), fever (90%), and chest pain (77%) as predominant symptoms. The case fatality rate was 8%. Our negative binomial regression model indicates that reduced precipitation levels in the current (p = 0.015) and preceding year (p = 0.001) predict heightened incidence. Unlike other hotspots, acidic soil characterizes this region. Brazilian strains differ genomically from other C. posadasii lineages. Northeastern Brazil presents a distinctive coccidioidomycosis profile, with armadillo hunters facing elevated risks. Low annual rainfall emerges as a key factor in increasing cases. A unique C. posadasii lineage in Brazil suggests potential differences in environmental, virulence, and/or pathogenesis traits compared to other Coccidioides genotypes.


Assuntos
Coccidioidomicose , Humanos , Feminino , Masculino , Animais , Brasil/epidemiologia , Coccidioidomicose/epidemiologia , Tatus , Genômica , Genótipo
12.
Mem Inst Oswaldo Cruz ; 108(6): 808-11, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24037207

RESUMO

Phospholipase is an important virulence factor for pathogenic fungi. In this study, we demonstrate the following: (i) the Paracoccidioides brasiliensis pld gene is preferentially expressed in mycelium cells, (ii) the plb1 gene is mostly up-regulated by infection after 6 h of co-infection of MH-S cells or during BALB/c mice lung infection, (iii) during lung infection, plb1, plc and pld gene expression are significantly increased 6-48 h post-infection compared to 56 days after infection, strongly suggesting that phospholipases play a role in the early events of infection, but not during the chronic stages of pulmonary infection by P. brasiliensis.


Assuntos
Macrófagos Alveolares/microbiologia , Paracoccidioides , Paracoccidioidomicose , Fosfolipases/genética , Fatores de Virulência/genética , Animais , Expressão Gênica , Masculino , Camundongos Endogâmicos BALB C , Paracoccidioides/citologia , Paracoccidioides/enzimologia , Paracoccidioides/patogenicidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Mycopathologia ; 175(5-6): 463-75, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23179449

RESUMO

Chromoblastomycosis (CBM) is a chronic subcutaneous mycosis, caused by several dimorphic, pigmented dematiaceous fungi. Patients with the disease are still considered a therapeutic challenge, mainly due to its recalcitrant nature. There is no "gold standard" treatment for this neglected mycosis, but rather there are several treatment options. Chemotherapy alternatives include 5-flucytosine, itraconazole, terbinafine, fluconazole, thiabendazole, ketoconazole and amphotericin B, although the healing of severe cases is still uncommon. However, several studies have reported the DNA vaccine to be promising in the treatment for fungal infections; this vaccine allows the host to restore depressed cellular immunity, minimizing the toxic effects from conventional antifungal therapies. This work was therefore carried out aiming to establish a suitable model for experimental CBM, suggesting also new therapies, including DNA-hsp65 vaccine. By analyzing the morphometrical and histopathological aspects and by quantifying the fungal burden, the results showed the establishment of a chronic, although transitory, experimental CBM model with lesions similar to those presented in humans. A treatment regimen using intralesional itraconazole or amphotericin B was effective in treating experimental CBM, as was a therapy using naked DNA-hsp65 vaccine. It has also been shown that chemotherapy associated with DNA-hsp65 vaccine is promising in the treatment for CBM.


Assuntos
Proteínas de Bactérias/imunologia , Chaperonina 60/imunologia , Cromoblastomicose/terapia , Fatores Imunológicos/administração & dosagem , Vacinas de DNA/administração & dosagem , Animais , Antifúngicos/uso terapêutico , Proteínas de Bactérias/genética , Chaperonina 60/genética , Cromoblastomicose/microbiologia , Cromoblastomicose/patologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Histocitoquímica , Fatores Imunológicos/genética , Masculino , Ratos Wistar , Resultado do Tratamento , Vacinas de DNA/genética
14.
J Fungi (Basel) ; 9(2)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36836338

RESUMO

Chromoblastomycosis (CBM) is a disease caused by several dematiaceous fungi from different genera, and Fonsecaea is the most common which has been clinically isolated. Genetic transformation methods have recently been described; however, molecular tools for the functional study of genes have been scarcely reported for those fungi. In this work, we demonstrated that gene deletion and generation of the null mutant by homologous recombination are achievable for Fonsecaea pedrosoi by the use of two approaches: use of double-joint PCR for cassette construction, followed by delivery of the split-marker by biolistic transformation. Through in silico analyses, we identified that F. pedrosoi presents the complete enzymatic apparatus required for tryptophan (trp) biosynthesis. The gene encoding a tryptophan synthase trpB -which converts chorismate to trp-was disrupted. The ΔtrpB auxotrophic mutant can grow with external trp supply, but germination, viability of conidia, and radial growth are defective compared to the wild-type and reconstituted strains. The use of 5-FAA for selection of trp- phenotypes and for counter-selection of strains carrying the trp gene was also demonstrated. The molecular tools for the functional study of genes, allied to the genetic information from genomic databases, significantly boost our understanding of the biology and pathogenicity of CBM causative agents.

15.
J Fungi (Basel) ; 8(4)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35448624

RESUMO

Cryptococcus spp. are human pathogens that cause 181,000 deaths per year. In this work, we systematically investigated the virulence attributes of Cryptococcus spp. clinical isolates and correlated them with patient data to better understand cryptococcosis. We collected 66 C. neoformans and 19 C. gattii clinical isolates and analyzed multiple virulence phenotypes and host-pathogen interaction outcomes. C. neoformans isolates tended to melanize faster and more intensely and produce thinner capsules in comparison with C. gattii. We also observed correlations that match previous studies, such as that between secreted laccase and disease outcome in patients. We measured Cryptococcus colony melanization kinetics, which followed a sigmoidal curve for most isolates, and showed that faster melanization correlated positively with LC3-associated phagocytosis evasion, virulence in Galleria mellonella and worse prognosis in humans. These results suggest that the speed of melanization, more than the total amount of melanin Cryptococcus spp. produces, is crucial for virulence.

16.
Fungal Genet Biol ; 48(10): 947-55, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21708278

RESUMO

Thermodimorphic fungi include most causative agents of systemic mycoses, but the molecular mechanisms that underlie their defining trait, i.e. the ability to shift between mould and yeast on temperature change alone, remain poorly understood. We hypothesised that the heat shock factor (Hsf), a protein that evolved to sense thermal stimuli quickly, might play a role in this process in addition to the known regulator Drk1 and the Ryp proteins. To test this hypothesis, we characterised the Hsf from the thermodimorph Paracoccidioides lutzii (formerly Paracoccidioides brasiliensis isolate 01). We show in the present work that PlHsf possesses regulatory domains that are exclusive of the Eurotiomycetidae family, suggesting evolutionary specialisation; that it can successfully rescue the otherwise lethal loss of the native protein of Saccharomyces cerevisiae; and that its DNA-binding domain is able to recognise regulatory elements from the promoters of both Drk1 and Ryp1. An in silico screening of all 1 kb sequences upstream of P. lutzii ORFs revealed that 7% of them possess a heat shock element. This is the first description of a heat shock factor in a thermodimorphic fungus.


Assuntos
Proteínas de Choque Térmico/genética , Paracoccidioides/genética , Paracoccidioidomicose/microbiologia , Sequência de Bases , Proteínas de Ligação a DNA/classificação , Proteínas de Ligação a DNA/genética , Evolução Molecular , Proteínas de Choque Térmico/classificação , Humanos , Dados de Sequência Molecular , Paracoccidioides/fisiologia , Filogenia , Regiões Promotoras Genéticas , Sequências Reguladoras de Ácido Nucleico , Proteínas de Saccharomyces cerevisiae/classificação , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , Temperatura , Fatores de Transcrição/classificação , Fatores de Transcrição/genética
17.
Clin Ther ; 43(5): e103-e138, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33892966

RESUMO

PURPOSE: The field of human medicine is in a constant state of evolution, developing and incorporating technological advances from diverse scientific fields. In recent years, cellular and gene therapies have come of age, challenging regulatory agencies to define the path for commercial registration. Approval necessarily demands robust evidence for safety and efficacy, but these exigencies must not be such that they render unviable the development and testing of the therapeutic agent. Furthermore, reimbursement strategies are required to guarantee commercial viability of these products, to avoid the risk that they will be removed from the market or become unavailable to most patients through lack of financial resources. To address such challenges, several countries have created strategies to manage advanced therapy products. METHODS: Based on official documents published by regulatory agencies worldwide, this review summarizes the current scenario in the United States, Europe, Brazil, Japan, South Korea, and China in this regard, discussing the harmonized and dissonant aspects of the regulatory framework in different regions of the world and exploring perspectives for the future. FINDINGS: The technical aspects of advanced therapies are increasingly complex, bringing challenges for high mass commercialization and demanding specific regulation. The regulatory framework of the analyzed regions is mainly recent and discordant, but many harmonizing initiatives were observed. IMPLICATIONS: The comparative analysis of regulatory frameworks in different parts of the world is informative, as scientists must be aware of the rationale of regulators to assertively develop new technology and products that will be commercialized. The comparative analysis also provides insight into the main dissonances that must be addressed, fostering the harmonization of local regulatory frameworks. Many unanswered questions still lie ahead for the field of advanced therapies, and empirical evidence will be the most effective way to separate hype from hope and to establish the most sustainable mechanisms to regulate and finance such products in each part of the world.


Assuntos
Terapia Genética , Órgãos Governamentais , China , Europa (Continente) , Previsões , Humanos , Estados Unidos
18.
PLoS Negl Trop Dis ; 15(11): e0009956, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34843484

RESUMO

INTRODUCTION: Paracoccidioidomycosis (PCM) is caused by several species of the Paracoccidioides genus which can be differentiated by interspecific genetic variations, morphology and geographic distribution. Intraspecific variability correlation with clinical and epidemiological aspects of these species still remains unclear. This study aimed to sequence the loci GP43, exon 2 and ARF of 23 clinical isolates of Paracoccidioides spp. from patients in the Southeast Region of Brazil. METHODOLOGY AND MAIN FINDINGS: GenBank was used to compare the present (23) with previous described sequences (151) that included ARF and GP43. It was identified a high polymorphism rate among the 23 isolates in comparison to the other 151. Among the isolates, 22 (95.66%) were S1/P. brasiliensis and 1 (4.34%) was identified as PS2/P. americana. A total of 45 haplotypes were found as follows: 19 from S1/P. brasiliensis (13 from the present study), 15 from P. lutzii, 6 from PS2/P. americana (1 from the present study), 3 from PS3/P. restrepiensis and 2 from PS4/P. venezuelensis. Moreover, exclusive haplotypes according to clinical origin and geographical area were found. S1/P. brasiliensis (HD = 0.655 and K = 4.613) and P. lutzii (HD = 0.649 and K = 2.906) presented the highest rate of polymorphism among all species, from which 12 isolates of the present study were clustered within S1b/P. brasiliensis. The GP43 locus showed a higher variability and was found to be the main reason for the species differentiation. CONCLUSIONS: The results herein decribed show a high intraspecific genetic variability among S1/P. brasiliensis isolates and confirm the predominance of this species in the Southeast region of Brazil. The finding of exclusive haplotypes according to clinical origin and geographical area would suggest correlation between the molecular profile with the clinical form and geographic origin of patients with PCM.


Assuntos
Paracoccidioides/genética , Paracoccidioidomicose/microbiologia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Variação Genética , Hospitais de Ensino/estatística & dados numéricos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Paracoccidioides/classificação , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/epidemiologia , Filogenia , Adulto Jovem
19.
Pathogens ; 10(3)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33800117

RESUMO

Candida albicans is the most common species isolated from nosocomial bloodstream infections. Due to limited therapeutic arsenal and increase of drug resistance, there is an urgent need for new antifungals. Therefore, the antifungal activity against C. albicans and in vivo toxicity of a 1,3,4-oxadiazole compound (LMM6) was evaluated. This compound was selected by in silico approach based on chemical similarity. LMM6 was highly effective against several clinical C. albicans isolates, with minimum inhibitory concentration values ranging from 8 to 32 µg/mL. This compound also showed synergic effect with amphotericin B and caspofungin. In addition, quantitative assay showed that LMM6 exhibited a fungicidal profile and a promising anti-biofilm activity, pointing to its therapeutic potential. The evaluation of acute toxicity indicated that LMM6 is safe for preclinical trials. No mortality and no alterations in the investigated parameters were observed. In addition, no substantial alteration was found in Hippocratic screening, biochemical or hematological analyzes. LMM6 (5 mg/kg twice a day) was able to reduce both spleen and kidneys fungal burden and further, promoted the suppresses of inflammatory cytokines, resulting in infection control. These preclinical findings support future application of LMM6 as potential antifungal in the treatment of invasive candidiasis.

20.
Sci Rep ; 11(1): 15185, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312413

RESUMO

Parkinson's disease (PD) is a progressive and chronic neurodegenerative disease of the central nervous system. Early treatment for PD is efficient; however, long-term systemic medication commonly leads to deleterious side-effects. Strategies that enable more selective drug delivery to the brain using smaller dosages, while crossing the complex brain-blood barrier (BBB), are highly desirable to ensure treatment efficacy and decrease/avoid unwanted outcomes. Our goal was to design and test the neurotherapeutic potential of a forefront nanoparticle-based technology composed of albumin/PLGA nanosystems loaded with dopamine (ALNP-DA) in 6-OHDA PD mice model. ALNP-DA effectively crossed the BBB, replenishing dopamine at the nigrostriatal pathway, resulting in significant motor symptom improvement when compared to Lesioned and L-DOPA groups. Notably, ALNP-DA (20 mg/animal dose) additionally up-regulated and restored motor coordination, balance, and sensorimotor performance to non-lesioned (Sham) animal level. Overall, ALNPs represent an innovative, non-invasive nano-therapeutical strategy for PD, considering its efficacy to circumvent the BBB and ultimately deliver the drug of interest to the brain.


Assuntos
Barreira Hematoencefálica/metabolismo , Dopamina/administração & dosagem , Dopamina/farmacocinética , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Transtornos Parkinsonianos/tratamento farmacológico , Transtornos Parkinsonianos/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Humanos , Masculino , Camundongos , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanotecnologia , Oxidopamina/toxicidade , Transtornos Parkinsonianos/induzido quimicamente , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química
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