Project description:Examination and comparison of the transcriptional profile of bone marrow derived dendritic cells (BMDCs) in response to infection by the fungus Paracoccidioides brasiliensis in resistant/susceptible mice
Project description:This dataset supports a comparative proteomic analysis of extracellular vesicles (EVs) and whole-cell extracts from the pathogenic fungus Paracoccidioides brasiliensis isolate Pb18. The study investigates protein cargo differences between EVs derived from virulent (vEV) and attenuated (aEV) variants, including vEVs exposed to oxidative (vEVOxi) and nitrosative (vEVNO) stress. Characterization of EVs included NTA, DLS, and Zeta potential measurements. Proteins were enzymatically digested and analyzed via nano-flow LC-MS/MS.
Project description:Species of the genus Paracoccidioides cause a systemic infection in human patients. Yeast cells of Paracoccidioides spp. produce melanin in the presence of L-dihydroxyphenylalanine and during infection, which may impact the pathogen survival into the host. To better understand the metabolic changes that occur in melanized Paracoccidioides spp. cells, a proteomic approach was performed to compare melanized and non-melanized Paracoccidioides brasiliensis and Paracoccidioides lutzii yeast cells. Melanization was conducted using L-dihydroxyphenylalanine as a precursor and quantitative proteomics was performed using reversed-phase chromatography coupled to high resolution mass spectrometry. When comparing melanized versus non-melanized cells, 999 and 577 differentially abundant proteins were identified for P. brasiliensis and P. lutzii, respectively. Functional enrichment and comparative analysis revealed 30 abundant biological processes in melanized P. brasiliensis and 18 in P. lutzii, while non-melanized cells from these species had 21 and 25 differentially abundant processes, respectively. Melanized cells presented abundance of other virulence-associated proteins, such as phospholipase, proteases, superoxide dismutase, heat-shock proteins, as well as proteins related to cell-wall remodeling and vesicular transport. The results suggest that L-dihydroxyphenilalanine increases virulence of Paracoccidioides spp. through a complex mechanism involving not only melanin, but other virulence factors as well.
Project description:Paracoccidioides brasiliensis is a thermodimorphic fungus associated with paracoccidioidomycosis (PCM), the most common systemic mycosis in Latin America. The infection is initiated by inhalation of environmental dispersed conidia produced by the saprophytic phase of the fungus. In the lungs, P. brasiliensis assumes the parasitic yeast form and must cope with the adverse conditions imposed by cells of the host immune system, which includes a harsh environment highly concentrated in reactive oxygen species (ROS). In this work, we used the ROS-generating agent paraquat to experimentally simulate oxidative stress conditions in order to evaluate the stress-induced modulation in gene expression of cultured P. brasiliensis yeast cells using a microarray hybridization approach.
Project description:Paracoccidioides brasiliensis is a thermodimorphic fungus associated with paracoccidioidomycosis (PCM), a prevalent systemic mycosis in South America. In humans, infection starts by inhalation of fungal propagules, which reach the pulmonary epithelium and transform into the yeast parasitic form. Thus, the mycelium-to-yeast transition is of particular interest because conversion to yeast is essential for infection. We have used a P. brasiliensis biochip, carrying sequences of 4,692 genes from this fungus to monitor gene expression at several time points of the mycelium-to-yeast morphological shift (from 5 to 120 h). Keywords: Time Course
Project description:Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, an important systemic mycosis in Latin America. Few virulence factors have been identified for this pathogen. In this study, we quantitatively evaluated the protein composition of P. brasiliensis in the yeast phase using minimal and rich media to obtain a better understanding of its virulence and to gain new insights into pathogen adaptation strategies. This analysis was performed on two isolates of the Pb18 strain showing distinct infection profiles in B10.A mice. Using liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis, we identified and quantified 317 proteins in minimal medium, 29 of which were overexpressed in virulent Pb18. In rich medium, 29 out of 214 identified proteins were over-expressed in the virulent fungus. Alcohol dehydrogenase, mitochondrial peroxiredoxin PRX1 and protein vacuolar ATP synthase catalytic subunit A were up-regulated in virulent Pb18 in both media, suggesting potential roles of these proteins in virulence regulation in P. brasiliensis. Proteins up-regulated in both isolates were grouped according to their functional categories. Virulent Pb18 undergoes metabolic reorganization and increased expression of proteins involved in fermentative respiration. This approach allowed us to identify potential virulence regulators and to understand how Paracoccidioides modulates the host-pathogen interaction to its advantage. Data are available via ProteomeXchange Consortium with identifier PXD000804.
Project description:Paracoccidioides brasiliensis, a thermally dimorphic fungus, is the causative agent of paracoccidioidomycosis, a systemic mycosis that is widespread in Latin America. P. brasiliensis infection occurs when conidia or mycelial fragments are inhaled by the host, which causes these cells to transition to the yeast form. The development of disease requires conidia inside host alveoli to differentiate into yeast cells in a temperature-dependent manner. This fungus is a facultative intracellular pathogen able to survive and replicate inside non-activated macrophages. Therefore, the survival of P. brasiliensis inside the host depends on the ability to adapt to oxidative stress induced by immune cells, especially alveolar macrophages. For several years, reactive oxygen species (ROS) were only associated with pathological processes. Currently, a plethora of roles for ROS in cell signaling have emerged. We have previously reported that low ROS concentrations cause cell proliferation in the human pathogenic fungus P. brasiliensis. In the present report, we investigated the influence of phosphorylation events in that process. Using a mass spectrometry-based approach, we mapped 440 phosphorylation sites in 230 P. brasiliensis proteins and showed that phosphorylation at different sites determines fungal responses to oxidative stress. Furthermore, we described, for the first time, the presence of a two-component signal transduction system in P. brasiliensis. These findings will help us to understand the phosphorylation events involved in the oxidative stress response.
Project description:Phenothiazines are antipsychotic drugs used in the treatment of schizophrenia, which have been shown to present antimicrobial activity (in vitro and in vivo) against a great variety of pathogenic microorganisms, including bacteria, parasites (protozoa and helmints) and fungi. In this study, we used competitive microarray hybridization to evaluate the effects of increasing concentrations of the piperidinic phenothiazine derivative thioridazine (TR) on the transcriptome of Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis (PCM) - the most common systemic mycosis in Latin America. These analyses showed that the presence of TR affected expression of more than 1,800 genes from this fungus, including genes related to cellular processes such as cell wall metabolism and drug resistance.
