Kinetics of IFN-gamma, TNF-alpha, IL-10 and IL-4 production by mononuclear cells stimulated with gp43 peptides, in patients cured of paracoccidioidomycosis

We analyzed the kinetics of cytokine production by mononuclear cells from 17 patients who had been treated for paracoccidioidomycosis, using the stimulus of gp43 peptide groups (43kDa glycoprotein of Paracoccidioides brasiliensis) at 0.1 and 1µM, gp43 (1µg/ml) and crude Paracoccidioides brasiliensis antigen (PbAg; 75µg/ml). IFN-gamma production was a maximum at 144 hours in relation to the G2 and G8 peptide groups at 1µM and was greatest at 144 hours when stimulated by gp43 and by PbAg. The maximum TNF-alpha production was at 144 hours for the G2 group (0.1µM) and for gp43. IL-10 production was highest after 48 and 72 hours for G7 and G6 at 1µM, respectively. We also suggest the best time for analysis of IL4 production. These results may contribute towards future studies with gp43 peptides and encourage further investigations with the aim of understanding the influence of these peptides on the production of inflammatory and regulatory cytokines.

Analisamos a cinética da produção de citocinas de células mononucleares de 17 pacientes com paracoccidioidomicose tratada, usando como estímulo: grupos de peptídeos da gp43 (glicoproteina de 43kDa de Paracoccidioides brasiliensis) a 0,1 e 1µM, gp43 (1µg/mL) e antígeno bruto de Paracoccidioides brasiliensis - AgPb (75µg/mL). A produção de IFN-gama foi máxima em 144 horas frente aos grupos de peptídeos G2 e G8 a 1µM e maior em 144 horas quando estimuladas por gp43 e por AgPb. A produção de TNF-alfa foi máxima em 144 horas para G2 (0,1µM) e para gp43. A produção de IL-10 foi maior após 48 e 72 horas para G7 e G6 a 1µM, respectivamente. Sugerimos também o melhor período para a análise da produção de IL4. Tais resultados podem contribuir para estudos com peptídeos da gp43, estimulando investigações posteriores visando entender a influência de tais peptídeos na produção de citocinas inflamatórias e regulatórias.

Avaliacao das subpopulacoes de timocitos em camundongos BALB/c infectados com Paracoccidioides brasiliensis por via intratraqueal / Evaluation of thymocyte subpopulations in BALB / c mice infected with Paracoccidioides brasiliensis intratracheally

O P. brasiliensis e o agente etiologico da paracoccidioidomicose, uma doenca granulomatosa cronica que afeta primariamente os pulmoes e esta frequentemente relacionada com a diminuicao da resposta imune celular especifica. A inoculacao intraperitonial deste fungo em camundongos causa a trofia do timo, orgao respónsavel pela geracao de linfocitos T que dirigem a reposta imune especifica. Assim, este trabalho teve como objetivo avaliar a ocorrencia de atrofia timica em camundongos infectados com P. brasiliensis pela via intratraqueal, que constituium modelo mais fiel da doenca. A infeccao por esta via, resultou claramente em atrofia timica, que foi caracterizada por uma diminuicao do peso, celularidade e viabilidade celular, alem de alteracoes nas subpopulacoes dos timocitos, como diminuicao dos duplos dispositivos (CD4+CD8+) e consequente aumento dos duplos negativos (CD4-CD8-) e timocitos CD4+CD8- e CD4-CD8+.

Screening for glycosylphosphatidylinositol-anchored proteins in the Paracoccidioides brasiliensis transcriptome

Open reading frames in the transcriptome of Paracoccidioides brasiliensis were screened for potential glycosylphosphatidylinositol (GPI)-anchored proteins, which are a functionally and structurally diverse family of post-translationally modified molecules found in a variety of eukaryotic cells. Numerous studies have demonstrated that various GPI anchor sequences can affect the localization of these proteins in the plasma membrane or the cell wall. The GPI anchor core is produced in the endoplasmic reticulum by sequential addition of monosaccharides and phospho-ethanolamine to phosphatidylinositol. The complete GPI anchor is post-translationally attached to the protein carboxyl-terminus by GPI transamidases. Removal of this GPI lipid moiety by phospholipases generates a soluble form of the protein. The identification of putative GPI-attached proteins in the P. brasiliensis transcriptome was based on the following criteria: the presence of an N-terminal signal peptide for secretion and a hydrophobic region in the C-terminus presenting the GPI-attachment site. The proteins that were identified were in several functional categories: i) eight proteins were predicted to be enzymes (Gel1, Gel2, Gel3, alpha-amylase, aspartic proteinase, Cu-Zn SOD, DFG5, PLB); ii) Ag2/PRA, ELI-Ag1 and Gel1 are probably surface antigens; iii) Crh-like and the GPI-anchored cell wall protein have a putative structural role; iv) ECM33 and Gels (1, 2 and 3) are possibly involved in cell wall biosynthesis, and v) extracellular matrix protein is considered to be an adhesion protein. In addition, eight deduced proteins were predicted to localize in the plasma membrane and six in the cell wall. We also identified proteins involved in the synthesis, attachment and cleaving of the GPI anchor in the P. brasiliensis transcriptome.

Isolation and possible composition of glucosylceramides from Paracoccidioides brasiliensis

Twelve different species of neutral monohexosyl ceramides (CMHs) and two species of neutral monohexosyl ceramides were isolated form mycelium and yeast forms of Paracoccidioides brasiliensis, respectively, by a combination of ion-exchange chromatography, HPLC, and HPTLC. The glucosylceramides did not react with sera from patients with paracoccidioidomycosis (PCM). Carbohydrate analysis indicated that CMHs contain glucose. Analysis of (1)H-NMR and mass spectrometry data suggest that the structure of the CMHs is Glcpbeta1(Cer (mycelium forms present 12 different ceramides and yeast forms present 2 different ceramides). The composition of the lipid moieties was analyzed by negative fast atom bombardment mass spectrometry. No glycosphingolipid other than glucosylceramide was detected in P. brasiliensis.