Project description:Trichomonas vaginalis, a common sexually transmitted parasite that colonizes the human urogenital tract, secretes extracellular vesicles (TvEVs) that are taken up by human cells and are speculated to be taken up by parasites as well. While the crosstalk between TvEVs and human cells has led to insight into host:parasite interactions, the role of TvEVs in infection have largely been one-sided, with little known about the effect of TvEV uptake by T. vaginalis. Approximately 11% of infections are found to be co-infections of multiple T. vaginalis strains. Clinical isolates often differ in their adherence to and cytolysis of host cells, underscoring the importance of understanding the effects of TvEV uptake within the parasite population. To address this question our lab observed the effects of EV uptake by T. vaginalis on parasite gene expression. Using RNA-seq, we showed that TvEVs upregulate expression of predicted parasite membrane proteins and identified a novel adherence factor, heteropolysaccharide binding protein (HPB2).
Project description:Trichomonas vaginalis is a sexually transmitted anaerobic parasite that infects humans causing trichomoniasis, a common and ubiquitous sexually transmitted disease. The life cycle of this parasite presents a trophozoite form without a cystic stage. However, the presence of spherical forms with internalized flagella, non-proliferative, non-motile, viable and reversible, denominated pseudocysts, have been commonly observed in this parasite. To understand the mechanisms involved in the formation of pseudocysts, here we performed a mass spectrometry-based high-throughput quantitative proteomics study using a label-free approach and functional assays by biochemical and flow cytometric methods. We observed that morphological transformation of trophozoite to pseudocysts is coupled to (i) a metabolic shift toward a less glycolytic phenotype, (ii) alterations in the abundance of hydrogenosomal iron-sulfur cluster (ISC) assembly machinery; (iii) increased abundance of regulatory particles of the ubiquitin–proteasome system; (iv) significant alterations in proteins involved in adhesion and cytoskeleton reorganization; (v) arrest in G2/M phase associated to alterations in the abundance of regulatory proteins of the cell cycle. Such data supports that pseudocysts suffer important physiological and structural alterations for survive under unfavorable environmental conditions.
Project description:Trichomonas vaginalis is a sexually transmitted infection that causes vaginitis and increases the risk of HIV transmission. We are interested in the secreted and membrane glycoproteins of Trichomonas because they are likely involved in pathogenesis and may include novel vaccine targets. Four mass spectrometric methods (identification of all parasite proteins, glycoprotein enrichment with the plant lectin Concanavalin A, peptide:N-glycanase treatment to identify occupied N-glycans sites, and analysis of N-terminal peptides) were used to identify >300 Trichomonas secreted and membrane proteins. The first group of these proteins, which were present in multiple genome copies and had homologs in diverse eukaryotes, included 1) those involved in the N-glycan-dependent quality control protein folding in the ER lumen, 2) metalloproteases, serine proteases, cysteine proteases, and other lysosomal enzymes, and 3) transporters and membrane-associated cyclases. The second group of secreted and membrane proteins were, for the most part, encoded by single copy genes, unique to Trichomonas, and missing N-terminal signal peptides. The latter observation is despite evidence that the signal peptide peptidase functions normally in Trichomonas. As the unique secreted and membrane proteins of Trichomonas were often large and lacked features that make it easy to choose vaccine candidates, alternative strategies for vaccination and/or therapy are discussed.
Project description:Background: Transposable element 24 nucleotide small RNAs are not efficiently incorporated into the AGO1 protein, which is involved in endogenous RNAi and gene regulation through the microRNA and tasiRNA pathways. Results: The AGO1 protein incorporates large quantities of transposable element siRNAs when transposable elements are epigenetically activated and transcribed. The incorporation of transposable element siRNAs is at the expense of the most abundant microRNAs. These transposable element siRNAs can act as tasiRNAs, regulating genes that they have partial complementarity to. Conclusion: Transposable element small RNAs are more dynamic than previously thought. They can be incorporated into AGO1 and regulate genes. Three biological replicates of small RNA sequencing from two genotypes