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:The sexually transmitted parasite Trichomonas vaginalis secretes extracellular vesicles (TvEVs) that are internalized by human host cells. The goal of this experiment was to identify the effects of TvEV uptake on host cell gene expression.
Project description:The sexually transmitted parasite Trichomonas vaginalis is often found in symbiosis with the obligate intracellular pathogen Mycoplasma hominis. M. hominis is itself an opportunistic pathogen of the female reproductive tract associated with bacterial vaginosis. The goal of this experiment was to identify the effects of each pathogen individually and in symbiosis on host cell gene expression.
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: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:The protozoan parasite Trichomonas vaginalis (TV), exclusively adapted to the human genital tract, is one of the most common sexually transmitted pathogens. Adding to the complexity of the host-pathogen interactions, the parasite harbors TV-specific endosymbiont viruses (Trichomonasvirus, TVV). It was reported that small extracellular vesicles (exosomes) released by TV play a role in host immunity; however, the role of the viral endosymbiosis in this process remained unknown. We hypothesized that the virus may offer evolutionary benefit to its protozoan host at least in part by altering the immunomodulatory properties of exosomes spreading from the site of infection to non-infected immune effector cells. We infected human vaginal epithelial cells, the natural host of the parasite, with TV natively harboring TVV and an isogenic derivative of the parasite cured from the viral infection. Exosomes were isolated from vaginal cell culture 24 h post TV infection and from medium where the isogenic TV strains were cultured in the absence of the human host. Exosomes from TVV-negative but not TVV-positive parasites cultured alone caused NF-kB activation and increase of IL-8 and RANTES expression by uterine endocervical cells, which provide innate immune defense at the gate to the upper reproductive tract. Similarly, mononuclear leukocytes increased their IL-8, IL-6 and TNF-a output in response to exosomes from virus-negative, but not isogenic virus-positive parasites, the latter exosomes being immunosuppressive in comparison to TV medium control. The same phenomenon of suppressed immunity induced by the TVV-positive compared to TVV-negative phenotype was seen when stimulating the leukocytes with exosomes originating from infected vaginal cultures. In addition, the exosomes from the TVV-positive infection phenotype suppressed immune signaling of a toll-like receptor ligand derived from mycoplasma, another frequent TV symbiont. Quantitative comparative proteome analysis of exosomes from viruspositive versus virus-negative TV revealed differential expression of two functionally uncharacterized proteins and five proteins involved in Zn binding, protein binding, electron transfer, transferase and catalytic activities. These data support the concept that symbiosis with viruses may provide benefit to the protozoan parasite by exploiting exosomes as a vehicle for inter-cellular communications and modifying their protein cargo to suppress host immune activation.