In-Depth Quantitative Proteomic Analysis of Trophozoites and Pseudocysts of Trichomonas vaginalis

Abstract

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 possesses a trophozoite form without a cystic stage. However, the presence of nonproliferative and nonmotile, yet viable and reversible spherical forms with internalized flagella, denominated pseudocysts, has been commonly observed for this parasite. To understand the mechanisms involved in the formation of pseudocysts, 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 the 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; and (v) arrest in G2/M phase associated with alterations in the abundance of regulatory proteins of the cell cycle. These data demonstrate that pseudocysts experience important physiological and structural alterations for survival under unfavorable environmental conditions.

Membrane associated proteins of two Trichomonas gallinae clones vary with the virulence

“…Among proteins identified as more abundant in the clone with the highest initial virulence score (R17-12 C1) (Table 3 and Fig 5) are orthologes of two proteases, the immuno-dominant variable surface antigen-like protease, and the GP63-like protein. These proteases were shown to be involved in cell adhesion of other protozoa and pointed out as virulence factors [17, 22]. In addition, two other proteases have been found more abundant in the clone with the highest initial virulence, Clan SB family S8 subtilisin-like serine peptidase and Clan CA family C2 calpain-like cysteine peptidase.…”

“…vaginalis and Leishmania sp.. They act by binding and degrading various host components [17, 22]. In T .…”

“…BspA -like proteins act by binding to epithelial cells in many organisms, including Bacteria, Archea and Eukaryota [17]. Surface proteases participate in inflammation processes, neoplastic mechanisms and cell adhesion, and include cysteine proteases, serine proteases and metalloproteinases such as GP63-like proteins [17, 19, 20–22]. Proteins with dual functionality are called moonlighting proteins, since they are present in different compartments of the cell, including the plasmatic membrane.…”

Proteomic signatures of metronidazole-resistant Trichomonas vaginalis reveal novel proteins associated with drug resistance

“…Subsequent studies focused on the profiling of subcellular proteomes, such as the hydrogenosome [23] and surface proteomes [24]. Comparative proteomic analyses were conducted to identify the potentially important proteins involved in the adherence of trophozoites to fibronectin [25], iron availability [26], and the transformation of trophozoites to pseudocysts [27]. Additionally, differentially expressed proteins were identified from bovine and feline Tritrichomonas foetus genotypes, providing evidence of host-specific adaptation [28].…”

Demonstration and Characterization of Cyst-Like Structures in the Life Cycle of Trichomonas vaginalis

“…Previously some researchers believed pseudocysts to be degenerative structures (Petrin et al, 1998) but recent studies have highlighted its role in cervical neoplasia patients and transmission in rats (Zarei et al, 2018). Further, a recent comparative study of proteomes of T. vaginalis trophozoites and pseudocysts reported major differences between protein content and abundance of various sets of proteins in the two forms (Dias-Lopes et al, 2018). Recent work in the field has highlighted the relevance of non-sexual modes of transmission of the parasite from contaminated douche nozzle, toilet seats, and swimming pools (Pereira-Neves and Benchimol, 2008).…”