Differential soluble protein expression between Trichomonas vaginalis isolates exhibiting low and high virulence phenotypes.

A comparative analysis of proteomic maps of long-term grown and fresh clinical Trichomonas vaginalis isolates exhibiting low and high virulence phenotypes, respectively, was performed using two-dimensional gel electrophoresis and mass spectrometry. Of 29 protein spots differentially expressed between the isolates, 19 were over-expressed in the isolate exhibiting high virulence phenotype: proteins associated with cytoskeletal dynamics, such as coronin and several isoforms of actin, as well as proteins involved in signal transduction, protein turnover, proteolysis, and energetic and polyamine metabolisms were identified. Some malate dehydrogenase, fructose-1,6-bisphosphate aldolase and ornithine cyclodeamidase isoforms were exclusively expressed by the highly virulent isolate. During interaction assays with VEC, parasites exhibiting high virulence phenotype rapidly adhered and switched to amoeboid forms. In contrast, low adhesion and no morphological transformation were observed in parasites displaying low virulence phenotype. Our findings demonstrate that expression of specific proteins by high and low virulence parasites could be associated with the ability of each isolate to undergo morphological transformation and interact with host cells. Such data represent an important step towards understanding of the complex interaction network of proteins that participate in the mechanism of pathogenesis of this protozoan.

Tritrichomonas foetus pseudocysts adhere to vaginal epithelial cells in a contact-dependent manner.

Tritrichomonas foetus is a parasitic protist of the urogenital tract of cattle. It presents the trophozoite stage, a motile elongated form that constitutes most of the cells in a normal population, and a pseudocyst stage, an immotile rounded form that appears under unfavourable environmental conditions. In the present report pseudocysts were studied in natural conditions and after induction by chemicals or cycles of cooling and warming of cultures. The capacity of T. foetus to adhere to vaginal epithelial cells (VECs) was compared for both trophozoite and pseudocyst forms. By the use of video-enhanced-contrast microscopy, scanning and transmission electron microscopy, and immunofluorescence microscopy techniques, we present evidence that: (1) T. foetus easily internalizes the flagella and forms pseudocysts under several unfavourable conditions; (2) T. foetus in both pseudocyst and trophozoite forms is able to adhere to VECs; (3) the adhesion rate is higher for pseudocysts than for trophozoites; (4) the adhesin Tf190 is expressed in both forms during interaction; (5) the adhesion process of pseudocysts seems to occur in a contact-dependent manner. Thus, we propose that the pseudocyst stage is not a degenerative form, but a functional life form that is able to interact with and firmly adhere to VECs.