Production and Functional Characterization of a Recombinant Predicted Pore-Forming Protein (TVSAPLIP12) of Trichomonas vaginalis in Nicotiana benthamiana Plants

Chromatin accessibility and gene expression in the parasite Trichomonas vaginalis

Trichomonas vaginalis, the most common non-viral sexually transmitted parasite, causes more than 270 million infections annually. The infection's outcome varies greatly depending on different factors that include variation in human immune responses, the vaginal microbiome, and the inherent virulence of the strain. Although the pathogenicity of the different strains depends, at least partially, on differential gene expression of virulence genes; the regulatory mechanisms governing this transcriptional control remain incompletely understood. While many studies have reported a positive correlation between gene expression and chromatin accessibility in other cells, this relationship has not been analyzed in T. vaginalis. To address these questions, we selected two contrasting T. vaginalis strains based on their interactions with host cells: B7268 strain, a highly adherent one and resistant to metronidazole, and NYH209 strain, a poorly adherent one and sensitive to metronidazole. Next, we combined the assay for transposase-accessible chromatin using sequencing (ATAC-seq) with RNA sequencing (RNA-seq), to delve into the relationship between chromatin accessibility and gene expression in these distinct T. vaginalis strains. Our findings demonstrate a correlation between chromatin accessibility and gene expression across both strains. Moreover, we found that chromatin accessibility plays a pivotal role in modulating mRNA expression levels of several established genes linked to parasite pathogenesis and drug resistance. We also identified several open chromatin peaks residing at intergenic regions, revealing possible distal regulatory elements that may control gene expression. These results highlight the importance of chromatin accessibility in modulating gene expression in the parasite T. vaginalis, with possible consequences in pathogenesis and/or drug treatment.

Apicomplexan Pore-Forming Toxins

Pore-forming toxins (PFTs) are released by one cell to directly inflict damage on another cell. Hosts use PFTs, including members of the membrane attack complex/perforin protein family, to fight infections and cancer, while bacteria and parasites deploy PFTs to promote infection. Apicomplexan parasites secrete perforin-like proteins as PFTs to egress from infected cells and traverse tissue barriers. Other protozoa, along with helminth parasites, utilize saposin-like PFTs prospectively for nutrient acquisition during infection. This review discusses seminal and more recent advances in understanding how parasite PFTs promote infection and describes how they are regulated and fulfill their roles without causing parasite self-harm. Although exciting progress has been made in defining mechanisms of pore formation by PFTs, many open questions remain to be addressed to gain additional key insights into these remarkable determinants of parasitic infections.

Comparative genomics between Trichomonas tenax and Trichomonas vaginalis: CAZymes and candidate virulence factors

Introduction

The oral trichomonad Trichomonas tenax is increasingly appreciated as a likely contributor to periodontitis, a chronic inflammatory disease induced by dysbiotic microbiota, in humans and domestic animals and is strongly associated with its worst prognosis. Our current understanding of the molecular basis of T. tenax interactions with host cells and the microbiota of the oral cavity are still rather limited. One laboratory strain of T. tenax (Hs-4:NIH/ATCC 30207) can be grown axenically and two draft genome assemblies have been published for that strain, although the structural and functional annotation of these genomes is not available.

Methods

GenSAS and Galaxy were used to annotate two publicly available draft genomes for T. tenax, with a focus on protein-coding genes. A custom pipeline was used to annotate the CAZymes for T. tenax and the human sexually transmitted parasite Trichomonas vaginalis, the most well-characterized trichomonad. A combination of bioinformatics analyses was used to screen for homologs of T. vaginalis virulence and colonization factors within the T. tenax annotated proteins.

Results

Our annotation of the two T. tenax draft genome sequences and their comparison with T. vaginalis proteins provide evidence for several candidate virulence factors. These include candidate surface proteins, secreted proteins and enzymes mediating potential interactions with host cells and/or members of the oral microbiota. The CAZymes annotation identified a broad range of glycoside hydrolase (GH) families, with the majority of these being shared between the two Trichomonas species.

Discussion

The presence of candidate T. tenax virulence genes supports the hypothesis that this species is associated with periodontitis through direct and indirect mechanisms. Notably, several GH proteins could represent potential new virulence factors for both Trichomonas species. These data support a model where T. tenax interactions with host cells and members of the oral microbiota could synergistically contribute to the damaging inflammation characteristic of periodontitis, supporting a causal link between T. tenax and periodontitis.

Myrtle-Functionalized Nanofibers Modulate Vaginal Cell Population Behavior While Counteracting Microbial Proliferation

Vaginal infections affect millions of women annually worldwide. Therapeutic options are limited, moreover drug-resistance increases the need to find novel antimicrobials for health promotion. Recently phytochemicals were re-discovered for medical treatment. Myrtle (Myrtus communis L.) plant extracts showed in vitro antioxidant, antiseptic and anti-inflammatory properties thanks to their bioactive compounds. The aim of the present study was to create novel nanodevices to deliver three natural extracts from leaves, seeds and fruit of myrtle, in vaginal milieu. We explored their effect on human cells (HeLa, Human Foreskin Fibroblast-1 line, and stem cells isolated from skin), resident microflora (Lactobacillus acidophilus) and on several vaginal pathogens (Trichomonas vaginalis, Escherichia coli, Staphylococcus aureus, Candida albicans, Candida kefyr, Candida glabrata, Candida parapsilosis, Candida krusei). Polycaprolactone-Gelatin nanofibers encapsulated with leaves extract and soaked with seed extracts exhibited a different capability in regard to counteracting microbial proliferation. Moreover, these nanodevices do not affect human cells and resident microflora viability. Results reveal that some of the tested nanofibers are interesting candidates for future vaginal infection treatments.

Plant Expression of Hydrophobin Fused K39 Antigen for Visceral Leishmaniasis Immunodiagnosis

Visceral leishmaniasis is a Neglected Tropical Disease of high mortality caused by the protozoan Leishmania infantum. Its transmission cycle is complex, and it has in the domestic dog its main reservoir. The diagnostic tests currently used rely on prokaryotic systems' proteins, but their low sensitivity increases the disease's burden. The plant transient expression of recombinant proteins allows the production of complex antigens. However, this system has limited competitiveness against the bacterial production of purified antigens. Thus, we have shown that the L. infantum K39 antigen's fusion to a hydrophobin allows its production for diagnostic tests without the need for intensive purification. The sera of naturally infected dogs specifically detect the semi-purified rK39-HFBI protein. The test validation against a panel of 158 clinical samples demonstrates the platform's viability, resulting in sensitivity and specificity of 90.7 and 97.5%, respectively. Thus, the use of semi-purified antigens fused to hydrophobins can become the standard platform for large-scale antigens production to expand diagnostic tests for other human and veterinary diseases worldwide.

Recent advances in the molecular biology of the protist parasite Trichomonas vaginalis

Trichomonas vaginalis is an anaerobic/microaerophilic protist parasite which causes trichomoniasis, one of the most prevalent sexually transmitted diseases worldwide. T. vaginalis not only is important as a human pathogen but also is of great biological interest because of its peculiar cell biology and metabolism, in earlier times fostering the erroneous notion that this microorganism is at the root of eukaryotic evolution. This review summarizes the major advances in the last five years in the T. vaginalis field with regard to genetics, molecular biology, ecology, and pathogenicity of the parasite.

Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis

Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.