Experimental rat prostatitis caused by Trichomonas vaginalis infection

Trichomonas vaginalis adherence phenotypes and extracellular vesicles impact parasite survival in a novel in vivo model of pathogenesis

Trichomonas vaginalis is a human infective parasite responsible for trichomoniasis-the most common, non-viral, sexually transmitted infection worldwide. T. vaginalis resides exclusively in the urogenital tract of both men and women. In women, T. vaginalis has been found colonizing the cervix and vaginal tract while in men it has been identified in the upper and lower urogenital tract and in secreted fluids such as semen, urethral discharge, urine, and prostatic fluid. Despite the over 270 million cases of trichomoniasis annually worldwide, T. vaginalis continues to be a highly neglected organism and thus poorly studied. Here we have developed a male mouse model for studying T. vaginalis pathogenesis in vivo by delivering parasites into the murine urogenital tract (MUT) via transurethral catheterization. Parasite burden was assessed ex-vivo using a nanoluciferase-based gene expression assay which allowed quantification of parasites pre- and post-inoculation. Using this model and read-out approach, we show that T. vaginalis can be found within MUT tissue up to 72 hrs post-inoculation. Furthermore, we also demonstrate that parasites that exhibit increased parasite adherence in vitro also have higher parasite burden in mice in vivo. These data provide evidence that parasite adherence to host cells aids in parasite persistence in vivo and molecular determinants found to correlate with host cell adherence in vitro are applicable to infection in vivo. Finally, we show that co-inoculation of T. vaginalis extracellular vesicles (TvEVs) and parasites results in higher parasite burden in vivo. These findings confirm our previous in vitro-based predictions that TvEVs assist the parasite in colonizing the host. The establishment of this pathogenesis model for T. vaginalis sets the stage for identifying and examining parasite factors that contribute to and influence infection outcomes.

The correlation between Trichomonas vaginalis infection and reproductive system cancer: a systematic review and meta-analysis

BACKGROUND

Trichomonas vaginalis (T. vaginalis) is a microaerophilic protozoan parasite which is responsible for trichomoniasis, the most common non-viral sexually transmitted infection in the world. The infection greatly damages the reproductive system. However, whether T. vaginalis infection can cause reproductive system cancer remains controversial.

METHODS

This study systematically searched PubMed, EMBASE, Ovid and Google scholar, and 144 relevant articles were retrieved and classified into three categories: epidemiological investigations (68), reviews (30) and research articles (46). These three types of articles were verified according to their respective inclusion and exclusion criteria. Stata 16 was used to conduct a meta-analysis on the articles of epidemiological investigations for analysing the correlation between T. vaginalis infection and reproductive system cancer.

RESULTS

The result of meta-analysis indicated that the rate of T. vaginalis infection in the cancer group was significantly higher than that in the non-cancer group (OR = 1.87, 95% CI 1.29-2.71, I² = 52%). Moreover, the cancer rate of the population infected with T. vaginalis was significantly higher than that of the population without T. vaginalis infection (OR = 2.77, 95% CI 2.37-3.25, I² = 31%). The review articles and most research articles stated that the infection of T. vaginalis could lead to cancer and the pathogenic mechanisms were as follows: T. vaginalis promoting inflammatory response, T. vaginalis infection changing the internal environment around parasitic sites and signal transduction pathway, the metabolites secreted by T. vaginalis inducing carcinogenesis and T. vaginalis increasing other pathogenic microbial infection to promote the occurrence of cancer.

CONCLUSIONS

Our study confirmed that there was a correlation between the infection of T. vaginalis and reproductive system cancer, and provided some possible research directions for clarifying the carcinogenic mechanisms caused by T. vaginalis infection.

Point-of-Care Diagnostic for Trichomonas vaginalis, the Most Prevalent, Non-Viral Sexually Transmitted Infection

A point-of-care (POC) diagnostic is needed for both women and men to establish universal screening and surveillance for the number one, non-viral sexually transmitted infection (STI) caused by Trichomonas vaginalis. We developed a POC diagnostic for this STI using the MedMira Rapid Vertical Flow (RVF^®) Technology test cartridge with a membrane that includes a Vertical procedural/reagent control line (referred to as CVL) and spotted with 1 µg of a 72.4-kDa truncated version of α-actinin called ACT::SOE3. This protein is a specific diagnostic target for antibody in sera of individuals with trichomoniasis. Serum antibody to ACT::SOE3 is a positive reaction with the test spot. Specificity of ACT::SOE3 was revealed with monoclonal antibodies (MAbs) generated to ACT::SOE3. Addition of negative control serum with MAb 67B reactive to ACT::SOE3 shows detection of both ACT::SOE3 and the CVL. Only positive sera of individuals had antibody reactive with ACT::SOE3 and detected the presence of the spot and the CVL. Negative control sera were unreactive with ACT::SOE3 and only showed the presence of the CVL. Importantly, to show proof-of-principle for POC application, ACT::SOE3 was detected with the positive patient sera spiked with whole blood. Finally, packaged cartridges stored with desiccant packs at 37 °C for one year gave identical results with the positive and negative human sera. Our results show the validity of this new POC serodiagnostic for this STI.

Microbiology and immune mechanisms associated with male infertility

Up to 50% of infertility is caused by the male side. Varicocele, orchitis, prostatitis, oligospermia, asthenospermia, and azoospermia are common causes of impaired male reproductive function and male infertility. In recent years, more and more studies have shown that microorganisms play an increasingly important role in the occurrence of these diseases. This review will discuss the microbiological changes associated with male infertility from the perspective of etiology, and how microorganisms affect the normal function of the male reproductive system through immune mechanisms. Linking male infertility with microbiome and immunomics can help us recognize the immune response under different disease states, providing more targeted immune target therapy for these diseases, and even the possibility of combined immunotherapy and microbial therapy for male infertility.

Is There Any Relationship between Trichomonas vaginalis Infection and Male Urethritis Risk? A Systematic Review and Meta-Analysis

Background. Male urethritis is one of the most common genital tract syndromes. Though the number of patients with urethritis is increasing worldwide, the cause of many cases of non-gonococcal urethritis (NGU) is still unknown. Objectives. This study aimed to delineate the association between Trichomonas vaginalis (T. vaginalis) infection and male urethritis. Methods. The literature was searched in PubMed, Scopus, and Web of Science databases using the search terms “urethritis,” “Trichomonas vaginalis,” “trichomoniasis,” and “male urethritis” up to February 2020. Overall risk difference(RD) was applied to assess the relationship between T. vaginalis infection and male urethritis. Results. In total, seven articles were included in this systematic review and meta-analysis study. Our meta-analysis involved the review of case-control studies, including 2,242 urethritis cases and 929 individuals as controls. Among subjects examined for trichomoniasis, in the case group, 211 males were infected, and in the control group, 32 individuals were infected. The overall risk difference (RD) was 0.06, and the total reported $p$ value was 0.00001. Although the result of our meta-analysis was not significant, it was shown that the risk of urethritis is 0.06 more in trichomoniasis patients than in the non-exposed group. Conclusion. Findings from the included papers showed that trichomoniasis is not a risk factor for male urethritis. Although trichomoniasis alone is not the main cause of urethritis, it can be considered one of the risk factors in male urethritis. Therefore, in the future, it is necessary to perform further studies to clarify the detailed association between T. vaginalis infection and urethritis risk in male patients.

Signaling Role of Adipocyte Leptin in Prostate Cell Proliferation Induced by Trichomonas vaginalis

Leptin is a type of adipokine mainly produced by adipocytes and reported to be overproduced in prostate cancer. However, it is not known whether it stimulates the proliferation of prostate cells. In this study, we investigated whether benign prostatic hyperplasia epithelial cells (BPH-1 cells) infected with Trichomonas vaginalis induced the proliferation of prostate cells via a leptin signaling pathway. To investigate the effect of crosstalk between adipocyte leptin and inflamed epithelial cell in proliferation of prostate cells, adipocytes 3T3-L1 cells were incubated in conditioned medium of BPH-1 cells infected with T. vaginalis (T. vaginalis-conditioned medium, TCM), and then the adipocyte-conditioned medium (ATCM) was identified to cause proliferation of prostate cells. BPH-1 cells incubated with live T. vaginalis released pro-inflammatory cytokines, and conditioned medium of these cells caused migration of adipocytes. When prostate stromal cells and BPH-1 cells were incubated with adipocyte conditioned medium containing leptin, their growth rates increased as did expression of the leptin receptor (known as OBR) and signaling molecules such as JAK2/STAT3, Notch and survivin. Moreover, blocking the OBR reduced this proliferation and the expression of leptin signaling molecules in response to ATCM. In conclusion, our findings show that inflamed BPH-1 cells infected with T. vaginalis induce the proliferation of prostate cells through leptin-OBR signaling. Therefore, it is likely that T. vaginalis contributes to prostate enlargement in BPH via adipocyte leptin released as a result of inflammation of the prostate.

Mast cell tryptase-PAR2 pathway in proliferation of prostatic stromal cells reacted with Trichomonas vaginalis

We investigated whether tryptase released from mast cells activated by prostate stromal cells (PSC) reacted with Trichomonas vaginalis (Tv) promoted the proliferation of PSC through protease- activated receptor 2 (PAR2). Conditioned medium of PSC was prepared by stimulating them with Tv (Trichomonad-conditioned medium (TCM)), and mast cell-conditioned medium were prepared by incubating them with TCM (mast cell-TCM (M-TCM)). Mast cells incubated with TCM migrated more efficiently and produced more β-hexosaminidase and tryptase. M-TCM containing tryptase increased the proliferation of PSC, while inhibition of tryptase decreased proliferation. Expression of signalling molecules such as PAR2, p-ERK, COX-2, 15d-PGJ₂ and PPARγ, known to be involved in the tryptase-PAR2 pathway, increased in response to M-TCM, and blocking any of these signals decreased proliferation, indicating that tryptase-PAR2 signalling is involved in the proliferation of PSC. Inhibition of tryptase and PAR2 led to reduced expression of PAR2, p-ERK, COX-2, 15d-PGJ₂ and PPARγ, while inhibition of ERK or COX-2 reduced the expression of COX-2, 15d-PGJ₂ and PPARγ indicating that the tryptase-PAR2 pathway proceeds in the order p-ERK, COX-2, 15d-PGJ₂ , and PPARγ. These results show that interaction between PSC stimulated with Tv and mast cells causes proliferation of PSC through the tryptase-PAR2 pathway.

Polarization of M2 Macrophages by Interaction between Prostate Cancer Cells Treated with Trichomonas vaginalis and Adipocytes

Trichomonas vaginalis causes inflammation of the prostate and has been detected in tissues of prostate cancers (PCa), prostatitis and benign prostatic hyperplasia. Obesity is a risk factor for PCa and causes a chronic subclinical inflammation. This chronic inflammation further exacerbates adipose tissue inflammation as results of migration and activation of macrophages. Macrophages are the most abundant immune cells in the PCa microenvironment. M2 macrophages, known as Tumor-Associated Macrophages, are involved in increasing cancer malignancy. In this study, conditioned medium (TCM) of PCa cells infected with live trichomonads contained chemokines that stimulated migration of the mouse preadipocytes (3T3-L1 cells). Conditioned medium of adipocytes incubated with TCM (ATCM) contained Th2 cytokines (IL-4, IL-13). Macrophage migration was stimulated by ATCM. In macrophages treated with ATCM, expression of M2 markers increased, while M1 markers decreased. Therefore, it is suggested that ATCM induces polarization of M0 to M2 macrophages. In addition, conditioned medium from the macrophages incubated with ATCM stimulates the proliferation and invasiveness of PCa. Our findings suggest that interaction between inflamed PCa treated with T. vaginalis and adipocytes causes M2 macrophage polarization, so contributing to the progression of PCa.

Screening for chronic prostatitis pathogens using high-throughput next-generation sequencing

BACKGROUND

The pathogens responsible for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS; NIH category III) are not currently known. the present study utilized high-throughput next-generation sequencing to screen for potential pathogens associated with NIH category III CP (CP III).

METHODS

This study included 33 patients with CP III and 30 healthy men, from which one sample each of urethral secretions and expressed prostatic secretion (EPS) was collected. High-throughput next-generation sequencing was performed to detect the sequence variations and the relative abundance of the bacterial 16S ribosomal variable region and fungal internal transcribed spacer region in all samples. Bioinformatics software and databases were used for data analysis, and differences with P < .05 were considered statistically significant.

RESULTS

Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis, principal component analysis (PCA), and Spearman's rank correlation showed that the microbial compositions of the urethral secretions and EPS collected from the same subject were essentially the same.

CONCLUSIONS

No potential pathogens were identified in diagnosed patients with CP III. The EPS may be free from bacteria before and after infection. Changes in the urinary tract microbiome may disrupt the microecological balance of the urinary system, thereby leading to CP III. Conversely, the true pathogens of CP III may not be prokaryotic or eukaryotic microorganisms, Future research may involve the evaluation of noncellular microbes.

IL-6 produced by prostate epithelial cells stimulated with Trichomonas vaginalis promotes proliferation of prostate cancer cells by inducing M2 polarization of THP-1-derived macrophages

Trichomonas vaginalis (Tv), a protozoan parasite causing sexually-transmitted disease, has been detected in tissue of prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer (PCa). IL-6, a mediator of chronic inflammation, induces the progression of prostate cancer, and influences the polarization of M2 macrophages, which are the main tumor-associated macrophages. We investigated whether IL-6 produced by human prostate epithelial cells stimulated with Tv induces the M2 polarization of THP-1-derived macrophages, which in turn promotes the progression of PCa. Conditioned medium was prepared from Tv-infected (TCM) and uninfected (CM) prostate epithelial cells (RWPE-1). Thereafter conditioned medium was prepared from macrophages after incubation with CM (M-CM) or TCM (M-TCM). RWPE-1 cells infected with Tv produced IL-6 and chemokines such as CCL2 and CXCL8. When human macrophages were treated with conditioned medium of RWPE-1 cells co-cultured with Tv (TCM), they became polarized to M2-like macrophages as indicated by the production of IL-10 and TGF-β, and the expression of CD36 and arginase-1, which are M2 macrophage markers. Moreover, proliferation of the M2-like macrophages was also increased by TCM. Blockade of IL-6 signaling with IL-6 receptor antibody and JAK inhibitor (Ruxolitinib) inhibited M2 polarization of THP-1-derived macrophages and proliferation of the macrophages. To assess the effect of crosstalk between macrophages and prostate epithelial cells inflamed by Tv infection on the growth of prostate cancer (PCa) cells, PC3, DU145 and LNCaP cells were treated with conditioned medium from THP-1-derived macrophages stimulated with TCM (M-TCM). Proliferation and migration of the PCa cells were significantly increased by the M-TCM. Our findings suggest that IL-6 produced in response to Tv infection of the prostate has an important effect on the tumor microenvironment by promoting progression of PCa cells following induction of M2 macrophage polarization.

In male, T. vaginalis infection have been proposed to involve in several prostate diseases such as prostatitis, benign prostatic hyperplasia and prostate cancer. However, studies for these mechanisms have been rare. We have previously reported that T. vaginalis induce the production of inflammatory cytokines in prostate cells. Among these cytokines, IL-6 have been reported to play an important role in M2 macrophage polarization, which lead to formation of tumor microenvironment in various cancers. Here we show that IL-6 produced by T. vaginalis infection in prostate epithelial cells induces M2 polarization of macrophages and these macrophages promote proliferation of prostate cancer cells. These findings suggest that T. vaginalis indirectly induces progression of prostate cancer by creating a tumor microenvironment through an inflammatory response.

Inflammatory mediators of prostate epithelial cells stimulated with Trichomonas vaginalis promote proliferative and invasive properties of prostate cancer cells

BACKGROUND

Trichomonas vaginalis (Tv) is the most common sexually transmitted parasite. It is detected in prostatic tissue of benign prostatic hyperplasia, prostatitis, and prostate cancer (PCa) and has been suggested to cause chronic prostatitis. Moreover, up to 20% of all cancers worldwide are associated with chronic inflammation. Here, we investigated whether inflammatory mediators produced by normal human prostate epithelial cells (RWPE-1) stimulated with Tv could promote growth and invasiveness of PCa cells.

METHODS

Conditioned medium of RWPE-1 cells was prepared by stimulating them with Tv (trichomonad-conditioned medium [TCM]) and without Tv (conditioned medium [CM]). Promotion of PCa cells (PC3, DU145, and LNCaP) was assessed by wound healing, proliferation, and invasion assays.

RESULTS

We observed that the production of interleukin (IL)-1β, IL-6, CCL2, CXCL8, prostaglandin-E2 (PGE₂ ), and COX2 by RWPE-1 cells was increased by stimulating them with Tv. When PCa cells were incubated with TCM, their proliferation, invasion, and migration increased. Moreover, they showed increased epithelial-mesenchymal transition (EMT)-related markers by a reduction in epithelial markers and an increase in mesenchymal markers. In vivo, xenograft tumor tissues injected with TCM also showed increased expression of cyclin D1 and proliferating cell nuclear antigen, as well as induction of EMT. Receptors and signal molecules of PCa cells increased in response to exposure to TCM, and blocking receptors (CXCR1, CXCR2, C-C chemokine receptor 2, glycoprotein 130, EP2, and EP4) reduced the proliferation of PCa cells with decreased production of cytokines (CCL2, IL-6, and CXCL8) and PGE₂ , and expression of NF-κB and Snail1.

CONCLUSIONS

Our results suggest that Tv infection may be one of the factors creating the supportive microenvironment to promote proliferation and invasiveness of PCa cells.